赣南荡坪复合硫化矿的三氯化铁直接浸出试验研究

研究了用三氯化铁直接浸出赣南荡坪铜铅锌复合硫化矿的工艺条件。试验结果表明：在温度１０５℃、固液比４：１、Ｆｅ＾３＋浓度１９２ｇ／ｌ的条件下浸出３小时，铜、铅、锌浸出率分别高达９９．５％、９８．６％和９９．６％；９６％的硫呈元素硫或黄铁矿形态富集于渣中。     

Biofilm forming and leaching mechanism during bioleaching chalcopyrite by Thiobacillus ferrooxidans

The mechanism of attachment and leaching of thiobacillus ferrooxidans (T. f. ) on chalcopyrite were studied. The shaking flasks with bacteria were observed by SEM. The process of T. f attached to the surface of the mineral sample and the biofilm forming were described. The promoting role of the biofilm for bioleaching was discussed. The existence of Fe^2 in the exopolysaccharide layer of T. f was demonstrated by EM(electronic microscope)cell-chemistry analysis. These results show that under the proper growth condition of bacteria, bioleaching of chalcopyrite results in the formation of complete biofilm after 2 - 3 weeks. There are iron ions in the outer layer polymer of T. f. , which provides the micro-environment for themselves, and can guaruntee the energy needed for the bacteria growth in the blofilm. At the same time, Fe^3 ions produced oxidize sulfide which brings about the increase of both growth rate of the bacterial and leaching rate of sulfide minerals.     

一种浮选药剂新品种——巯基乙酸钠

介绍了新研制的一种浮选药剂新品种——巯基乙酸钠。实验室和工业试验结果表明,这种浮选药剂毒性低,用量少,完全可以取代剧毒的氰化物而成为黄铜矿的新型抑制剂。其用量仅为传统氰化物用量的一半。用巯基乙酸钠的浮选废水不用处理可供养鱼。红外光谱与俄歇能谱分析揭示,巯基乙酸钠可化学吸附在黄铜矿表面上,且呈多层吸附。吸附后的黄铜矿处于被抑制状态。     

常温酸性条件下黄铜矿的电化学行为

在温度为25℃及pH=2的条件下，通过循环伏安法和恒电位I-t曲线研究了黄铜矿特殊的电化学分解行为。通过循环伏安曲线发现：电位在400-800mV（vs SHE）范围内，黄铜矿电极表面的阳极氧化反应电流很小0主要是由于生成的中间产物很难被进一步氧化分解，从而产生了钝化；当电位小于-400mV（vs SHE）时，黄铜矿阴极还原反应电流较大，晶格中的Fe^3＋能较快地溶解出来，产生的中间产物（铜的硫化物）在氧化电位下发生较强的阳极氧化分解反应，但是随后反应进一步被钝化。黄铜矿的阴极还原反应较强烈，且对黄铜矿氧化浸出具有重要意义。此外，恒电位I-t曲线也证实了以上结论。     

Mechanism of bioleaching chalcopyrite by Acidithiobacillus ferrooxidans in agar-simulated extracellular polymeric substances media

The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can release H+ and concentrate Fe3+; Fe2+ is movable between agar-simulated EPS phase and bulk solution phase, but it is difficult for Fe3+ to move due to its hydroxylation and EPS complex action; A. ferrooxidans first prefer Fe2+ as energy to metabolize compared with chalcopyrite, and a suitable ...     

Influences of collector DLZ on chalcopyrite and pyrite flotation

The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments, zeta potential measurements and infrared spectrum analysis. Flotation test results indicate that DLZ is the selective collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems, while the recovery of pyrite is less than 10%. When using CaO as pH regulator, at pH=7-11, the floatability of pyrite is depressed and the recovery is less than 5%. Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ, confirming that collector DLZ shows selectivity to chalcopyrite and pyrite. And FT1R results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.     

Kinetics of chemical leaching of chalcopyrite from low grade copper ore: behavior of different size fractions

The kinetics of the chemical leaching of copper from low grade ore in ferric sulfate media was investigated using the constrained least square optimization technique.The experiments were carried out for different particle sizes in both the reactor and column at constant oxidation-reduction potential (Eh),pH values,and temperature.The main copper mineral was chalcopyrite.About 40％ of Cu recovery is obtained after 7 d of reactor leaching at 85℃ using -0.5 mm size fraction,while the same recovery is obtained at 75℃ after 24 d.Also,about 23％ of Cu recovery is obtained after 60 d of column leaching for +4-8 mm size fraction whereas the Cu recovery is as low as about 15％ for +8-12.7 and +12.7-25 mm size fractions.A 4-stage model for chalcopyrite dissolution was used to explain the observed dissolution behaviors.The results show that thick over-layers of sulphur components cause the parabolic behavior of chalcopyrite dissolution and the precipitation of Fe3+ plays the main role in chalcopyrite passivation.In the case of coarse particles,transformation from one stage to another takes a longer time,thus only two stages including the initial reaction on fresh surfaces and S0 deposition are observed.     

脂类捕收剂DLZ对黄铜矿和黄铁矿浮选的选择性作用

通过浮选实验、吸附量和红外光谱测定,考察了捕收剂DLZ对黄铜矿和黄铁矿浮选性能的影响及作用机理.结果表明:DLZ在pH=2.7～12.05时对黄铜矿的捕收能力强,最大回收率95.7%,而对黄铁矿的捕收能力弱,且PH=6.9～12.05时其回收率小于10%.用CaO作pH调整剂时,在pH=7～11时黄铜矿的回收率与用NaOH调PH相差不大,但黄铁矿可浮性被抑制,回收率低于5%.DLZ在黄铜矿上的吸附量比在黄铁矿上的大,特别是强碱条件下;其吸附量随用量的增加而增大.DLZ与矿物作用的红外光谱分析表明:黄铜矿与DLZ作用后出现了DLZ的相关特征吸收峰,而黄铁矿与DLZ以及Cu~(2+)作用前后的红外光谱曲线基本没有变化,可见DLZ在黄铜矿表面的吸附属于化学吸附,在黄铁矿表面的吸附属于物理吸附.     

Occurrence mechanism of silicate and aluminosilicate minerals in Sarcheshmeh copper flotation concentrate

The Sarcheshmeh copper flotation circuit is producing 5×104 t copper concentrate per month with an averaging grade of 28% Cu in rougher,cleaner and recleaner stages.In recent years,with the increase in the open pit depth,the content of aluminosilicate minerals increased in plant feed and subsequently in flotation concentrate.It can motivate some problems,such as unwanted consumption of reagents,decreasing of the copper concentrate grade,increasing of Al2O3 and SiO2 in the copper concentrate,and needing a hi...