选择性还原氨浸从高硅低品位铜钴矿中提取铜、钴 的工艺及其浸出动力学

研究了非洲高硅低品位铜钴矿氨浸体系下的浸出工艺与动力学。首先采用控制变量法,通过单因素实验,系统研究了浸出剂浓度、添加剂用量、反应温度、反应时间及液固比对铜钴浸出率的影响,其次通过X射线衍射(XRD)、电感耦合等离子体(ICP)和扫描电镜-能谱(SEM-EDS)对高硅低品位铜钴矿和浸出渣的物相及化学成分进行了分析对比。最后,对高硅低品位铜钴矿氨浸提取铜的动力学模型进行分析。结果表明,用硫酸铵作为浸取剂,在硫酸铵浓度为300 g/L、还原剂用量为0.7 g、浸出温度为353 K、反应时间为240 min、液固比为6:1的工艺条件下,铜的浸出率可达97.29%,钴的浸出率可达95.18%。高硅低品位铜钴矿氨浸提取铜的活化能、硫酸铵浓度的反应级数及粒度的反应级数分别为76.06 kJ/mol, 1.50和0.25,表明其应遵循界面化学反应控制,并建立了相应的动力学方程。     

南方稀土矿浸出传质的研究

本文从传质的角度，研究了淋侵速度、浸出剂浓度、矿石粘度、原矿稀土品位对南方某稀土矿浸出效果的影响；用色层塔板理论和vanDeemter方程进行分析，找出了然浸速度与浸出效果之间的规律，为高效、低耗、合理地开采南方稀土矿提供了理论依据．     

硫酸-糖蜜酒精废液浸出软锰矿的动力学(英文)

The kinetics of reductive leaching of manganese from low grade pyrolusite in dilute sulfuric acid in the presence of molasses alcohol wastewater was investigated. The shrinking core model was applied to quantify the effects of reaction parameters on leaching rate. The leaching rate increases with reaction temperature, concentrations of H 2 SO 4 and organic matter in molasses alcohol wastewater increase and ore particle size decreases. The leaching process follows the kinetics of a shrinking core model and the apparent activation energy is 57.5 kJ·mol –1 . The experimental results indicate a reaction order of 0.52 for H2SO4 concentration and 0.90 for chemical oxygen demand (COD) of molasses alcohol wastewater. It is concluded that the reductive leaching of pyrolusite with molasses alcohol wastewater is controlled by the diffusion through the ash/inert layer composed of the associated minerals.     

常压下高浓度NaOH浸取铝土矿预脱硅

探讨了常压下高浓度NaOH浸取铝土矿的预脱硅过程中初始NaOH浓度、反应温度、浸出时间和碱矿比等因素对氧化铝、氧化硅浸出率及剩余固相中铝硅比的影响,并得出动力学方程. 结果表明,在50% NaOH溶液、碱矿比2.5及135℃浸出时,反应时间5~20 min内,可使铝土矿铝硅比由7.6提高到12以上,从而满足拜尔法生产氧化铝对铝土矿的品位要求. 用此方法处理铝土矿预脱硅,可以免去物理选矿环节,与其他化学选矿方法相比,具有节能降耗的优点,同时提高铝土矿品位,为中低品位铝土矿的开发利用开辟了一条新途径.     

二氧化硫浸出软锰矿

研究了用纯ＳＯ２浸出软锰矿（含锰量２５％）的动力学,在系统研究了温度、锰矿粒度、ＳＯ２流量、液固比和搅拌强度对锰浸出率影响的基础上,导出了浸出过程的动力学方程：实验结果表明,浸出过程为矿粒表面化学反应所控制,浸出反应可在常温下进行．同时也研究了杂质铁的行为,证实了二价铁离子对锰浸出的催化作用．浸出液经过净化除杂以后,蒸发浓缩制得了饲料级结晶硫酸锰ＭｎＳＯ４·Ｈ２Ｏ．     

Bioleaching of acid‐consuming low‐grade nickel ore with elemental sulfur addition and subsequent acid generation

The bioleaching of a nickel concentrate and an acid‐consuming nickel ore was studied using a co‐culture of Acidithiobacillus ferrooxidans and A. thiooxidans, as well as a thermophilic enrichment culture, VS2. The VS2 was dominated by a Sulfolobus species related to Sulfolobus metallicus. Nickel concentrate was readily solubilized with A. ferrooxidans and the VS2, resulting in nickel yields of 56% and 100%, respectively. Low‐grade nickel ore required 350 g H₂SO₄ kg^?1 ore for maintaining the pH of the leaching solution below 3. To overcome the high acid demand, biological elemental sulfur oxidation was combined with the ore leaching. Leaching of a 2% (wt/vol) nickel ore with a co‐culture of A. thiooxidans and A. ferrooxidans resulted in nickel yield of up to 86% with acid supplementation of 290 g H₂SO₄ kg^?1 ore. When coupled with biological sulfur oxidation, an 86% nickel recovery was achieved with 0.5% (wt/vol) ore concentration without further sulfuric acid addition. The VS2 oxidized sulfur at a rate of 0.063 g L^?1 d^?1 and the simultaneous nickel ore leaching resulted in 100% nickel yield. In summary, the potential of using elemental sulfur addition and subsequent biological acid generation to maintain the low pH during bioleaching of an acid‐consuming nickel ore was demonstrated. Copyright © 2005 Society of Chemical Industry     

我国南方某稀土矿浸出动力学研究

本文研究了南方某稀土矿浸出动力学，考察了浸出反应温度、浸出剂初始浓度及搅拌强度对浸出速率的影响，结果表明，其浸出过程可用收缩未反应芯模型描述。属内扩散控制，导出了浸出动力学方程．为高效抵耗浸出稀土提供了理论依据。     

Thermodynamic and kinetic studies of the MgCl2‐NH4Cl‐NH3‐H2O system for the production of high purity MgO from calcined low‐grade magnesite

To improve the overall sustainability of MgO‐based refractory production, a novel process to produce high purity MgO from calcined low‐grade magnesite in ammonium chloride solution was developed. The process was designed on the basis of the phase equilibria of the NH₄Cl‐MgCl₂‐NH₃‐H₂O system obtained using the Mixed Solvent Electrolyte model embedded in OLI software. The optimum calcination temperature of low‐grade magnesite was determined to be 650°C in terms of the conversion ratio of magnesium and calcium in the leaching experiments. An apparent activation energy of Mg extraction was 30.98 kJ/mol, which is slightly lower than that of Ca leaching. An empirical kinetic model of magnesium extraction was also developed to describe the effects of NH₄Cl concentration, particle size of calcined magnesite, and solid‐to‐liquid ratio on the extent of extraction of magnesium. At leaching time of 10 min, the leachate with high Mg/Ca molar ratio was obtained. Then, MgO with a purity of 99.09% was produced through the decomposition of intermediate 4MgCO₃·Mg(OH)₂·4H₂O. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1933–1946, 2015     

Separation of Metal Impurities from Metallurgical Grade Silicon via CaO-SiO2-CaF2 Slag Treatment Followed by Leaching with Hydrochloric Acid

The separation of metal impurities from metallurgical grade silicon by a combination of slag treatment and acid leaching was investigated. Based on a detailed analysis of microstructure evolution in metallurgical grade silicon, the primary precipitated phase in silicon was tended to form Si-Ca system intermetallics after CaO-SiO₂-CaF₂ slag treatment. Moreover, the extraction efficiency of metal impurities from silicon with slag treatment was higher than that without slag treatment in the leaching process. Some parameters such as acid concentration, temperature, particle size, stirring speed and leaching time were also discussed. The extraction of impurities Fe, Al and Ca increased with increasing acid concentration, leaching time and decreasing particle size. Besides, the leaching kinetics of these metal impurities was confirmed to be controlled by chemical reaction with the application of cracking shrinking model.     

磷矿除氟工艺研究

讨论了磷矿浸取过程中各个因素对脱氟的影响.通过调整工艺参数和采用特殊的反应方式,在磷酸浸取磷矿的过程中控制氟向液相的转移,从而实现与反应同步除氟,生成高质量的湿法磷酸,该磷酸可直接用于生产饲料级磷酸氢钙.     

Bioleaching of copper and other metals from low‐grade oxidized mining ores by Aspergillus niger

A study was initiated to determine the feasibility of using the fungus Aspergillus niger for bioleaching metals from oxide low‐grade ore. Large quantities of the metals are embodied in the low‐grade ores and mining residues that can be recovered. Presently available techniques (pyrometallurgical and hydrometallurgical) are expensive or may have a negative impact on the environment. An oxidized mining ore containing mainly copper (7245 mg kg^?1 residue) was studied. In this study, the fungus A niger produced a variety of organic acids. Addition of small quantities of sulfuric acid enhanced the organic acids, efficiency. Various agricultural wastes were evaluated as substrates and a maximum solubilization of 68% for copper for a medium containing potato peels was achieved. In conclusion, leaching of copper from a mining ore is technically feasible using A niger. Further research must be performed to increase the rate of copper removal. Copyright © 2003 Society of Chemical Industry     

硫铁矿尾矿中铜的硫酸浸出

采用酸浸法提取硫铁矿尾矿中有价元素铜。研究了硫酸质量分数、浸出时间、矿石粒度、矿石投加量、浸出温度和转速对铜浸出的影响。在单因素实验的基础上,采用正交实验法对浸出工艺条件进行优化。采用扫描电镜(SEM)和能谱仪(EDS)对酸浸前后尾矿表面的微观形貌进行了分析,初步探讨了酸浸反应后期抑制Cu浸出的影响机制。结果表明,酸浸铜的最佳工艺条件为：硫酸质量分数30%、浸出时间6 h、矿石粒度150 ?m、矿石用量5 g、浸出温度108℃、转速440 r/min,在此条件下,铜的浸出率为50.68%。扫描电镜和能谱分析表明,浸出残渣表面被微米级的二氧化硅颗粒紧密包裹,钝化了后期的浸出反应。     

Kinetics of Rare Earth Leaching from a Mangnese‐Removed Weathered Rare‐Earth Mud in Hydrochloric Acid Solutions

Abstract

The kinetics of leaching rare earth from a manganese‐removed weathered rare earth mud (MRW‐RE mud) in hydrochloric acid solutions was investigated in this study as a function of temperature, particle size, and HCl concentration. It was found that the leaching process can be described by a shrinking‐core model, with the apparent activation energy about 10.17 kJ/M. When the concentration of hydrochloric acid was below 4M, the RE leaching rate was controlled by the diffusion of reactants and leaching products through a porous ore. However, when HCl concentration was higher than 4 M, the leaching process was limited by both chemical reaction and reagent diffusion. Based on the experimental results, an empirical equation relating the rate constant of rare earth leaching to the particle size and leaching temperature was established for the purpose of process deign.     

攀西高锰稀土矿泥盐酸浸取稀土动力学

采用盐酸浸取攀西高锰稀土矿泥,考察了浸取反应温度、矿石粒度及盐酸浓度对浸取速率的影响. 结果表明,当盐酸浓度为2 mol/L时,浸取过程符合缩核模型,表观活化能为9.59 kJ/mol,属内扩散控制,宏观动力学方程为：K=(4.15?10–4)/r02 · exp(9590/RT); 当盐酸浓度大于2 mol/L时,矿石中的锰被大量浸出,其结构被破坏,浸取过程为混合控制.     

浮选-浸出处理土耳其氧化铜矿工艺

采用浮选-浸出处理含铜2.09%的土耳其氧化铜矿,该矿有用矿物主要为孔雀石、蓝铜矿、硅孔雀石及少量硫化铜,铜矿物氧化率高,嵌布粒度较细,矿石易泥化. 通过浮选回收易浮的硫化铜和部分孔雀石和少量蓝铜矿,获得品位25.04%、回收率为57.25%的浮选铜精矿,浮选尾矿中的蓝铜矿和硅孔雀石采用硫酸浸出,含铜量由0.94%降至0.05%,浸出率达94.68%,实现了目的矿物的有效回收.     

Leaching of Silver from Boorchi Ag-Pb Ore in Mongolia with

A hydrometallurgical process to extract silver from the silver-lead ore in Boorchi, Mongolia by using thiourea leaching solution is studied in this work. Through the observation of optical and scanning electron microscopes, and energy spectral analysis, it is determined that 5 kinds of silver minerals exist in the ore, including argentite, Ag-tetrahedrite, Ag-Zn-Sb-tetrahedrite, freibergite and acanthite. The experimental results of direct thiourea leaching of the ore show that 56%~60% of silver is leached. The main reason for the low leaching rate is due to silver minerals enveloped in galena and other minerals, even though the ore is ground to the particle size of 75 mm. When the ore is pretreated with ammonium carbonate solution under oxidation, the experimental results of thiourea leaching show that the leaching rate of silver increases to near 75% with the pretreatment. Based on the leaching experiments, a principle hydrometallurgical technological route to extract silver from the Ag-Pb ore is proposed.     

酸法浸铀与生物浸铀浸泡试验的对比研究

近年来,生物技术在我国低品位砂岩型铀矿及老采区残留难浸铀矿的开发研究已开始起步。凭借生物浸铀具有的氧化性强、浸出液铀浓度及浸出率高等特点而成为开采该类铀矿的重要手段。文章以新疆某砂岩型难浸铀矿石浸泡浸出试验为例,系统开展了不同酸度条件下酸法浸出及不同Fe3+浓度条件下细菌浸铀试验。试验结果表明,生物浸铀在浸出液平均铀浓度、铀浸出率及浸出量等方面均高于酸法试验结果。     

混合铜矿酸浸动力学实验与计算

以混酸(H2SO4+HNO3)为浸取剂研究了混合铜矿浸出动力学,详细考查了温度、粒度以及浸取剂的浓度对反应速率的影响.结果表明:浸出过程的控制步骤为化学反应过程,浸出过程的表观活化能为45.73 kJ/ml,根据研究结果建立了反应的动力学方程.     

Investigation of selective leaching and kinetics of copper from malachite ore in aqueous perchloric acid solutions

In this study, the leaching kinetics of malachite in perchloric acid solutions was investigated. The dissolution behaviors of copper, zinc, and iron in the ore matrix were determined at different acid concentrations and reaction temperatures. It was observed that the concentration of perchloric acid had a major effect on the dissolution of copper, zinc, and iron. It was determined that the effect of temperature on the dissolution of these species was not as significant as concentration impact. The results obtained shown that copper in the ore matrix was completely leached while zinc and iron were partially dissolved in perchloric acid solutions. In addition, the effects of the acid concentration, reaction temperature, stirring speed, particle size, and solid-to-liquid ratio on the leaching of malachite were researched. In these experiments, it was observed that the leaching rate of copper increased with increasing solution concentration, stirring speed, and reaction temperature, and with decreasing solid-to-liquid ratio and particle size. A kinetic analysis was performed, and it was found that the rate of leaching reaction obeyed the mixed kinetic control model in the unsteady state. The activation energy of the leaching process was calculated to be 34.69 kJ/mol.     

褐铁型高锰红土矿微波预处理-酸浸提取镍钴

以褐铁型高锰红土矿为研究对象,采用微波预处理-酸浸工艺提取Ni、Co。对矿样物相组成及Ni、Co、Fe、Mn等主要元素赋存状态进行X射线衍射（XRD）和电子探针（EPMA）表征,研究常压条件下硫酸浓度、浸出时间、浸出温度等因素对微波预处理矿样中Ni、Co浸出效果的影响。结果表明：矿样中镍钴品位较高但物相结构复杂,Ni主要与Mn以NiMn₃O₇?3H₂O形式赋存,Co伴生于针铁矿和碱式氧化锰中;在最优浸出条件下,即硫酸浓度300g/L、浸出时间5h、浸出温度90℃、液固比6∶1（以mL/g计）、搅拌速度280r/min,Ni、Co浸出率分别达到95.4%和97.1%,与相同浸出条件下未经微波处理的矿样相比,Ni、Co浸出率分别提高了69.4%和70.1%,实现镍钴的高效浸出;对比微波处理前后矿样XRD图谱,发现微波作用下矿物中Ni、Fe、Mn等物相结构出现明显转变,利于Ni、Co酸浸反应。