Key Laboratory of Pollution Process and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin, China.
Environ Technol. 2011 May-Jun;32(7-8):911-20. doi: 10.1080/09593330.2010.521951.
Pyrite cinders are the main industrial waste generated from the process of sulphuric acid production using pyrite ores. The pyrite cinders may have utilization value in preparing a new polyferric chloride (PFC) coagulant. In order to attain this objective, a preparation method for PFC products from pyrite cinders was studied by a Taguchi orthogonal array experiment. On the basis of the successful preparation, the morphologies and coagulation characteristics of three PFC products, with different basicities, were observed by transmission electron microscopy (TEM) and examined by jar tests, respectively. The results showed that the molar ratio of NaOH to Fe should be in a range between 0.75:1 and 1:1, the molar ratio of stabilizer NaH2PO4 to Fe should be in a range between 0.12:1 and 0.15:1, the curing time should be 2 h, the curing temperature can be 60 degrees C and the molar ratio of NaHCO3 to Fe can be determined according to the basicity required in order to get the optimal stability of PFC products and the best flocculation efficiency. Although the degree of aggregation of the PFC products became larger with the increase in the basicity, the coagulation efficiency could be only improved with an increase in the basicity within a certain range. When the basicity exceeded a certain value, the coagulation efficiency started to decrease. In this study, PFC2 (B = 11.16%) had better coagulation characteristics than either PFCl (B = 6.08%), PFC2 (B = 11.16%), PFC3 (B = 15.92%) or polyaluminium chloride (PAC).
黄铁矿渣是硫酸生产过程中产生的主要工业废料。黄铁矿渣在制备新型聚合氯化铁（PFC）混凝剂方面可能具有利用价值。为了实现这一目标，采用正交试验设计研究了由黄铁矿渣制备 PFC 产品的方法。在此基础上，成功制备了三种不同碱度的 PFC 产品，并通过透射电子显微镜（TEM）观察其形态，通过烧杯试验考察其混凝性能。结果表明，NaOH 与 Fe 的摩尔比应在 0.75:1 至 1:1 之间，稳定剂 NaH2PO4 与 Fe 的摩尔比应在 0.12:1 至 0.15:1 之间，固化时间应为 2 h，固化温度可为 60℃，NaHCO3 与 Fe 的摩尔比可根据所需碱度确定，以获得 PFC 产品最佳稳定性和最佳絮凝效率。尽管 PFC 产品的团聚程度随碱度的增加而增大，但在一定范围内仅能通过增加碱度来提高混凝效率。当碱度超过一定值时，混凝效率开始下降。在本研究中，PFC2（B = 11.16%）比 PFC1（B = 6.08%）、PFC2（B = 11.16%）、PFC3（B = 15.92%）或聚合氯化铝（PAC）具有更好的混凝性能。
