Abstract:

Stainless steel pickling sludge contains high concentrations of iron, chromium, nickel, which are hazardous solid wastes. In this paper, study on valuable components in stainless steel pickling sludge was separated in cascade, and the influencing variables of the separation effect of Fe, Cr, Ni are sodium phosphate, initial pH, temperature, and time, which were investigated. Average precipitation rate of Cr³⁺, Fe²⁺ and Ni²⁺ is 94.47%, 0.88%, 0.79% respectively under the optimum conditions including P/Cr=1.00 (molar ratio), initial pH of 1.00, reaction temperature of 90℃, holding time of 70min. Precipitation rate of iron and nickel is 99.83% and 0.68% respectively under the optimum conditions including P/Fe=0.80 (volume ratio), initial pH of 1.00, reaction temperature of 45℃, holding time of 60min. The experiment proved the feasibility of separating Fe, Cr and Ni from stainless steel pickling sludge leaching solution by phosphate precipitation, which provide theoretical basis and technical application reference for the separation of iron, nickel and chromium from stainless steel pickling sludge.

Key words: stainless steel pickling sludge, chromium, iron, nickel, metal separation

摘要：

不锈钢酸洗污泥含有高浓度的Fe、Cr、Ni金属离子，属于危险固体废弃物。本文对不锈钢酸洗污泥浸出液有价组分梯级分离展开研究，探讨了磷酸钠用量、浸出液初始pH、反应温度、搅拌时间对酸洗污泥中浸出液中Fe、Cr、Ni分离效果的影响。确定Cr³⁺沉淀的最佳工艺条件：P/Cr摩尔比为1.00，初始pH为1.00，反应温度为90℃，反应时间70min。Cr³⁺平均沉淀率为94.47%，Fe²⁺、Ni²⁺平均沉淀率为0.88%、0.78%。Fe³⁺优化条件为P/Fe体积比0.80、初始pH为1.00、反应温度为45℃、搅拌时间为60min，Fe³⁺沉淀率最高为99.83%、Ni²⁺沉淀率稳定在0.68%，证明了磷酸盐沉淀法可以有效分离不锈钢酸洗污泥浸出液中Fe、Cr、Ni，为不锈钢酸洗污泥铁、镍、铬分离提供理论依据和技术应用参考。

关键词: 不锈钢酸洗污泥, 铬, 铁, 镍, 金属分离