Technology for Producing Composite Solid Fuel From Coals of Kyzyl-Bulak and Kozho-Kelen Deposits and Heated Bitumen

Abstract

The paper presents the results of a study of the production of composite solid fuels (CSF) from compositions of coal from the Kyzyl-Bulak and Kozho-Kelen deposits and a bitumen binder. The possibilities of producing CSF from a mixture of bitumen and preheated coals have been studied. To determine the dependence of the quality of the resulting CSF on the grinding size, the above coal was crushed into three fractions: a fraction with a particle size of 0-1mm, a fraction with particles of 0-3 mm and a fraction of 0-5 mm. These 3 fractions of coal were subjected to sieve analysis and the granulometric composition was determined, then each fraction individually was subjected to briquetting on a hydraulic press, in a mold with a diameter of 40 mm. Based on the task, pressing took place at 3 parameters, namely: at a pressure of 10 MPa, 15 MPa and 20 MPa. The use of different pressures made it possible to trace the dependence of the quality of the resulting CSF on the pressing pressure and determine the optimal pressure parameter. Briquetting was also carried out at different concentrations of the charge and the mechanical properties of the CSF were determined at a binder concentration of 6, 8, 10%. It has been established that the use of a bitumen-like product (bitumen) as a binding material, obtained as a result of thermal dissolution of coal with oil waste at a temperature of 320-380°C, produces mechanically strong briquettes that have compression resistance up to 106 kg/cm2 and bending resistance up to 7.5 kg/cm2. It has been shown that the mechanical strength of briquettes increases with increasing degree of coal grinding, and also an increase in pressing pressure increases the mechanical strength of briquettes. As the moisture level of coal increases, the mechanical strength of the briquette decreases. The optimal parameters for producing CHP have been established: coal size 0-3 mm: humidity 6.5%, pressing pressure 200 kg/cm2.