浮选尾煤脱泥再选及其可浮性评价

Recleaning of coal flotation tailings desliming and floatability evaluation

为了解决开滦集团公司某选煤厂浮选尾煤产量大、灰分低、异质细泥含量多的问题,采用φ150、φ75、φ50、φ10 mm串联小锥角水力旋流器组进行脱泥试验研究,通过顺序评价试验,对旋流器组脱泥前后和各级底流煤泥进行可浮性评定。结果表明:各级底流灰分均低于原煤泥灰分,其中φ10mm旋流器底流与溢流灰分差值为11.15%;小于0.015 mm的高灰细泥脱除量占全级的19.73%,脱泥后煤泥灰分降低2.73%,说明小锥角旋流器组脱泥有效。原煤泥可浮性为极难浮,脱泥后提升为难浮,其中φ75 mm与φ50 mm混合底流、φ10 mm底流为较难浮,在精煤灰分不大于11.50%时,脱泥后入浮精煤产率较脱泥前(19.21%)提高8.91%,各级底流单独入浮精煤产率和为31.48%,较脱泥前提高12.27%,说明脱泥后煤泥可浮性得到有效改善。

In order to solve the problem of large amount,low ash and high content of heterogeneous fine mud of coal fotation tailings from a coal preparation plant of Kailuan Group, desliming experiment was conducted using small taper angle hydrocyclone group installed in se- ries of φ150 mm ,φ75 mm ,φ50 mm,φ10 mm. Through sequential evaluation experiment the hydrocyclone group before and after as well as all levels of the underflow coal slime were evaluated. The results show that all levels of the underfow ash are less than raw fine coal. With φ1 mm hydrocyclone,the ash difference between underflow and overflow is 11.15% ;the removal rate of less than 0. 015 mm high ash content fine slime is 19.73% ;the ash yield of fine coal after desliming decreases 2. 73% indicating high effective of hydrocyclone group desliming. The floatability of the raw fine coal is extremely diffficuh-to-float;after desliming it is promoted to be difficult-to-float. The mixed underflow of φ75 mm and φ50 mm, and underflow of φ10 mm are less difficult-to-float. When ash content of cleaned coal is 11.50% or less,the yield of the clean coal after desliming is 8.91% higher than before （ 19. 21% ） ;the mixed yield of the clean coal from separating flotation is 31.48% （12. 27% increase） ,which means the desliming is able to improve the flotability of fine coal.