稀土硫酸焙烧烟气中H_(2)S的产生机制研究  

Study on Production Mechanism of H_(2)S in the Flue Gas of Rare Earth Sulfuric Acid Roasting

作　　者：孟玉琴 尹亮 杨锦锋 邓可华 马永宏 黄伟军 MENG Yuqin;YIN Liang;YANG Jinfeng;DENG Kehua;MA Yonghong;HUANG Weijun(Gansu New Rare Eart h Materials Co.,Ltd.,Baiyin 730922,Gansu,China;State Key Laboratory for Research and Comprehensi ve Utilization of Bayan O bo District Rare Earth Resources,Baotou China Rare Earth Research Institute,Baotou 014030,Inner Mongolia,China)

机构地区：[1]甘肃稀土新材料股份有限公司,甘肃白银730922 [2]白云鄂博稀土资源研究与综合利用国家重点实验室,包头中国稀土研究院,内蒙古包头014030

出　　处：《有色金属(冶炼部分)》2025年第4期261-272,共12页Nonferrous Metals(Extractive Metallurgy)

基　　金：中央领导地方科技发展资金资助项目(2023-0401-0076);甘肃省科技重大专项(22ZD6GA008)。

摘　　要：混合稀土高温硫酸焙烧时,烟气成分复杂,现有烟气处理系统对H_(2)S气体未能有效处理。基于此,考察硫酸与黄铁矿在不同条件下的分解与H_(2)S的生成机理。浓硫酸在还原条件下H_(2)S与SO_(2)的生成量随着温度下降、流量与气体中氧含量减少而增加,但是SO_(3)生成条件与H_(2)S、SO_(2)的相反,因此为有效控制硫酸生成H_(2)S的量,应提高供气量、降低反应温度与增加气体中氧含量。降低反应温度或增加空气流量会降低炉内温度,导致稀土矿物与钍矿物反应不彻底,得不到目标矿相。因此,在生产中可以适当提高鼓风中氧气含量,即富氧鼓风,可有效避免硫酸还原生成H_(2)S的现象。室温下黄铁矿与稀硫酸生成硫酸亚铁、硫磺及硫化氢气体;在使用浓硫酸时,黄铁矿生成硫酸铁、二氧化硫、单质硫,没有产生硫化氢气体,这主要是由于浓硫酸具有较强的氧化性。空气气氛下硫化铁、浓硫酸与碳混合物在500℃反应,生成磁铁矿与硫化氢,而在富氧空气中仍然生成硫化氢、氧化铁。因此,在还原剂存在的条件下减少原料中黄铁矿的含量可有效减少H_(2)S的产生。When mixed rare earth is roasted with sulfuric acid at high temperature,the flue gas composition is complex,and the existing flue gas treatment system cannot effectively treat H_(2)S gas.Based on this,the decomposition of sulfuric acid and pyrite under different conditions and the formation mechanism of H_(2)S were investigated.Under the reduction condition and addition of concentrated sulfuric acid,the production amount of H_(2)S and SO_(2)increases with the decrease of temperature,flow rate and oxygen content in the gas,but the formation condition of SO_(3)is opposite to that of H_(2)S and SO_(2).Therefore,in order to effectively control the amount of H_(2)S generated by sulfuric acid,the gas supply should be increased,the reaction temperature should be lowered and the oxygen content in the gas should be increased.Reducing the reaction temperature or increasing the air flow will reduce the temperature in the furnace,resulting in incomplete reaction between rare earth minerals and thorium minerals,and no target mineral phase can be obtained.Therefore,in the production,the oxygen content of the blast can be appropriately increased,that is,the oxygen-rich blast,which can effectively avoid the phenomenon of sulfuric acid reduction to produce H_(2)S.At room temperature,pyrite and dilute sulfuric acid produce ferrous sulfate,sulfur and hydrogen sulfide gas;In concentrated sulfuric acid,pyrite produces iron sulfate,sulfur dioxide,elemental sulfur,and no hydrogen sulfide gas,which is mainly due to the strong oxidation of concentrated sulfuric acid.The reaction of iron sulfide,concentrated sulfuric acid and carbon mixture at 500℃ in an air atmosphere generates magnetite and hydrogen sulfide,while hydrogen sulfide and iron oxide are still generated in oxygen-rich air.Therefore,in the presence of reducing agents,the content of pyrite in raw materials should be reduced to effectively reduce the production of H_(2)S.

关 键 词：稀土 焙烧烟气 硫化氢 氧含量 硫酸 黄铁矿 

分 类 号：TF845[冶金工程—有色金属冶金]