从钕铁硼二次废料铁尾渣制备高品质硫酸亚铁  

Preparation of High Quality Ferrous Sulfate from NdFeB Secondary Waste Iron Tailing Slag

作　　者：蔡彬华 Cai Binghua(Industry and Information Technology Bureau of Longyan City,Longyan,364000,Fujian;Fujian Shanhai Collaborative Innovation Center of Rare-earth Functional Materials,Longyan,366300,Fujian;Fujian Key Laboralory of Rare-earth Functional Materials,Longyan,366300,Fujian)

机构地区：[1]龙岩市工业和信息化局,福建龙岩364000 [2]福建省稀土功能材料山海协作创新中心,福建龙岩366300 [3]福建省稀土功能材料重点实验室,福建龙岩366300

出　　处：《福建冶金》2024年第6期24-28,共5页Fujian Metallurgy

摘　　要：本文通过“碳还原-酸溶”路径从钕铁硼二次废料铁尾渣制备高品质硫酸亚铁并得到稀土、镓富集物,为钕铁硼二次废料铁尾渣的综合回收利用提供了新途径。该工艺主要包括高温碳还原、稀硫酸优溶、除杂沉淀、硫酸亚铁冷却结晶等工序。结果表明,以活性炭为还原剂,在温度为850℃,炭、渣比为1:10的条件下,反应2 h可将氧化铁还原。在稀硫酸溶液中,还原渣中的铁元素被优先浸出,可获得稀土和镓的富集渣,硫酸亚铁溶液经除杂后冷却结晶,可得到高纯度的七水合硫酸亚铁。This article introduces a novel method for producing high-quality ferrous sulfate from secondary waste iron tailings of neodymium iron boron,employing the"carbon reduction acid dissolution"pathway.Additionally,rare earth and gallium-enriched substances are obtained,providing a new avenue for the comprehensive recovery and utilization of these tailings.The process encompasses several essential steps,including high-temperature carbon reduction,optimal dissolution using dilute sulfuric acid,impurity removal through precipitation,and the subsequent cooling crystallization of ferrous sulfate.Experimental results demonstrate that employing activated charcoal as a reducing agent at 850°C with a charcoal to slag ratio of 1:10 facilitates the reduction of iron oxide within a 2-hour timeframe.In a dilute sulfuric acid solution,the iron element within the reducing slag is preferentially leached,yielding an enriched slag containing rare earth and gallium.Following impurity removal,the ferrous sulfate solution undergoes cooling crystallization to yield high-purity heptahydrate ferrous sulfate.This method not only highlights the effectiveness of utilizing secondary waste for valuable material extraction but also contributes to sustainable practices in the mining and processing industries.

关 键 词：废铁渣 还原焙烧 硫酸亚铁 稀土、镓富集物 

分 类 号：TQ138.11[化学工程—无机化工] TM273[一般工业技术—材料科学与工程]