The crude sodium tungstate solution obtained from scheelite decomposition contains a certain concentration of fluorine,which easily leads to the concentration of fluoride in smelting wastewater exceeding the national discharge standard.In this study,hydroxyapatite was used as a fluoride-removing reagent,which reacted with fluorine ions to form calcium fluorophosphate precipitate with very low solubility,so as to deeply remove fluoride from the crude sodium tungstate solution.The effects of hydroxyapatite dosage,reaction temperature,solution pH value,reaction time and initial fluoride concentration on the fluoride removal were investigated.The experimental results show that hydroxyapatite has an excellent fluoride-removing performance in the crude sodium tungstate solution.Under the conditions where the fluoride concentration is 0.5~5.5 g/L,the dosage of hydroxyapatite is 1.8 times of the theoretical amount,reaction temperature is 80℃,the solution pH value is 10.5,and reaction time is 60 min,the fluoride removal rate is more than 96%,and the tungsten loss rate in the precipitated slag is less than 0.27%,thereby realizing the high-efficiency removal of fluoride with low tungsten loss.After fluoride removal,the crude sodium tungstate solution is subjected to subsequent ion exchange treatment,and the fluoride concentration in the discharged smelting wastewater meets the national discharge standard.

To improve the tungsten-molybdenum loading capacity of the deactivated organic phase(with N263 as the extractant)in the alkaline extraction section during the preparation of ammonium paratungstate from low-grade complex scheelite,this study adopted the ion exchange method and employed NaCl solution as the ion exchanger to remove harmful anions from the organic phase.The effects of NaCl solution concentration,O/A phase ratio,reaction temperature,single ion exchange duration and the number of ion exchange cycles on the tungsten-molybdenum loading capacity of the organic phase were systematically investigated through single-factor experiments.Furthermore,through counter-current extraction-washingstripping experiments,the tungsten and molybdenum extraction rates of the organic phase after NaCl ion exchange and NH₄HCO₃ conversion were explored,along with an assessment of whether the raffinate and stripping solution meet the requirements of industrial production.The results of single-factor experiments show that the optimal conditions for treating the deactivated alkaline extraction organic phase by the NaCl ion exchange method are as follows:NaCl concentration of 3 mol/L,O/A phase ratio of 1∶1,reaction temperature of 35℃,single ion exchange duration of 3 min,and 7 ion exchange cycles.After the organic phase obtained under these optimal conditions is converted with NH₄HCO₃,its WO₃ loading capacity is increased by 85.49%and Mo loading capacity by 72.56%,compared with those of the deactivated alkaline extraction organic phase.Under the conditions where the O/A phase ratios for extraction,washing,and stripping are 1∶2,1∶0.35,and 1∶2.6 respectively,and other parameters remain consistent with the current industrial production conditions,a comparison of the tungsten-molybdenum extraction performances of different organic phases after 6-stage counter-current extraction,4-stage washing,and 10-stage stripping experiments shows that the organic phase modified by NaCl ion exchange-NH₄HCO₃ conversion achieves extraction rates of 92.12%for WO₃ and 95.31%for Mo.Although these rates remain lower than those of the freshly prepared alkaline extraction organic phase,they increase by 42.46%and 40.08%respectively compared with the deactivated alkaline extraction organic phase without NaCl ion exchange treatment.Its tungstenmolybdenum loading capacity meets the requirements of industrial production,which breaks the restriction of the alkaline extraction section on production output during the preparation of ammonium paratungstate from low-grade complex scheelite.Various indexes of the raffinate and stripping solution obtained after extraction and stripping of the organic phase modified by NaCl ion exchange-NH₄HCO₃ conversion all meet the industrial production requirements.The increased tungsten content in the stripping solution reduces the evaporation energy consumption of the subsequent APT crystallization section,while the decreased tungsten content in the raffinate improves the direct recovery rate of the extraction section.Therefore,the NaCl ion exchange treatment of the deactivated organic phase can effectively reduce the production cost.

To achieve efficient separation and recovery of Ga from sulfuric acid leaching solution of claystone of the coal-aluminum rock series,this study employed Seplite^®LSC-900 gallium-extraction chelating resin for adsorption-desorption experiments on a single Ga solution.The effects of solution pH,adsorption time,types and concentrations of desorbent,and desorption time on Ga adsorption-desorption efficiency were investigated.The microstructure of the resin before and after adsorption was characterized via SEMEDS.Meanwhile,FTIR was employed to analyze the adsorption mechanism of the resin for the sulfuric acid leaching solution of claystone of the coal-aluminum rock series.Additionally,under the optimized adsorption-desorption conditions,the separation efficiency of Ga from other impurity ions in the sulfuric acid leaching solution of claystone of the coal-aluminum rock series was explored.The results show that when the pH value of the single Ga solution is 4 and the adsorption time is 120 min,the Ga adsorption rate reaches approximately 80%.After adsorption,the cross-linked structure of the resin's strip-like fibers increases,and Ga embeds into the pore channels and induces an increase in surface roughness of the pore channels.The adsorption of Ga from the sulfuric acid leaching solution by the resin is attributed to the synergy between electrostatic interaction and chemical coordination.Specifically,the—OH and—NH2 functional groups generate electrostatic interactions with[Ga(SO₄)]⁺,while the O atoms in—OH form Ga—O coordination bonds with Ga.The optimal desorption effect of Ga is achieved when the saturated adsorption resin is eluted with 1.5 mol/L HCl for 1 h,with a desorption rate of about 80%.The results of adsorptiondesorption experiments on the sulfuric acid leaching solution of claystone of the coal-aluminum rock series indicate that LSC-900 gallium-extracting chelating resin exhibits excellent selective adsorption capacity for Ga and Zr.Furthermore,Ga can be almost completely desorbed whereas Zr is difficult to desorb,thus successfully achieving effective separation of Ga from other metal ions in the leaching solution.This study provides technical support for the efficient recovery of Ga from the leaching solution of claystone of the coal-aluminum rock series.

Using hydrochloric acid as a catalyst,selenium and tellurium were recovered from gold-precipitated solution by SO₂ reduction.The effects of concentrated hydrochloric acid dosage,reaction time and H+concentration on the recovery rates of selenium and tellurium were investigated.The phase and morphology of the reduction products were analyzed by XRD and SEM,respectively.Besides,a comparative study was conducted on the effects of sodium sulfite and hydrazine hydrate as reducing agents on the recovery rates of selenium and tellurium from gold-precipitated solution.The results show that when selenium and tellurium are recovered from the gold-precipitated solution via hydrochloric acid-catalyzed SO₂ reduction,the recovery rates of selenium and tellurium reach 99.63%and 97.14%,respectively,under the conditions of a reaction temperature of 85℃,a concentrated hydrochloric acid(36%)dosage of 6%of the volume of the goldprecipitated solution,a reaction time of 4 h,and a H+concentration of 5.1 mol/L.In the reduction products,both selenium and tellurium exist in elemental form,with a strip-like morphology interspersed with particles.When sodium sulfite is used as the reducing agent with a dosage of 7.58 times the theoretical amount,the recovery rates of selenium and tellurium are only 76.88%and 35.71%,respectively.When hydrazine hydrate(80%)is used as the reducing agent with a dosage of 2.5%of the volume of the gold-precipitated solution,the selenium recovery rate reaches 99.38%and the tellurium recovery rate is 92.86%.Comparative analysis indicates that sodium sulfite is not suitable as a reducing agent for selenium and tellurium recovery from the gold-precipitated solution.Although hydrazine hydrate as a reducing agent achieves high recovery rates,it exhibits a relatively high cost.By comparison,the hydrochloric acid-catalyzed SO₂ reduction process for selenium and tellurium recovery from the gold-precipitated solution not only delivers ideal recovery efficiency,but also offers advantages of simple operation and low cost,thus demonstrating greater development prospects.

A methanesulfonic acid-bismuth methanesulfonate solution,characterized by its high stability and bismuth salt solubility,was employed as the electrolyte to systematically study bismuth membrane electrodeposition.The effects of current density,electrode distance,electrodeposition temperature,methanesulfonic acid concentration,bismuth concentration,and iron ion concentration on the bismuth electrodeposition process in the methanesulfonic acid system were investigated.The experimental results indicate a wide optimization window for bismuth electrodeposition from an iron-free methanesulfonic acid-bismuth methanesulfonate solution:current density of 150~200 A/m²,electrode distance of 5 cm,electrodeposition temperature of 40℃,methanesulfonic acid concentration of 50~80 g/L,and bismuth concentration of≥50 g/L.Under these optimized conditions,the cathode current efficiency for bismuth electrodeposition exceeds 99%,the DC power consumption per ton of bismuth is below 950 kW·h/t,and the deposited cathode bismuth metal exhibits a compact and smooth surface.In iron-containing(0~30 g/L)methanesulfonic acidbismuth methanesulfonate solution,the cathode current efficiency for bismuth electrodeposition could reach over 99%,with DC power consumption per ton of bismuth below 900 kW·h/t and cathode bismuth purity exceeding 99.90%.However,the bismuth surface is rough,which could be mitigated by methods such as adding surfactants.The methanesulfonic acid-based membrane electrodeposition process for bismuth proposed in this study is suitable for treating iron-rich bismuth-containing electrolyte.

近日,国家工业和信息化部正式发布2025年度重点产品、工艺“一条龙”应用计划方向清单。长沙有色院参与联合申报的“无氨氮钼冶金产业化技术”成功入选,标志着我国钼冶金行业向绿色化、高端化转型迈出关键一步。作为该项目的重要参与单位,长沙有色院依托有色金属冶炼工艺研发、工程转化与标准制定方面的综合优势,与牵头单位全渠钼业及各合作方协同推进该技术产业化落地与推广。在为期三年的“一条龙”应用计划中,项目团队将聚焦我国钼产业长期面临的4N高纯钼原料进口依赖度高、相关产品标准体系不健全、钼冶炼过程中氨氮污染治理难度大、无氨氮冶金技术工业化成熟度不足四大核心问题,通过系统化协作与分工攻关,力争实现四大目标,即完成关键技术知识产权布局、构建高纯钼原料产品标准体系、实现绿色低成本制造、打造全流程示范生产线,为我国钼冶金产业高质量发展提供坚实支撑。

近日,湖南省科学技术厅公布了“2025年创新联合体建设试点企业名单”,长沙有色冶金设计研究院有限公司(简称长沙有色院)成功获批湖南省深地矿产资源绿色智能开发产业创新联合体。这一重要成果标志着长沙有色院在深地矿产资源开发领域的技术实力和创新能力得到了高度认可,为推动我国深地资源开发技术的突破和产业升级奠定了坚实基础。

《稀有金属与硬质合金》创刊于1973年,是中文核心期刊,致力于稀有金属冶金与材料领域的科研创新与产业应用。本刊坚持“传播先进科技成果,引领创新,贴近科研与生产”的办刊宗旨,为科研人员及工程技术人员提供高水平的学术交流平台。为提升学术成果传播效率,缩短出版周期,本刊已于2025年7月1日起正式开通中国知网(CNKI)网络首发服务,录用定稿将优先在线发布,与印刷版具有同等学术效力。