选煤废水()混凝过程中~(+)作用特性研究 ~(+) ()

用硫酸钙和硫酸铝作凝聚剂、PAM作絮凝剂对同一选煤废水(CPW)做混凝试验,测定电动电位和澄清水的SS。通过试验数据和试验现象的分析认为Ca~(2+)和Al~(3+)的作用机理不同。Ca~(2+)是和煤粒表面通过化学键发生化学吸附,即在双电层内产生定位离子吸附,既改变了煤粒的表面电位,又改变了电动电位。ξ电位随Ca~(2+)浓度的增大而降低,但降幅不大。Ca~(2+)被沉淀物带走的较少,澄清水中含有大量可循环利用的Ca~(2+)。必须保证废水体系中Ca~(2+)浓度足够高才能使Ca~(2+)具有足够强的与其他离子(如Al~(2+)、H~(+)、Na~(+)、K~(+))的竞争性。Ca~(2+)能降低PAM的利用效率。 The calcium inorganic salts have become a coagulant to clarify coal preparation wastewater(CPW) in recent years, but the mechanism of action is unknown. Made clarifying CPW test using coagulant of CaSO_4 or AI_2 (SO_4)_3 and the flocculant of PAM, the electrokinetic potential of mine drainage and the SS of clarified water are determined. The experimental results show that there is different effect mechanism between Ca~(2+) and AI~(3+). Ca~(2+) being locative cation will be absorbed to the surface of coal particle in the electrical double layer by chemical bond and the surface potential and electrokinetic potential are changed. The electrokinetic potential will be reduced when the density of Ca~(2+) is amplified, but the dropping range was not much. The Ca~(2) being taken away by the sediment is smaller. In clarified water Ca~(2+) amount is bigger in endless cycles in the slurry system. The content of Ca~(2+) was must enough to use in compete with other cation ( AI~(3+) ,H~+ , Na~+ , K~+). Ca~(2+) can make the PAM efficiency cut down