Pulverized fuel production from coal slimes of Hema Kandilli washing plant below 0.5 mm using Reichert spiral

In HEMA Zonguldak coal washing plant located in Kandilli region which is owned by Hattat Energy and Mining Company Ltd., about 750 tons of ROM coal per day is produced by underground methods. After production, the ROM coal at -100+10 mm and -10+ 0.5 mm size ranges are washed in Drewboy Heavy Media Drums and Heavy Media Cyclones respectively. In addition, the coal slime under 0.5 mm, firstly dewatered by detritus tank and then fed to the pressure filters. After these processes, an ultimate product of 0.5 mm sized coal with 40-47 % ash content and 18-22 % moisture is obtained. Although, this product can not be used in industrial applications due to its characteristics, it can be sold under 70 TL per tonne price in particular to cement factories Thus, in this washing plant, 200 tons which accounts for 30 % of daily production, stands out as slime (-0.5 mm) coal. After bringing the ash and moisture content of that slime coal into 10-12 % content, it can be sold under 240 TL per tonne price to particularly iron and steel industries. In recent years, Reichert Spiral is one of the most widely used washing unit for beneficiation of fine and dust sized ores. The separation process in spirals is mainly utilized in terms of density and -3+0.075 mm size ranges which can be successfully used in the washing of coals. In addition, the absence of moving parts out of pump and less investment and operating costs make out the reasons for choice of spirals. In this study, a pilot scale Reichert Spiral was utilized for evaluation of coal slimes from preparation plant which is under consideration. Experimental studies were carried out for two types of coal classified as slimed and deslimed (sample without 0.106 mm sized coal) coal products. The result of these tests indicated that after desliming coal samples about 34.6 wt. % of spiral feed could be produced as clean coal product with 9.76 % ash content and 63 % combustible recovery. On the other hand, the results of tests with slime coal, about 48 wt. % of spiral feed was produced as clean coal with 26.2 % ash content and 65 % combustible recovery. However by screening the clean coal of this process with 0.106 mm screen, the oversize product accounts for 34.6 wt. % of spiral feed where an ultimate clean coal with 8.8 % ash content with 58 % combustible recovery was produced.