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%。     

高碱脉石低品位铜镍复合矿的诱变细菌浸出

金川低品位铜镍复合矿为高碱脉石的氧化—硫化混和矿 ,矿区无土著浸矿细菌。采用经诱变改良的外源混合T .f浸矿菌和控制矿浆 pH(<4 ) ,有效地浸出了该复合矿中的镍和铜 ;控制矿浆pH在细菌生长最适的范围内 ,钙、镁实际耗酸分别只占其总含量的 2 2 %～32 % ;铜、镍在不同浸出阶段表现为相反的浸出行为 ,酸浸时铜优先被浸出 ,菌浸时镍优先被浸出 ;渣样分析表明硫化镍、硫化铜的浸出机制为间接作用。物相分析表明这些浸出行为与浸出对象的赋存状态有关。     

细菌浸出含镍磁黄铁矿金矿的研究

在温度３０℃,ｐＨ＝２的条件下,研究了用氧化亚铁硫杆菌和氧化硫硫杆菌浸出含镍磁黄铁矿金矿。试验结果表明,只用氧化亚铁硫杆菌浸矿１６ｄ,铜的浸出率为５７％,镍的浸出率为８５％;用混合菌浸出含镍磁黄矿金矿,铜的镍的浸出率均有所提高,分别达到６３％和９１％。向浸出体系中加入一定量的Ａｇ＾＋,铜的浸出率明显提高,而镍的浸出率却降低。     

复合硫化矿在台架规模柱式反应器中的细菌浸出

测定了以黄铜矿，镍黄铁矿，黄铁矿，磁黄铁矿和闪锌矿为主要矿物的复合硫化矿柱式生物浸出的若干参数。所用的矿样具有不同比例的磁黄铁矿，黄铁矿，石英岩（低酸耗）和硅卡岩（高酸耗）用接种子最初来源于矿水能氧化铁和硫的嗜酸菌的台架规模的柱式浸出反应器进行了试验，无菌对照试验中的浸出速率是可以忽略不计的，在接种后的柱中，生成了新的固相（铜蓝，黄钾铁矾，氧化铁（Ⅱ）以及元素硫）在低ｐＨ和低氧化还原电位的条件下，     

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。     

难处理低品位铜钴矿的微生物浸出

以赞比亚某典型难处理低品位氧化铜钴矿为研究对象,配入适量硫化铜钴矿,采用人工调配的高效微生物浸矿菌群对铜钴矿进行微生物浸出,同时分别与摇瓶酸浸、搅拌酸浸和柱浸进行了对比.结果表明,采用微生物浸出难处理铜钴矿,随着温度升高和时间延长,铜浸出率增大.浸出温度为40℃时,微生物浸出铜浸出率为90.7%,高于摇瓶酸浸和搅拌酸浸浸出结束时浸出率(69.4%~73.2%)以及柱浸结束时浸出率(约85%).由于微生物浸出群落对该难处理铜钴矿作用时间周期较长,适用于堆浸生产.细菌的存在使得铁离子不断的在二价与三价间循环,通过具有强氧化性的Fe3+与硫化矿物相互作用,使得矿物分解,提高浸出率.     

某低品位硫化镍矿石细菌氧化堆浸工艺研究

针对吉林省某高镁型低品位硫化镍矿石,利用细菌氧化堆浸工艺,通过诱变驯化培养高效率的浸矿菌株,对催化剂及柱浸粒度、制粒与否、浸出pH、接种菌量等工艺条件进行了研究。结果表明：使用诱变改良菌种H4₃,在柱浸粒度-10 mm、浸出pH值2、接种菌量30%、氧化浸出时间150 d、室温及添加Ag⁺催化剂的条件下,镍、铜浸出率分别为72.22%、71.03%,指标良好,为低品位硫化镍矿石资源的开发利用提供了技术依据。     

低品位钴矿的细菌浸出试验研究

介绍了含钴硫化矿细菌浸出的研究现状和机理.用T.f菌对某地贫钴矿进行了探索性浸出试验,结果表明,在矿浆浓度＜20%,浸出时间＞10 d条件下,钴浸出率可达55%～60%.     

氯化钠—氧气浸取镍钴铜硫化精矿

论述氯化钠溶液中氧气浸出浮选镍铜钴硫化精矿的过程，讨论了镍和钴的浸出行为和浸出动力学、实验证实，镍和钴的浸出速率及最科浸出率主要取决于取溶液中铜离子浓度和氧分压；过高的反应温度不利于镍和钴的浸出；溶液ＰＨ值基本不影响浸出，镍和然的同速度受浸取液中铜离子扩散及一价铜离子与氧的化学反应混合控制。     

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%。     

镁离子对低品位硫化镍矿氧化浸出电化学行为的影响

低品位硫化镍矿中含镁硅酸矿物易被酸溶解出Mg^2+而影响其有价金属提取。采用不同氧化浸出体系研究了Mg^2+对硫化镍矿中Ni、Cu、Mg、Fe浸出的影响,利用循环伏安、动电位极化、交流阻抗等方法研究了Mg^2+影响硫化镍矿中硫化矿物氧化溶解电化学行为。结果表明,试验范围内,低品位硫化镍矿中硫化矿物氧化浸出受氧化产物扩散影响控制,含镁矿物被酸溶解释放出Mg^2+进入溶液,游离的Mg^2+受硫化矿物表面负电性离子吸引而吸附在矿石表面,降低矿物表面氧化溶解双电层电荷转移内阻,加速电荷转移过程;另一方面,由于Mg^2+吸附影响,使得硫化镍矿表面氧化产物膜致密生长而显著负影响硫化矿物浸出,致使硫化矿物自腐蚀速率随Mg^2+浓度增加而降低。Mg^2+对含S物种电对间转化不利,与Fe^3+协同影响硫化矿物氧化浸出效率,低Mg^2+浓度促进Fe^3+/Fe^2+循环,而高Mg^2+浓度引起硫化矿物腐蚀产物层致密生长而降低矿物被溶解的速率。硫化镍矿在不同体系氧化浸出时,初始含Mg^2+条件下,Ni、Cu、Fe浸出效率低于无Mg^2+体系。     

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.     

氧化亚铁硫杆菌及中度嗜热菌的紫外诱变对黄铜矿的浸出

利用紫外线对氧化亚铁硫杆菌和采自酸性温泉水的中度嗜热菌进行诱变,对黄铜矿浸出。诱变后菌活性分别提高40.6%和35.9%,浸出率分别提高了36.6%和23.5%,并对这两种菌混合后浸出做了探讨。     

Bioleaching of Rare Metals from Manganese Nodules by Thiobacillus Ferrooxidans

Manganese nodules, which constitute a potential future resource of rare metals, are composed mainly of oxides of manganese and iron, with various metals such as copper, nickel, and cobalt. Although physical and chemical processes have been developed for extracting the rare metals from manganese nodules, another possible process is the leaching of metals by microbial means.

This paper describes leaching of raw manganese nodules by sulfurous acid and sulfuric acid which are biologically produced by oxidation of elemental sulfur by Thiobacillus ferrooxidans. The bioleaching behavior of each metal from nodules was measured at 30°C and pH 2 in a well-mixed batch reactor. The metal content of the nodules used in this work was 0.29% Cu, 0.49% Ni, 0.27% Co, 16% Fe and 17% Mn by weights. For both the microbial system and the control culture containing no T.ferrooxidans, copper and nickel exhibited close to 100% leaching in two weeks and less than 5% for iron and manganese. On the other hand, leaching of cobalt was markedly accelerated in the microbial system reaching 50% in two weeks compared with the sterile control. The bioleaching rate of cobalt was enhanced as the initial sulfur-liquid loading ratio became higher, but is was practically independent of the nodule size which was less than 330 mesh. Moreover, there was an optimal relation between the bioleaching rate and the initial cell concentration, and the addition of T.ferrooxidans cells in excess of the optimal concentration resulted in a decrease in the leaching rate of cobalt.     

Silver-catalyzed bioleaching of low-grade copper ores.: Part I: Shake flasks tests

A study of the effect of different variables (inoculation, pulp density, [Ag], nutrient medium, pH and [Fe³⁺]) on the silver-catalyzed bioleaching of a low-grade copper sulfide ore has been carried out in shake flasks. Chalcopyrite was the dominant copper mineral in the ore. Preliminary tests showed that addition of other ions (Sb, Bi, Co, Mn, Ni and Sn) did not enhance the copper dissolution rate. Conversely, an inoculation with mesophilic microorganisms and the addition of silver had a markedly catalytic effect on the extraction of copper. The kinetics of the silver-catalyzed chalcopyritic ore bioleaching was greatly affected by pulp density and silver concentration. Small amounts of silver (14.7 g Ag/kg Cu) dramatically accelerated the copper dissolution process while large amounts (294.12 g Ag/kg Cu) had an inhibitory effect. The copper dissolution rate was slightly affected in the range of pH between 1.2 and 2.5 but was significantly slower at pH 3.0. The effect of [Fe³⁺] in the presence of silver was studied both in abiotic and biotic conditions. High ferric iron concentrations in abiotic tests recovered similar copper amounts (∼ 95%) to those obtained without or with low [Fe³⁺] in the presence of bacteria. The leaching of copper from the low-grade copper ore can be very effectively enhanced with silver and mesophilic microorganisms. For that system, the onset of oxidizing conditions starts at an Eh value slightly higher than 650 mV. Above that critical value of potential the copper dissolution rate slows down. This also corresponds with the completion of the leaching process. As the potential rises past 650 mV, the copper extraction reaches a plateau.     

矿石粒度和矿浆浓度对原生硫化铜矿细菌浸出的影响

通过摇瓶试验研究矿石粒度和矿浆浓度对原生硫化铜矿石中细菌浸出的影响,并初步探讨了浸矿过程中细菌的氧化活性及其对浸矿的影响。研究结果表明:在原生硫化铜矿石细菌浸出过程中,有利于铜浸出的矿石粒度和矿浆浓度分别是5 mm和20%~25%;溶液中三价铁含量过高或产生的铁沉淀都会直接影响细菌的氧化活性和浸矿效果。     

微裂纹对硫化铜矿生物浸出的影响研究

利用紫金山低品位硫化铜矿,研究了微裂纹对铜生物浸出效果的影响。分别利用颚式破碎机、对辊破碎机和高压辊磨机对硫化铜矿进行破碎,采用体式显微镜、扫描电镜、核磁共振岩心成像系统和比表面积分析仪对矿石微裂纹及孔隙度进行观察统计与表征。结果表明,高压辊磨较颚式破碎和对辊破碎可以产生更多的微裂纹,同时高压辊磨破碎铜矿样品的孔隙度均高于颚式破碎和对辊破碎。-1.7mm粒级铜矿样品摇瓶浸出试验表明,由于高压辊磨破碎样品的比表面积和孔隙度更大,铜矿物与浸出液接触更加充分,浸出效果比颚式破碎和对辊破碎好。另外,-6.7+3.35mm粒级铜矿样品生物柱浸试验结果表明,含有更多微裂纹的高压辊磨破碎样品铜浸出率比颚式破碎提高9.10~15.43个百分点,比对辊破碎提高3.12~9.45个百分点。     

低品位次生硫化铜矿的细菌浸出研究

在硫酸体系中 ,对含有辉铜矿、蓝辉铜矿和铜蓝的低品位次生硫化铜矿的Fe3+ 浸出和细菌浸出进行了研究 ,通过对浸出过程的动力学进行分析 ,揭示了次生硫化铜矿的浸出过程和细菌浸出的作用机理 ,得出了细菌浸铜主要以间接机理进行的结论 ,提出了加快铜浸出速率的 2条途径。     

某铀矿生物浸铀过程中金属离子与铀协同浸出研究

通过室内柱浸试验,探析不同粒度（2.5~5、5~10、2.5~10 mm）铀矿在生物浸出过程中金属离子与铀浸出的规律,分析柱浸过程中pH、Eh、K+、Ca2+、Na+、Mg2+、Al3+、Fe3+与铀的浸出行为,并运用PHREEQC计算金属离子的饱和指数及浸出液中铀的存在形式。结果表明,铀矿中K+、Ca2+、Na+、Mg2+、Al3+、Fe3+与铀的浸出趋势相似,粒度越小该铀矿中浸出的金属离子越多,经过66 d柱浸试验,三种粒度的铀矿铀浸出率分别为85.93%、69.75%、79.65%。酸化阶段及菌浸阶段硬石膏达到饱和,酸化阶段磷酸铀酰达到饱和,菌浸阶段氟化铁达到饱和。柱浸浸出液中铀主要以正六价存在,酸化阶段铀化学形态主要为硫酸铀酰及磷酸铀酰,菌浸出阶段主要为硫酸铀酰及氟化铀酰。