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Abstract

In recent years, the Budryk Coal Mine (KWK Budryk) reached the mining depth of 1300 m, where there is about 160 million tons of coal, including 120 million tons of coking coal (type 35). The task of the Coal Processing Plant complex modernization was undertaken. The article presents the modernization of coal screening, classification and dewatering systems at the KWK Budryk Processing Plant and the implementation of screening of PROGRESS ECO sp. z o.o. SK. The modernization project defined the following technical requirements for all screens in the KWK Budryk Coal Processing Plant extension project: - Vibrating screens with a linear type drive with a drive unit placed on the drive beam of the trommel screen in the form of vibration generators; - Screen drives equipped with a starting-braking device; - The use of main screen drive bearings with a nominal service life of at least 40,000 man-hours; - All work surfaces made of materials with a strength of up to 80 mm grain and abrasion resistance; side strips and sieves fixed in a way ensuring trouble-free operation, and at the same time quick and easy replacement; - Sheets made of stainless steel; - Side walls, beams and other elements attached to them connected with screws using a system protecting against corrosion and elements separation; - The use of a work parameters monitoring and visualization system, i.e. - pitch of the riddle, - bearing operating temperatures and the condition of their wear. Three types of screens were provided: - PWP1-1Z-2,8x6,0 screeners that alternatively perform sieving or desliming processes, - PWP1-2.4x6.0 screening machines performing desliming processes, - PWP1-2.0x6.0 screens performing the classification process.
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Abstract

With the increase in wall thickness of the casting of iron-nickel-aluminium-bronze, by the reduction of the cooling rate the size of κII phase precipitates increases. This process, in the case of complex aluminium bronzes with additions of Cr, Mo and W is increased. Crystallization of big κII phase, during slow cooling of the casting, reduces the concentration of additives introduced to the bronze matrix and hardness. Undertaken research to develop technology of thick-walled products (g> 6 mm) of complex aluminium bronzes. Particular attention was paid to the metallurgy of granules. As a result, a large cooling speed of the alloy, and also high-speed solidification casting a light weight of the granules allows: to avoid micro-and macrosegregation, decreasing the particle size, increase the dispersion of phases in multiphase alloys. Depending on the size granules as possible is to provide finished products with a wall thickness greater than 6 mm by infiltration of liquid alloy of granules (composites). Preliminary studies was conducted using drip method granulate of CuAl10Fe5Ni5 bronze melted in a INDUTHERM-VC 500 D Vacuum Pressure Casting Machine. This bronze is a starting alloy for the preparation of the complex aluminium bronzes with additions of Cr, Mo, W and C or Si. Optimizations of granulation process was carried out. As the process control parameters taken a casting temperature t (°C) and the path h (mm) of free-fall of the metal droplets in the surrounding atmosphere before it is intensively cooled in a container of water. The granulate was subjected to a sieve analysis. For the objective function was assume maximize of the product of Um*n, the percentage weight "Um" and the quantity of granules 'n' in the mesh fraction. The maximum value of the ratio obtained for mesh fraction a sieve with a mesh aperture of 6.3 mm. In the intensively cooled granule of bronze was identified microstructure composed of phases: β and fine bainite (α+β'+β'1) and a small quantity of small precipitates κII phase. Get high microhardness bronze at the level of 323±27,9 HV0,1.
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Abstract

The formulas have been entered and approved for the calculation of porosity distribution on the thickness of layer of fine-grained mixture during its separation by the inclined flat or vertical cylinder vibro sieves. It has been attained as a result of approximation of tabular information of the obtained numerical computer integration of the specially worked out nonlinear differential equations of the second order in a dimensionless form. For approximation, the function of degree coefficients and index is used for the degrees which are certain by the Aitken's method. Coefficients of the entered analytical dependence are the vibro sieves related to the parameters obtained by mechanical descriptions of the separated material. Coefficients of the entered analytical dependence are related to the parameters of vibro sieves and mechanical descriptions of the separated material. In the case of cylinder vertical vibro sieve the action of centrifugal force is also taken into account. The method of mixture porosity calculation does not need a computer numerical integration of nonlinear differential equations conducted by other authors for solving this problem. Comparison of numerical results of the proposed analytical method of calculation with the ones described in literature, have confirmed its high accuracy results, for the differences do not exceed one percent. The expounded method is universal enough and simple in use, besides it opens the possibilities of subsequent analytical integration of differential equalizations of motion at the calculation of kinematics descriptions of grain flow. The developed method gives the opportunity to also solve the inverse task when, according to experimental measurements of porosity values of grain mixtures on the thickness of movable separated layer, it is needed to find the value of phenomenological permanent that is included in the expressions of coefficients of initial differential equalization. In this way, the adequacy of the mathematical model is improved. The use of approximation of degree considerably simplifies the method of authentication of differential equalization coefficients. In the article, the examples of grain mixture porosity calculation as well as the examples of phenomenological permanent authentication have been resulted after experimental calculations for both the variants of vibro sieves.
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