高、低温条件下黄铁矿、黄铜矿和闪锌矿的生物浸出机理

Y .Rodr姫ｇｕｅｚ等在《Ｈｙｄｒｏｍｅｔａｌｌｕｒｇｙ》第 71卷上连续发表 3篇文章 ,分别介绍了黄铁矿、黄铜矿和闪锌矿在高、低温条件下的生物浸出机理。研究结果表明 ,黄铁矿的生物浸出明显受溶解铁的氧化状态的影响。Fe2 和Fe3 的比率控制着过程中的氧化反应的相对速率。另外 ,黄铁矿的溶解也受Fe2 、Fe3 在矿物表面的竞争吸附控制。矿物表面Fe2 的积累形成了扩散阻挡层 ,抑制了Fe3 的腐蚀作用 ,使得本体溶液中Fe3 浓度增高 ,在浓度为 16 g/L时 ,抑制了微生物的氧化能力。细胞附着到矿物表面的速率与矿物溶解速率…     

生物浸出低品位镍铜硫化矿

阐述了氧化亚铁硫杆菌 (TF5)和氧化硫硫杆菌 (TT)浸出金川低品位镍铜硫化矿的机理、过程动力学、工艺条件和反应工程。研究表明 ,含镍磁黄铁矿的细菌浸出以细菌氧化生成的Fe3 +的作用为主 ,浸出速率受表面反应控制 ;镍黄铁矿的细菌浸出以矿物表面吸附菌的作用为主。细菌对Mg2 +离子的耐受浓度因驯化而提高 ,极限浓度可达 15～ 2 0g/L。低品位镍铜矿的细菌浸出过程中 ,pH控制、细菌的初始接种量、矿浆浓度及TF和TT的混合比是影响镍、铜、钴等有价金属元素浸出速率和最终浸出率的主要因素。优化条件下气升式和搅拌式反应器中试验表明 ,优化条件下 ,在生物浸出低品位镍铜硫化矿 ,镍浸出率可达到 92 %～ 94 % ,铜达 4 8%～ 50 % ,钴达 88%～ 91%。     

低品位铜矿石的银催化生物浸出

J．A．Munnoz等研究了低品位铜矿石的银催化生物浸出。在摇瓶试验中，研究了接种、矿浆密度、[Ag]、培养基、pH及[Fe^3＋]对低品位硫化铜矿石银催化生物浸出的影响。矿石中的主要矿物是黄铜矿。预试验结果表明，其他离子（Sb，Bi，Co，Mn，Ni及Sn）的加入不会加快铜的溶解，相反，嗜温微生物的接种和银的加入对铜的浸出有明显影响。     

含砷复杂硫化镍矿低温生物浸出行为研究

针对某硫化镍矿含砷、品位低、多金属矿混杂、地处寒冷地区等特点,为了保持较高的浸出率,低温驯化后浸矿细菌需要具有较常温细菌更高的氧化速率。基于热力学基本公式,推导了电位(E)与温度(T)的函数关系式,并使用HSC软件绘制15℃下Fe-As-Ni-S-H2O体系和Fe-Cu-S-H2O体系的E-p H图,对含砷复杂硫化镍矿进行了热力学分析。在综合了两个体系的E-p H图后,排列出在温度为15℃的微生物浸出体系中矿物随电位升高的溶解顺序,同时对比了不同反应物活度对矿物溶解的影响。在低温(15℃)下的微生物浸出过程中,研究矿浆浓度、细菌接种量、初始p H值对含砷复杂硫化镍矿中镍、铜、砷浸出率的影响。经过14 d的浸出,在优化的条件下,镍的浸出率可达65%以上,与此同时钴的浸出率可达70%以上,铜的浸出率大于50%。浸出过程中镍钴铜砷的溶解规律符合之前基于E-p H图的热力学分析结果,砷黄铁矿被优先浸出。经42 d的浸出,镍钴的浸出率大于70%,铜的浸出率则可以达到60%以上。     

Fe3+对低品位原生硫化铜矿细菌浸出影响的研究

为了提高永平低品位原生硫化铜矿细菌浸出的效率,通过摇瓶试验,研究了Fe3 对低品位原生硫化铜矿细菌浸出的影响.研究表明:在细菌浸出的初始阶段,添加Fe3 可以提高浸出液的氧化还原电位.但不会提高铜的浸出速度和浸出率,相反会抑制铜的浸出,而且随着添加的初始Fe3 浓度增加,抑制作用进一步加强.     

Fe3 对低品位原生硫化铜矿细菌浸出影响的研究

为了提高永平低品位原生硫化铜矿细菌浸出的效率,通过摇瓶试验,研究了Fe3 对低品位原生硫化铜矿细菌浸出的影响.研究表明在细菌浸出的初始阶段,添加Fe3 可以提高浸出液的氧化还原电位.但不会提高铜的浸出速度和浸出率,相反会抑制铜的浸出,而且随着添加的初始Fe3 浓度增加,抑制作用进一步加强.     

高砷硫低镍钴硫化矿浸矿菌的选育与生物浸出研究

采用化学分析和偏光矿相显微镜矿物鉴定方法研究了高砷硫低镍钴硫化矿的生物浸出工艺矿物学：黄铁矿是有益组分镍、钴的主要载体矿物,结晶程度差,结构松散,易被细菌侵蚀,镍、钴容易被浸取,但细菌氧化黄铁矿而将产出较多的酸和浸出较多的铁;矿石中存在一部分颗粒微细并分散在结构致密的脉石中的含镍矿物,这是影响镍细菌浸出速率的主要原因。结合工艺矿物学研究结果,采用现代微生物驯化育种技术,选育了抗毒性强和适合浸出高砷硫低镍钴硫化矿的浸矿菌种RetechⅢ三代驯化菌,并采用亚铁离子氧化速率法、生物显微镜直接计数法及氧化还原电位法测定其浸矿活性,Fe^2＋氧化为Fe3＋速率达到1.4g.（L·h）^-1,培养60h细菌浓度由初始时的3.78×105cells·ml^-1上升到1.67×10^8cells·ml^-1,菌液氧化还原电位达到600（mV,vs.SCE）。采用摇瓶细菌浸出方法研究了浸出介质pH值、细菌接种量、浸出周期、矿浆浓度、温度等影响生物浸出的关键因素,获得了高砷硫低镍钴硫化矿生物浸出最优工艺参数,镍和钴的浸出率分别达到85.46%和99.23%。     

高能场作用下低品位红土镍矿的浸出研究

研究了常规热酸浸出低品位红土镍矿过程中加入高能场对镍浸出率以及浸出渣形貌的影响。结果表明:在高能场中,Ni、Fe的浸出率都有不同程度提高,高能场作用15min时,浸出率提高幅度最大,其中Ni浸出率较Fe浸出率提高幅度更高。     

黄铁矿表面XPS分析与生物浸出机制研究

黄铁矿的溶解过程受表面化学反应控制,表面性质的变化是影响溶解动力学的关键因素。X射线光电子能谱技术(XPS)是研究矿物溶解过程先进的表面分析技术,可分析矿物表面5 nm范围内化学组成的变化,为解释矿物溶解机制和动力学提供可靠的数据指导。本文采用XPS分析了常温下黄铁矿生物浸出过程中矿物表面的变化,黄铁矿表面主要由含Fe和含S的两种化合物组成。其中,含Fe化合物主要为FeS_2、针铁矿、硫酸盐、高铁络合物;含S化合物主要为FeS_2、硫酸盐、半胱氨酸、多硫化合物。研究表明,黄铁矿的溶解与表面硫的氧化密切相关(从S_2~(2-)氧化至SO_4~(2-)),黄铁矿溶解过程首先是Fe-S键断裂,在细菌、溶氧等氧化剂的作用下,Fe~(2+)和S_2~(2-)迅速被氧化,化学反应界面逐步内扩至黄铁矿本体,最后铁氧化物或氢氧化物型氧化产物稳定存在于未反应的黄铁矿表面。黄铁矿的生物浸出遵循硫代硫酸盐机制,间接浸出和直接浸出机制同时存在,浸出过程中形成稳定的铁氧化物或氢氧化物型氧化产物,在一定程度上加快了表面电子传递速率,促进了黄铁矿电化学氧化溶解。     

外源Fe2+浓度及矿物粒径对生物浸铀的影响

为改善以往生物浸铀效率不高的缺陷,通过添加外源Fe2+及改变矿物粒径来提高生物对铀的浸出率。研究结果表明：外源Fe2+浓度分别为0、0.5、1.0和2.0 g/L时,铀浸出率分别为87.34%、88.27%、91.23%、89.13%,当浸出体系中Fe2+浓度为1.0 g/L时,铀矿石会产生部分溶解且表面粗糙孔隙明显,有利于铀的浸出,溶浸液中存在适量的Fe2+对生物浸铀的能力具有提升效果。另外,外源Fe2+对铀矿生物浸出符合固体产物层缩核模型,浸出过程主要受扩散控制。当粒径＜- mm和-5 mm时铀浸出率分别为91.23%和83.70%,矿物粒径适当减小可增大颗粒比表面积,同样利于铀的浸出。     

印尼某红土矿硫酸加压浸出矿物组成变化研究

印尼苏拉威西岛La-paopao矿区红土镍矿储量约7326万吨,含镍约为1.25％,以此红土镍矿为对象,系统分析了矿样中主要矿物的种类、赋存状态及产出特征.结果 表明:矿样含Fe (40.15％),Ni(1.42％),Co(0.15％),Mg(0.37％),SiO2(6.92％)(质量分数),是典型的褐铁型红土镍矿;组...     

低品位硫化镍铜矿生物浸出工艺研究

研究了某低品位硫化镍铜矿的生物浸出工艺矿物学,考察了接种量、初始pH、矿石粒度、浸出周期对该矿摇瓶浸出过程的影响。在矿石粒度-0.074 mm占90%、矿浆浓度2%、细菌接种量30%、初始pH 1.5、浸出周期30天、摇床转速150 r/min的条件下,可获得最大的镍铜浸出率,分别为89.79%和41.80%。     

The effect of preferential flow on extraction and surface morphology of copper sulphides during heap leaching

Despite the commercial achievement of heap leaching of some copper, gold, zinc, and nickel minerals, there is limited comprehension of the flow pattern within the heap. Several field investigations have suggested that bypassing of ore by leaching solution is a common phenomenon, and the leaching process was significantly influenced by it. The extraction and surface morphology of low-grade copper sulphides under the condition of preferential flow was investigated in this paper. The experiment result, conducted within a novel bioleaching apparatus, shown that majority of acid was consumed by alkaline gangue and matrix, so the concentration of Cu²⁺ and total Fe increased slightly at the initial leaching stage. The ore extraction decreased with the increasing of its location depth, for instance, the ore extractions of the top and bottom region were 29% and 2% respectively. Preferential flow happened within the fine region due to the low irrigation employed by this experiment, and the extraction of fine ores was larger than that of coarse ores. The SEM images showed that the surface of top ores within the column was degraded seriously, but the middle and bottom ores were attacked slightly. Plenty of cracks were observed on the bottom ore surface due to the precipitation layer of sulfur and jarosite.     

Sulfation Kinetics of Low-Grade Nickel–Copper Sulfide Ore in the Sulfuric Acid Roasting Process

The enormous demand for and consumption of nickel in industrial applications has induced the depletion of high-grade nickel sulfide ore, which has inevitably led to the utilization of the substantial deposits of depreciated low-grade nickel-copper sulfide ore. In this work, the mineral phase transformation and sulfation kinetics of nickel, copper, iron, and magnesium in the roasting process were studied. The kinetic parameters of the metals were calculated by using the sulfation rates under different roasting temperatures, ratios of acid to ore and particle size of ore. The results showed that the sulfation process of metals is fit well by the kinetic function $$1 - {{\text{2}} \mathord{\left/ {\vphantom {{\text{2}} 3}} \right. \kern-0em} 3}x - {{(1 - x)}^{{{{\text{2}} \mathord{\left/ {\vphantom {{\text{2}} 3}} \right. \kern-0em} 3}}}} = kt$$ (G–B equation) over 0–20 min and 30–150 min for nickel, copper, and iron, as well as over 5–30 min in the case of magnesium. Furthermore, internal diffusion (three-dimensional diffusion, D4) was the restricting factor in the sulfation processes of the metals, as suggested by experimental data regarding the ratio of acid to ore and the particle size of ore.     

Column bioleaching of a low grade nickel-bearing sulfide ore containing high magnesium as olivine,chlorite and antigorite

This work investigates the bioleaching of Jinchuan low grade nickel-bearing sulfide ore containing rather high levels of olivine, chlorite and antigorite (MgO 30–35%) present in the main gangue minerals using a mixed mesophiles which are composed of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. It aims to test the technical feasibility to recover valuable metals from Jinchuan low-grade nickel-bearing sulfide ore by bioleaching process. The tolerance of the mixed bacteria to Mg²⁺ could be improved markedly from 10 g/L to 25 g/L after nearly 2 years adaptation. A nickel recovery of 91% and a cobalt recovery of 81% were achieved in 312 days column leaching process including 60 days acid pre-leaching stage and 252 days bioleaching stage.     

元江红土镍矿加压浸出试验研究

对元江铁质和镁质红土镍矿进行加压浸出试验,详细考察了浸出温度、反应时间和初始酸度对镍浸出率及酸耗的影响。结果表明,铁质矿的镍浸出率可达90%以上,吨镍酸耗可降低至45t以下;镁质矿的镍浸出率可达80%,吨镍酸耗70t左右。采用两段加压浸出工艺处理该红土矿,镍浸出率可达88%以上,吨镍酸耗50t左右。     

Effect of Mechanical Activation on Pressure Leaching of Küre Massive Rich Copper Ore

The effect of mechanical activation on metal dissolutions by pressure leaching of massive rich copper ore taken from Küre copper ore deposit (Turkey) was investigated. The dissolution efficiencies of sulfide minerals are significantly improved by ultrafine grinding, also known as mechanical activation. This grinding results in decrease of particle size and an increase in crystal distortion of sulfide minerals. Leaching efficiencies of copper, cobalt, and Zinc increased from 45.2%, 25.9%, and 87.7% to 98%, 85%, and 97%, respectively, after 3-h mechanical activation. At the end of the activation, leaching was carried out at a temperature of 110°C, 10-bar oxygen partial pressure, and 150-g/L solid concentration without addition of acid. This study has also indicated that mechanical activation involving fine milling as a pretreatment is not only effective on copper minerals dissolution but also on the dissolution of other associated minerals, such as cobalt and zinc sulfides.     

低品位红土镍矿焙烧-碱浸过程中硅的转化

针对目前红土镍矿碱法处理过程中存在的问题提出工艺改进,研究低品位红土镍矿焙烧活化-碱浸过程中含硅矿物的转化。考察了焙烧温度对红土镍矿活性的影响,探索了红土镍矿经焙烧后碱浸过程中温度、时间、搅拌强度、液固比以及碱初始质量浓度对硅转化的影响。结果表明,红土镍矿经650 °C焙烧2 h后,活性得到明显提高,红土镍矿经焙烧后采用初始质量浓度为60 g/L的碱溶液,在搅拌速度为400 r/min、浸出温度为140 °C、液固比为5∶1的条件下浸出120 min,硅的转化率可达89.42%。     

紫金山铜矿生物堆浸过程酸铁平衡实践与优化方向

紫金山铜矿低品位矿石采用生物堆浸—萃取—电积工艺产出阴极铜。矿石中主要铜矿物为蓝辉铜矿及铜蓝,同时含有较高含量的黄铁矿,耗酸脉石含量低。铜矿物浸出过程中,伴随着黄铁矿的氧化产酸产铁,造成堆浸系统溶液中酸铁浓度的不断累积,影响到浸出、萃取及环保处理工序,需要通过不断地中和来降低酸铁浓度。介绍了紫金山铜矿生物堆浸的技术特点,对生物堆浸过程中高酸高铁和低酸低铁两种工艺实践中酸铁平衡实践进行总结;结合紫金山铜矿矿石矿物学信息,进行酸平衡计算,确定了堆浸过程中黄铁矿氧化过程对酸铁平衡的影响;分析工艺条件对酸铁平衡的影响,并提出未来解决酸铁过剩的工艺优化方向。     

硫酸法生产钛白所产废酸浸取铂钯矿浸出液中镁和铁的回收

用硫酸法钛白生产的废酸作浸取剂浸取某铂钯矿时,浸出液中Fe2+含量高达40～50g/L,Cr3+、Mn2+、TiO32+等杂质含量也高达每升数克,使浸出液综合回收的难度增大。试验证明:用黄铵铁矾法能够很好地实现除铁和铁镁分离。比其它方法能够制得质量更好的铁红,而含镁溶液经过这一步净化以后,采用混沉镁剂,可成功地沉镁,并制取优质的轻质氧化镁。