Modelling of oil shale concentration processes in Estonian mines Juri-Rivaldo Pastarus*, Enno Reinsalu and Martin Saarnak Faculty of Power Engineering, Department of Mining, Tallinn University of Technology, Tallinn, Estonia (Received 25 March 2014; accepted 30 August 2014) In Estonia, oil shale is used as a fuel for producing energy and as raw material for processing shale oil. Concentration plants at mines must guarantee required oil shale quality and quantity parameters. The processing rock material (run-of-mine) is the mineral composition, the quality of which depends on geological conditions and technology in mine. Mathematical description and data analysis are performed on working processes from working place (face) to a concentration plant: extraction, crushing, screening and concentration. A mathematical model for a concentration plant was created based on these studies. This model allows determining the optimum parameter kinds of trade oil shale and helps to design processing flow sheet. Keywords: oil shale; heating value; waste limestone; concentration processes; flow sheet; model Introduction The oil shale industry of Estonia provides a significant contribution to the economy of the country. Oil shale is used as a fuel for producing energy and as a raw material for processing shale oil. More than 80% of electricity in Estonia comes from oil shale. The mining sector faces challenges to increase the output of mines, and at the same time to supply power and shale oil plants with suitable quality fuel and raw material. The Estonian oil shale power plants use two heating technologies – pulverised fir- ing and circulating fluidised bed combustion technology. These technologies require fuel grain size in the range (grade or class) 0–300 mm. The heating value must be no less than 8.4 MJ/kg. Shale oil generation has two technologies: processing lump oil shale in vertical retorts and pyrolysing fine oil shale with solid heat carrier. Heating value of lump oil shale (class 25–125 mm) must be no less than 11.4 MJ/kg. Raw material for solid heat carrier reactors is class 0–25 mm with heating value >8.4 MJ/ kg. Concentration plants at mines must guarantee all kinds of saleable oil shale quality parameters in optimum ratios [1]. Feed of a concentration plant is run-of-mine (ROM), the quality of which depends on geological conditions of the mine field, and extraction technology including breakage, haulage, transporting and hoisting. *Corresponding author. Email: juri-rivaldo.pastarus@ttu.ee © 2014 Taylor & Francis International Journal of Mining, Reclamation and Environment, 2014 http://dx.doi.org/10.1080/17480930.2014.962807 Downloaded by [Tallinn University of Technology] at 06:16 12 January 2015