{"title":"Selective removal of Fe impurities in the recovery of rare earth elements from carbonatite tailings using chemical routes","authors":"Shuronjit Kumar Sarker , Mark Pownceby , Sachin Yadav , Warren Bruckard , Nawshad Haque , Nahar Singh , Biplob Kumar Pramanik","doi":"10.1016/j.hydromet.2023.106249","DOIUrl":null,"url":null,"abstract":"<div><p><span><span>The increasing demand for rare earth elements (REEs) has led to the exploration of mining tailings as a potential secondary source. This study offers novel insights into the recovery of REEs from Fe-rich mine tailings sourced from a weathered </span>carbonatite<span><span><span> deposit. The REEs were recovered by selectively removing Fe impurities after acid-leaching. The paper details the comprehensive methodologies employed, including initial hydrochloric acid </span>leaching and variable optimization such as acid concentration, liquid-to-solid ratio, temperature, and time. An alkali pre-treatment using NaOH was also investigated to assess its impact on the efficiency of REEs recovery. The study reveals that pH plays a significant role in the selective removal of Fe impurities and offers avenues for the production of high-purity, industry-grade REEs. The work is particularly ground-breaking in its exploration of selective Fe removal using a combination of dilute </span>ammonium hydroxide and </span></span>ammonium chloride<span>. Through this method, a significant milestone was achieved: the precipitated solid primarily contained Fe (>96%), with minimal loss of REEs (only 0.22%) at a solution pH of 3.25 at 40 °C. This study is the first to demonstrate such high selectivity in the removal of Fe from acid leach liquors of this nature.</span></p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2023-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hydrometallurgy","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0304386X23002323","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
引用次数: 0
Abstract
The increasing demand for rare earth elements (REEs) has led to the exploration of mining tailings as a potential secondary source. This study offers novel insights into the recovery of REEs from Fe-rich mine tailings sourced from a weathered carbonatite deposit. The REEs were recovered by selectively removing Fe impurities after acid-leaching. The paper details the comprehensive methodologies employed, including initial hydrochloric acid leaching and variable optimization such as acid concentration, liquid-to-solid ratio, temperature, and time. An alkali pre-treatment using NaOH was also investigated to assess its impact on the efficiency of REEs recovery. The study reveals that pH plays a significant role in the selective removal of Fe impurities and offers avenues for the production of high-purity, industry-grade REEs. The work is particularly ground-breaking in its exploration of selective Fe removal using a combination of dilute ammonium hydroxide and ammonium chloride. Through this method, a significant milestone was achieved: the precipitated solid primarily contained Fe (>96%), with minimal loss of REEs (only 0.22%) at a solution pH of 3.25 at 40 °C. This study is the first to demonstrate such high selectivity in the removal of Fe from acid leach liquors of this nature.
期刊介绍:
Hydrometallurgy aims to compile studies on novel processes, process design, chemistry, modelling, control, economics and interfaces between unit operations, and to provide a forum for discussions on case histories and operational difficulties.
Topics covered include: leaching of metal values by chemical reagents or bacterial action at ambient or elevated pressures and temperatures; separation of solids from leach liquors; removal of impurities and recovery of metal values by precipitation, ion exchange, solvent extraction, gaseous reduction, cementation, electro-winning and electro-refining; pre-treatment of ores by roasting or chemical treatments such as halogenation or reduction; recycling of reagents and treatment of effluents.