动力煤选煤厂末混煤减量化研究

Study on reduction of mixed small coal yield of power coal preparation plant

为了解决块煤入选时末混煤过多,发热量和水分易超标的问题,龙华选煤厂结合现场实际情况,在确保对小块限下率影响较小的基础上,提出减少块精煤脱介筛上层筛板筛孔数量、后移脱介筛喷水管等末混煤减量化方案。生产实践表明,在产品水分和发热量指标达标的情况下,末混煤减量可达30～40 t/h,每年企业增收1 000万元以上。

The problem facing the Longhua Coal Preparation Plant is that the coarse coal treated contains an excessive proportion of mixed small coal , which is liable to exceed the limit in calorific value and moisture. For tackling this problem, under the prerequisite of ensuring that only limited effect is imposed on undersize fraction of small sized coal, the scheme for reducing mixed small coal yield is proposed in line with the specific conditions of the plant. The scheme proposed involves diminishing the size of the hole on upper deck of cleaned coarse coal medium draining screen and moving backward the medium draining screen＇s water-spraying pipe. Practice shows while ensuring the products are up to the required standards in moisture and calorific value, the yield of mixed small coal is reduced by a level of up to 30-40 t/h, bringing about an additional revenue of over 10 million yuan for the plant.