不锈钢酸洗废水蒸发结晶渣中铁镍铬的分离与回收  

Separation and recovery of iron,nickel and chromium from evaporativecrystalline product of spent pickling solutions from stainless steel processing

作　　者：李衍林 李旻廷[2] 魏昶[2] 李兴彬[2] 邓志敢[2] LI Yan-lin;LI Min-ting;WEI Chang;LI Xing-bin;DENG Zhi-gan(Yunnan Chihong Zn&Ge Co.Ltd.,Qujing 655011,Yunnan,China;Faculty of Metallurgy and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]云南驰宏锌锗股份有限公司,云南曲靖655011 [2]昆明理工大学冶金与能源工程学院,昆明650093

出　　处：《矿冶》2021年第4期71-78,共8页Mining And Metallurgy

摘　　要：针对不锈钢酸洗废水蒸发结晶渣含铁、硫酸、镍和铬的特点,采用溶解—结晶—纯化工艺,实现结晶渣中铁与镍铬的分离。研究表明,结晶渣中铁主要以FeSO_(4)·H_(2)O形式存在;温度和初始铁浓度是影响硫酸亚铁结晶效率和纯度的重要因素,随着结晶温度降低和初始铁浓度的增加,结晶效率随之升高,但其纯度有所降低;在溶解温度64℃,Ⅰ段和Ⅱ段结晶温度分别为30、5℃,Ⅰ段和Ⅱ段结晶时间为30 min,搅拌转速300 r/min的条件下,可获得湿基纯度93%的硫酸亚铁初级产品;该产品通过重溶—再结晶的纯化处理后,制备得到符合国标GB/T 10531—2016Ⅱ类要求的硫酸亚铁产品;溶解—结晶过程的结晶母液通过蒸发—冷冻结晶—中和—蒸发工艺制备硫酸钠,可获得含镍4%的提镍原料和纯度为99.42%的无水硫酸钠。In view of characteristics that crystal produced from stainless steel pickling wastewater evaporative crystallization contains iron,nickel,chromium and sulfuric acid,the process of dissolution-recrystallization-purification was carried out to separate iron and nickel and chromium in crystal.The results show that iron in crystal mainly exists in form of FeSO_(4)·H_(2)O.Temperature and initial concentration of iron are the important factors for crystallization efficiency and purity of ferrous sulfate.With drop of crystallization temperature and increase of initial iron concentration,crystallization efficiency of iron rises,but ferrous sulfate purity reduces.The ferrous sulfate primary product of wet base purity of 93%is obtained under the conditions of solution temperature of 64℃,crystallization temperature of step Ⅰ and step Ⅱ of 30℃and 5℃,respectively,both crystallization time of step Ⅰ and step Ⅱ of 30 min,and speed of agitator of 300 r/min.The primary product is purified through resolution-recrystallization to prepare ferrous sulfate product meeting Chinese standard GB/T 10531—2016 type Ⅱ.Materials of Ni 4%and anhydrous sodium sulfate with purity of 99.42%are prepared from crystallization mother liquor by evaporation concentration-freeze crystallization-neutralization-preparation of sodium sulfate through evaporation.

关 键 词：硫酸亚铁 镍 结晶 纯化 分离回收 

分 类 号：X756[环境科学与工程—环境工程] TF111.3[冶金工程—冶金物理化学]