Preparation of high-purity fluorite and nanoscale calcium carbonate from low-grade fluorite  

作　　者：Qianqian Lu Haisheng Han Wenjuan Sun Xingfei Zhang Weiwei Wang Bilan Zhang Wensheng Chen Qin Zou 

机构地区：[1]School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China [2]Hunan Nonferrous Chenzhou Fluoride Chemical Co.,Ltd.,Chenzhou 423000,China [3]State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou Research Institute of Rare Earths,Baotou 014030,China [4]Hunan Shizhuyuan Nonferrous Metal Co.,Ltd.,Chenzhou 423000,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2024年第6期1198-1207,共10页矿物冶金与材料学报（英文版）

基　　金：supported by the National Key Research Center and Development Program of the 14th Five-Year Plan,China(No.2022YFC2905105);National Natural Science Foundation of China(Nos.52122406 and 52004337);Hunan High-tech Industry Technology Innovation Leading Plan,China(No.2022GK4056);Hunan Innovative Province Construction Special Project,China(No.2020RC3001);Hunan Postgraduate Research and Innovation Project,China(No.CX20220200).

摘　　要：Flotation separation of calcite from fluorite is a challenge on low-grade fluorite flotation that limits the recovery and purity of fluorite concentrate.A new acid leaching–flotation process for fluorite is proposed in this work.This innovative process raised the fluor-ite’s grade to 97.26wt%while producing nanoscale calcium carbonate from its leachate,which contained plenty of calcium ions.On the production of nanoscale calcium carbonate,the impacts of concentration,temperature,and titration rate were examined.By modifying the process conditions and utilizing crystal conditioning agents,calcite-type and amorphous calcium carbonates with corresponding particle sizes of 1.823 and 1.511μm were produced.The influence of the impurity ions Mn^(2+),Mg^(2+),and Fe^(3+)was demonstrated to reduce the particle size of nanoscale calcium carbonate and make crystal shape easier to manage in the fluorite leach solution system compared with the calcium chloride solution.The combination of the acid leaching–flotation process and the nanoscale calcium carbonate preparation method improved the grade of fluorite while recovering calcite resources,thus presenting a novel idea for the effective and clean usage of low-quality fluorite resources with embedded microfine particles.

关 键 词：FLUORITE CALCITE nanoscale calcium carbonate waste recovery 

分 类 号：TD985[矿业工程—选矿] TB383.1[一般工业技术—材料科学与工程] TQ132.32[化学工程—无机化工]