氰化堆浸技术在低品位银矿提取银生产中的应用

氰化堆浸技术在低品位矿提金方面应用广泛,而在提银方面应用较少。区吾银矿采用该技术从低品位矿中提银,取得了成功,值得推广和借鉴。     

Bioleaching of metals from sewage sludge: Microorganisms and growth kinetics

Microbial leaching is one of the advantageous methods of removing heavy metals from sewage sludge, however, the microbiological aspects of this technology have not been studied. This study presents the characterization of the naturally occurring microorganisms, responsible for the metal leaching activity, in 21 different sewage sludges. The results obtained indicate that the bioleaching of metals is carried out by successive growth of less-acidophilic and acidophilic thiobacilli. Several species of less-acidophilic thiobacilli participate in the sludge acidification, but Thiobacillus thioparus is the most important species. In contrast, Thiobacillus thiooxidans seems to be the only species involved in the acidophilic group of thiobacilli. The growth kinetics of the two groups of thiobaciili was followed in five different sewage sludges. After 5 days of incubation in shake flasks, the pH of the sludge was decreased to about 2.0 and this pH decrease solubilized the toxic metals (Cd: 83–90%; Cr: 19–41%; Cu: 69–92%; Mn: 88–99%; Ni: 77–88%; Pb: 10–54%; Zn: 88–97%). The maximum specific growth rate (μ_max) for the less-acidophilic thiobacilli varied between 0.079 and 0.104 h⁻¹ and that for the acidophilic thiobacilli varied between 0.067 and 0.079 h⁻¹.     

Characterization of copper bioreduction and biosorption by a highly copper resistant bacterium isolated from copper-contaminated vineyard soil

Copper is an essential but toxic heavy metal that negatively impacts living systems at high concentration. This study presents factors affecting copper bioremoval (bioreduction and biosorption) by a highly copper resistant monoculture of Pseudomonas sp. NA and copper bioremoval from soil. Seven bacteria resistant to high concentration of Cu(II) were isolated from enrichment cultures of vineyard soils and mining wastes. Culture parameters influencing copper bioreduction and biosorption by one monoculture isolate were studied. The isolate was identified by 16S rRNA gene sequence analysis as a Pseudomonas sp. NA (98% similarity to Pseudomonas putida, Pseudomonas plecoglossicida and other Pseudomonas sp.). The optimal temperature for growth was 30 °C and bioremoval of Cu(II) was maximal at 35 °C. Considerable growth of the isolate was observed between pH 5.0 and 8.0 with the highest growth and biosorption recorded at pH 6.0. Maximal bioreduction was observed at pH 5.0. Cu(II) bioremoval was directly proportional to Cu(II) concentration in media. Pseudomonas sp. NA removed more than 110 mg L^− 1 Cu(II) in water within 24 h through bioreduction and biosorption at initial concentration of 300 mg L^− 1. In cultures amended with 100 mg L^− 1, 20.7 mg L^− 1 of Cu(II) was biologically reduced and more than 23 mg L^− 1 of Cu(II) was biologically removed in 12 h. The isolate strongly promoted copper bioleaching in soil. Results indicate that Pseudomonas sp. NA has good potential as an agent for removing copper from water and soil.     

硫化矿细菌浸出机理及协同作用研究现状

细菌浸出作为一种经济、环保的处理技术,广泛应用于金属硫化物的金属提取和预处理过程中。为进一步理解细菌在硫化物浸出过程中的作用,详细阐述了细菌在浸出过程中的作用机理及其在矿物表面的作用机制,系统描述了金属硫化物溶解的硫代硫酸盐与多硫化合物途径。同时,还重点介绍了常见浸矿细菌的生存环境,并对不同种类浸矿细菌之间的协同作用进行了分析。     

缅甸莱比塘铜矿生物堆浸场翻堆提升浸出效果工业实践

针对缅甸莱比塘辉铜矿生物堆浸场生产,建立了完整的翻堆作业技术体系,包括作业节点判定、翻堆工艺、过程控制、效果评价等,通过机械手段将矿堆内部结构重组,改善渗滤性和浸出效果,稳定矿堆地质结构。对9个单元堆进行了翻堆作业,日均浸出速率平均增加0.86~4.09倍,浸出铜产量净增2648.38t,经济收益增加总计17739547美元,产量和经济效益均非常明显。     

破碎花岗岩型铀矿石的酸法制粒堆浸

破碎花岗岩型铀矿石渗透性差,不能直接堆浸。采用制粒技术,改变矿石的颗粒及其粒级分布,不但提高了溶液通过堆浸矿石的渗透速率,而且有效地改善了全矿堆渗透的均匀性。研究了硫酸浸出条件下影响制粒质量的因素,并提出了各因素的最佳水平。浸出结果表明,在酸性介质中,矿粒完好率大于92%。与直接堆浸相比,制粒堆浸矿石的渗透速率从32 5L/(m2·h)提高到638L/(m2·h)以上,液固质量比2 5时铀浸出率从56 2%提高到96 9%。     

基于图形处理器的形态学重建系统

形态学重建是医学图像处理中非常基础和重要的操作。它根据掩膜图像的特征对标记图像反复进行膨胀操作，直到标记图像中的像素值不再变化为止。对于传统基于中央处理器（CPU）的形态学重建系统计算效率不高的问题，提出了使用图形处理器（GPU）来加速形态学重建。首先，设计了适合GPU处理的数据结构：并行堆集群；然后，基于并行堆集群，设计和实现了一套基于GPU的形态学重建系统。实验结果表明，相比传统基于CPU的形态学重建系统，基于GPU的形态学重建系统可以获取超过20倍的加速比。基于GPU的形态学重建系统展示了如何把基于复杂数据结构的软件系统高效地移植到GPU上。     

Cooperative bioleaching of chalcopyrite and silver-bearing tailing by mixed moderately thermophilic culture: An emphasis on the chalcopyrite dissolution with XPS and electrochemical analysis

In this work, the interactions between one sample of silver-bearing tailing (223 g/t silver) and chalcopyrite during bioleaching by mixed moderately thermophilic culture were investigated. Bioleaching results showed that copper can be almost totally extracted from chalcopyrite as the result of addition of the silver-bearing tailing, and silver (Ag) extraction can be significantly improved with the addition of chalcopyrite. Hence, cooperative bioleaching process of chalcopyrite and the chosen silver-bearing tailing was feasible. Ag mainly occurred as silver sulfate (Ag₂SO₄), and further work of enhancing the Ag extraction and its recovery is currently in progress. The catalytic effect of the silver-bearing tailing on chalcopyrite dissolution was investigated mainly with X-ray photoelectron spectroscopy (XPS) and electrochemical analysis. Results proved that the presence of the silver-bearing tailing enhanced the oxidation rate of chalcopyrite and also eliminated the passivation effect of polysulfide, thus resulting in an extremely high copper extraction.     

生物冶金ORP与关键工艺参数关联规则的挖掘

针对生物冶金提金率难以提高这一难题,通过深入分析生物冶金工艺,依据工艺现场实测数据库、新型数据分析方法和数据挖掘方法,得到氧化还原电位(ORP)与工艺过程可控因素间的可描述数学关系,为可控工艺参数的优化控制提供指导依据,进而提高生物冶金提金率。     

人工堆山工程对周边环境影响数值模拟研究

对软土地基上的拟建堆土工程进行了有限元计算,探讨了当堆土高度较高时引起周边土体的沉降和水平位移,并通过超孔隙水压力消散时间分析堆土引起的沉降固结达到稳定所需的时间,得出了一些有参考价值的结论。