粒度组成细、高灰细泥含量大的煤泥浮选时,浮选精煤易于超灰且精煤产率低、生产操作困难。针对这些问题,在总结载体浮选理论的基础上,研究了以浮选精煤作为自载体改善煤泥浮选效果的作用和机理。结果表明:用浮选出的精煤作自载体可显著改善煤泥的浮选效果。随自载体量的增加,精煤产率、浮选完善指标、尾煤灰分均提高,浮选精煤灰分降低。乌海煤泥采用该工艺浮选时,确定出最佳自载体用量为入浮煤泥的10%,加入自载体经4次循环后即可达到稳定的浮选效果,浮选精煤产率提高7.11%、灰分降低1.14%,浮选完善指标提高7.25%。EDLVO理论的计算研究表明,精煤本身的疏水性和捕收剂在煤粒表面吸附产生的疏水力,促使细煤粒黏附于粗颗粒载体,细颗粒间也会发生疏水絮凝,改善了浮选环境和浮选效果。

According to the carrier flotation theory,this paper provides a method of using flotation cleaned coal as au- togenous-carrier to improve the flotation efficiency of coal slime. This method tends to fix the problem that because the ash of flotation cleaned coal is often higher than the required ash and the yield of clean coal is low,the production op- eration is difficult for the coal slime containing fine particles and high ash clay. Moreover,the results show that the coal slime flotation effect can be significantly improved by this method. Experiment results illustrate that with the increase of the amount of autogenous-carrier,the clean coal yield,the flotation perfect index and the tail coal ash are increased, besides the ash of the flotation cleaned coal is reduced. This flotation process has been used to separate the slime from Wuhai and the feedback shows the yield of flotation refined coal increases by 7． 11% , ash content decreases by 1.14% and the improvement index of flotation improves by 7． 25% . Furthermore,the results show the optimum dosage of autogenous-carrier is 10% of the floating slime and the stable flotation effect can be achieved after 3-4 cycles by adding autogenous-carrier. The EDLVO theory has been studied and the results show that the hydrophobicity of the cleaned coal itself and the adsorption of the collector on the coal particle surface lead to the hydrophobic force which encourages the fine coal particles are adhered to the coarse particle carrier and the hydrophobic flocculation occurs be- tween the fine particles. Finally,the flotation environment and flotation effect were improved.