Technology survey and development tendency investigation on tantalum-niobium hydrometallurgical extraction

介绍了钽铌湿法冶金技术的发展概况和现状。根据分解介质的不同,钽铌湿法治金技术可分为碱熔融法、酸法和氯化法,碱熔融法可分为钠碱熔融法和钾碱熔融法,酸法主要有氢氟酸法和硫酸法。分别介绍了以上各方法的工艺路线,并对其优缺点进行了分析。针对现行氢氟酸工艺存在严重氟污染和对低品位钽铌矿分解率低的问题,依据清洁冶金原理,提出了钽铌亚熔盐清洁冶金新工艺,从生产源头消除了氟污染,可实现钽铌资源的高效清洁利用,具有良好的应用前景。The developments and current situation of tantalum-niobium hydrometallurgical extraction are presented.According to different decompositive medium,the tantalum-niobium hydrometallurgical extraction process can be classified as alkali fusion decomposition process,which mainly involves the sodium alkali fusion decomposition process and potassium alkali fusion decomposition process,while the acid decomposition process involving the hydrofluoric acid process and sulfuric acid process,and chlorination process.The principle of these process mentioned above is introduced respectively,and its merits and demerits are analyzed.At present,most minerals containing niobium and tantalum are decomposed by the hydrofluoric acid process.However,such a treating approach brings serious fluorin pollution to human beings and environment,and it is hard to decompose the refractory niobium-tantalum ore.With an objective to eliminate the fluorin pollution at the source,a new process for leaching the low-grade niobium-tantalum ore with alkali metals sub-molten salt is proposed.In the new process,alkali metals sub-molten salt is used as reaction medium to substitute the highly concentrated and toxic hydrogen fluoride solution of the traditional hydrofluoric acid process.And the clean conversion of niobium-tantalum ore is expected to be achieved.国家自然科学基金资助项目(20306031

Study on the Leaching Mechanism of Refractory Niobium-tantalum Ore by Concentrated Potassium Hydroxide

实验研究了难分解铌钽矿在高浓度氢氧化钾溶液中浸出过程的机理。考察了搅拌转速、反应温度、碱矿比、初始氢氧化钾浓度和矿粒度对铌钽矿中铌的浸出速率的影响。结果表明铌的浸出速率与铌钽矿粒径的平方成反比,浸出过程受克-金-布产物层固膜扩散控制,即1+2(1-X)-3(1-X)2/3=kt,并由阿累尼乌斯方程得到铌的表观活化能为72.2kJ﹒mol-1。结合动力学实验结果和电子扫描电镜(SEM)及X-射线能谱(EDAX)分析,进一步证明了在浸出过程中铌钽矿的表面形成了固相产物层,其主要组成元素为铁、锰等,并指出六铌(钽)酸根离子([(Ta,Nb)6O19]8-)通过固相产物层的内扩散为浸出过程的控制步骤。研究结果为浸出过程的强化提供了依据。The leaching mechanism of niobium from a refractory niobium-tantalum ore by concentrated potassium hydroxide was studied. The effects of stirring speed, reaction temperature, mass ratio of alkali-to-ore, initial potassium hydroxide concentration and particle size on the leaching rate of niobium were reported. The results show that the leaching rate is direct proportional to the inverse square of particle diameter, and the experimental data of the leaching rate are fit to the Crank-Ginsting-Braunshtein’s diffusion-through-layer-reaction-control model,that is: 1+2(1-X)-3(1-X)2/3=kt. According to the Arrhenius expression, the apparent activation energy for the leaching of niobium is 72.2kJ?mol?1. Based upon the result of the kinetic experiment as well as the SEM and EDAX analysis results, it is proved that during the leaching process of niobium-tantalum ore by concentrated potassium hydroxide, a solid product layer is formed on the surface of the unreacted core and its main composition elements are iron and manganese, the diffusion of [(Nb,Ta)6O19]8? through that layer is presumed to be the rate-controlling step of the leaching proces. The results obtained in this paper provide important basis for the strengthening of the leaching process.国家“十五”863资助项目(2001AA647010);; 国家自然科学基金资助项目(20306031)

铜绿山春秋早期炼铜技术续探

1973年湖北大冶铜绿山发现的古矿冶遗址,规模宏大,年代久远,集中反映了我国早期铜矿开采和冶炼的情况。遗址年代至迟始于西周,下迄汉代,还发现了宋代的冶炼场。关于春秋早期炼铜遗址、竖炉结构和炼铜技术,已由一些研究者作了探讨和复原。本文拟就筑炉材料、冶炼技术水平和竖炉结构特点等问题作进一步的探讨

Nb2O5在KOH亚熔盐体系中的溶解行为

对Nb2O5在KOH亚熔盐体系中的溶解行为进行了研究，通过正交实验和因素实验分析了KOH浓度、反应温度、反应时间、搅拌速率和碱矿比等因素对Nb2O5在KOH亚熔盐体系中溶解行为的影响。结果表明：反应温度和KOH浓度是最重要的影响因素；在一定温度下，KOH浓度越高越有利于得到可溶性的六铌酸钾；而在一定KOH浓度下，温度越高越容易得到不溶性的铌酸盐沉淀。不溶性沉淀经ICP-AES和XRD分析证明为偏铌酸钾(KNbO3)

钽铌湿法冶金技术概况及发展趋势探讨

介绍了钽铌湿法冶金技术的发展概况和现状。根据分解介质的不同,钽铌湿法治金技术可分为碱熔融法、酸法和氯化法,碱熔融法可分为钠碱熔融法和钾碱熔融法,酸法主要有氢氟酸法和硫酸法。分别介绍了以上各方法的工艺路线,并对其优缺点进行了分析。针对现行氢氟酸工艺存在严重氟污染和对低品位钽铌矿分解率低的问题,依据清洁冶金原理,提出了钽铌亚熔盐清洁冶金新工艺,从生产源头消除了氟污染,可实现钽铌资源的高效清洁利用,具有良好的应用前景

Nb2O5在KOH亚熔盐体系中的溶解行为

对Nb2O5在KOH亚熔盐体系中的溶解行为进行了研究，通过正交实验和因素实验分析了KOH浓度、反应温度、反应时间、搅拌速率和碱矿比等因素对Nb2O5在KOH亚熔盐体系中溶解行为的影响。结果表明：反应温度和KOH浓度是最重要的影响因素；在一定温度下，KOH浓度越高越有利于得到可溶性的六铌酸钾；而在一定KOH浓度下，温度越高越容易得到不溶性的铌酸盐沉淀。不溶性沉淀经ICP-AES和XRD分析证明为偏铌酸钾(KNbO3)

Nb2O5在KOH亚熔盐体系中的溶解行为

对Nb2O5在KOH亚熔盐体系中的溶解行为进行了研究，通过正交实验和因素实验分析了KOH浓度、反应温度、反应时间、搅拌速率和碱矿比等因素对Nb2O5在KOH亚熔盐体系中溶解行为的影响。结果表明：反应温度和KOH浓度是最重要的影响因素；在一定温度下，KOH浓度越高越有利于得到可溶性的六铌酸钾；而在一定KOH浓度下，温度越高越容易得到不溶性的铌酸盐沉淀。不溶性沉淀经ICP-AES和XRD分析证明为偏铌酸钾(KNbO3)

The Behaviors Study in Reemployment of Laid-off Job Seekers and Psychological Counseling Model

通过问卷调查、深度访谈、案例分析和培训实验等实证方法 ,研究发现下岗职工的认知归因、情绪控制、求职自我效能和求职应对技能等心理行为因素是制约其能否再就业的关键要素。以这些心理行为因素为干预辅导内容 ,采用小组讨论学习法等主动性学习方法进行的针对性辅导 ,可增强下岗职工的求职自信心和应对技能 ,提高其再就业的成功率和稳定性

钽铌湿法冶金技术概况及发展趋势探讨

介绍了钽铌湿法冶金技术的发展概况和现状。根据分解介质的不同，钽铌湿法治金技术可分为碱熔融法、酸法和氯化法，碱熔融法可分为钠碱熔融法和钾碱熔融法，酸法主要有氢氟酸法和硫酸法。分别介绍了以上各方法的工艺路线，并对其优缺点进行了分析。针对现行氢氟酸工艺存在严重氟污染和对低品位钽铌矿分解率低的问题，依据清洁冶金原理，提出了钽铌亚熔盐清洁冶金新工艺，从生产源头消除了氟污染，可实现钽铌资源的高效清洁利用，具有良好的应用前景