A study on the property of the coal slime and product mix at Hongliu Coal Preparation Plant

The adoption of the heavy medium separation process for treating the full size range raw coal at Hongliu Plant is adaptable to the raw coal property and hence the product produced is up to the standard as required. However,due to use of this,washing process,a large quantity of high-ash and low calorific value coal slime is produced,which is dull of sales and hard to put into utilization,causing,therefore,the waste of coal resources and contamination of the environment of the plant. As evidenced by result of test on flotation of the high-ash slime with A_d=39. 30% and Q_net,ar=10. 88 MJ/kg,a much upgraded concentrate product having A_d=15. 88%,γ =57. 61% and Q_net,ar=18. 31 MJ/kg can be obtained.Through flotation,the value of Ecis increased up to 80. 12% while the yield of saleable coal is increased by 10. 63 percentage points. After the flotation concentrate is blended into the clean small coal product,the composite calorific value of latter goes up to 20. 55 MJ/kg,well up to the required "Shenning-1#"power coal standard. After flotation of the slime,apart from the full use of coal resource,there has been seen a much improved product mix. This is of great importance to the improvement of social and economic result and environment friendliness.