Vanadium recovery from clay vanadium mineral using an acid leaching method

A technique including direct acid leaching, vanadium precipitation with alkaline, sodium hydroxide releaching, impurity removing by adjusting pH value, precipitation vanadium with ammonium chloride, and vanadium pentoxide by roasting steps was proposed according to the characteristic of Xichuan clay vanadium mineral. The factors influencing leaching vanadium such as temperature and the concentration of sulfuric acid were investigated and optimized. The experimental results indicate that the extract ratios of V205 can reach 94% and 92% at a sodium chlorate ratio of 3% and a manganese dioxide ratio of 3%, respectivdy. A completely chemical precipitation method was adopted to decontaminate and enrich the vanadium in the acid leaching solution. The X-ray diffraction （XRD） pattern and the purity analysis of vanadium pentoxide indicate that the purity of final vanadium pentoxide can reach 99% and meet the standard specifications. The total recovery can reach about 75%. The technique has the characteristics of simplicity, less investment, and more environment safety as compared with the traditional salt roasting method.

Recovery of waste rare earth fluorescent powders by two steps acid leaching

The effects of the acid leaching and alkali fusion on the leaching efficiency of Y,Eu,Ce,and Tb from the waste rare earth fluorescent powders were investigated in this paper.The results show that hydrochloric acid is better than sulfuric acid in the first acid leaching,and NaOH is better than Na2CO3in the alkali fusion.In the first acid leaching,the Wloss is 20.94%when the waste rare earth fluorescent powders are acid leached in H?concentration 3 mol L-1and S/L ratio 1:3 for 4 h due to red powders dissolved.The better results of the alkali fusion can be got at 800℃ for 2 h when the NaOH is used.The blue powders and the green powders can be dissolved into NaAlO2and oxides such as rare earth oxide(REO).The REO can be dissolved in H?concentration 5 mol L-1,S/L1:10 for 3 h in the second acid leaching.The leaching rates of the Y,Eu,Ce,and Tb are 99.06%,97.38%,98.22%,and 98.15%,respectively.The leaching rate of the total rare earth is 98.60%.

Recovery of scandium from silicate minerals by high-pressure leaching in sulfuric acid

This study investigated the leaching of scandium from a Sc-bearing silicate ore.The Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%Fe.The main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of isomorphism.High-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this samples.The Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 h.The X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multi-hole shape.Compared with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.

Removal of phosphorus from iron ores by chemical leaching

Alkali-leaching and acid-leaching were proposed for the dephosphorization of Changde iron ore, which contains an average of 1.12% for phosphorus content. Sodium hydroxide, sulfuriced, hydrochloric and nitric acids were used for the preparation of leach solutions. The results show that phosphorus occurring as apatite phase could be removed by alkali-leaching, but those occurring in the iron phase could not. Sulfuric acid is the most effective among the three kinds of acid. 91.61% phosphorus removal was attained with 1% sulfuric acid after leaching for 20 min at room temperature. Iron loss during acid-leaching can be negligible, which was less than 0.25%.The pH value of solution after leaching with 1% sulfuric acid was about 0.86, which means acid would not be exhausted during the process and it could be recycled, and the recycle of sulfuric acid solution would make the dephosphorization process more economical.

Dissolution kinetics of iron oxides in clay in oxalic acid solutions

Clay samples containing 8.15% iron oxides and 27.49% alumina were leached in oxalic acid. Leaching experiments were per-formed in aqueous solutions of oxalic acid of 0.2-2 mol/L at 40-80 C for up to 90 min. The mixed kinetic mechanism, i.e., t/τ=[（1 2X/3） （1 X）2/3 ]＋b[ 1 （1 X）1/3], seemed to be the most appropriate one to fit the kinetic data of leaching iron oxides contained in clay in the aqueous oxalic acid solutions. The Arrhenius activation energy for leaching in the 1.8 mol/L oxalic acid was found to be 41.035 kJ/mol.

贵州某钡渣酸浸渣浮选实验

这是一篇矿物加工工程领域的论文。钡渣为有毒固废,大量钡渣堆存严重危害环境且对国土资源造成巨大浪费。酸性浸出钡渣中酸溶钡是钡渣无害处理及回收钡最佳途径之一。论文采用浮选工艺回收富集钡渣酸浸尾渣中硫酸钡,以期实现综合回收钡渣中钡资源。浮选回收钡渣酸浸渣实验研究,在碳酸钠用量2000 g/t,硅酸钠用量500 g/t以及油酸钠用量3000 g/t的条件下,通过一次粗选、四次精选、两次扫选的浮选闭路流程,获得重晶石精矿品位85.38%、回收率69.35%的浮选指标,精矿产品达到工业生产碳酸钡用料重晶石标准。

褐铁矿型红土镍矿中有价金属的酸浸工艺

镍是一种战略性稀有金属,从低品位红土镍矿中生产单质镍或镍的合金是解决镍铁合金需求的主要途径。采用盐酸选择性浸出印尼褐铁矿型红土镍矿中的有价金属,结果表明:当盐酸浓度10 mol/L,原料粒度74μm,浸出温度353 K,固液体积比1∶4,浸出时间120 min时,镍、钴、锰、铁和镁的浸出率分别为34.3%、90.67%、64.23%、76.46%和48.12%,且盐酸作为常见的工业副产品,易回收再生。镍、钴、锰的浸出动力学研究可知,其浸出过程不符合广泛采用的收缩核模型,而用Avrami方程进行拟合具有很好的线性,根据Arrhenius公式求得浸出过程中镍、钴和锰的表观活化能分别为7.96、4.00kJ/mol和4.98 kJ/mol,三者浸出的活化能值均介于4~12 kJ/mol范围内,且浸出温度对反应速率常数的影响并不明显,判断出镍、钴和锰的浸出过程受扩散条件控制。本研究结果可为褐铁矿型红土镍矿的高效开发利用提供理论参考。

用氢氟酸从白云鄂博矿中浸出铌及动力学研究

针对白云鄂博尾矿中含铌矿物综合回收利用中存在的问题,研究了用氢氟酸浸出含铌矿物中的铌,确定了最佳工艺条件,并探讨了浸出动力学。结果表明:在反应温度90℃、液固体积质量比7/1、氢氟酸浓度20 mol/L、反应时间2 h、搅拌速率300 r/min条件下,铌浸出率达90.91%;铌的浸出过程符合核收缩模型,浸出过程由化学反应和扩散混合控制,表观活化能为35.459 kJ/mol。该法能有效提取尾矿中的铌,有利于后续分离提纯。

Pressure nitric acid leaching of alkali-pretreated low-grade limonitic laterite

The pressure nitric acid leaching of alkali-pre- treated low-grade limonitic laterite, as well as removing impurity AI（III） and preparing intermediate product of nickel/cobalt sulphide from leaching liquor were investi- gated. After pretreatment, iron exists in the form of amorphous iron oxides, while nickel is adsorbed on the surface of iron oxides in the form of nickel oxide. The preferable pressure leaching conditions are determined as follows： leaching temperature of 458 K, leaching duration of 60 min, initial acidity of nitric acid of 1.90 mol.L-~ and liquid to solid ratio of 3：1 （volume to mass ratio）. Under these conditions, the leaching efficiencies of Ni, Co and A1 are 95 %, 88 % and 55 %, respectively, and that of Fe is less than 1%. The loss rates of Ni and Co are 1.8 % and 1.5 %, respectively, during the step of removing impurity AI（III）. The sulphide precipitation process produces the interim production of nickel/cobalt sulphides, recovering greater than 99 % of Ni and Co in the purified solution. The iron-rich （〉60 %） pressure leaching residue with low Cr, S can be further reclaimed as the raw materials for iron making.

内蒙古某白伟晶岩纯化制备高纯石英砂

这是一篇矿物加工工程领域的文章。针对内蒙古某白伟晶岩样品进行工艺矿物学研究,采用“焙烧水淬-热压混合酸浸”实验工艺流程对内蒙古某地白伟晶岩进行选矿实验研究。通过条件实验研究得到较佳工艺条件,高纯石英砂中SiO_(2)含量由99.917%提高到99.994%,杂质元素总含量从419.9 g/t下降到54.79 g/t,总去除率达86.95%;主要杂质元素Al含量从250.9 g/t下降到26.09 g/t,Al元素去除率达到了89.60%,取得了较好的纯化效果。

铜碲渣综合回收工艺与实践

简述了从碲铜渣中综合回收Te、Cu等有价金属的工艺试验。采用“氧化酸浸脱铜→碱浸提碲→酸中和沉碲→络合净化提纯”的工艺对铜碲渣处理得到高纯TeO_(2);含铜溶液置换回收海绵铜;残留渣中的Ag、Se可返回银硒系统回收。

低品位红土镍矿镍钴沉淀技术发展概述

本文介绍了低品位红土镍矿高压浸出(HPAL)工艺中镍钴沉淀富集技术的由来及发展情况,详细阐述了目前应用过程中存在的问题,同时着重介绍了中国恩菲独创的碱基活化控制技术(AACP)。该核心技术包括3个关键环节,即氢氧化钠原位碱基转化、前置晶种重整与模板诱导生长、收敛式系统调控,其规避了国外企业在硫化氢、氧化镁沉淀技术中通过专利等手段设置的技术壁垒,技术工艺巧妙,装备简单通用,与高压浸出系统兼容性强,氢氧化镍钴(MHP)产品质量优异且稳定。此外,中国恩菲针对HPAL存在的问题,开发了高压酸浸工艺装备工程系统(ENFIHPAL),缩短了项目实施周期,且对装备系统整体进行基本选型设计、优化以及问题判别,可最大程度保证装备系统在复杂运行条件下的稳定性和作业率。AACP技术继巴布亚新几内亚的瑞木镍钴项目成功应用后,于印尼的力勤、华越等项目亦获得了显著的应用效果,生产的MHP产品已成为目前EV动力电池产业链原料供应端质量最好的中间产品。HPAL-AACP工艺路线有望成为低品位红土镍矿高效利用的首选之路。

粉煤灰提取氧化铝研究进展

我国铝土矿对外依存度高,粉煤灰作为富铝产品,如何从粉煤灰中回收铝是铝及煤化工行业关注的热点之一,粉煤灰提铝技术的开发对于改善环境、实现资源优化配置具有重要意义。本文分析了不同产地(内蒙古、山西、安徽、北京)的粉煤灰的物化性能,介绍了从粉煤灰提取氧化铝的技术进展,系统总结了碱法(碱烧结法和碱溶法)、酸法(硫酸浸出法、盐酸浸出法和硫酸氢铵法)、酸碱联合法及其他方法(碳热还原法、微波助溶法和生物浸出法)的工艺流程、原理及不足之处,调查了对大唐国际、蒙西集团、神华集团、华电集团等企业在粉煤灰提取氧化铝项目的产业化进展,并提出开发更加经济高效的工艺、铝尾渣的进一步资源化利用和其他有价金属的提取等建议。

高纯石英应用及化学提纯技术研究进展

高纯石英作为—种稀有矿产资源,由于其稳定的物理化学性质,在半导体、光伏、光学及光纤通信等高新技术领域有着广泛的应用。总结了高纯石英在高精尖产业的应用现状,详细介绍了脉石矿物杂质、包裹体杂质、类质同象类杂质的存在形式及特征,在此基础上综述了酸浸出法、碱浸出法、热处理法等化学提纯技术研究现状,并展望了我国高纯石英提纯技术未来的发展方向。

碱酸法提纯鳞片石墨的试验研究

针对传统碱酸法石墨提纯度不高的问题,提出了一种利用十六烷基三甲基溴化铵(CTAB)辅助碱酸法制备高纯鳞片石墨的方法,以鸡西天然鳞片石墨浮选精矿为原料,考察碱熔焙烧温度与时间、石墨与氢氧化钠及水的质量比、酸浸盐酸用量与浓度、表面活性剂用量及时间等因素对石墨提纯效果的影响。结果表明,CTAB辅助碱酸法优于传统碱酸法制备高纯石墨,石墨固定碳质量分数由99.91%提升至99.93%。

硅锰渣基沸石的合成及其表征

硅锰渣是生产硅锰合金时产生的一种工业副产物,年排放量巨大,综合利用水平低,已经成为冶金业绿色发展急需解决的难题。为实现硅锰渣的高值化利用,将硅锰渣通过“酸洗—碱熔—陈化—晶化”水热合成反应来制备沸石。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、傅里叶红外光谱仪(FT-IR)、比表面积及孔径分析仪对沸石的晶相、形貌、官能团等进行表征;探究了碱度、温度、时间等因素对合成沸石的物相组成及微观形貌的影响。实验结果表明,原料酸浸后MnO、Fe_(2)O_(3)、CaO含量均有所减少,碱熔后体系中生成了合成沸石所需的硅酸盐。在最优条件(碱度为0.5 mol/L、温度为80℃、时间为8 h)下合成了纯度及结晶度较好的沸石;与传统的工业固废制备沸石相比,该实验晶化所需的碱度更低,且采用了硅锰渣为原料制备沸石,为硅锰渣的高值化利用提供了新思路。

芒来铀矿石酸法铀浸出与矿物黏土化特征

酸法浸铀过程中浸出液铀浓度及化学成分通常会随时间发生改变,同时伴随有黏土矿物的产生。以内蒙古芒来铀矿石为研究对象,开展了4种酸度(5、10、15、20 g/L H2SO_(4))条件下室内酸法浸泡浸铀试验,对试验过程中浸出液化学成分及铀浸出特征与矿物的黏土化蚀变特征进行了系统探讨。研究结果表明,铀浸出过程中六价铀浸出迅速而四价铀浸出较慢,铀渣计浸出率为83.73%~88.07%;矿石中的含铀、含钠、含钾、含钙、含铁、含铝等矿物发生溶解,使溶浸液中的U6+、U4+、Na+、K+、Ca_(2)+、Al3+、Fe2+、Fe3+浓度大幅增高;矿石中的长石类矿物发生了明显的黏土化蚀变,黏土矿物以伊利石为主。这些研究成果可以为该铀矿的开发工艺技术的确定和预防含矿层堵塞提供技术支撑。

基于常压酸浸的低品位红土镍矿综合利用研究

低品位红土镍矿在常压下用硫酸浸出后,浸出液与浸出渣中的镍、铁、镁、硅等有价元素可进行综合利用。本文首先采用常压酸浸对低品位红土镍矿进行处理,然后通过各工艺环节的试验研究有价金属综合利用的工艺流程,明确最佳工艺参数,实现低品位红土镍矿高附加值资源化综合利用。其间,可利用黄钠铁矾法对红土镍矿浸出液沉铁;过滤渣焙烧后获得Fe_(2)O_(3)矿粉,它可作为钢铁原料或深加工为铁红等产品;除铁后液利用化学沉淀法进行处理,分别得到氢氧化镍与氢氧化镁产品;过滤后的硫酸钠溶液经过净化后可送回配料环节循环使用;浸出渣则通过碱浸处理、碳化分解得到高纯度SiO_(2)产品。

气化渣基多孔材料的制备及在水处理中的应用

随着煤气化技术的不断改进,气化渣的排放量逐年递增,如不及时有效处理,将会对生态环境造成重大危害。气化渣是一种硅铝酸盐,富含Si和Al元素,且具有比表面积大、孔道发达的特点,是制备多孔材料的理想原料。由气化渣制备的介孔微玻璃球、活性炭、介孔复合材料、X型沸石/碳复合材料等均可用于水处理。综述了气化渣的特性,气化渣制备多孔材料的方法及在水处理方面的应用,并对今后的研究方向进行了展望。

蛇纹石酸浸渣碱溶脱硅反应动力学

以蛇纹石酸浸渣为原料,系统研究了碱溶脱硅反应动力学。通过X射线衍射(XRD)、X射线荧光(XRF)、热重-差热(TG-DTA)和场发射扫描电镜-能谱(FESEM-EDS)对蛇纹石酸浸渣物相、化学组成、热稳定性及形貌结构进行了详细分析。利用单因素变量法对蛇纹石酸浸渣碱溶脱硅反应过程进行了研究,详细讨论了NaOH质量分数、反应温度、液固比、搅拌速度和粒度对酸浸渣中SiO_(2)溶出率的影响,并分别采用收缩核模型及Avrami方程拟合动力学,并建立了反应动力学方程。结果表明:在该体系中,蛇纹石酸浸渣碱溶过程动力学不符合传统的收缩核模型,而符合Avrami方程且拟合相关性较高;整个溶出过程受扩散控制,模型特征参数n_(1)=0.21,反应表观活化能E_(a)=8.62 kJ/mol。