Journal articles: 'Heavy cement'

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Orlovskyi, V. "Heavy cement materials." Мінеральні ресурси України, no. 1 (June 3, 2020): 48–51. http://dx.doi.org/10.31996/mru.2020.1.48-51.

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Emphasis is placed on the urgency of the problem of creating cementitious materials and solutions of high density. The analysis of scientific sources in the field of development and research of modified cement materials with high density is carried out. The application of different types of weighting impurities to well cements is considered. The advantages and disadvantages of the weighting impurities that are used in the modification of well cements are shown. The technological schemes of the most widespread ways of creation of the weighted cement materials are resulted. The assortment of weighted cement materials manufactured by the Ukrainian industry is analyzed. It is noted that improving the quality of the delineation of rocks and oil and gas horizons in exploration areas and industrial fields during the cementing of high-pressure layers and zones with abnormally high reservoir pressures is possible by the development possible and application of weighted heat-resistant cements with high technological properties on the basis of ash mixtures, as well as mixtures of standard well Portland cement PTSTI-100 and acidic ash removal of thermal power plants and barite weighing agent. Weighted and heat-resistant grouting materials with high performance properties with the use of industrial anthropogenic products have been developed and investigated. The selection of optimal recipes of new weighted cement materials was carried out. The results of the work have practical application in cementing oil and gas wells in complex mining and geological conditions in exploration areas and industrial hydrocarbon deposits.

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Ma, Bao Guo, Jing Ran Wang, and Xiang Guo Li. "Effect of Heavy Metals and Leaching Toxicity of Magnesium Potassium Phosphate Cement." Applied Mechanics and Materials 117-119 (October 2011): 1080–83. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.1080.

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Solidiﬁcation / stabilization (S/S) is a popular method for treating solid wastes containing heavy metals. In recent years, it shows positive results of magnesium potassium phosphate cement as stabilizing agent. In the work, the influence of heavy metal Cu、Zn and Pb on magnesium phosphate cement and the leaching behavior of magnesium phosphate cement were studied. Two proportions of cements were employed with hard burned magnesia and potassium phosphate. The hydration products were analyzed by XRD showing that: Cu、Zn and Pb would not take on obvious effect during magnesium phosphate cement hydration process. Leaching toxicity tests showed that: Cu、Zn and Pb were immobilized within cement hydration products through physical fixation, adsorption mechanisms, and the results were far lower than that of the National Standard in China.

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Wei, Guo Xia, Han Qiao Liu, and Shu Guang Zhang. "Using of Different Type Cement in Solidification/Stabilization of MSWI Fly Ash." Advanced Materials Research 291-294 (July 2011): 1870–74. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.1870.

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Solidification tests of MSWI fly ash (FA) with three types of cement including ordinary Portland cements (OPC), calcium sulfoaluminate cement(CSA) and calcium aluminate cement (CAC) were carried out to discuss the effect of cement type on of the FA-cement solid matrix by means of setting time, compressive strength and heavy metals leachability. Results show that the setting time of the FA-cement mixtures using CSA and CAC is shorter than that of OPC. According to compressive strengths demand and the standard of landfill site of municipal solid waste, the dosage of OPC should be limited about 35% by weigh, the dosage of CAC should be limited about 25% by weigh, and the dosage of CSA should be limited more than 40% by weigh.

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Cheng, Qiangqiang, Jixiong Zhang, Nan Zhou, Yu Guo, and Shining Pan. "Experimental Study on Unconfined Compression Strength of Polypropylene Fiber Reinforced Composite Cemented Clay." Crystals 10, no. 4 (March 26, 2020): 247. http://dx.doi.org/10.3390/cryst10040247.

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The effects of three main factors, including polypropylene fiber content, composite cement content and curing time on the unconfined compressive strength of fiber-reinforced cemented clay were studied through a series of unconfined compressive strength tests. The experimental results show that the incorporation of fibers can increase the compressive strength and residual strength of cement-reinforced clay as well as the corresponding axial strain when the stress peak is reached compared with cement-reinforced clay. The compressive strength of fiber-reinforced cement clay decreases first, then increases with small-composite cement at curing time 14 d and 28 d. However, fiber-reinforced cement clay’s strength increases with the increase of fiber content for heavy-composite cement. The compressive strength of fiber-composite cement-reinforced marine clay increases with the increase of curing time and composite cement content. The growth rate increases with the increase of curing time. The failure mode of composite cement-reinforced clay is brittle failure, while the failure mode of fiber-reinforced cemented clay is plastic failure.

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Zhang, Dong Mei, and Ming Shi Lu. "Preliminary Experimental Study on Self-Leveling Ground Mortar." Applied Mechanics and Materials 357-360 (August 2013): 689–93. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.689.

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The effects of the different content of cement-sand ratio,fineness modulus of sand, heavy calcium carbonate and high alumina cement on the self-leveling mortar was studied according to orthogonal experiment.The results show that when cement-sand ratio is 1.33,fineness modulus of sand is 2.2,heavy alumina is 20%,alumina cement is 10%,the mix amount of mortar is optimum.It can get a good performance of self-leveling mortar.

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Fan, Zhi Jin, Jin Chuan Gu, Yi Chen, Yong Xin Jin, Min Yin, and Wei Zhao. "Experimental Study of Cement on Heavy Metal Ion Removal." Advanced Materials Research 1073-1076 (December 2014): 889–93. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.889.

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Utilize cement specific surface area is larger and neutralizes the acidic aqueous ,which can adsorb heavy metal,properties and can precipitate heavy metal.Study on removal rate of Cu2+,Pb2 +, Zn2 +, Cd2 +. By study the properties of the cement and analyzing the experimental data on the cement dosage,the ion concentration,PH and the stirring time, the results show that cement has better adsorption and the effect of precipitation on the above four kinds of ion, removal rate increased with increasing PH,the mount of dosage and stirring time.

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Johnson, C. Annette. "Cement stabilization of heavy-metal-containing wastes." Geological Society, London, Special Publications 236, no. 1 (2004): 595–606. http://dx.doi.org/10.1144/gsl.sp.2004.236.01.33.

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HAYASHI, Akihiko, Yuko OGAWA, Kenichiro NAKARAI, and Kenji KAWAI. "CAPTURING IN CEMENT PASTE OF HEAVY METAL ADDED WITH DIFFERENT METHODS." Cement Science and Concrete Technology 68, no. 1 (2014): 375–81. http://dx.doi.org/10.14250/cement.68.375.

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Tang, Qiang, Peixin Shi, Yu Zhang, Wei Liu, and Lei Chen. "Strength and Deformation Properties of Fiber and Cement Reinforced Heavy Metal-Contaminated Synthetic Soils." Advances in Materials Science and Engineering 2019 (February 19, 2019): 1–9. http://dx.doi.org/10.1155/2019/5746315.

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Heavy metals are not only hazardous to environment and public health, but they degrade the physicochemical and biological properties of soils increasing difficulty to the redevelopment of contaminated sites. This study proposes a method for reinforcing contaminated soils with fiber and cement. The feasibility of using wheat straw as fiber reinforcement is discussed. The strength of heavy metal-contaminated soil reinforced with wheat straw and cement is investigated through laboratory testing. Twelve groups of soil samples were prepared at three fiber contents (i.e., 0.1%, 0.2%, and 0.3% by weight), three water contents (i.e., 9%, 12%, and 15%), and three cement contents (i.e., 5%, 7.5%, and 10% by weight). Unconfined compression strength (UCS) was tested after 28 days of curing period and various freeze-thaw cycles. The testing results show that the increase in the number of freeze-thaw cycles results in the decrease of UCS. The inclusion of fiber reinforcement within cemented soil causes an increase in the UCS and changes the brittle behavior of cemented soil to a more ductile one. The UCS of the fiber-reinforced soils first increases, then decreases with the increase of water content, and reaches the maximum value at the optimum moisture content.

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Lu, Juan Juan, Yu Bing Liu, Wei Han, and Ping Dai. "Determination of Heavy Metal Oxide in Cement by X-Ray Fluorescence Spectrometer." Key Engineering Materials 768 (April 2018): 69–74. http://dx.doi.org/10.4028/www.scientific.net/kem.768.69.

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When the MLD method is used to determine the main chemical composition in the cement, it is assumed that the sum of the measured chemical composition is 100%. When the trace amount of heavy metal oxide is present in the cement sample without measuring, a positive error will be caused for main chemical composition results. On the other hand, according to the national standards GB/T 30760-2014 "technical specification for coprocessing of solid waste in cement kiln", also need to determine the heavy metals in cement. In this work, vanadium pentoxide, chromium oxide, copper oxide, zinc oxide, strontium oxide and barium oxide were measured by using melt beads for the determination of the main chemical components in cement. The calibration sample was calibrated using the standard addition – fusion method, using the theoretical MLD coefficient to calculate the standard dilution ratio. The method has been applied to the determination of heavy metal oxides in cement samples and achieved good results.

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Wang, Lei, and Qi Chen. "Study on the Stabilization of Heavy Metal by Cement with Quantum Chemistry." Advanced Materials Research 955-959 (June 2014): 2935–39. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.2935.

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The quantum chemistry is a kind of efficient theoretical research methodology; it has become an important foundation and core technology to the computational materials science. The researches of melting mechanism, doping mechanism, mechanism of hydration activity can be used in the related areas of stabilization of heavy metal by cement. Density functional theory is reviewed in the study of the affective mechanism of cement hydration activity and the intensity of hydration by heavy metal, the mechanism of fixating heavy metals by mineral and the mechanism of lowering melting temperature. It is considered that quantum chemistry can be used to make a simulation at the micro level to explore the mechanism of cement-enclosed heavy metals and has a perfect theoretical guiding significance for further research.

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Li, Zaoyuan, Yan Wang, Xiaowei Cheng, and Xiaoyang Guo. "The Slag Influence on High Temperature Resistance of Aluminophosphate Cementfor Heavy Oil Thermal Recovery." High Temperature Materials and Processes 33, no. 4 (August 1, 2014): 325–28. http://dx.doi.org/10.1515/htmp-2013-0064.

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AbstractThe sharp strength recession of silicate cement in high temperature is the crucial reason of casings damage and zonal isolation failure in heavy oil thermal recovery. Although aluminophosphate cement has a better high temperature resistance in comparison with silicate cement, its compressive strength recession in high temperature slightly recessed. The results show that adding slag into aluminophosphate cement can not only develop compressive strength of cement at low temperature, but it can also improve the high temperature resistance of the cement. After adding slag, the formation of C2ASH8 conduces to develop cement strength at low temperature, and C3AS2H2 conduces to high temperature resistance. To increase temperature resistance of aluminophosphate cement, C3ASH4 generation and Al(OH)3 decomposition should be avoided. Crystal structure of cement after high temperature is well developed with compactly and neatly arranged, allowing cement to maintain good mechanical properties to help protect the casing and improve zonal isolation performance.

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13

Ahmed, T., R. Chowdhury, and M. Rahman. "Stablization of medical waste incineration fly ash in cement mortar matrix." Bangladesh Journal of Scientific and Industrial Research 55, no. 2 (June 16, 2020): 131–38. http://dx.doi.org/10.3329/bjsir.v55i2.47633.

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Laboratory experiments were performed to assess the suitability of using medical waste incineration fly ash in cement as a construction material based on the engineering properties of fly ash-cement matrix and the leaching potential of toxic heavy metals from the stabilized mix. Fly ash-cement samples were prepared with different proportions of fly ash (0%, 5%, 10%, 15% and 20% by weight) in the laboratory under controlled conditions. The solidified matrix exhibited a compressive strength from 3950 to 4980 psi when fly ash is mixed in varying proportions. The 28-day compressive strength has been found to decrease with the increase in fly ash content but it meets the minimum requirement of compressive strength for cement-mortar. Soundness test exhibited acceptable results for cement-mortar mixes having up to 15% fly ash. Final and initial setting times of cement have been found to generally increase with fly ash content. Water requirement (for normal consistency) also increased with the increase in fly ash content in cement. Based on physical properties of the cement-mortar matrix it is recommended that up to 10% (by weight) medical waste incineration fly ash can be incorporated for producing cement-mortar of optimum quality. Leaching behaviors of several targeted heavy metals (As, Cu, Ni, Cd, Pb, Hg and Zn) were analyzed using Toxicity Characteristics Leaching Procedure (TCLP) of fly ash and solidified fly ash-cement matrix which shows that the leached concentrations of As, Cu, Cd, Pb and Zn were reduced by 80.13%, 89.47%, 33.33%, 23.9% and 100% respectively for 10% fly ash incorporated cement-mortar matrix compared to that of original fly ash. The leached concentrations of heavy metals from the matrix were far below the EPA land disposal limits. These results suggest that the solidified fly ash incorporated cement-mortar matrix can effectively confine and immobilize the heavy metals contained in the fly ash without significantly diminishing the engineering properties of cement-mortar. Bangladesh J. Sci. Ind. Res.55(2), 131-138, 2020

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14

Nishiwaki, Takumi, Shaojun Zhou, Masaharu Yamasaki, Yuko Ogawa, and Kenji Kawai. "Effect of co-existing ions on lead leaching behaviour from hardened cement paste." MATEC Web of Conferences 195 (2018): 01007. http://dx.doi.org/10.1051/matecconf/201819501007.

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Recently, in the concrete field, the use of industrial wastes for concrete materials is expected for environmental reasons. However, these wastes may contain hazardous heavy metals. It is well known that cement paste has an ability to fix heavy metal ions, whereas it was also found that absorbed heavy metal ions can easily leach from cement paste in the presence of a CaCl2 solution. The present study aims to investigate the lead leaching behaviours from hardened cement pastes in various chloride solutions by tank leaching tests. The water-to-cement ratios of the cement paste specimens were 0.40 and 0.55. Lead was added to the cement pastes at 1 mass% of cement. Each chloride solution for the tank leaching test had three kinds of concentrations (5%, 10%, and 20%). After the tank leaching tests, the chemical changes of the specimens were analysed to discuss the effect of co-existing ions in the solutions. The results indicate that the cumulative lead leaching amount is related to the types of chloride solution as well as the concentrations of the solutions. The lead leaching amount in the CaCl2 solution was much higher than that in other solutions.

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15

Oproiu, Carmen, Georgeta Voicu, Adrian Ionut Nicoara, and Alina Ioana Badanoiu. "The Influence of Partial Substitution of Raw Materials with Heavy Ash on the Main Properties of Portland Cements." Revista de Chimie 69, no. 4 (May 15, 2018): 860–63. http://dx.doi.org/10.37358/rc.18.4.6216.

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The use of wastes in cement industry have impact both from economic and environmental point of views. Wastes can be used in clinker manufacture (to substitute raw materials or as alternative fuel) as well as supplementary cementitious materials in cement. This paper presents results regarding the use of heavy ash (bottom ash) as component of raw mix used for the clinker manufacture. Two types of cements were obtained by the milling of clinker produced with/without heavy ash (HA) as component of raw mix and gypsum (2%). The compressive strengths of these cements was assessed on plastic mortars (water:binder = 1:2 ratio and binder:aggregate = 1:3 ratio), cast in prismatic moulds (14x14x160 mm3), hardened different periods of time comprised between 1 to 28 days. The hydration and hardening processes which occur in the cementitious systems with/without waste content were assessed on pastes with water to binder ratio of 0.5, hardened for 1 up to 90 days. X-ray diffraction (XRD) and complex thermal analysis (DTA-TG) were used for pastes� characterization. The composition of clinker was assessed by XRD and microstructure by scanning electron microscopy (SEM). The results obtained in the framework of this research do not show any important difference between the clinkers� characteristics produced with alternative raw material (heavy ash) as compared with the ones produced with natural raw materials. Also, the properties of cements produced of these clinkers are similar.

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Kim, Kyung Nam, Jin Ho Kim, Dae Yong Shin, Beom Goo Lee, and Hyun Park. "Properties of Cement Paste Using Mine Tailing and Polymer Materials." Materials Science Forum 620-622 (April 2009): 623–26. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.623.

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In this study, mine tailings obtained in a region near to Youngwol Sangdong(Korea) was used to investigate the contamination of heavy metal ions. Some amount of mine tailings and lignin(AE agent) were added in the general cement pastes, of which the compressive strength and leaching rate were investigated. X-ray fluorescence analysis shows that the major constituents of mine tailings are 56.9wt% of SiO2, 10.8wt% of Fe2O3, 11.2wt% of CaO and 11.4wt% of Al2O3, and the major phases are quartz and calcite. In the content of heavy metal ions, the concentration of As ion is the highest as 257.261mg/ℓ. When mine tailings and lignin were added in cement pastes, the compressive strength was higher in the cement pastes adding only lignin. Lignin addition significantly improved the compressive strength of cement pastes by approximately 15% when being cured in distilled water. The compressive strength was lower in the cement pastes adding mine tailings than in the cement pastes not adding. The leaching rates of Cr, Pb and As ion in distilled water were decreased in the cement pastes adding lignin, compared to in the cement pastes not adding. The leaching rates of all heavy metal ions in the cement pastes curing for 28 days were within the maximum permitted limits in KSLT and EPT method. Therefore, it is thought that mine tailings can be used as an ecological material.

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El-Awady, M. H., and T. M. Sami. "Removal of Heavy Metals by Cement Kiln Dust." Bulletin of Environmental Contamination and Toxicology 59, no. 4 (October 1, 1997): 603–10. http://dx.doi.org/10.1007/s001289900522.

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Peysson, S., J. Péra, and M. Chabannet. "Immobilization of heavy metals by calcium sulfoaluminate cement." Cement and Concrete Research 35, no. 12 (December 2005): 2261–70. http://dx.doi.org/10.1016/j.cemconres.2005.03.015.

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Tang, Qiang, Yang Liu, Fan Gu, and Ting Zhou. "Solidification/Stabilization of Fly Ash from a Municipal Solid Waste Incineration Facility Using Portland Cement." Advances in Materials Science and Engineering 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/7101243.

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This study investigated the solidification/stabilization of fly ash containing heavy metals using the Portland cement as a binder. It is found that both the cement/fly ash ratio and curing time have significant effects on the mechanical (i.e., compressive strength) and leaching behaviors of the stabilized fly ash mixtures. When the cement/fly ash ratio increases from 4 : 6 to 8 : 2, the increase of compressive strength ratio raises from 42.24% to 80.36%; meanwhile, the leaching amount of heavy metals decreases by 2.33% to 85.23%. When the curing time increases from 3 days to 56 days, the compressive strength ratio of mixtures raises from 240.00% to 414.29%; meanwhile, the leaching amount of heavy metals decreases by 16.49% to 88.70%. The decrease of compressive strength with the lower cement/fly ash ratios and less curing time can be attributed to the increase of fly ash loading, which hinders the formation of ettringite and destroys the structure of hydration products, thereby resulting in the pozzolanic reaction and fixation of water molecules. Furthermore, the presence of cement causes the decrease of leaching, which results from the formation of ettringite and the restriction of heavy metal ion migration in many forms, such as C-S-H gel and adsorption.

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Wei, Liang, and Yi Chun Dai. "Experimental Study on Treatment of Hospital Waste Incineraten Fly Ash by Solidification Process with Cement." Advanced Materials Research 610-613 (December 2012): 1645–49. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1645.

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It was found that cement can immobilize the heavy metals of hospital waste incineration fly ash. Based on this, a method of hospital waste fly ash management with cement solidification was proposed. In the nature hospital waste incineration fly ash, the leachate concentration of Zn (279.2 mg/L) and Pb (19.88 mg/L)) exceed the regulatory limit for the TCLP test. In the cement solidified fly ash, the leachate concentration of Zn was in excess of the standard limit while the leachate concentration of Cd, Ni, Cu and Pb were under the limit of the standard, and the leachate concentration of the heavy metals decreased with the increase of curing time (experimental curing time from 3 days to 28 days）and cement rate (cement rate was respectively 40%, 50% and 60% in the experiment).

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Wang, Ya Li, Su Ping Cui, Xi Kui Xu, and Ming Zhang Lan. "Impact of pH Value and Temperature on Cement-Based Materials Adsorbing Heavy Metal Ions." Materials Science Forum 847 (March 2016): 265–71. http://dx.doi.org/10.4028/www.scientific.net/msf.847.265.

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The development of the city traffic and its increasing traffic flux are the signs of the development of the society, but causing a serious pollution on the city's ecological environment. Cement hydration reactions are needed to generate Ca (OH)2, C-S-H gel, and AFt, as well as other hydrated products. Meanwhile, heavy metal ions are contained and fixed in a cement paste under physical encapsulation, absorption, isomorphous replacement, and double decomposition. This paper mainly discusses the impact of hydration environment on the adsorption law of materials adsorbing heavy metal ions and the adsorption mechanism under different pH values and temperatures, analyzing specific reasons from the perspective of micro-structure. Through the analysis it can be seen that, in addition to zinc ions, the cement-based materials’ capacity of adsorbing heavy metal ions increases as the pH value and the temperature increase. Micro-structure analysis shows that cement-based materials’ main adsorption methods are different when pH values are different.

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Silfwerbrand, Johan. "Concrete and Sustainability – Some Thoughts from a Swedish Horizon." Nordic Concrete Research 63, no. 2 (December 1, 2020): 79–87. http://dx.doi.org/10.2478/ncr-2020-0019.

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Abstract Concrete production, especially the cement production, stands for 5-8 percent of the global CO2 emissions. Since concrete is the most frequently used man-made construction materials, this fact is not surprising. Concrete is also the only realistic alternative in order to improve the living circumstances in many countries around the world. Due to its size, the concrete sector has a great responsibility for limiting the consequences of the on-going climate change. The Swedish cement producer Cementa has an ambitious zero vision stating zero CO2 emissions in year 2030. The measures include energy efficiency, bio mass instead of fossil fuels, blended cements, CO2 uptake through carbonation and Carbon Capture Storage (CCS). This paper discusses these measures but also others such as optimization of the concrete mix, optimization of the structural geometry and prolongation of the service life. The paper is ended by a section on adaptation since concrete will also have an important role concerning protection of the built environment for climate change. Protection structures against flood, reconstruction of dams, new waste-water systems and bright permeable concrete pavements reflecting sunlight and improving drainage after heavy rain constitute some examples.

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Krunic, Nebojsa, and Goran Tonic. "Impact of various luting cements on the fixed dentures bonding strength." Vojnosanitetski pregled 63, no. 3 (2006): 293–96. http://dx.doi.org/10.2298/vsp0603293k.

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Background/Aim. Various luting cements are used to fix dental crowns to prepared teeth, and should provide an adhesive bond to the tooth structure giving reliable retention. The aim of this study was to establish in vitro which type of the tested luting cement provided the strongest adhesive bond of the prepared teeth to the fixed denture. Methods. Testing was carried out on the sample of 100 intact human premolars extracted for orthodontic reasons. The preparation of the teeth was performed by a heavy-duty machine. The surfaces of the prepared teeth were mathematically calculated. Dental crowns from the Nickel-Chromium- Molybenum (Ni-Cr-Mo) alloy were made in a standard fashion, and fixed to prepared teeth (two samples of each group) with 5 different types of luting cements. The strength of force applyed to separate the cast crowns from the prepared teeth was measured by an electronic dynamometer, after 7 days. Results. The obtained results revealed the connection between the type of luting cement and the values of retention power. The best adhesive bond under the constant convergence angle of the prepared teeth was provided by the resin cement. Conclusion. When choosing a luting cement for fixing dental crowns to prepared teeth, the advantage should be given to the resin cement in case the glassionomers are not available.

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Rauf, Annisa Utami, Anwar Mallongi, and Ratna Dwi Puji Astuti. "Heavy Metal Contributions on Human Skin Disease near Cement Plant: A Systematic Review." Open Access Macedonian Journal of Medical Sciences 8, F (July 25, 2020): 117–22. http://dx.doi.org/10.3889/oamjms.2020.4396.

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AIM: The aim of this systematic review was to investigate heavy metal roles at skin disease of humans in the cement industrial area. METHODS: All research reporting a specific heavy metal, which could be increasing the risk of the disease, cause cement induced to skin. Fourteen selected articles from our inclusion criteria rated using eight quality-appraisal criteria derived from Strengthening the Reporting of Observational Studies in Epidemiology checklist and following preferred reporting items for systematic reviews and meta-analyses methodology. RESULTS: We performed a systematic review of published articles between 2009 and 2019 from ten case–control, two cohort, one ecological study, and one cross-sectional study showed the heterogeneity of the study design. The studies are focusing on the relationship between heavy metal and skin disease that appeared in cement plant areas such as dermatitis, skin cancer, eczema, and other allergies. Chromium, nickel, cobalt, zinc, cadmium, mercury may present and play an important role for human skin disease. CONCLUSION: Heavy metals have been found in the skin of human living and work around the cement industry. Chromium, cobalt, and nickel are almost certainly present in every case of dermatitis and eczema. Signs and mild symptoms of skin disease include redness, itching, starch, and dryness. Elements such as cadmium, lead, and mercury usually are found in chronic skin disease (psoriasis and skin cancer) on a biologic test. These findings should raise an important concern and recommendation policy for controlling raw materials contains heavy metal in cement industrial areas and proper protection for workers and non-worker.

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Chang, Jheng-Shin, Yi-Chin Cho, and Yi-Pin Lin. "Regeneration of heavy metal contaminated soils for cement production by cement kiln co-processing." Resources, Conservation and Recycling 176 (January 2022): 105909. http://dx.doi.org/10.1016/j.resconrec.2021.105909.

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Gołuchowska, Beata, Zygmunt Strzyszcz, and Grzegorz Kusza. "Magnetic Susceptibility and Heavy Metal Content in Dust From the Lime Plant and the Cement Plant in Opole Voivodeship." Archives of Environmental Protection 38, no. 2 (January 1, 2012): 71–80. http://dx.doi.org/10.2478/v10265-012-0019-3.

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Magnetic Susceptibility and Heavy Metal Content in Dust From the Lime Plant and the Cement Plant in Opole Voivodeship Until now, dust arising from lime manufacture has been considered harmless to the environment so it has been investigated marginally from the standpoint of environmental protection, especially when it came to magnetic properties and heavy metal content. The aim of the research was filling the gap in this area. The research comprised measurements of magnetic susceptibility, the content of heavy metals, reaction (pH) and specific conductivity of lime dust and also raw material and fuel used for lime production. The samples were taken from one of the lime plants located in Opole Province. Similar investigations were also performed for dust taken from the nearby cement plant using dry method of cement production. It was proven that magnetic susceptibility, heavy metal content and conductivity of lime dust was lower in comparison to cement dust, which resulted from the fact that the lime plant used neither low raw materials nor additives. Due to the high atmosphere dust level in the vicinity of the investigated plants, extremely basic reaction of the tested dust and high content of metals, the studied dust cause alkalization of soils and contribute to the increase of heavy metal content in soils, posing a threat to the environment.

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Guan, Su Min, Zao Yuan Li, Peng Xie, Zhi Qiang Wu, and Xiao Yang Guo. "Study on New Cement Slurry System for Heavy Crude Oil Thermal Recovery in Well Cementation." Advanced Materials Research 339 (September 2011): 526–32. http://dx.doi.org/10.4028/www.scientific.net/amr.339.526.

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The multi-cycle recovery of heavy crude oil thermal by steam injection and stimulation has serious effects on the integrity of cementing sheath. At present, the class G oil well cement with silica sands, less resistant to high temperatures, does not meet the quality of the heavy crude oil well cementation and requirements of recovery and production. The laboratory results show that Aluminates cement has the characteristics of high early strength; meanwhile, it can maintain strength and stability in a long-term under the circulation of high and low temperature conditions. However, its hydration product C3AH6, which makes it a sharp recession in intensity at low temperature, limits its application. According to the clinker selection and compounding with the main item of Aluminates cement indoor experimentation, there comes out a new type of cement binder which generates C3ASH4 and other stable phase within rounds of high and low temperature cueing, and made the crystal structure of cement in dense arrangement. With this method, cement hydration structure can be maintained with a long-term stability; and it has the value of further development.

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Gots, Volodimir, Oles Lastivka, Elizabeth Volunska, and Oleksandr Tomin. "RECYCLING OF AURIFEROUS ORE FLOTATION TAILINGS IN SLAG-ALKALINE CEMENT." EUREKA: Physics and Engineering 4 (July 29, 2016): 11–16. http://dx.doi.org/10.21303/2461-4262.2016.000123.

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Research analysis aimed at stabilizing processes in industrial waste and other, similar hazardous ion containing materials, shows that these materials can be successfully stabilized, if they are bound as a mineral component in cement. Considering that auriferous ore flotation waste contains heavy metals that are useless for any production and accumulated in dumps, storages and sumps, this impairs the ecology of the country. This is why current study is conducted on recycling of auriferous ore flotation tailings by binding it as a cement component, which is also can be one of its effective applications. For heavy metal bonds stability evaluation in the composition of the cement matrix, the method of leaching elements by atomic spectroscopy was applied. According to the research it was found that application of slag-alkaline viscid systems for recycling of auriferous ore dump flotation tailings provides considerable advantages over traditional Portland cement systems based on PC I-500. It was shown that along with the physical blocking in the artificial stone matrix, based on slag-alkaline viscid systems, elements of heavy metals were also bound chemically as a part of structure-forming compounds. In this regard use of auriferous ore dump flotation tailings (10…30 %) in the compound of slag-alkaline cement results in the prolonged solidification and provides the same level of cement stone durability as the check sample compound.

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Ning, Xun An, Jian Bo Zhou, Jing Yong Liu, Zuo Yi Yang, Yu Tian, and Ning Zhang. "Experimental Study on the Solidification/Stabilization of Textile Dyeing Sludge." Advanced Materials Research 197-198 (February 2011): 1010–15. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.1010.

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Sludge from the textile dyeing industries was solidified and stabilized using cement, fly ash（PFA）and cinder as the solidifying agents, and the optimum conditions of sludge solidification/stabilization were analyzed. The mechanical property of solidified sludge block was evaluated by compressive strength test, at the same time， the chemical oxygen demand (COD） and heavy metal concentration of the leaching from the cured block were tested as well. With the dosage of cement, PFA and cinder, 0.15kg/kg, 0.02kg/kg and 0.08kg/kg respectively, and curing time was 6ds, the compressive strength of the solidified sludge block reached 330kPa.Results showed that addition of cement and cinder had good effects on the compressed strength of sludge block, cement, PFA and cinder enhanced the solidification and stabilization of organic and heavy metal in the sludge. Under the above conditions, COD of the leaching from the sludge solidification block was 488mg/L, and the heavy metal concentrations had reached the related national standards. After 6ds of curing time, water ratio of the solidified block was maintained at 40%~45%, which met the prescribed standards of landfill.

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Zhen, Shu Cong, Yong Xun, and Bu Quan Miao. "Solidification/Stabilization of Heavy Metals by Magnesium Potassium Phosphate Cement." Advanced Materials Research 664 (February 2013): 683–89. http://dx.doi.org/10.4028/www.scientific.net/amr.664.683.

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Heavy metals, including Pb, Cr, Cd, Zn, Cu and Ni, were solidified/stabilized by magnesium potassium phosphate cement (MKPC). The unconfined compressive strength test shows that the strengths of the solidified bodies containing 10%-40% MKPC all exceeded 0.5 MPa, which have met the requirements of storage and landfilling. The toxicity characteristic leaching procedure (TCLP) test shows that no detectable Pb, Cr and Cd were leached from the solidified body containing 40% MKPC after being cured standardly for 28 days, and the concentrations of heavy metals leached from the solidified body containing 10% MKPC after being cured for only 7 days were still significantly lower than the limits in related Chinese National Standards. The leaching concentrations of heavy metals followed a descending order of Cu＞Zn＞Ni＞Pb＞Cd＞Cr. In the simulated acid rain eluviation test, heavy metals were eluviated in different patterns, and the sequence of releasing amounts was similar to that of leaching concentrations. The experimental results indicate that heavy metals can be satisfactorily solidified by MKPC.

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Vyas, Charu, and Ashwini A. Waoo. "Prognostication of Bioremediation Requisite Around Industrially Contaminated Environment: A Review." Current Biotechnology 9, no. 1 (July 13, 2020): 3–14. http://dx.doi.org/10.2174/2211550109666200305092457.

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Background: Noxious effects of heavy metal pollution on environment have created an alarming situation for human life and aquatic biota and a consequent want for focus on an effort for remediation, because of its high persistence, non-degradable nature, high toxicity and bioaccumulation tendency. Further, heavy metals cannot be converted into non-toxic forms and can only be transformed into less toxic species. Cement dust includes heavy metals like nickel, cobalt, lead, chromium and many other pollutants unsafe to the biotic surroundings, with unfavorable effects on plants, human and animal fitness and ecosystems. Objective: In the present work, research objectives were to study heavy metal pollution, with a view to establish the contamination status of soil, from cement dust contaminated soils/sediments from various locations around different cement industrial zones in Satna region. The main purpose of this research was to emphasize on the efforts and requisites towards microbial consortium-enhanced bioremediation of heavy metals by bacteria and then study microbial diversity profile through shotgun metagenomics approach. Methods: For this, the isolation of heavy metal tolerant bacterial strains, biostimulation of native strains of microorganisms (bacterial strains) for heavy metal degradation and evaluation of bioaugmented mediated microbial consortium-enhanced bioremediation potential of selected bacterial strains as individual isolates and/or their consortium at the laboratory scale level and then at a large scale were carried out. Result: Through these efforts, in the future, novel efficient tolerant species and their consortium could be explored which could have great bioremediation potential for the uptake of heavy metals from cement dust contaminated soil/sediments, near areas of cement and other industries in Satna region. This review article confirms the prognostication of bioremediation in Satna region. Conclusion: This small vision and efforts of bioremediation could prove to be a small beneficial step and lead to an overall improvement of the socio-economic condition of the locality of Satna and the nearby region. This could be very beneficial for residential people by creating a healthy environment. Soil metagenomics initiatives might be a useful resource to the scientific community and will provide a much greater understanding of microbial diversity and functions in the soil.

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Anis, Dr, Abdullah Khan, Narendra Kumar, and Mujeebul Hasan. "Diagenesis and Porosity Evolution of the Pachmarhi Sandstones (Early Triassic), Satpura Gondwana Basin, Central India." Journal of The Indian Association of Sedimentologists 37, no. 2 (December 31, 2020): 37–48. http://dx.doi.org/10.51710/jias.v37i2.104.

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This study deals with the diagenetic history of the Pachmarhi Sandstones of Satpura Gondwana Basin, Central India. The sandstones are classified as quartz-arenite and sub-arkose type. Monocrystalline quartz grains dominate the detrital mineralogy followed by polycrystalline quartz grains, feldspars (more alkali-feldspar than plagioclase), rock fragments, detrital mica and heavy minerals. The diagenetic signatures observed in the Pachmarhi Sandstones include mechanical compaction, cementation (Fe-oxide, quartz overgrowths, calcite, matrix and clay minerals), replacement and dissolution of feldspar and calcite cement. The most commonly observed type of secondary porosity is dissolution of feldspars. The porosity loss is mainly due to cementation by pore occlusion and by early stage of mechanical compaction. In addition, several clay minerals occurred as pore-filling and pore-lining cements. The nature of various types of grain- to grain contacts suggests early cementation and consequent minor compaction. Among the various cements, calcite is the earliest followed by iron oxide while silica cementation occurred probably at a late stage. The carbonate cement formed during burial by dissolution and re-precipitation represents redistributed calcite which was buried with the sandstone. The iron cement was perhaps derived from weathering and leaching of ferromagnesian minerals of overlying Deccan traps. Silica cement was derived from the corrosion of quartz and feldspar grains. Types of grain contacts, minus-cement porosity and porosity reduction indicate a shallow depth of burial conditions for these sandstones.

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Zhang, Hai Ying, and Shu Zhen Li. "XRD (X-Ray Diffraction) Analysis of the Stabilized Ash." Applied Mechanics and Materials 459 (October 2013): 7–10. http://dx.doi.org/10.4028/www.scientific.net/amm.459.7.

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MSWI (municipal solid waste incineration) fly ash, generated in incineration process of municipal solid waste, contains lots of heavy metals, which will do harm do the environment if extracted. In this work, the ash is stabilized by cement to reduce leaching toxicity of heavy metals. Besides, mineralogical compositions of the product of different cement / ash ratios after conservation for different period were analyzed by means of XRD (X-ray diffraction). It was found that major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

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Nindyapuspa, Ayu, Taty Alfiah, and Virgo Indrawan Toda. "Stabilization/Solidification of used lubricating oil containing Fe and Pb with Portland cement and bentonite." MATEC Web of Conferences 276 (2019): 06011. http://dx.doi.org/10.1051/matecconf/201927606011.

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Used lubricating oil belong hazardous waste based on the Government Regulation Number 101 in 2014 about Hazardous Waste Management. Used lubricating oil contain hydrocarbon and heavy metals such as Fe and Pb. One of method to immobilize used lubricating oil is stabilization/solidification (S/S). S/S method always uses Portland cement to immobilize the heavy metals, but Portland cement can not immobilize the hydrocarbon. In this research, S/S method used Portland cement and bentonite are binding the heavy metals and hydrocarbon in the used lubricating oil. The composition used was cement bentonite 25:75, cement bentonite 75:25, cement 100%, and bentonite 100%. Used lubricating oil was added in 5%, 10%, and 15% weights. The S/S products were examined by measuring the TCLP of the Fe and Pb. The TCLP test was compared with the Fe and Pb concentration in the used lubricating oil. The results showed that the TCLP test of the Fe on the S/S product containing 5%, 10%, 15% used lubricating oil with cement 100% was 371.14 mg/L, 403.66 mg/L, and 417.89 mg/L respectively. Meanwhile, the Fe concentration in the used lubricating oil was 47.78 mg/L. The adding of bentonite to the S/S product decreased the Fe concentration that was leached. The TCLP test of the Fe in the S/S products that contained 5%, 10%, and 15% used lubricating oil with bentonite 100% were 15.24 mg/L, 0.085 mg/L, and 0.428 mg/L respectively. The S/S method using Portland cement and bentonite decreased the Pb concentration leached into the environment.

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Choi, Hun, Hyun-Ju Kang, Myung-Shin Song, Eui-Dam Jung, and Ju-Seng Kim. "Solidification of Heavy Metal Ions Using Magnesia-phosphate Cement." Journal of the Korean Ceramic Society 48, no. 1 (January 31, 2011): 20–25. http://dx.doi.org/10.4191/kcers.2011.48.1.020.

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Vallejo, Begoña, Riansares Muñoz, Andrés Izquierdo, and M. Dolores Luque de Castro. "Cement for stabilisation of industrial residues containing heavy metals." Journal of Environmental Monitoring 1, no. 6 (1999): 563–68. http://dx.doi.org/10.1039/a903668g.

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Lasheras-Zubiate, M., I. Navarro-Blasco, J. I. Álvarez, and J. M. Fernández. "Interaction of carboxymethylchitosan and heavy metals in cement media." Journal of Hazardous Materials 194 (October 2011): 223–31. http://dx.doi.org/10.1016/j.jhazmat.2011.07.085.

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Shih, Pai-Haung, Juu-En Chang, Hsing-Cheng Lu, and Li-Choung Chiang. "Reuse of heavy metal-containing sludges in cement production." Cement and Concrete Research 35, no. 11 (November 2005): 2110–15. http://dx.doi.org/10.1016/j.cemconres.2005.08.006.

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Ivey, D. G., R. B. Heimann, M. Neuwirth, S. Shumborski, D. Conrad, R. J. Mikula, and W. W. Lam. "Electron microscopy of heavy metal waste in cement matrices." Journal of Materials Science 25, no. 12 (December 1990): 5055–62. http://dx.doi.org/10.1007/bf00580129.

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Yu, Qijun, S. Nagataki, Jinmei Lin, T. Saeki, and M. Hisada. "The leachability of heavy metals in hardened fly ash cement and cement-solidified fly ash." Cement and Concrete Research 35, no. 6 (June 2005): 1056–63. http://dx.doi.org/10.1016/j.cemconres.2004.03.031.

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Leelarungroj, Kittitat, Suched Likitlersuang, Thanakorn Chompoorat, and Dao Janjaroen. "Leaching mechanisms of heavy metals from fly ash stabilised soils." Waste Management & Research: The Journal for a Sustainable Circular Economy 36, no. 7 (June 12, 2018): 616–23. http://dx.doi.org/10.1177/0734242x18775494.

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Fly ash is an industrial waste material that is repurposed as a soil stabiliser worldwide. In Thailand, many ground improvement projects utilise mixtures of cement and fly ash to stabilise weak soils. In this study, leaching mechanisms of arsenic, chromium, lead, and zinc from cement and fly ash stabilised soils were investigated in the laboratory. Leaching tests were performed, with different leachants and pH conditions, on cement and fly ash stabilised soils used for soil improvement in road embankment construction projects in Northern Thailand. The results suggested that chemical compounds (CaO and MgO) on fly ash surfaces can control the pH of the fly ash and soil leachant. The dissolution of chromium and zinc was found to be amphoteric and controlled by oxide minerals at a high or low pH. Arsenic leaching was found to be oxyanionic where AsO43- prevented the adsorption of arsenic onto the negatively charged fly ash surface. Different types of leachant also leached out in different amounts of heavy metals.

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Tong, Yan, Sha Long, Zhong Fu Wang, Xiao Ming Xu, and An Hou Long. "Composition and Properties of Phosphate Cement." Advanced Materials Research 284-286 (July 2011): 2327–30. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.2327.

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The composition and properties of phosphate cement, the requirement of its materials needed are discussed. Its compositional materials are heavy burnt magnesia and polyphosphatic solution. The effect of features, the amount of magnesium oxide and phosphate on the cement properties are described. It can be used in large fabrication repairing and in industrial waste disposal.

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Tomita, Rokuro, Hiroshi Hirao, Takashi Tochigi, and Takamiki Tamashige. "ECOCEMENT Innovative Cement for Contributing to Sustainable Society." Key Engineering Materials 302-303 (January 2006): 44–54. http://dx.doi.org/10.4028/www.scientific.net/kem.302-303.44.

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In Japan, a majority of urban waste is incinerated to reduce the volume and the residue (incineration ash) is land filled. Japanese municipalities, however, are confronted with serious shortages of waste landfill sites. To mitigate this situation, Taiheiyo Cement Corporation has developed two technologies, which are Ash Rinsing Process and Ecocement. Incineration ash is a suitable material for cement production because it primarily contains essential chemical components of cement clinker. The problem is that chlorine and heavy metals accompanying primary components cause operational trouble and deteriorate quality and material safety of cement. Ash rinsing technology will be effective to remove chlorine and heavy metals in the ash. Therefore, for municipalities closely located existing Ordinary Portland cement plants, it is the simplest way to use waste incineration ash as a raw material in those cement plants. Ecocemet, on the other hand, will be an attractive option for the municipalities distant from cement plants. Ecocement is defined as cement that is produced from over 500 kg (dry base) waste incineration ash supplemented with other wastes (sludge, etc) per ton of Ecocement. According to the discharged amount of ash, correspondingly scaled Ecocement plant is needed. In Ecocement production process, chlorine in the ash is combined with intentionally added alkalis or heavy metals and is extracted. Extracted metal chlorides are recycled as metal sources. Two types of Ecocement can be used in the fields of ready mixed concrete, concrete blocks or soil stabilizer. The first commercial plant of Ecocement constructed in Chiba prefecture started operation in April 2001. In July 2002, Japanese Industrial Standard of Ecocement was published. Consequently, Ecocement has become an authorized product in Japan. The second Ecocement plant is now under construction in Tokyo.

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Souidi, F., N. Chelouah, and M. Bouzeroura. "Use of calcined clay as cementitious addition in mortars to immobilize heavy metals." Cerâmica 66, no. 380 (December 2020): 516–23. http://dx.doi.org/10.1590/0366-69132020663802917.

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Abstract The aim of this study was to examine the use of calcined clay (CC), which is a pozzolanic material, as a substitute for 10% by weight of the amount of cement, for the stabilization/solidification (S/S) of hazardous waste using a hydraulic binder. For comparison, an ordinary Portland cement was used. The standard toxicity characteristic leaching procedure (TCLP) test showed that the average concentrations of heavy metals in the raw hazardous waste far exceeded those of the required standards. Leaching of heavy metals from the mortar was evaluated by the monolithic leaching test (MLT) under dynamic leaching conditions for 64 days in sulfated and neutral media. Tests of compressive strength, setting times, and X-ray diffraction were carried out. The addition of CC considerably improved the strength of the mortar specimens containing hazardous waste. Following the MLT test, CC cement-made mortar was more efficient in the S/S of heavy metals than mortar made without CC.

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Yu, Wei, Yan Nan Zhang, Xuan Cang Wang, and Zhi An Feng. "Analysis on Bearing Capacity of Heavy-Load Cement Concrete Pavement." Applied Mechanics and Materials 505-506 (January 2014): 200–203. http://dx.doi.org/10.4028/www.scientific.net/amm.505-506.200.

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The current cement concrete pavement design specification considerate the limit state of pavement via using the most adverse combination of maximum load stress and temperature load stress. This method enlarged the effect of temperature stress which lead to the overly conservative results. According to it, the reasonable combination of the ultimate axle load and temperature stress was deeply researched. The proper value of temperature gradient, reliably coefficient, stress reduction coefficient, comprehensive coefficient and the effect of load position in structure calculations were studied respectively. The improved calculation method of cement ultimate axle load of concrete pavement was proposed and verified, rely on the practical construction.

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FUKUNAGA, Takayuki, Nobuaki OTSUKI, Tsuyoshi SAITO, and Yuji MAENO. "STUDY ON FIXING HEAVY METALS BY CEMENTITIOUS MATERIALS WITH MUNICIPAL WASTE COMBUSTION ASH, OPC, BLAST FURNACE SLAG AND ANHYDRITE." Cement Science and Concrete Technology 66, no. 1 (2012): 600–606. http://dx.doi.org/10.14250/cement.66.600.

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Chen, Ke, Chang Hui Yang, Fang Wu, Jian Xiong Ye, Shu Ang Zhao, and Xiao Bin Xiang. "Study on Expansion of Cement-Based Material with Addition of Magnesium Oxide." Materials Science Forum 610-613 (January 2009): 968–74. http://dx.doi.org/10.4028/www.scientific.net/msf.610-613.968.

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In this paper, the influence of the types and addition dose of MgO expanding agent and the age of cement on expansion value and expansion performance of cement based material added with MgO expanding agent was systematically studied.The expansion characteristics of cement based material added with MgO expanding agent or calcium sulphoaluminate expanding agent were compared. The expansion of such material increases with the addition dose of MgO expanding agent and cement mortar age. During the test period, the expansion of cement based material increases continuously. The light-burned MgO expanding agent modified by CaO expanding agent is able to increase the 28d expansion of such material effectively. The temperature of calcination for the heavy-burned MgO expanding agent is higher than that of light-burned one, thus the heavy-burned MgO expanding agent has a rather dense structure with slow hydration rate and gives a small expansion of the cement based material at early age, showing an obvious expansion delay. The calcium sulphoaluminate expanding agent gives most expansion of the material in the early 28d and there is small expansion at middle and later age of the material.

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Hsiao, P. C., and S. L. Lo. "Extractability and fractionation of heavy metals in chemically treated sewage sludges." Water Science and Technology 44, no. 10 (November 1, 2001): 91–94. http://dx.doi.org/10.2166/wst.2001.0590.

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Four chemically treated sludges, lime-treated (LS), lime/sodium silicate-treated (LSS), cement-treated (CS), and cement/sodium silicate-treated (CSS) were produced form the chemical treatment of aerobic digested sewage sludge cake, using lime, cement, and sodium silicate as additives. Ex tractability and fractionation of the heavy metals (Cu, Pb, Cr, and Zn) in these products and untreated sludge (S) were investigated using sequential extraction, single extraction, and 13C cross-polarization magic angle spinning nuclear magnetic resonance analysis (13C-NMR). These approaches revealed that chemical treatment of sewage sludge makes sludge Cu, Pb, and Cr more extractable. It was attributed to the irreversible dissolution of a portion of organics at very high pH during chemical treatment of sludge. The enhanced extraction of some metals having higher affinity to organics, e.g. Cu and Pb, from the chemically treated sludges was due to their complexion with the above soluble organics.

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ELNakeib, Dr Salem M., Dr Fathi K. Elyaagubi, Dr Mohamed A. Alrabib, Eng Afaf Abouzed, and Eng Hanan Saleh Wanis. "ASSESSMENT OF HEAVY METAL CONTAMINATION OF SOIL SAMPLES COLLECTED FROM THE AREA AROUND AL-MARQUB CEMENT PLANT." Scientific Journal of Applied Sciences of Sabratha University 2, no. 2 (November 14, 2019): 1–9. http://dx.doi.org/10.47891/sabujas.v2i2.1-9.

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Soil samples were collected from and around Almarqub cement factory, AL-Khums city, Libya. These samples were collected from four different sites M1 (inside the factory), M2 (150 m from the factory), M3 (350 m from the factory) and M4 (60 km away from the factory as the control samples. The study was conducted to determine the heavy metal concentration in the soil. Organic matter, pH and water content value were determined according to the method described by Chaturvedi and Sankar (2006). Metals were determined by Atomic Absorption Spectrophotometer. The results obtained for the examined physiochemical properties of soil in the area studied prove that cement dust from the Almarqub cement factory has had a significant impact on the soil. The affected soil properties are pH and total calcium content. These properties were found to be higher than those in similar soils from the same area unpolluted. The increase of soil pH in the same area may be a result of precipitation of cement dust over the years. Metal uptake from cement to soil and plants. Metals determined in contamination soil indicated high concentrations in M1 inside cement factory compared to soil samples as control. Results of the analysis have shown that there are signs of slight impact of soil properties arising from the cement dust on the soils, especially at location inside the factory. Recommendations were offered to monitor the dust falling on the soils through trapping and utilizing the dust emissions of cement.

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Chang, Dave Ta-Teh, Wen-ping Liao, and Shin-yueh Chen. "Effectiveness of Various Sludge Stabilization and Solidification Methods." Transportation Research Record: Journal of the Transportation Research Board 1546, no. 1 (January 1996): 41–52. http://dx.doi.org/10.1177/0361198196154600105.

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If sludge contaminated with heavy metals is not properly treated, water flowing over the sludge can cause the heavy metals in it to leach out, polluting groundwater. To establish an effective means of dealing with this problem, the engineering applicability and stability of sludge solidified using portland cement (A1), a gypsum-type agent (B1), a cement Type I agent (A2), and a cement Type II agent (B2) were studied. The sludge was obtained from Keelung River. After the treated sludge had cured for 7, 14, 28, and 60 days, each sample was tested to ascertain its compressive strength and the rate at which six different hazardous heavy metals leached out. This was done to evaluate the feasibility of sludge solidification. The findings indicate that the ratio at which the solidifying agent is used determines the strength of the treated sludge. No significant improvement was found when the treatment agent was used at rates of less than 10 percent. Except for the A1 agent, marked improvement was observed for all types of solidifying agents except when the amount of additive was increased to 20 percent. The heavy-metal leaching rate of treated specimens met the requirements of the pollution control regulations, indicating that hazardous heavy metals had been effectively fixed within the sludge. Therefore, solidifying agents comprise an effective and feasible method of solidifying and stabilizing Keelung riverbed sludge.

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Journal articles on the topic 'Heavy cement'

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