尼日利亚钛铁矿的矿物学特征和浸出行为

研究尼日利亚钛铁矿矿物学特征和经机械活化和碱性焙烧处理后的浸出行为。研究了 NaOH/矿石比、H2SO4浓度、浸出和焙烧温度对钛回收率的影响。结果表明,机械活化对钛铁矿石的浸出有明显的增强作用。钛铁矿经机械活化后,加入60%NaOH在850°C下焙烧,在温度为90°C,经60%H2SO4浸出4 h下的浸出率为72%。对焙烧矿、水处理后残渣和酸浸滤渣的XRD物相分析证实了反应机理和实验结果。     

KOH亚熔盐法分解钛铁矿的动力学分析

对钛铁矿在氢氧化钾亚熔盐体系中的分解动力学进行研究,考察反应温度及矿粒粒径对钛铁矿分解率的影响.结果表明:钛铁矿在氢氧化钾亚熔盐体系中的分解符合未反应收缩核模型,受界面化学反应控制;提高反应温度或减小矿粒粒径均能提高钛铁矿的分解率.在一定的操作条件下,根据Arrherius方程得到钛铁矿在氢氧化钾亚熔盐体系中的分解活化能,且活化能随矿粒粒径的减小而减小;当矿粒粒径为58～180 μm时,钛铁矿的分解活化能为54.78～46.82 kJ/mol.     

综合利用钛铁矿制备二氧化钛、钛酸锂和磷酸铁锂

以钛铁矿为原料,经机械活化-盐酸浸出得到水解钛渣和富铁浸出液;用H2O2将水解钛渣中的Ti配位溶出,得到配位浸出液,并以其为反应物制备纳米级片状的过氧钛化合物;该过氧钛化合物经洗涤、煅烧制备得到纳米级片状的TiO2,其纯度高达99.31%(质量分数)。将过氧钛化合物与Li2CO3混合,球磨后煅烧合成性能优良的锂离子电池负极材料Li4Ti5O12。以富铁浸出液为原料,经选择性沉淀制备含少量Al和Ti的FePO4.xH2O,并以其为前驱体制备了Al-Ti掺杂的LiFePO4。该LiFePO4在1C和2C倍率下的首次放电比容量分别达151.3和140.1(mA.h)/g,循环100次之后容量无衰减。该方法也可用于钛白粉副产品硫酸亚铁的回收利用,制备性能优异的LiFePO4。     

Two-stage precipitation process of iron and arsenic from acid leaching solutions

A leaching process for base metals recovery often generates considerable amounts of impurities such as iron and arsenic into the solution. It is a challenge to separate the non-valuable metals into manageable and stable waste products for final disposal, without loosing the valuable constituents. Boliden Mineral AB has patented a two-stage precipitation process that gives a very clean iron-arsenic precipitate by a minimum of coprecipitation of base metals. The obtained product shows to have good sedimentation and filtration properties, which makes it easy to recover the iron-arsenic depleted solution by filtration and washing of the precipitate. Continuos bench scale tests have been done, showing the excellent results achieved by the two-stage precipitation process.     

盐酸浸出机械活化和碳热还原钛铁矿制备纳米二氧化钛

采用一个新工艺来处理天然钛铁矿并制备高品位的人造金红石纳米颗粒.该工艺主要包括球磨、碳热还原和盐酸浸出步骤.天然钛铁矿通过球磨处理后,颗粒尺寸会大幅度减小;后续的碳热还原会导致高钛渣的形成.在盐酸浸出工序中,重点考察了酸浸时间、温度和酸的浓度对浸出过程的影响.通过优化工艺条件,最后所得到的产品为纯度超过98.0％、颗粒尺寸为10～200nm的TiO2纳米颗粒.     

高炉尘泥化学除锌

为了降低经物理分选后的高炉精泥中锌的含量,对高炉精泥进行化学浸出除锌研究,考察浸出剂、浸出时间、温度、液固比和搅拌速度等对浸出的影响,并进行理论分析。结果表明：硫酸对锌的浸出率最高,氯化铁次之,氨水最低;在合适的浸出条件下：液固比8-1,温度20℃,硫酸浓度125 g/L,浸出时间35 min和搅拌速度150 r/min,锌浸出率为73.9%,高炉精泥中的锌含量从1.46%降低到0.38%。对硫酸浸出脱锌的动力学和反应机制的研究表明,浸出过程遵从1-2α/3-（1-α）2/3=kt,浸出反应的活化能为8.89 kJ/mol,属于扩散控制过程。     

Kinetics of iron removal from metallurgical grade silicon with pressure leaching

In this paper, the kinetics of pressure leaching for purification of metallurgical grade silicon with hydrochloric acid was investigated. The effects of particle size, temperature, total pressure, and concentration of hydrochloric acid on the kinetics and mechanism of iron removal were studied. It was found that the reaction kinetic model followed the shrinking core model, and the apparent activation energy of the leaching reaction was 46.908 kJ/mol. And the apparent reaction order of iron removal with pressure leaching was 0.899. The kinetic equation was ob-tained and the mathematical model of iron removal from metallurgical grade silicon (MG-Si) was given as follows: 1-2/3x-(1-x)2/3=exp(5.1654-4811.4591/T+1.287lnp+1.046ln[C])·t/r02· The values calculated from the equation were consistent with the experimental results.     

Kinetics of iron removal from metallurgical grade silicon with pressure leaching

In this paper, the kinetics of pressure leaching for purification of metallurgical grade silicon with hydrochloric acid was investigated. The effects of particle size, temperature, total pressure, and concentration of hydrochloric acid on the kinetics and mechanism of iron removal were studied. It was found that the reaction kinetic model followed the shrinking core model, and the apparent activation energy of the leaching reaction was 46.908 kJ/mol. And the apparent reaction order of iron removal with pres...     

盐酸浸出机械活化和碳热还原钛铁矿制备纳米二氧化钛(英文)

采用一个新工艺来处理天然钛铁矿并制备高品位的人造金红石纳米颗粒。该工艺主要包括球磨、碳热还原和盐酸浸出步骤。天然钛铁矿通过球磨处理后,颗粒尺寸会大幅度减小;后续的碳热还原会导致高钛渣的形成。在盐酸浸出工序中,重点考察了酸浸时间、温度和酸的浓度对浸出过程的影响。通过优化工艺条件,最后所得到的产品为纯度超过98.0%、颗粒尺寸为10～200nm的TiO2纳米颗粒。     

不同钛、铁含量对熟料烧结和溶出的影响

通过研究熟料烧结的生料配比及烧结工艺过程,分析熟料中钛、铁含量对熟料烧结及溶出的影响。指出在碱比一定的情况下,熟料中钛、铁含量对熟料烧结及溶出的影响。熟料中钛含量越高,熟料的溶出率越低,当碱比为0.82左右时,铁含量升高,熟料的溶出率也升高。     

锌浸渣还原焙烧-磁选回收铁

在查明锌浸渣工艺矿物学的基础上,采用还原焙烧将铁酸锌分解为氧化锌和磁性氧化铁,再通过磁选的方法回收铁,达到锌、铁分离的目的。实验考查了焙烧温度、焙烧时间、还原剂用量对铁酸锌分解率、铁回收率和铁品位的影响。结果表明:在焙烧温度为950℃、焙烧时间为1 h及还原剂添加量为10%和5%的条件下,铁酸锌分解率达到72.05%,铁回收率可达到91.79%,精矿中铁的品位为50%左右。焙烧及磁选过程中颗粒的团聚包裹是铁精矿品位不高的主要原因。     

铅阳极泥脱砷预处理研究

采用氢氧化钠溶液循环浸出法对铅阳极泥进行预脱砷,考察了液固比、氢氧化钠浓度、浸出温度和浸出时间对脱砷效果的影响;在液固比10∶1、氢氧化钠浓度2.5 mol/L、浸出温度80℃、浸出时间8 h的条件下,砷的浸出率可达94%以上;含砷浸出液经硫化钠沉砷后可返回浸出工序循环使用,硫化钠与砷质量比为3∶1时,沉砷率可达88%以上,同时回用浸出工序后,砷浸出率达94%以上,浸出液循环使用对脱砷没有影响。     

Selective leaching and recovery of V as iron vanadate from industrially generated Mo-V residue

A commercial process was developed to treat a Ca-based Mo-V residue generated in Mo processing plant. Vanadium was selectively leached using acetic acid and recovered as iron vanadate by hydro process. Process conditions for selective V leaching and iron vanadate precipitation were investigated. V recovery efficiency of 90.3% was achieved with a V content of 26.5% and an Fe content of 29% in the iron vanadate cake suitable for ferrovanadium industry. The overall Mo recovery in the whole process was 98.6%. The obtained leach residue containing 14.3% Mo with negligible impurities can be used as a feed material for the Mo production process or ferromolybdenum industry. This simple and economical process generates two product streams from a single operation and has the potential to solve a long standing problem of handling such a mixed Mo-V residue.     

烧结电除尘灰中钾盐的回收及其浸出动力学

为了研究烧结电除尘灰中回收钾盐的强化浸出措施,使用ICP-AES、SEM-EDS和XRD分析技术对除尘灰的表面和内部形态,特别是钾盐的赋存形式进行分析。结果表明,该电除尘灰的主要成分是铁氧化合物,在其表面裸露吸附着一定含量的KCl晶体。水浸实验表明,该粉尘中的KCl可以通过水浸出、蒸发结晶的方式回收,其收率为18.56%。结晶产物的分析结果表明,KCl占61.21%,NaCl占13.40%,CaSO4占14.62%,K2SO4占10.86%。其水浸出动力学符合外扩散控制模型控制。强化浸出实验表明,提高浸出温度、加强搅拌、增加液固比等措施可以提高钾盐的浸出率和浸出速率。     

酸洗去除冶金硅中的典型杂质

以王水和氢氟酸为酸洗介质,研究酸洗对冶金硅中典型杂质元素的脱除效果。结果表明:王水和氢氟酸对金属类杂质均有明显的去除作用,但对非金属B和P去除效率差。Al杂质经王水和氢氟酸酸洗后去除率分别为80%和86.3%,Fe杂质的去除率分别为78.6%和89.4%。氢氟酸对总杂质去除率比王水提高12%,但其对Cu的去除率仅为4.8%。Cu的相态分析表明:Cu在冶金硅中主要是以Al-Si-Cu合金相存在,抗氢氟酸腐蚀性强。与氢氟酸不同,王水通过化学破碎作用使硅粉粒度变小,利于杂质相暴露。两种酸对硅粉的损失率均小于3.5%。     

难冶金精矿烟尘中铁砷碳的脱除对氰化浸金的影响

以难冶金精矿烟尘为原料,研究了氢氧化钠浸出、硫酸浸出以及硫酸与氢氧化钠联合浸出对烟尘中砷、铁和碳脱除及氰化浸金的影响。结果表明:在氢氧化钠浓度为6mol/L时,砷、碳脱除率分别为99.66%和60.63%,金浸出率为58.90%,较直接氰化浸出仅提高4.60%,砷的有效去除不能有效提高金的浸出率。在硫酸质量分数为15%时,铁、砷和碳脱除率分别为33.65%、80.38%和12.59%,金的浸出率为80.40%,与氢氧化钠浸出相比,硫酸浸出解离铁能有效提高金的浸出率。烟尘分别经过质量分数为15%硫酸浸出后氰化浸金,两次2 mol/L氢氧化钠浸出和氰化浸金后,烟尘中铁、砷和碳的总脱除率分别为33.65%、95.63%和79.60%,渣率为80.33%。此时,金的总浸出率为91.90%,氰化渣中金的含量为3.31g/t。与烟尘直接氰化浸出相比金的浸出率提高37.60%。     

Kinetic study on pressure leaching of high iron sphalerite concentrate

The kinetics of pressure leaching high iron sphalerite concentrate was studied.The effects of agitation rate,temperature, oxygen partial pressure,initial acid concentration,particle size,iron content in the concentrate and concentration of Fe2 added into the solution on the leaching rate of zinc were examined.The experiment results indicate that if the agitation rate is greater than 600 r/min,its influence on Zn leaching rate is not substantial.A suitable rise in temperature can facilitate the leaching reaction,and the temperature should be controlled at 140-150℃.The increase trend of Zn leaching rate becomes slow when pressure is greater than 1.2 MPa,so the pressure is controlled at 1.2-1.4 MPa.Under the conditions of this study,Zn leaching rate decreases with a rise in the initial sulfuric acid concentration;and Zn leaching rate increases with a rise of iron content in the concentrate and Fe 2 concentration in the solution.Moreover,the experiment demonstrates that the leaching process follows the surface chemical reaction control kinetic law of“shrinking of unreacted core”.The activation energy for pressure leaching high iron sphalerite concentrate is calculated,and a mathematical model for this pressure leaching is obtained.The model is promising to guide the practical operation of pressure leaching high iron sphalerite concentrate.     

Preparation of Ti-rich material from titanium slag by activation roasting followed by acid leaching

A method of activation roasting followed by acid leaching using titanium slag was introduced to prepare Ti-rich material. The effects of H₃PO₄ dosage, roasting temperature, and roasting time on TiO₂ grade were investigated. A Ti-rich material containing 88.54% TiO₂, 0.42% (CaO+MgO) was obtained when finely ground titanium slag was roasted with 7.5% H₃PO₄ at 1000 °C for 2 h, followed by a two-stage leaching in boiling dilute sulfuric acid for 2 h. The XRD patterns show that the product is titanium dioxide with a rutile structure. Mechanism studies show that structures of anosovite solid solution and silicate minerals are destroyed in the roasting process. As a result, titanium components in titanium slag are transformed into TiO₂ (rutile) while impurities are transformed into acid-soluble phosphate and quartz.     

活化焙烧-酸浸法富集中低品位富钛料

采用还原磨选法制得的富钛料TiO2品位低,不适合直接作生产氯化法钛白和海绵钛的原料.热力学分析表明,采取添加Na2CO3进行焙烧处理后,可破坏富钛料中主要矿物组分黑钛石(Me3O5型固溶体,Me=Ti、Fe、Mg、Mn等)的固溶体结构,使固溶于其中的杂质元素铁和镁等转变为易溶于稀盐酸的物质.结果表明,用稀盐酸浸出活化富钛料可使浸出产物TiO2品位提高到90%以上,比直接用稀盐酸浸取未经活化的富钛料浸出产物TiO2的品位提高了近10%.