Hussain SA, Dem&idot;rc&idot; S, özbayoğlu G
Mining Engineering Department, University of Engineering and Technology, Lahore-31, Pakistan
J Colloid Interface Sci. 1996 Dec 25;184(2):535-41. doi: 10.1006/jcis.1996.0649.
There is a growing trend of characterizing coal and coal wastes in order to study the effect of clays present in them during coal washing. Coarse wastes from the Zonguldak Coal Washery, Turkey, were characterized and found to contain kaolinite, illite, and chlorite. These three clays, obtained in almost pure form from various locations in Turkey, have been subjected to X-ray diffraction (XRD) analysis to assess their purity and zeta potential measurements in order to evaluate their properties in terms of their surface charge and point of zero charge (pzc) values. It was found from XRD data that these clays were almost pure and their electrokinetic potential should therefore be representative of their colloidal behavior. All three clay minerals were negatively charged over the range from pH 2.5 to 11. Chlorite and illite have pzc at pH 3 and pH 2.5, respectively, whereas kaolinite has no pzc. The effect of these clays in Zonguldak coal, wastes, and black waters on coal flotation was studied by floating artificial mixtures of Zonguldak clean coal (4.5% ash) and individual clay. The flotation tests on coal/individual clay revealed that each clay influences coal flotation differently according to its type and amount. Illite had the worst effect on coal floated, followed by chlorite and kaolinite. The loss of yield in coal was found to be 18% for kaolinite, 20% for chlorite, and 28% for illite, indicating the worst effect of illite and least for kaolinite during coal flotation.
为了研究洗煤过程中煤及其废弃物中所含黏土的影响，对煤和煤矸石进行表征的趋势日益增长。对土耳其宗古尔达克选煤厂的粗煤矸石进行了表征，发现其中含有高岭石、伊利石和绿泥石。这三种黏土几乎以纯形式从土耳其各地获取，已进行X射线衍射（XRD）分析以评估其纯度，并进行了zeta电位测量，以便根据其表面电荷和零电荷点（pzc）值评估其性质。从XRD数据发现，这些黏土几乎是纯净的，因此它们的电动电位应代表其胶体行为。在pH值2.5至11的范围内，所有三种黏土矿物均带负电荷。绿泥石和伊利石的pzc分别为pH 3和pH 2.5，而高岭石没有pzc。通过浮选宗古尔达克精煤（灰分4.5%）与单一黏土的人工混合物，研究了这些黏土在宗古尔达克煤、废弃物和黑水中对煤浮选的影响。煤/单一黏土的浮选试验表明，每种黏土根据其类型和用量对煤浮选的影响不同。伊利石对浮选煤的影响最差，其次是绿泥石和高岭石。发现高岭石导致煤的产率损失为18%，绿泥石为20%，伊利石为28%，这表明在煤浮选过程中伊利石的影响最差，高岭石的影响最小。
