变频刚柔搅拌反应器强化锰矿浸出及除铁过程

传统锰矿浸出过程采用刚性搅拌反应器,存在矿粉悬浮效果差、锰矿利用率低、浸出液中铁含量较高的问题。本文采用变频刚柔搅拌反应器强化锰矿的浸出过程,实验对比分析了不同桨叶类型、搅拌桨操作方式和变频间隔时间对锰矿浸出效果、搅拌功耗的影响,同时分析了变频刚柔桨耦合空气射流在除铁过程的效果。结果表明,变频刚柔桨通过柔性钢丝绳对流体的扰动作用以及变频操作对稳定流场的更新作用,提高浸出液中Mn^(2+)含量;同时,由于体系变频操作的频率变化,降低了搅拌功耗。相同功耗下,刚柔组合桨体系浸出液中Mn^(2+)含量相对于刚性桨体系提高了10.8%;相同转速下,刚柔组合桨体系在浸出过程的功率消耗相对于刚性桨体系提升了25.4%。变频间隔时间为30min时,变频刚柔桨体系浸出液中Mn^(2+)含量相对于刚柔组合桨体系降低了2.17%,但相应搅拌功耗降低了28%。调节体系pH后,采用变频刚柔桨耦合偏心空气射流操作,可有效降低浸出液中Fe^(2+)含量。在通气60min后,浸出液中Fe^(2+)浓度已至较低水平,低于0.15mg/L。

刚柔组合桨搅拌反应器强化锰矿浸出的中试试验研究

锰矿浸出搅拌反应器大多为刚性搅拌桨,其卷吸力较小,轴向输送能力较弱,容易形成对称性流场,固液两相悬浮程度较低,浸出时间较长、效率较低。提出了一种刚柔组合强化锰矿浸出的新方法,对比研究了刚性桨和刚柔组合对浸出时间及搅拌电耗的影响。结果表明:与刚性桨相比,刚柔组合桨能够缩短浸出时间近1h,增强了设备的生产能力。

氧化亚铁硫杆菌对低品位锰矿浸出的试验研究

以软性塑料纤维为填料而构建了氧化亚铁硫杆菌的固定化生物反应器,经低pH值和高浓度Fe2+长期驯化后,在初始pH=1.6、Fe2+浓度25 g/L、温度30℃、进气量0.45 m3/h、循环液体流量0.85 L/h的条件下,固定化细胞只需3 d,Fe2+氧化率可达82.27%,其Fe2+平均氧化速率为0.29 g/(L.h);固定化细胞达到80%以上的氧化率所需时间比游离细胞提前了4 d,其平均氧化速率是游离细胞的2.5倍。对低品位菱锰矿的浸出,在pH为1.7、温度60℃、Fe3+浓度20 g/L、矿浆浓度10%条件下,搅拌3.5 h可达将近85%的浸出率。

锰矿浸出硫酸锰溶液的净化除杂工艺研究

硫酸锰作为基础锰盐,是生产电解锰产品、锰氧化物以及其他锰盐的重要中间物料,应用非常广泛。硫酸锰主要由锰矿通过硫酸浸取后再经除杂而成,但是因为其溶液中所含杂质成分复杂并且有些杂质很难去除使其使用受到限制。文章针对工业硫酸锰的深度净化工艺进行介绍,并总结了几种除杂的方法,最后对高纯硫酸锰的应用领域进行了分析。

Reductive leaching of manganese oxide ores using waste tea as reductant in sulfuric acid solution

Manganese oxide ores from Gabon and Xiangxi were leached with waste tea as reductant in dilute sulfuric acid solution. The effects of waste tea dosage, concentration of sulfuric acid, liquid-to-solid ratio, leaching temperature and reaction time on leaching process were explored. The leaching efficiency of Gabonese manganese oxide ore reached almost 100% under the optimal condition which was determined as follows： manganese oxide ore to waste tea mass ratio of 10：1, sulfuric acid concentration of 2.5 molFL, liquid-to-solid ratio of 7.5：1, leaching temperature of 368 K, time of 8 h. The leaching efficiency of Xiangxi manganese oxide ore reached 99.8% under the optimal condition which was determined as follows： manganese oxide ore to waste tea mass ratio of 10：1, sulfuric acid concentration of 1.7 mol/L, liquid-to-solid ratio of 7.5：1, leaching temperature of 368 K, time of 8 h. The leaching process followed the internal diffusion controlled kinetic model, and the apparent activation energies of Gabonese manganese oxide ore and Xiangxi manganese oxide ore were calculated to be 38.2 kJ/mol and 20.4 kJ/mol, respectively. The morphological changes and mineralogical forms of the ore before and after the chemical treatment were discussed with the support of XRD analysis and SEM analysis.

Manganese extraction by reduction-acid leaching from low-grade manganese oxide ores using CaS as reductant

The extraction of manganese from low-grade manganese oxide ores using Ca S derived from Ca SO4 as reductant was investigated. The effects of mass ratio of Ca S to ore, reduction temperature, reduction time, liquid to solid ratio（L/S ratio）, stirring speed, leaching temperature, leaching time and H2SO4 concentration on the leaching rates of Mn and Fe during the reduction–acid leaching process were discussed. The leaching rates of 96.47% for Mn and 19.24% for Fe were obtained under the optimized conditions of mass ratio of Ca S to manganese oxide ore 1：6.7, L/S ratio 5：1, stirring speed 300 r/min, reduction temperature of 95 °C for 2.0 h in the reduction process and leaching stirring speed of 200 r/min, H2SO4 concentration of 1.5 mol/L, leaching temperature of 80 °C for 5 min in the leaching process. In addition, this process can be employed in the recovery of manganese from various manganese oxide ores, and Mn leaching rate above 95% is obtained.

A primary study of simultaneous leaching of silver containing manganese ore and a sphalerite concentrate

It is demonstrated that a low grade, silver containing manganese deposit can be exploited by reaction with a ZnS concentrate. In the process, Mn(IV) is reduced to Mn(II) and the ZnS converted to ZnSO4. In the process, Mn and Zn are solubilized. By studying the effects of quantity of reducing agent and sulfuric acid added and of time, temperature and liquid-to-solid ratio on the leaching process, the optimum technological conditions have been achieved under which the amount of manganese leached was 98 %. The silver can be removed from remaining solids by adding ammonia liquor. Then by adding hydrazine hydrate, sponge silver with purity up to 99 % can be obtained with a recovery of 87 %.

Manganese extraction from high-iron-content manganese oxide ores by selective reduction roasting-acid leaching process using black charcoal as reductant

Reduction roasting-acid leaching process was utilized to process high-iron-content manganese oxide ore using black charcoal as reductant. The results indicate that, compared with the traditional reductant of anthracite, higher manganese extraction efficiency is achieved at lower roasting temperature and shorter residence time. The effects of roasting parameters on the leaching efficiency of Mn and Fe were studied, and the optimal parameters are determined as follows: roasting temperature is 650 °C, residence time is 40 min, and black charcoal dosage is 10%(mass fraction). Under these conditions, the leaching efficiency of Mn reaches 82.37% while that of Fe is controlled below 7%. XRD results show that a majority of MnO2 and Fe2O3 in the raw ore are reduced to MnO and Fe3O4, respectively.

Simultaneous electrogenerative leaching of chalcopyrite concentrate and MnO_2

In order to enhance the electrogenerative leaching rate of chalcopyrite concentrate reasonably, the principle of generative process was applied to simultaneous leaching of chalcopyrite concentrate and MnO2. The results show that Cu^2＋ and Mn^2＋ in addition to electrical energy could be acquired in the simultaneous electrogenerative leaching process. The leaching cell has the open circuit potential of about 1.0 V and gains quantity of electricity of about 700 C. The optimum leaching rates of Cu^2＋ and Mn^2＋ are 23.10% and 22.1%, respectively after electrogenera- tive leaching for about 10 h under the present conditions.

Kinetics of reductive leaching of manganese oxide ore using cellulose as reductant

The kinetics of reductive leaching of manganese from a low-grade manganese oxide ore were studied using cellulose as reductant in dilute sulfuric acid medium.It was found that when the stirring speed was higher than 200 r/min,the effect of gas film diffusion on manganese extraction efficiency could be neglected,and the kinetic behavior was investigated under the condition of elimination of external diffusion influence on the leaching process.Effects of leaching temperature,mass ratio of cellulose and ore,and the sulfuric acid concentration on manganese extraction efficiency were discussed.The kinetic data were analyzed based on the shrinking core model,which indicated that the leaching process was dominated by both ash layer diffusion and chemical reaction at the initial stage,with the progress of leaching reaction,the rate-controlling step switched to the ash layer diffusion.It was also concluded that the sulfuric acid concentration had the most significant influence on the leaching rate,the reaction orders with respect to the sulfuric acid concentration were 2.102 in the first 60 min,and 3.642 in the later 90 min,while the reaction orders for mass ratio of cellulose and ore were 0.660 and 0.724,respectively.An Arrhenius relationship was used to relate the temperature to the rate of leaching,from which apparent activation energies were calculated to be 46.487 kJ/mol and 62.290 kJ/mol at the two stages,respectively.Finally,the overall leaching rate equations for the manganese dissolution reaction with cellulose in sulphuric acid solution were developed.The morphological changes and mineralogical forms of the ore before and after the chemical treatment were discussed with the support of SEM and XRD analyses.