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。     

澳大利亚某红土镍矿硫酸泡浸试验研究

研究了用硫酸溶液从澳大利亚某红土镍矿中浸出镍,考察了酸度、浸出时间和矿石粒度对镍浸出率和酸耗的影响。试验结果表明:矿石粒度对镍浸出率影响较大;在酸度2.51mol/L、矿石粒度-8～+2mm、两段逆流浸出时间均为12d的最佳条件下,镍浸出率为78.52%,浸出液中残酸质量分数小于5%,酸耗在64t/t镍左右。该工艺投资少,流程短,工艺简单。     

用堆浸法从某选镍尾矿中回收镍的试验研究

某选镍尾矿镍品位为0.35%,其氧化率较高,属难选矿石。试验研究了采用碎磨-堆浸-沉淀工艺从尾矿中回收镍,考察了试料粒度、硫酸用量、浸出时间、浸出温度和液固比等对镍浸出率的影响,在矿石粒度-0.074 mm占65%、硫酸用量160 g/L、浸出时间56 h、浸出温度60℃、液固比3:1的条件下,镍的浸出率为61.11%。     

黑曲霉浸铀过程中的形态特征及其对铀浸出的影响

黑曲霉(A.niger)在深层培养时具有复杂的生长形态,其直接影响黑曲霉的代谢产能。然而,黑曲霉浸矿过程中的形态特征及其对浸出效果的影响还未得到重视。通过黑曲霉浸铀的单因素实验,考察浸出时间、孢子接种量、碳源种类与用量、初始pH值、矿浆浓度对黑曲霉的形态特征与铀浸出的影响,分析两者之间关系。结果表明,在不同的浸出条件下,黑曲霉呈现出3种不同形态:紧实的生物矿石颗粒、松软的生物矿石颗粒和散状菌丝,当铀矿粉被黑曲霉完全包裹形成紧实的生物矿石颗粒时,铀的浸出率最高。在浸出时间4 d、孢子接种量1×10~8 spores·L~(-1)、蔗糖浓度25 g·L~(-1)、初始pH 6、矿浆浓度2%的条件下,可形成紧实的生物矿石颗粒,铀的浸出率达76.26%。     

某红土镍矿加温搅拌浸出试验研究

某低品位红土镍矿的碱性脉石含量较高,矿石嵌布粒度细,平均镍品位0.91%,属难处理氧化镍矿,采用加温搅拌浸出方法可以有效地从中浸出镍.研究了加温搅拌浸出过程中各因素对镍浸出率的影响.结果表明,在温度85 ℃、矿石粒度-20目、酸矿质量比2∶5、液固体积质量比3∶1、搅拌浸出2 h条件下,镍浸出率可达60%以上.     

澳大利亚某红土镍矿搅拌浸出试验研究

研究了从澳大利亚某红土镍矿中搅拌浸出镍,考察了酸度、浸出时间、浸出温度、矿石粒度和液固体积质量比对镍浸出率和酸耗的影响。试验结果表明,在酸度1.94mol/L、矿石粒度-2mm、浸出时间3h、浸出温度80℃、液固体积质量比3∶1条件下,镍浸出率为73.58%,酸耗在80t/t镍左右。该工艺具有投资少、工艺简单等特点,为处理红土镍矿提供一种可选择工艺。     

一株氧化亚铁硫杆菌的筛选及对低品位碲矿的浸出

从四川石棉矿区的酸性矿坑水和土壤中筛选到一株细菌PD-1,对其形态、理化特征及16SrDNA序列研究表明:细菌细胞呈杆状,革兰氏染色阴性,最适生长温度30℃,最适初始pH2.0,其16SrDNA序列与氧化亚铁硫杆菌的序列相似度高达99%以上,可鉴定为氧化亚铁硫杆菌菌株。利用该菌株对低品位碲矿进行摇瓶浸出实验,结果表明:菌株在接种量10%、温度30℃、初始pH2.0、转速150r/min、碲矿粒度-150μm及矿浆浓度2%的条件下浸矿,30d碲的浸出率可达67.8%。     

一株氧化亚铁硫杆菌的筛选及对低品位碲矿的浸出北大核心

从四川石棉矿区的酸性矿坑水和土壤中筛选到一株细菌PD-1,对其形态、理化特征及16SrDNA序列研究表明:细菌细胞呈杆状,革兰氏染色阴性,最适生长温度30℃,最适初始pH2.0,其16SrDNA序列与氧化亚铁硫杆菌的序列相似度高达99%以上,可鉴定为氧化亚铁硫杆菌菌株。利用该菌株对低品位碲矿进行摇瓶浸出实验,结果表明:菌株在接种量10%、温度30℃、初始pH2.0、转速150r/min、碲矿粒度-150μm及矿浆浓度2%的条件下浸矿,30d碲的浸出率可达67.8%。     

用巨大芽孢杆菌浸出矿石中的金

研究了用巨大芽孢杆菌(Bacillus megaterium)从金矿石中浸出金,考察了矿石粒度、矿石与细菌培养基用量配比、甘氨酸用量、体系pH对金浸出率的影响。结果表明:在矿石粒度为200～300目、矿石与培养基的配比为2 g/200 mL、甘氨酸用量12 g/L、体系pH=9.5、浸出时间24 d条件下,金浸出率达91.47%,浸出效果较好。     

含砷低品位硫化铜矿生物堆浸工业试验

福建紫金山含砷低品位硫化铜矿年产300tCu和1000tCu生物堆浸工业试验结果表明:铜浸出率随着矿石粒度的减小而提高,矿石粒度为-30mm,浸出周期为270d,铜的浸出率达到80.58%;铜萃取率和电积电流效率随着浸出液pH值的降低和电积液中铁的质量浓度的增加而降低,当浸出液pH值下降到1.19时,铜萃取率下降到了50%;通过增加堆高、定期中和萃余液、增加负载有机相洗涤和活性炭+沙滤+气浮塔脱除电积原液中有机物等工艺改进后,降低了萃取剂、煤油和电能的消耗量,提高了铜的浸出速率,浸出周期为200d,铜浸出率为81.31%,铜萃取--电积的耗电量为2679.98kW.h.t-1,高纯阴极铜生产成本1.05万元.t-1.     

产氨细菌浸出碱性氧化铜矿

采用产氨菌种Providencia JAT-1,对云南某矿高碱性氧化铜矿进行氨浸体系下的摇瓶浸出试验.结果显示温度、矿浆液固质量比、助浸剂种类、助浸剂浓度以及细菌初始接种浓度对铜浸出率具有显著影响.在温度为30℃、矿浆液固质量比7:1、助浸剂硫酸铵浓度0.024 mol·L-1以及细菌初始接种浓度20%的条件下,产氨细菌浸出碱性氧化铜矿144 h后铜浸出率可达42.35%.通过对浸渣铜物相分析发现矿石中次生硫化铜浸出率最高.      

活性炭在原生硫化铜矿细菌浸出中对铜与铁离子吸附的影响

通过摇瓶实验,研究了活性炭在原生硫化铜矿细菌浸出中对铜与铁离子吸附的影响。研究结果表明,活性炭浓度和pH值对活性炭吸附铜和铁离子有重要影响,活性炭对铜和铁离予的吸附量随活性炭浓度增加而增加。在原生硫化铜矿石细菌浸出的初始阶段,添加活性炭可以大大加快铜的浸出速度和提高铜的浸出率,在600h内,铜的浸出率可以达到79％,比不添加活性炭时提高了68％。     

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.     

镍钴硫化矿生物浸出研究进展

概括了镍、钴硫化矿生物浸出机理并综述了近些年来国内外镍、钴硫化矿生物浸出工艺以及工业化应用实例,指出了镍、钴硫化矿生物浸出工艺的发展方向.     

Elevated-pH bioleaching of a low-grade ultramafic nickel sulphide ore in stirred-tank reactors at 5 to 45 °C

This study is a continuation of previous work designed to assess the effect of elevated-pH bioleaching on a low-grade ultramafic nickel sulphide ore from Manitoba, Canada. The ore contains 21% magnesium and 0.3% nickel. Nickel is the only significant metal value, and is present primarily as pentlandite. A substantial fraction of the magnesium is present as lizardite, making processing of the ore difficult with conventional pyro- and biohydrometallurgical techniques. This work has two objectives: to maximize nickel extraction, and to minimize magnesium mobilization. Five-week stirred-tank bioleaching experiments were conducted with finely ground ore (− 147 µm) at three pH levels (3, 4 and 5) and five temperatures (5, 15, 22.5, 30, and 45 °C). The initial rate of nickel extraction from pentlandite was observed to be inversely correlated to acidity at all temperatures, while the final extraction of nickel after 5 weeks was determined to be moderately correlated to acidity at high temperatures and negatively correlated to acidity at low temperatures. The advantage of elevated-pH bioleaching was most evident at 5 °C, in which the final extraction of nickel at pH 5 was approximately 250% greater than at pH 3. Electron probe X-ray microanalysis of the post-leach residues revealed that the un-reacted lizardite was enriched with nickel during experiments conducted at pH 5, and that the extent of enrichment was a strong function of temperature. The undesirable extraction of magnesium exhibited a strong negative pH–temperature interaction and the consumption of sulphuric acid directly tracked the extraction of magnesium over all experimental conditions. Bioleaching at elevated pH substantially increased the ratio of nickel to magnesium in the leachate, and resulted in a substantial reduction in sulphuric acid consumption.     

硫化铜矿细菌浸出试验研究

针对大红山硫化铜矿细菌浸矿的工艺参数及影响因素进行了试验研究,在pH1.5～2.5、温度20～35℃、铁离子浓度在10～20g/L的条件下,-20mm粒级矿石经24周柱浸,铜浸出率达30.62％。     

P507萃取废弃线路板微生物浸出液中镍的研究

废弃线路板(PCB)浸出液经萃取提铜除铁后利用P507富集分离浸出液中的Ni 2+,考察萃取剂浓度、皂化率、相比(O/A)、萃取时间、浸出液pH对Ni 2+萃取率的影响。结果表明,在皂化率为30%、相比1∶1、P507浓度20%、萃取搅拌时间3min、浸出液pH 2.07的条件下,PCB微生物浸出液中Ni 2+的萃取率可达99.4%以上。     

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。     

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。     

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.