用硫铁矿烧渣制取聚合硫酸铁的实验研究

Preparation of Polyferric Sulfate by Pyrite Cinder

以硫铁矿烧渣为原料,采用酸浸,催化氧化,水解聚合的工艺制取高附加值的无机高分子絮凝剂聚合硫酸铁(PFS),在氧化聚合工艺中引入非亚硝酸盐催化剂,降低了产品毒性,扩大了其在水处理中的应用领域。研究结果表明:(1)硫酸浓度40%,酸浸时间40min,硫酸过量系数1.3,硫铁矿烧渣中铁的浸出率可达91.69%;(2)选用投加量为4%的KClO3和0.9%的HNO3作催化剂,0.2%的KI为助催化剂,保持n(H2SO)4/n(Fe2+)的比值在0.29~0.32之间,在50℃下氧化30min(保温2h),制得聚合硫酸铁产品各项指标均符合国家标准。(3)按以上条件制得的PFS对废水具有很好的除浊效果,当pH值在6.0~10.0,投放量为2mg/L时,处理洗煤废水的除浊率可达90%以上。

Taking the pyrite cinder as a raw material,by acid leaching,catalytic oxidation,hydrolysis and polymerization processes,the production of polyferric sulfate(PFS),an inorganic polymer flocculants with high added value,is prepared.In order to reduce product toxicity and expand application areas in water treatment,non-nitrite catalysts are introduced in the oxidative polymerization process.Results show that on the condition that sulfuric acid concentration of 40%,acid leaching time 40min,sulfuric acid excess coefficient 1.3,the iron leaching rate can be up to 91.69%.Using KClO3 and HNO3 as catalysts,and KI as an additives,keeping the ratio of n(H2SO4)/n(Fe2+)between 0.29~0.32,oxidizing 30min and insulating 2h at 50℃,the product PFS is prepared whose performance index is in line with national standards.The product PFS prepared by the above conditions has a good turbidity effect to the wastewater,turbidity removal rate dealing with coal-washing wastewater is up to 90%,when the pH value is between 6.0~10.0,the amount of PFS is 2mg/L.