H_(3)AsO_(4)-FeSO_(4)-K_(2)SO_(4)-H_(2)O体系水热法臭葱石矿化固砷  

Hydrothermal mineralized arsenic precipitation in H_(3)AsO_(4)-FeSO_(4)-K_(2)SO_(4)-H_(2)O system

作　　者：罗劲松 李存兄[1] 张兆闫 邓戈 曹远栋 李玉东 唐晓明 LUO Jin-song;LI Cun-xiong;ZHNAG Zhao-yan;DENG Ge;CAO Yuan-dong;LI Yu-dong;TANG Xiao-ming(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;Southwest Copper Branch of Yunnan Copper Co.Ltd.,Kunming 650102,China;Yunnan Copper Science Technology Development Co.Ltd.,Kunming 650101,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,昆明650093 [2]云南铜业股份有限公司西南铜业分公司,昆明650102 [3]云南铜业科技发展股份有限公司,昆明650101

出　　处：《矿冶》2023年第2期65-72,共8页Mining And Metallurgy

基　　金：国家自然科学基金资助项目(52064034);云南省重点研发计划项目(202202AB080005);国家重点研发计划项目(2021YFC2902801)。

摘　　要：研究H_(3)AsO_(4)-FeSO_(4)-K_(2)SO_(4)-H_(2)O体系中K+对水热臭葱石矿化沉砷过程中砷铁沉淀率、沉砷渣物相组成及转变规律的影响。结果表明:K^(+)的存在对沉砷渣物相组成影响显著,处于过饱和状态的Fe(Ⅲ)除与As(Ⅴ)共沉淀生成FeAsO_(4)·2H_(2)O并自身水解沉淀为Fe(OH)SO_(4)外,还会与K^(+)结合以KFe_(3)(SO_(4))_(2)(OH)_(6)形态竞争析出;当初始K^(+)浓度为5 g/L、初始砷浓度为10 g/L、初始铁砷摩尔比为1.5、初始pH值为1、反应温度为160℃、搅拌转速为500 r/min、反应时间为3 h、氧分压为0.6 MPa时,砷、铁沉淀率分别为96.7%、96.5%;沉砷渣物相组成主要为臭葱石、黄钾铁矾、碱式硫酸铁,其含量分别为65.0%、24.2%、10.8%,臭葱石以大颗粒、多面体状晶体形式产出,黄钾铁矾呈不规则晶体形态的小颗粒分散于臭葱石颗粒间;沉砷渣中的As、Fe、K、S含量分别为23.39%、25.72%、1.84%、4.09%。通过将臭葱石矿化沉砷初始铁砷摩尔比控制在合理范围内可有效抑制亚稳态黄钾铁矾物相的形成,实现砷的高效沉淀,提高沉砷渣中砷含量并降低其产量。The effects of K+on precipitation rate of arsenic and ferric,phase and chemical composition of As-bearing precipitate,and phase transition behavior were studied during hydrothermal mineralized arsenic precipitation in H_(3)AsO_(4)-FeSO_(4)-K_(2)SO_(4)-H_(2)O system.The results show that the presence of K+in the system has a significant effect on composition of As-bearing precipitate.In addition to co-precipitation with As(Ⅴ)to form scorodite(FeAsO_(4)·2H_(2)O)and self-hydrolysis precipitation to basic ferric sulfate Fe(OH)SO_(4),supersaturated Fe(Ⅲ)will also competitive precipitation with K^(+) in the form of K-jarosite(KFe_(3)(SO_(4))_(2)(OH)_(6)).With conditions of the initial concentration of K^(+) 5 g/L,arsenic concentration 10 g/L,iron-arsenic molar ratio 1.5,solution pH value 1,reaction temperature 160℃,agitation speed 500 r/min,reaction time 3 h,and the oxygen partial pressure 0.6 MPa,the precipitation rates of As and Fe were 96.7% and 96.5%,respectively,and the phase compositions of As-bearing precipitate were mainly scorodite,jarosite and basic ferric sulfate,the contents of which were 65.0%,24.2% and 10.8%,respectively,the content of As,Fe,K and S in arsenic slag was 23.39%,25.72%,1.84% and 4.09%,respectively.The formation of metastable state K-jarosite phase can be effectively inhibited by controlling the initial iron-arsenic molar ratio in a reasonable range,so as to achieve efficient precipitation of arsenic,increase the arsenic content in As-bearing precipitate and reduce its yield.

关 键 词：水热体系 矿化固砷 臭葱石 沉砷率 

分 类 号：TF811[冶金工程—有色金属冶金]