破碎方式对中煤表面性质及后续浮选的影响

摘要

Under the role of the different crushing methods,due to the variation of the surface properties,the middlings would affect the sta-tus of the crushed coal floatation behavior.Based on a phase composition analysis,the jaw crushing and wet iron medium ball milling meth-od were individually applied to crush the middlings to -0.5 mm.The experiment results of the middlings and the crushed products showed that the dissociation effect of the products crushed with the wet ball milling would be better than the products crushed with the jaw crush-ing.The X-ray photoelectron spectroscopy analysis showed that dissociation of the associated pyrite could detect the pyrite and iron sulfide from the surface of the products crushed with the jaw crushing.An oxidative atmosphere of the wet iron medium ball milling could make the pyrite and iron sulfide on the surface of the coal particle turned to hydroxyl iron oxide.An infrared spectrum analysis showed that the wet i-ron medium ball milling could improve the water methyl group content on the coal particle surface and the content of the hydrophilic hy-droxyl group would be reduced.The dissociation degree of different crushed products and the differential of the surface property would make the floatation effect different.When a floated clean coal yield was 10%,an ash content of the clean coal crushed with the wet ball milling would be 2.16% lower than the ash content of the products crushed with the jaw crushing.The stage floatation results showed that except for the 0.25~ 0.125 mm,the floatation effect of the products with 0.5~ 0.25,0.125~ 0.076 and -0.076 mm crushed with wet ball milling would be all higher than the relevant particle products crushed with the jaw crushing.%针对中煤在不同破碎方式作用下由于表面性质的变化，进而影响破碎产物浮选行为的现状，在物相组成分析基础上，分别采用鄂式破碎和湿法球磨方法将中煤破碎至-0.5 mm，试验结果表明，湿法球磨破碎产品的解离效果较鄂式破碎产品好。X 射线光电子能谱分析显示：伴生黄铁矿解离致使在鄂式破碎产物表面检测到 FeS2、FeS；湿法球磨的氧化氛围导致煤粒表面的 FeS2、FeS 变为FeOOH。红外光谱分析表明：湿法球磨可增加煤粒表面疏水甲基基团含量，而亲水羟基基团的含量则降低；不同破碎产品解离程度及表面性质的差异导致其浮选效果不同，当浮选精煤产率为10%时，湿法球磨精煤灰分较鄂式破碎产物灰分降低2.16%。分级浮选结果表明：除粒级0.25~0.125 mm 外，湿法球磨产物中0.5~0.25、0.125~0.076以及-0.076 mm 的浮选效果均高于相应粒级的鄂式破碎产物。