低品位红土镍矿焙烧-碱浸过程中硅的转化流程应用研究现状与展望流程应用研究现状与展望

针对目前红土镍矿碱法处理过程中存在的问题提出工艺改进,研究低品位红土镍矿焙烧活化-碱浸过程中含硅矿物的转化。考察了焙烧温度对红土镍矿活性的影响,探索了红土镍矿经焙烧后碱浸过程中温度、时间、搅拌强度、液固比以及碱初始质量浓度对硅转化的影响。结果表明,红土镍矿经650°C焙烧2h后,活性得到明显提高,红土镍矿经焙烧后采用初始质量浓度为60g/L的碱溶液,在搅拌速度为400r/min、浸出温度为140°C、液固比为5∶1的条件下浸出120min,硅的转化率可达89.42%。     

高硫高硅铝土矿的焙烧脱硫—碱浸脱硅

研究了中低品位高硫高硅铝土矿焙烧脱硫—碱浸脱硅工艺,考察了焙烧前、后铝土矿的物相变化,以及碱浸时间、碱浸温度、液固体积质量比和碱液质量浓度对脱硅效果的影响。结果表明:在碱浸温度95℃、碱质量浓度110 g/L、碱浸时间60 min、液固体积质量比10/1条件下,脱硅率为45.89%,氧化铝损失率为3.89%。适宜条件下,脱硅后铝溶出率达97.21%,较未脱硅焙烧工艺的铝溶出率提高4.89%。     

镁质红土镍矿酸浸结果影响因素的数学模型

为了研究红土镍矿酸浸过程中各因素对浸出结果的影响以及各因素之间的关系,利用正交试验法考察了硫酸浓度、液固比、浸出时间、浸出温度和搅拌速率对红土镍矿酸浸镍浸出率的影响,并对试验结果进行正交多项式回归分析。结果表明,硫酸浓度、液固比和浸出温度是影响镍漫出率的显著因素,而浸出时间及搅拌速率是影响镍浸出率的不显著因素。同时建立了红土镍矿酸浸镍浸出率与硫酸浓度、液固比和浸出温度之间相关关系的数学模型。研究为进一步优化红土镍矿酸浸试验条件提供一定的理论依据。     

硅酸盐对红土镍矿焙烧料酸浸过滤的影响

通过对浸出条件的改变,考察了不同硅酸盐浓度对红土镍矿焙烧料酸浸浆体过滤性能的影响。发现当滤液中硅酸盐浓度大于7.5 g/L时,酸浸浆体的过滤性能急剧下降。研究表明:当酸矿比为1.0、液固比10∶1、反应温度70℃、反应时间90 min时,红土镍矿焙烧料Co、Ni、Fe2+的浸出率均可达90%以上,滤液中硅酸盐浓度为6.66 g/L,浆体过滤性能良好。     

低品位铝土矿的高效脱硫脱硅工艺研究

通过采用悬浮焙烧-碱浸脱硅的方式对铝土矿进行处理,并研究了焙烧温度、苛碱浓度、碱浸温度对焙烧矿碱浸脱硅的影响。结果表明,悬浮焙烧较优温度为930 ℃,在碱浸脱硅条件下液固比为8∶1,脱硅时间为30 min,苛碱浓度为110 g/L,脱硅温度为95 ℃时,可获得较高脱硅率,可达49.24%。Al₂O₃损失率为2.03%,精矿铝硅质量比可提至8.21,悬浮焙烧的脱硅精矿实际溶出率最高可达94.79%。采用石灰为脱硅剂,对碱浸脱硅后的碱液进行脱硅后,可对焙烧矿进行循环脱硅利用,脱硅后的精矿铝硅比均可达到7以上,从而使碱液实现了循环利用。      

高铁铝土矿焙烧/高压碱浸提取镓的研究

采用钠化焙烧—高压碱浸的方法对高铁三水铝石型铝土矿中的镓进行浸出研究,探讨了焙烧过程中的碳酸钠加入量、焙烧时间、焙烧温度,以及高压碱浸过程中温度、NaOH浓度、液固比、时间等对镓浸出率的影响。在下述最优条件下,镓浸出率达到91.25%:焙烧温度1 000℃、焙烧时间60min、碳酸钠配比100%、浸出温度160℃、浸出时间120min、NaOH浓度15%、液固比15。     

用碱从低品位氧化锌矿石中浸出锌

研究了用氢氧化钠溶液从某低品位氧化锌矿石中浸出锌,考察了反应温度、反应时间、初始碱浓度、搅拌速度等对锌浸出的影响。结果表明:氢氧化钠浓度增大有利于矿石中的锌转化成可溶性Na_2Zn(OH)_4;在反应温度65℃、初始碱浓度4 mol/L、液固体积质量比10/1、搅拌速度300 r/min条件下浸出120 min,锌浸出率达90.08%。此工艺为低品位氧化锌矿石的资源化提供了一种可供选择的方法。     

碱浸提钛渣提硅实验过程及其动力学研究

硫酸氢铵焙烧高钛渣提钛后的滤渣中存在大量的硅,对苛刻碱浸渣提硅实验过程中各参数的影响进行系统的研究。结果表明:在反应温度220℃,苛性碱与浸出渣质量比为3.5∶1,液固比5.5∶1,反应时间50 min,搅拌速度400 r/min的实验条件下,SiO_2提取率可达78.4%。碱浸过程动力学分析表明此反应过程受内扩散控制,反应的表观活化能为24.047 kJ/mol,动力学方程为:1+2(1-x)-3(1-x)~(2/3)=2.415exp[-24 047/(RT)]·t。     

铝灰除杂试验研究

研究了铝灰酸浸、焙烧除杂工艺.试验结果表明:在盐酸质量浓度150 g/L、矿浆粒度小于325目、浸出温度80 ℃、液固体积质量比4∶1、搅拌时间120 min条件下,铝灰的除杂效果较好.酸浸后的铝灰经焙烧,不仅可脱除杂质,而且还转变了晶型,改变了结构和性质,为其综合利用创造了条件.     

铜闪速炉烟灰硫酸化焙烧后焙砂浸出试验研究

考察了搅拌速度、浸出时间、初始硫酸浓度、浸出温度、液固质量比等条件对稀硫酸浸出铜闪速炉烟灰硫酸化焙烧所得焙砂的影响。结果表明,在下述最佳浸出条件下:搅拌速度400r/min、浸出时间70min、初始硫酸浓度0.8mol/L、浸出温度60℃、液固质量比5∶1,铜、铁、砷、铟等有价金属浸出率均在90%以上。     

红土镍矿湿法冶金工艺现状及前景分析

随着硫化镍矿资源的不断消耗以及镍需求量的持续增长,红土镍矿将是未来镍的主要来源。红土镍矿具有储量丰富、易开采、便于运输等特点,成为研究开发的热点。对还原焙烧 氨浸工艺、加压酸浸工艺、常压酸浸工艺等湿法冶金处理红土镍矿的工艺特点及现状进行了阐述,并分析了各工艺的优势与不足,介绍了红土镍矿湿法冶金工艺的研究进展。最后探讨了未来红土镍矿湿法冶金工艺的发展前景,指出加压酸浸工艺将在今后红土镍矿湿法冶金中扮演重要角色。     

广西某低品位软锰矿还原焙烧—酸浸工艺研究

针对广西某低品位软锰矿,探究以煤为还原剂进行还原焙烧,焙烧矿采用硫酸浸出的工艺条件,通过单因素实验,考察了还原剂用量、焙烧温度与时间的组合、浸出酸量、时间、液固比、搅拌强度及浸出温度对浸出结果的影响。实验表明:在取300g软锰矿进行实验时,配煤11%、在温度750℃下焙烧60min的焙烧矿,在理论酸量、固液比5∶1、搅拌强度300r/min、常温下浸出45min后,锰的浸出率可达到95.57%的良好指标。     

Leaching behavior of metals from a limonitic nickel laterite using a sulfation–roasting–leaching process

The leaching behavior of metals from a limonitic laterite was investigated using a sulfation–roasting–leaching process for the recovery of nickel and cobalt. The ore was mixed with water and concentrated sulfuric acid followed by roasting and finally leaching with water. Various parameters were studied including the amount of acid added, roasting temperature and time, sample particle size, addition of Na₂SO₄ and solid/liquid ratio in leaching process. More than 88% Ni, 93% Co and < 4% Fe are extracted under the determined conditions. Simultaneously, about 90% Mn and Cu, 70% Mg, 45% Al, 25% Zn, 4% Cr and Ca are extracted respectively. The pH of the leach solution is about 2. The leaching efficiency is independent of sample particle size due to decomposition of ferric sulfate formed during roasting. The roasted mass was characterized by various physico-chemical techniques such as DSC/TGA, XRD and SEM. This process provides a simple and effective way for the extraction of nickel and cobalt from laterite ore.     

Effect of pre-roasting on leaching of laterite

The effect of pre-roasting on leaching of the gamierite laterite ore, obtained from Yunnan province, China, was investigated in this study. The phase transformation of laterite minerals roasted at different temperatures was investigated with X-ray powder diffraction (XRD). The roasting experiment results show that there are two phase transformation processes of dehydroxylation of goethite and lizardite at roasting temperatures of 277 °C and 610 °C, respectively, which accord with the result of DTA–TG analysis. Pre-roasting of the laterite not only alters its mineralogical composition but also increases its porosity and surface area, thus making it more amenable to leaching. Compared to the leaching result of raw ore and ores roasted at different temperatures, it indicates that increasing roasting temperature up to 300 °C appears to provide the optimum nickel recovery and further heating appears to be detrimental to the nickel recovery.     

Decomposition of mixed rare earth concentrate by NaOH roasting and kinetics of hydrochloric acid leaching process

A new clean extraction technology for the decomposition of Bayan Obo mixed rare earth concentrate by NaOH roasting is proposed.The process mainly includes NaOH roasting to decompose rare earth concentrate and HCl leaching roasted ore.The effects of roasting temperature,roasting time,NaOH addition amount on the extraction of rare earth and factors such as HCl concentration,liquid-solid ratio,leaching temperature and leaching time on the dissolution kinetics of roasted ore were studied.The experimental results show that when the roasting temperature is 550℃ and the roasting time is 60 min,the mass ratio of NaOH:rare earth concentrate is 0.60:1,the concentration of HCl is 6.0 mol/L,the ratio of liquid to solid(L/S) 6.0:1.0,and the leaching temperature 90℃,leaching time 45 min,stirring speed 200 r/min,and the extraction of rare earth can reach 92.5%.The relevant experimental data show that the process of HCl leaching roasted ore conforms to the shrinking core model,but the control mechanism of the che mical reaction process is different when the leaching temperature is different.When the leaching temperature is between 40 and 70℃,the chemical reaction process is controlled by the diffusion of the product through the residual layer of the inert material.The average surface activation energy of the rare earth element is E_a=9.96 kJ/mol.When the leaching temperature is 75-90℃,the chemical reaction process is controlled by the interface transfer across the product layer(product layer interface mass transfer) and diffusion.The average surface activation energy of rare earth elements is E_a=41.65 kJ/mol.The results of this study have certain significance for the green extraction of mixed rare earth ore.     

两段硫酸化焙烧-水浸从红土镍矿中回收镍钴

以澳大利亚某红土镍矿为原料,采用两段硫酸化焙烧—水浸工艺回收镍钴。重点探讨酸料比、低温焙烧段温度及时间、高温焙烧段温度及时间对镍钴浸出率的影响。结果表明,在酸料比为0.6,一段低温焙烧温度250℃,焙烧时间60min,二段高温焙烧温度650℃,焙烧时间3h的条件下进行硫酸化焙烧,焙烧产物经过水浸,Ni和Co浸出率分别达到93.38%和91.95%。     

红土镍矿微波水热法浸提镍钴

采用微波水热盐酸浸出方法对腐泥土型红土镍矿提取镍钴进行了研究,详细探讨了焙烧预处理、微波水热浸出温度和浸出时间对镍钴浸出率的影响.对于300℃焙烧预处理后的红土镍矿,微波水热温度为50℃,浸出时间为1 h时,镍的浸出率高达93.65%,钴的浸出率为87.86%.红土镍矿的微波水热浸出体系与普通水热浸出体系相比,镍和钴的浸出效果更好.研究表明,扩散过程是镍、钴浸出过程的主要限制环节.      

Leaching Ni and Co from Saprolitic Laterite Ore by Employing Atmospheric Acid Leaching Solution with High Concentration of FeCl 3 at Mild Conditions

Limonitic and saprolitic laterite ores are used to produce Ni by employing different kinds of processes. Acid leaching is an energy-saving process for pure Ni metal production. The high concentration of Fe in atmospheric acid leaching solution caused difficulties in metal-ions separation. In this work, saprolitic laterite ore was leached by atmospheric acid leaching solution of limonitic laterite ore at moderate temperatures. Conditions affecting the leaching of valuable metals and the conversion ratio of Fe were investigated. The results showed that optimal output was obtained after 1.5 h of leaching at 150°C with 1.0 liquid/solid ratio (volume/weight). X-ray diffraction analysis and mineral liberation analysis indicate that some nickel was adsorbed by leached residues, resulting in the loss of nickel. The physiochemical properties of leached residues could be changed due to the presence of Al and Cr. The decrease in zeta potential and the increase in specific surface area resulted in the increase of Ni adsorption.     

红土镍矿选择性还原焙烧过程中的相变转化

针对传统选矿方法难以回收低品位红七镍矿中有价金属镍的问题,采用选择性还原焙烧法研究了不同焙烧温度以及不同焙烧时间条件下红土镍矿(Ni品化为1.49%)中发生的微观结构变化以及相变转化.通过X射线衍射、扫描电镜及X射线能谱分析等测试手段分析表明,在不同焙烧温度及不同时间条件下经选择性还原后的红土镍矿中,镍氧化物逐渐被还原成镍铁合金相,铁氧化物主要转变成浮氏体相,硅酸盐主要以橄榄石形式存在.最后通过还原焙烧磁选试验证实,还原剂为烟煤,添加剂为NCS,两者用量分别为原矿质量的2%和7%,在1200℃条件下焙烧50min,磁选分离得到镍铁产品中镍品位为9.78%,镍的回收率为92.06%,镍铁回收率差为62.51%,实现了红土镍矿中镍铁的选择性还原.