煤泥浮选过程中的细泥夹带与罩盖机理

选用开滦矿区钱家营矿的高灰难选煤泥和大同塔山选煤厂煤系高岭石，通过单矿物和混合矿物浮选试验研究了影响高灰细泥夹带和罩盖的主要因素。研究发现：影响高灰细泥夹带的主要因素为细泥粒度、起泡剂用量和矿浆浓度，捕收剂用量对其影响较小；矿浆pH值接近8时，可燃体回收率最大。EDLVO理论计算发现：微细粒的高岭石与煤粒间存在着“能垒”，当颗粒间距约为30 nm时，“能垒”达到最大值；高岭石的粒度越细，“能垒”越低。外界能量输入可以打破“能垒”，使细泥颗粒发生罩盖。试验表明：强烈的机械搅拌使混合煤样的精煤产率和可燃体回收率分别降低10.87%和13.16%。

Mechanism of entrainment and slime coating on coal flotation

Using the high ash and hard-to-float coal slime from Kailuan mining area and the coal-seam kaolinite from Tashan coal preparation plant as the experimental materials，the major influencing factors of high ash slime entrainment and coating were studied by carrying out a series of flotation tests of single mineral and mixed minerals.The results indicate that the primary factors affecting slime entrainment are particle size，frother dosage and pulp density while the amount of collector had less effect.When the pulp pH is close to 8，the combustible recovery reaches the maximum.EDLVO theoretical calculations show that there is an “energy barrier” between micro-fine kaolinite particle and coal particle，when the distance between particles is about 30 nm，the “energy barrier” reaches the maximum，and the smaller size of kaolinite，the lower “energy barrier”.The external energy input breaks the “energy barrier”，as a result，slime coating occurs.Tests illustrate that strong mechanical stirring makes the clean coal yield and combustible recovery decrease by 10.87% and 13.16% respectively.