利用氧化铁红厂废水制备氧化铁红晶种的研究

针对氧化铁红生产过程产生的废水二价铁含量高、pH低的特点，开辟了利用氧化铁红厂含亚铁盐酸性废水处理产生的污泥制备氧化铁红晶种的新工艺。研究表明：每吨废水投加质量分数为30%的工业烧碱溶液2.8 L，可使出水pH至6~9、二价铁离子去除率达到99.5%、色度≤40倍，满足GB 18918-2002《城镇污水处理厂污染物排放标准》的二级标准；生成的氢氧化亚铁和氢氧化铁混合污泥可用于制备氧化铁红晶种并进一步生产氧化铁红产品，最终产品三氧化二铁质量分数达到96.8%，满足GB/T 1863-2008《氧化铁颜料》的标准。

Study on preparation of crystal seed of iron oxide red with wastewater from red iron oxide plant

Based on properties of wastewater produced in the process of producing iron oxide red with high Fe²⁺ content and low pH，a new process of producing iron oxide red crystal seed using the sludge produced from the treatment of acid ferrous wastewater in red iron oxide plant was developed.Results showed that pH of effluent could be adjusted to 6~9，removal efficiency of Fe²⁺ reached 99.5%，and chroma was less than 40 times，while adding caustic soda solution（mass fraction of 30%）2.8 L per ton of wastewater.The effluent quality could meet the secondary standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant（GB 18918-2002）.Mixed sludge of Fe（OH）₂ and Fe（OH）₃ could be used to produce iron oxide red crystal seed and to further produce iron oxide red.Fe2O3 content of the final product reached 96.8%，which could meet the standard of Iron Oxide Pigments（GB/T 1863-2008）.