Известия Томского политехнического университета: Инжиниринг георесурсов (Sep 2017)
Physical characteristics of briquettes produced from shale fines and sawdust
Abstract
The relevance of the research is caused by the necessity of treatment of great amount of waste of oil shale processing and wood industries - shale fines and sawdust, which complicates the technological scheme of processing these materials. The main aim of the study is to determine the optimal conditions for briquetting oil shale fines and to study water saturation of fuel briquettes and pellets produced from wood sawdust. The methods used in the study. The authors have used modern laboratory equipment (granulometric classificatory ASControl, laboratory hydraulic press PVL-20, muffle furnace SNOL-8.2/1100). Determining the strength characteristics of the obtained briquettes of oil shale was carried out according to standard methods according to GOST 21289-75 «Coal briquettes. Methods for determination of mechanical strength». The briquette was placed between the cylindrical inserts of the press in the way that the insert rests on its centers is parallel to the surface, brings the preform to fracture. As the oil shale contains up to 50 % of mineral impurities, the authors decided to increase the number of drops from 4 (according to the State Standard 21289-75) up to a maximum amount. Oil shale briquette thermal stability (they are not broken at thermal treatment) was determined at 800-1000 °С. The results. The author studied the influence of fractional composition and pressure of briquetting on strength characteristics (shock and compression resistance) of the obtained oil shale briquettes as well as the manufacturing method of briquettes (dry or hot) on water saturation of their produced from wood sawdust. The authors determined the optimal conditions for briquetting oil shale fines of different composition and grain size of the material: fraction is less than 125 mkm, water content is 37 %, pressure is 15 MPa; the obtained briquette has mechanical characteristics: shock resistance is 6 quantity of falls, compression resistance is 5 kg/cm2 , thermal stability is at 800-1000 °С; fraction is less than 125 mkm and from 2 mm to 125 mkm (1:1), water content is 23 %, pressure is 15 MPa, the obtained briquette has mechanical characteristics (shock resistance is 4 quantity of falls, compression resistance is 3 kg/cm2 ), thermal stability is at 800-1000 °С.
