Application of Yunnan lignite semi-coke in ferrosilicon production

In view of excellent properties of Yunnan lignite semi-coke,which is used to replace 50 percent metallurgical coke to produce ferrosilicon.Investigate the impact of lignite semi-coke particle size,reactivity,ash and other indicators.The results show that,the moisture of feeding lignite semi-coke should be controlled around 10 percent,the particle size less than 4 mm component of semi-coke should not exceed 10 percent,the mass fraction of component ranging from 4 mm to 6 mm should reach about 50 percent.The high reactivity property of semi-coke is favorable to the smelting ferrosilicon,while improving the reduction ratio of Al2O3in ash content which is negative to the75 percent ferrosilicon production,so the ash content in semi-coke should not be over 7 percent.Application tests on mixed semi-coke and metallurgical coke show that,the mass fraction of Al in the product made by mixed coke is2.27 percent on an average.Product rate of ferrosilicon,whose Al content is less than 2 percent is 28.56 percent,down 7.39 percent compared with wholly using metallurgical coke.Using mixed coke,electricity consumption decrease 37 kWh/t,reductant consumption increase 3.2 percent,while lower Al content product drop slightly.All of these indicate partial substitution of lignite semi-coke for metallurgical coke in ferrosilicon production is feasible,and has a certain role in saving energy.