聚氯化铁盐基度测试方法的探究

在研究、生产高浓度聚氯化铁的过程中,影响产品性能的关键指标是产品的盐基度,因此需解决聚氯化铁盐基度的测定问题。目前,关于聚氯化铁盐基度测试未见报道。笔者采用氧化法制备了聚氯化铁,重点研究了聚氯化铁盐基度的测试影响因素,并考察了稳定剂(磷酸)对盐基度的影响。试验表明,盐基度测试的准确性与测试过程中的取样量、盐酸浓度、解聚温度、氢氧化钠的浓度、掩蔽剂的选择等因素有关。通过氧化法制备理论盐基度为19.49的聚氯化铁试样,采用2.5 mol/L的盐酸在热水下解聚、以氟化钠为掩蔽剂、用0.1 mol/L的氢氧化钠回滴,实测值为20.14,与理论值相接近;通过加标回收试验,该方法的回收率达到97%以上。

Investigation on Testing Method of the Basicity of Polyferric Chloride

In the research and production processes of high concentration of polyferric chloride （PFC）, the key indicator of the product performance is the basicity, therefore it is essential to solve the problem of the determination of the basicity of PFC. At present, there is no report about the testing of the basicity of PFC The author prepares a sample of PFC by using oxidation, focuses on the influence factors of testing of the basicity of PFC, and the influences of stabilizer（phosphoric acid） on the basicity is investigated. The test shows that, the accuracy of basicity is relation to the sampling volume, the concentration of hydrochloric acid, the temperature of depolymerization, the concentration of sodium hydroxide, the type of masking agent, etc. in the testing process. With depolymerization in hot water using 2.5 mol/L hydrochtoride, with sodium fluoride as masking agent, with titration by 0.1 mol/L sodium hydroxide, the measured value of the basicity of PFC made by using oxidation whose basicity is 19.49 is 20.14, which is close to the theoretical value. By the standard recovery test, the recovery rate is more than 97 %.