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Wastewater treatment in coal washing plants
The main purpose of coal preparation in coal preparation plants is to improve the quality of raw coal, reduce ash content, and remove impurities. It is a process of washing out different grades of coal according to the content of raw coal components. Since the specific gravity of coal is less than that of water, the buoyancy of water can be used to separate coal and gangue. This process is called coal washing. A large amount of wastewater will be generated during the coal washing process. In this wastewater, there is a lot of pulverized coal. If not handled properly, it will cause waste of resources and environmental pollution. Polyacrylamide (PAM) has a good effect on coal washing wastewater and low cost. It is an indispensable water treatment agent in the treatment of coal washing wastewater. The following Henan Laixing Water Purification will answer the role of polyacrylamide (PAM) in coal washing plants in detail.
在洗煤过程中将使用多种药剂，如发泡剂、浮选剂、消泡剂、絮凝剂等，具体使用的药剂有硫酸铝和硫酸铁作为混凝剂使用。聚合氯化铝（PAC）是选煤厂常用的混凝剂和助滤剂。当煤泥胶结严重时，单纯使用絮凝剂的效果较差，必须先加入混凝剂使胶体破碎，再使用聚丙烯酰胺（PAM）絮凝剂。
洗煤厂一般采用阴离子聚丙烯酰胺（HPAM）处理洗煤废水，分子量约800-1800万。根据洗煤废水的不同指标，也可采用非离子聚丙烯酰胺（NPAM）或阳离子聚丙烯酰胺（CPAM）。在混凝反应池阶段，洗煤废水需要加入完全溶解的聚合氯化铝（PAC）溶液，然后加入溶解的聚丙烯酰胺（PAM）溶液。两种剂量投加的时间差应根据实验确定。在此之后，洗煤废水将迅速发生絮凝反应，颗粒物被吸附在一起，然后沉淀。 在污水处理中，水质的任何变化都会受到外界因素的影响。由于聚丙烯酰胺（PAM）分子链中含有一定数量的极性基团，通过电荷中和作用，将水中悬浮固体颗粒吸附在水中，使颗粒架桥或凝聚形成大的絮凝体。因此，应根据小试的选择确定聚丙烯酰胺（PAM）的具体型号。
