中温及嗜热菌对不同成因黄铜矿浸出行为的影响

以斑岩型黄铜矿和矽卡岩型黄铜矿为研究对象,考察了嗜酸氧化亚铁微螺菌(L f)和嗜热硫氧化硫化杆菌(S t)对不同成因黄铜矿浸出行为的影响。结果表明,在2种不同细菌浸出体系中矽卡岩型黄铜矿均表现出比斑岩型黄铜矿浸出率高;S t浸出2种不同成因黄铜矿的效率均比L f的好。通过对不同浸矿时间黄铜矿浸出渣的XRD检测并结合黄铜矿浸出过程反应步骤的分析表明,2种细菌浸出不同成因黄铜矿的机制相同,细菌的代谢途径及反应温度是影响同类成因黄铜矿浸出率和代谢产物差异的主要原因。S t作用下浸出后期黄铜矿表面有黄钾铁矾生成,而L f浸出体系黄铜矿表面主要是S的不断积累。同种浸矿菌种浸出不同成因黄铜矿时,矽卡岩型黄铜矿在浸出第15 d有S生成,斑岩型黄铜矿在S t浸出体系S生成的时间更晚,在L f浸出体系S的生成量则更少,推测矿物性质是引起其差异的主要原因。     

低品位铜铅多金属硫化矿浮选分离试验研究

对四川汉源地区某高硫型低品位铜铅多金属硫化矿进行了浮选分离试验研究。采用混合浮选得到铜铅混合精矿, 铜铅混合精矿经铜铅分离, 分别得到铜品位18.72%、含铅0.66%、含硫22.03%、铜回收率87.12%的铜精矿和铅品位59.66%、含铜0.58%、含硫14.89%、铅回收率85.72%的铅精矿; 铜铅混合浮选尾矿再浮选可进一步得到硫品位48.73%、含铜0.05%、含铅0.22%、硫回收率87.93%的硫精矿, 实现了该低品位多金属硫化矿中有价金属的综合回收。     

假乙内酰硫脲酸在铜-钼浮选分离中的抑制性能(英文)

将合成的假乙内酰硫脲酸(PGA)用作铜-钼分离抑制剂。该药剂闭路实验结果表明:假乙内酰硫脲酸在较小的用量下对黄铜矿有较强的抑制作用,经一次粗选、一次扫选、两次精选,可获得Mo品位大于26%、回收率大于89%的浮选指标,而用Na2S做抑制剂时钼的回收率下降了2%。药剂吸附量测试结果表明,PGA与丁基黄药在矿物表面发生竞争吸附,PGA在黄铜矿表面上的吸附量远大于在辉钼矿表面的。红外光谱分析表明,PGA在黄铜矿表面是化学吸附,而在辉钼矿表面属于物理吸附。前线轨道计算结果表明,在PAG分子中,硫原子是反应活性的中心。利用矿物、丁黄药及PGA的费米能级能量大小可以从电化学作用角来度解释PGA的抑制机理。     

嗜酸兼性异养菌Acidiphilium sp.DX1-1的分离、特征及其浸矿行为(英文)

研究了一株源自江西德兴铜矿矿区的中温嗜酸兼性异养菌Acidiphilium sp.DX1-1的分离、鉴定、特征及其浸矿行为。菌株Acidiphilium sp.DX1-1为短杆状革兰氏阴性菌,最适合的生长温度为30℃,最适合的生长pH约为3.5。该菌株具有广泛的底物利用特性,可以利用有机物进行异养生长并在细胞内积累聚羟基丁酸酯,也可以利用单质硫、三价铁等无机物进行自养生长。系统发育分析表明DX1-1属于Acidiphilium属,与Acidiphilium cryptum and Acidiphilium multivorum的同源性大于99%。在铁闪锌矿生物浸出过程中,Acidiphilium sp.DX1-1表现出极强的浸矿能力,其作用不仅仅是之前报道的作为其他自养嗜酸浸矿细菌的辅助者。在初始pH3.5时,DX1-1能够在一个月内单独地浸出铁闪锌矿中40%的锌。该浸出率高于它与A.ferrooxidans混合以及A.ferrooxidans单独浸出铁闪锌矿(初始pH均为2.0)的浸出率。     

INVESTIGATIONS ON THE MECHANISMS OF SULFURIC ACID LEACHING OF CHALCOPYRITE IN THE PRESENCE OF HYDROGEN PEROXIDE

The sulfuric acid leaching behavior of chalcopyrite in the presence of hydrogen peroxide was studied at 25°C using electrochemical techniques. The effects of increasing the concentrations of hydrogen peroxide up to 3 M on chalcopyrite dissolution were carried out in shake flasks prior to electrochemical studies. Electrochemical investigations were carried out on particulates electrode made from powdered chalcopyrite samples using potentiodynamic and chronoamperometric techniques. Increasing the concentrations of hydrogen peroxide considerably accelerated the leaching of both copper and iron. Morphologies of the leached residues examined by scanning electron microscope revealed similar products on the surfaces of chalcopyrite for all the conditions of leaching. A reduction in sizes of the particles, which increase the porosity of the residues, was observed at increasing concentrations of hydrogen peroxide. X-ray analysis revealed the presence of elemental sulfur in the solid residues with increasing crystallinity as the concentration of hydrogen peroxide increased. Polarization curves showed that hydrogen peroxide raised the dissolution potentials of chalcopyrite toward more noble values. The addition of hydrogen peroxide also drastically increased the dissolution currents, current densities, and dissolution rates, and reduced the passivity of chalcopyrite. Increasing the concentration of hydrogen peroxide and dissolution potential resulted in a characteristic current increase/decrease behavior of the ore. Higher dissolutions obtained at increased concentrations of hydrogen peroxide were attributed to the porous agglomerate nature of the leached residues that did not passivate the chalcopyrite surface, but aided further dissolution through electron transfer.     

磁选在复杂难选矿浮选流程中的合理应用

对于磁性和可浮性都较好的矿物,用单一的选矿方法往往不能有效分离,将磁选和浮选有机的结合,才能获得较好的分离效果。本文以应用实例结合理论研究对磁选在复杂难选矿浮选流程中的合理应用加以陈述。     

Structural tuning of wide‐gap chalcopyrite CuGaSe2 thin films and highly efficient solar cells: differences from narrow‐gap Cu(In,Ga)Se2

Simultaneous realization of high values of open circuit voltage (V_oc), fill factor (FF), and energy conversion efficiency (η) in wide‐gap CuGaSe₂ (CGS) solar cells has long been one of the most challenging issues in the realm of chalcopyrite photovoltaics. In this communication, structural tuning of CGS thin films by means of controlling the amount of Se flux used during CGS film growth and improvements in solar cell performance (V_oc > 0.9 V, FF > 0.7, and η > 10%) are demonstrated. Systematic variations in CGS film properties with the Se flux and correlation with device properties are shown. The unique CGS thin‐film growth kinetics, which are different from narrow‐gap Cu(In,Ga)Se₂, are also presented and discussed. This development of double digit efficiency for CGS solar cells opens a new frontier for the broad application of a new class of chalcopyrite‐based devices. Copyright © 2014 John Wiley & Sons, Ltd.     

Analysis of current-voltage characteristics of Al/p-ZnGa2Se4/n-Si nanocrystalline heterojunction diode

The polycrystalline ZnGa₂Se₄ thin film was prepared by thermal evaporation technique on n-Si wafer followed by annealing at 700 K. Then, the Al/p- ZnGa₂Se₄/n-Si/Al heterojunction diode was fabricated. XRD pattern shows that the annealed ZnGa₂Se₄ film has a polycrystalline structure. AFM images indicate that the ZnGa₂Se₄ film is formed of nanoparticles. The dark current-voltage characteristics of the heterojunction diode at various temperatures have been investigated to determine the electrical parameters and conduction mechanism. The Al/p-ZnGa₂Se₄/n-Si/Al diode shows a rectification ratio of 2.644 × 10² at ±2 V at room temperature. It was found that at forward bias voltages ≤0.5 V, the conduction mechanism of the diode is controlled by the thermionic emission mechanism, while at bias voltages higher than 0.5 V, it is controlled by the space charge limited current mechanism. The series resistance R_s, the ideality factor n and the barrier height ?_b values of the diode are determined by performing different plots from the forward current-voltage characteristics. The reverse current mechanism of the diode is controlled by the carrier generation-recombination process in the depletion region. The obtained results show that the Al/p-ZnGa₂Se₄/n-Si/Al heterojunction is a good candidate for the electronic device applications.     

Effect of temperature,oxygen partial pressure and calcium lignosulphonate on chalcopyrite dissolution in sulfuric acid solution

The pressure leaching mechanism of chalcopyrite was studied by both leaching tests and in-situ electrochemical measurements. The effects of leaching temperature, oxygen partial pressure, and calcium lignosulphonate, on copper extraction and iron extraction of chalcopyrite pressure leaching were investigated. The leaching rate is accelerated by increasing the leaching temperature from 120 to 150 °C and increasing oxygen partial pressure to 0.7 MPa. The release of iron is faster than that of copper due to the formation of iron-depleted sulfides. Under the optimal leaching conditions without calcium lignosulphonate, the copper and iron extraction rates are 79% and 81%, respectively. The leaching process is mixedly controlled by surface reaction and product layer diffusion with an activation energy of 36.61 kJ/mol. Calcium lignosulphonate can effectively remove the sulfur passive layer, and the activation energy is 45.59 kJ/mol, suggesting that the leaching process with calcium lignosulphonate is controlled by surface chemical reactions. Elemental sulfur is the main leaching product, which is mixed with iron-depleted sulfides and leads to the passivation of chalcopyrite. Electrochemical studies suggest that increasing the oxygen partial pressure leads to increasing the cathodic reaction rate and weakening the passivation of chalcopyrite.     

黄铜矿浮选工艺及捕收剂研究进展

阐述了黄铜矿的矿物特征和浮选特性,对黄铜矿的浮选工艺、新型浮选捕收剂以及浮选捕收剂的组合应用进行了概述,认为研制出捕收性能强、选择性好的新型捕收剂是黄铜矿浮选捕收剂的发展方向。