煤炭高梯度磁选-浮选脱硫降灰试验

Experimental study on high-gradient magnetic separation and flotation for coal desulfurization and desliming

通过分析煤样性质,说明原煤中无机硫主要以硫化铁硫为主,有机硫较高,仅依靠物理方法很难达到理想脱除效果。通过煤粉高梯度磁选试验研究了磁介质、磁通密度、脉冲对煤炭磁选效果的影响。结果表明:聚磁介质选用不加铜套细网介质,当磁通密度为1.295 T,脉冲为25次/min时,煤粉湿法高梯度磁选脱硫效果最好,此时硫分为1.59%,精煤产率为85.44%,脱硫率为31.87%,脱灰率为38.17%,黄铁矿硫脱除率为45.02%。通过正交试验确定了最佳高梯度磁选条件为:煤粉粒度0.075 mm,磁通密度1.295 T,脉冲25次/min,可得到硫分1.35%,灰分10.37%的磁选精煤产品。最后对磁选精煤进行再浮选试验,得到最佳浮选条件为:石灰500 g/t,捕收剂1360 g/t,起泡剂90 g/t,可获得产率76.29%,硫分1.28%,灰分8.14%的精煤,产品脱硫率为57.73%,脱灰率为58.52%,黄铁矿硫脱除率为84.56%。采用磁选-浮选综合流程,煤粉基本达到理想的脱硫降灰效果,可作为煤种脱硫降灰技术方案的参考。

The analysis of coal sample properties show that, the iron sulfide is the main component. So it is difficult to achieve ideal removal effects just depending on physical removal methods. Investigate the influence of magnetic medium ,magnetic flux density and pulse on the effects of magnetic separation through coal fines high-gradient magnetic separation experiments. The results show that, taking the fine network without copper bush as assembled magnetic medium, when the magnetic flux density is 1. 295 T, pulse is 25 times per minute, the desulfurization effects is the best. Under this condition, the sulfur content, clean coal yield, desulfurization rate, desliming rate, desulfurization rate of pyrite is 1.59 percent, 85.44 percent, 31.87 percent, 38.17 percent, 45.02 percent respectively. Determine the best high-gradient magnetic separation condition through orthogonal test. When the coal fines size is 0. 075 mm, the magnetic flux density is 1. 295 T, the pulse is 25 times per minute, obtain clean coal with 1.35 percent sulfur content, 10. 37 percent ash content. At last, conduct the secondary flotation experiment, get the best flotation condition. When the dosage of lime, collector and frother is 500 g/t, 1360 g/t,90 g/t, obtain clean coal with 1.28 percent sulfur content, 8.14 percent ash content and 76. 29 yield, and desulfurization rate, desliming rate,desulfurization rate of pyrite is 57.73 percent,58.52 percent and 84.56 percent. The research show that,the high-gradient magnetic separation and flotation can decrease effectively sulfur and ash content in coal.