Academic literature on the topic 'According to the size and the method of crushing'

Coal principal stresses with reservoir plane is analyzed, consequently coal seam crushed classification method is presented based on Hoek-Brown criterion. According to the coefficient of coal crushing, coal seam crushed coefficient size, four grades of A,B,C,D are divided for coal crushed degree along wellbore direction, and coal crushed classification standard is determined. Using the classification method and standard, the distribution regularity of coal crushing is studied for ZP-05 Well in QinShui basin. The research results show that coal crushing of ZP-05 is considered as grade B. The prediction results agree well with the measured values.

Using adjustable speed crushing regeneration test device for the recovery experiment of thermosetting phenolic plastic waste, this paper analyses the principle of recovery process. Through particle size analytical technique, FTIR, XRD and SEM etc. various testing method is analyzed mechanochemical effects of crushing process. Research the speed, time, temperature process parameters of the influence of recycling process conditions. According to the experimental results, it established the mechanochemical model and analyzed the degradation and regeneration mechanism of thermosetting phenolic plastic waste.

More cuttings producing in higher penetration rate of gas drilling are usually in the larger non-uniform size at the bottom and in the smaller uniform size back to the wellhead. It is indicating that cuttings in the well should be appeared in the successive breaking in the process of upward migration. According to the particle broken theories, the successive breaking phenomenon were analyzed, and given the calculating method for the probability of secondary impact crushing, and applied the breaking process matrix and the particle size distribution function to the cuttings migration crushing in the whole wellbore. The calculating results show that the cuttings in the wellbore are broken by the uneven size volumetric fracture progressively turned into the surface fracture of the uniform process, and ultimately stabilized the small size distribution.

The ore fragment size on the conveyor belt of concentrators is not only the main index to verify the crushing process, but also affects the production efficiency, operation cost and even production safety of the mine. In order to get the size of ore fragments on the conveyor belt, the image segmentation method is a convenient and fast choice. However, due to the influence of dust, light and uneven color and texture, the traditional ore image segmentation methods are prone to oversegmentation and undersegmentation. In order to solve these problems, this paper proposes an ore image segmentation model called RDU-Net (R: residual connection; DU: DUNet), which combines the residual structure of convolutional neural network with DUNet model, greatly improving the accuracy of image segmentation. RDU-Net can adaptively adjust the receptive field according to the size and shape of different ore fragments, capture the ore edge of different shape and size, and realize the accurate segmentation of ore image. The experimental results show that compared with other U-Net and DUNet, the RDU-Net has significantly improved segmentation accuracy, and has better generalization ability, which can fully meet the requirements of ore fragment size detection in the concentrator.

According to the Spanish National Research Council (CSIC) report, the ex-situ leaching method (ESL) is more appropriate and accurate than other methods for measuring pH value in terms of repeatability and reproducibility. In this study, the ESL method was used to measure the pH value of cement matrix materials. The design test process aimed to avoid underestimating the variation in pH during the process of solution stirring and pH measurement without using both argon and nitrogen to block the specimen contact with air, with good repeatability and reproducibility. This study also considered the influence of the dryness of the specimen before crushing, the size of the powder, the air-exposed specimen, the air-exposed solution, the temperature of the solution, etc. After testing and analysis, a standard procedure for detecting the pH value of cement matrix materials was established which is known as the S-ESL method.

The article provides a detailed overview of the process of splitting the kernel of a walnut. Examples of many ways to split the shell are given, all of their disadvantages and advantages are listed. The mechanical method of peeling nuts using low-frequency oscillations has been theoretically investigated and substantiated. The kinematics of the process of crushing nuts between two parallel plates has been extensively analyzed. Graphical correlations were obtained between the size of the nut shell and the dynamics of the driving force of the nut moisture. It is revealed that the process of destruction of the shell of a walnut consists of four stages, corresponding to the laws of brittle destruction. Presents: - dependence of the maximum force of crushing of a shell of a nut at 5% humidity; - the dependence of the maximum crushing force of nuts at different shell thickness for the case of horizontal positioning of the nut between two plates with perpendicular force on the surface of the joint halves of the nut; - the dependence of the maximum crushing force according to the humidity of the nuts at different shell thicknesses for the case of vertical positioning of the nut between two parallel plates with a vertical driving force; - the dependence of the maximum crushing force with the moisture of the nuts at different shell thicknesses for the case of horizontal positioning of the nut between two parallel plates with a force action along the slit. The energy of splitting (crushing) of nuts at their location in different positions between two parallel plates is also determined. Where it has been proved that the energy consumed in the process of crushing increases with the thickness of the shell of a walnut. At the same time, it is proved that energy consumption depends on the location of the nut in the process of crushing. Graph analyzes were performed to show that maximum crushing energy is recorded in the case of a horizontal arrangement of a nut with a perpendicular crack action. In this study, a large amount of information was obtained regarding the splitting of the walnut, depending on the structural and mechanical characteristics of the products, which in the process of processing are important for the determination of certain rational technological parameters.

Today due to the unique properties of magnesia carbon refractories, the iron and steel industries are of special interest. Therefore, it is important to extend the life of the refractory. The effect of calcined alumina and nanocarbon on the mechanical strength and corrosion resistance against slag refractories magnesia carbon has been studied. Mechanical strength of cold crushing strength (CCS) was measured according to ASTM C0133-97R03 numbers. The bulk density (BD) and apparent porosity (AP) were determined respectively, relative to the size and weight measured using Archimedes method according to ASTM C0020-00R05 numbers and corrosion resistance against slag shrub procedure. Samples prepared at cylinder 50×50 mm were tempered on 250 °C for three hours. The corrosion resistance of the samples cocked on 1350 °C for two hours under reducing atmosphere (coke bed) was evaluated. During the review process of characterization methods, XRD, SEM-EDX has been used. The results showed that the properties improved.

A model of the relative compression ratio for single-particle crushed products, based on the distinct element method (DEM) and numerical analysis, was established to describe precisely the crushed products of granular particles during laminated crushing. The relative compression ratio model was used to describe the functional relationship between the total compression ratio and the single-particle compression ratio, which can be described by lognormal distribution. The single-particle crushed products model was used to describe the functional relationship between the single-particle compression ratio and the distribution of single-particle crushed products. The distribution of single-particle crushed products was described by a three-parameter beta distribution. On the basis of the above model, the function of laminated crushed products of granular particles was established. According to the simulation results of EDEM under confining pressure, a functional relationship between total compression ratio, particle size, and height of the granular particles for laminated crushed products of granular particles was built. It was proved that the function of the theoretical particle size distribution coefficient of laminated crushed products of granular particles was not too different from the actual value determined by simulation. The function is universal and can be used to provide a theoretical basis and a design reference for the design of cone crushers, high-pressure roller mills, and other crushing equipment.

A method in experimental studies and industrial-polygon particular conditions justifying the choice of a rational design of an explosive charge. The comparative results of the evaluation of the stress wave’s amplitudes studies and the character of crushing hard media from the explosion of the charge explosives-variable and constant cross section. The dependences of the particle size distribution of various designs explosive charges destroyed by the explosion are constructed. In industrial conditions, the rationale for the explosive boreholes location according to the massif structure. Adjusted boreholes location grid on rational parameters blasting unit, determined using a novel method of breaking rock complex structure. A new design of a combined borehole charge of variable cross section has been proposed. Industrial tests performed and evaluation of the effectiveness of the proposed method blasting locally fractured rocks and ore deposits on non-metallic minerals. Recommendations on their use are given.

The side-gusset plate is connector of the combined-roller, which is the key component of the High-pressure Grinding Roller equipment that is applied in crushing raw iron ore, Fracture occurred at the bottom of the side-gusset plate while the roller’s operation. For exploring the reason of fracture, the stress distribution and corresponding critical location of the side-gusset plate were computed and analyzed according to two working situations based on finite element method. The analysis result illustrates that it is the failure of infant mortality because of overloading, not belongs to fatigue behavior, with the presence of the component operating time and the fracture cross-section’s granular feature as well. This result is a reliable foundation for succeeding redesign and manufacturing of side-gusset plate and other component, the feasible plan was brought forward to improve the component operation’s stability.