Abstract. The purpose of the work is to assess the possibility of preparation of poor washability, high-ash coals demonstrated by the example of the Apsat deposit. The following tasks have been accomplished. The analysis of modern equipment produced for washing of large classes of coal: heavy-medium separators and jigging machines. The most preferred were the heavy-media separator SKVP, jigging machines ROMJIG and BATAC. The analysis of mathematical models of processes and technologies of gravitational processing for determining the yield and ash content of the concentrate has been carried out. Algorithms and computer programs have been developed in which two mathematical models of the processes of heavy-media preparation and jigging machines have been used that allow determination of the separation densities at which the maximum yield of the total concentrate of the required ash content is reached. The computational experiment carried out showed that in processing of high ash diluted coals with poor washability, it is expedient to use SKVP separator and a jigging machine ROMJIG.
Abstract. Changing the source of raw materials for producing aluminum and the emergence of a huge number of secondary alumina waste (foundry slag, sludge, spent catalysts, mineral parts of coal and others that are formed in various industrial enterprises) require the creation of scientific and theoretical foundations for their processing. In this paper, the aluminum alloys (GOST 4784-97) are used as an aluminum raw material component, containing the aluminum component produced as chips in the machine-building enterprises. The aluminum waste is a whole range of metallic aluminum alloys including elements: magnesium, copper, silica, zinc and iron. Analysis of the aluminum waste Al-Zn-Cu-Si-Fe shows that depending on the content of the metal the dissolution process of an aluminum alloy should be treated as the result of the chemical interaction of the metal with an alkaline solution. It is necessary to consider the behavior of the main components of alloys in an alkaline solution as applied to the system Na2O -Al2O3 -SiO2 -CO2 -H2O.
The study considers sixteen functions of the first degree that were used for the analytical presentation of the aggregate size characteristics by "plus" of the Kuznetsk basin coal in the size range from 0 to 300 mm. The computational experiment was carried out for 500 aggregate coal size characteristics. The parameters of the functions were determined by the known method of least squares. When required, the formulas were reduced to a linear form. To solve systems of linear algebraic equations, the Cramer method was used in Excel (using the built-in function MDETERM () for calculating matrix determinants), Gauss method in the TurboPascal (reduction of matrices to a triangular form). The quality of the approximations was estimated by the value of the standard deviation between experimental and calculated values of the total yields (ash content) of the size classes. To carry out the computational experiment in TurboPascal, computer programs Gran16_V.pas have been developed -to calculate the total yields of classes and Gran16_A.pas for calculating the ash content of the same classes. It is established that the Pogosov formula is the best in comparison with the others, including, with the well-known functions of Rosin-Rammler and Goden-Andreev.
Coal preparation currently has a number of significant problems concerning the dewatering processes (water purification, coal sludge thickening). These processes polymeric flocculants are used to their enhancement. To select a floculant for its further use at the preparation plant is currently a quite complicated and mainly empirical process. The authors have conducted research in order to establish a possibility to recommend certain flocculants to be chosen based on the properties of coal pulp, that were established during the experiments, and the properties of the aforementioned flocculants. In this paper are listed the methods, that were used during the research, the results of the laboratory tests of anionic flocculants Magnaflock, that were conducted on various coal pulp samples with various properties. The industrial testing of the selected flocculant at the coal preparation plant “Anzherskaya” was examined in detail. After the analysis of the obtained results certain conclusion was conducted.
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