高温嗜热菌浸出硫化矿的研究现状与展望

介绍了高温嗜热菌的种类、特性、高温嗜热菌浸出硫化矿的研究现状 ,指出了其存在的问题和应用前景。     

嗜温菌、中等嗜热菌、嗜热菌分段浸出原生硫化铜矿表外矿万吨级工业堆浸试验

针对原生硫化铜矿表外矿浸出周期长、速度慢、效率低等问题,在江西德兴铜矿进行了万吨级生物堆浸工业试验。采用本土选育驯化的高效嗜温嗜酸菌与嗜热嗜酸菌依次接种、分段浸出新技术,铜浸出率达到22.04%,效果良好。     

铜锌硫化矿分离技术研究及进展

铜锌硫化矿由于可浮性相近,铜离子易活化闪锌矿等原因一直难以分离,是选矿界一大难题,为此,针对铜锌硫化矿浮选分离现状进行了研究,分别从工艺、药剂、理论研究等角度进行了概述.结果表明,随着研究的深入,铜锌硫化矿分离的工艺及药剂都得到了很大地发展,新工艺及新药剂不断涌出,尤其是浮选柱法,由于其操作易控制、节能等诸多优点,在铜锌分离中应用前景广阔,同时加强铜锌分离的理论研究及继续开发新工艺、新药剂势在必行.      

铜铅锌多金属硫化矿分离试验研究

多金属硫化矿嵌布粒度较细,传统的选冶方法难以经济地分离出铜、铅、锌矿物。研究了采用化学冶金法,在探索试验基础上,选用焙烧、浸出、萃取等方法,从此类多金属硫化矿中分离铜、锌、铅等有价金属,取得了较好结果。     

铜镍硫化矿冶金过程的铜镍分离与精炼方法探究

铜镍分离与精炼方法是镍冶金工艺中的关键问题。本文通过对传统的分层熔炼、磨浮分离及五种湿法选择浸出方法、羰基法进行简要分析对比,指出各种镍(铜)锍分离方法的优缺点。     

永平铜矿硫化铜矿中自由氧化铜的分离测定

在测定硫化铜矿中自由氧化铜的含量时,容易造成自由氧化铜结果偏高,原因是次生硫化铜矿物的部分溶解而产生干扰。本文选择乙酸?硫酸羟胺溶液作为分离测定硫化铜矿物中自由氧化铜的选择性溶剂,不仅对提高赤铜矿等氧化铜矿物的浸出率有良好效果,而且对抑制次生硫化铜矿物的部分溶解而产生的干扰也有明显作用。     

铜锌硫化矿浮选分离技术的研究与进展

铜锌硫化矿浮选分离技术研究的重点在高效铜捕收剂、锌抑制剂的配制与合成方面,同时,浮选工艺的优化也为铜锌分离提供了良好的基础。复杂难选铜锌硫化矿运用选冶联合流程实现综合利用,也是实现铜锌分离的一种趋势。     

富银多金属硫化矿的分离

根据某地富银多金属硫化矿连体共生、互相嵌布的特点采用浮选混合精矿的方法提高了浮选的金属收率。在热力学分析的基础上进行了多金属硫化精矿的焙烧和浸出试验,提出了富银多金属硫化矿的分离流程。可在现有湿法炼锌的装置上直接处理多金属硫化精矿而生产锌,同时分离出铜、铅、银。得到较高的金属总收率     

Purification and properties of serine hydroxymethyltransferase from Sulfolobus solfataricus

Serine hydroxymethyltransferase (SHMT) catalyzes the reversible cleavage of serine to glycine with the transfer of the one-carbon group to tetrahydrofolate to form 5,10-methylenetetrahydrofolate. No SHMT has been purified from a nonmethanogenic Archaea strain, in part because this group of organisms uses modified folates as the one-carbon acceptor. These modified folates are not readily available for use in assays for SHMT activity. This report describes the purification and characterization of SHMT from the thermophilic organism Sulfolobus solfataricus. The exchange of the alpha-proton of glycine with solvent protons in the absence of the modified folate was used as the activity assay. The purified protein catalyzes the synthesis of serine from glycine and a synthetic derivative of a fragment of the natural modified folate found in S. solfataricus. Replacement of the modified folate with tetrahydrofolate did not support serine synthesis. In addition, this SHMT also catalyzed the cleavage of both allo-threonine and beta-phenylserine in the absence of the modified folate. The cleavage of these two amino acids in the absence of tetrahydrofolate is a property of other characterized SHMTs. The enzyme contains covalently bound pyridoxal phosphate. Sequences of three peptides showed significant similarity with those of peptides of SHMTs from two methanogens.     

Protein-encoding genes in the sulfothermophilic archaea Sulfolobus and Pyrococcus

Functional studies revealed that two groups of B chronic lymphocytic leukemia (B-CLL) can be distinguished based on their capacity to mount a proliferative response following B-cell antigen receptor (BCR) cross-linking. The molecular basis for the functional distinction between these B-CLL groups most probably resides within or proximal to the BCR since non-responsive B-CLL, in marked contrast to responsive B-CLL, do not respond to BCR ligation with tyrosine phosphorylation of cellular substrates and increases in the free intracellular [Ca++]. Detailed biochemical analysis showed overall structural identity between responsive and non-responsive B-CLL with respect to both transmembrane and intracellular associates of the BCR complex. However expression levels of the protein tyrosine kinase syk, which is a key enzyme for the early signalling through the BCR, were found to be markedly lower in non-proliferating B-CLL. Here we will review current functional and biochemical data on responding and non-responding B-CLL and discuss the relevance of these findings for disease progression and our insight into the immunobiology of B-CLL.     

高位板坯托出机结构动态特性研究

建立高位板坯托出机有限元模型,求解出振动频率与振型,为研制高位板坯托出机具有良好的动力学特性提供依据。     

裂隙岩体的渗流特性研究

砂及土体的渗流特性可由达西定律得到很好的描述。但对于岩体,因其内部裂隙的交叉贯穿分布致使岩体的渗生复杂化。Ｄｉｅｎｅｓ提出的裂隙统计成功地解释了岩体中发生的渗流现象。笔者在此基础上建立起一个新的渗流模型,着重考虑了３个因素,即：流体通过第五裂湎的平均流量;单位体积内裂隙的数密度裂隙贯通程度（比例）。根据随机理论与流体通过单一裂隙的水动力学理论,获得了渗透率的积分表达式,其形式与各向异性介质中的达西     

试论徐志摩散文特色

徐志摩以诗歌创作饮誉文坛,而他的散文创作亦有很高的成就。徐志摩散文个性化色彩强烈,自成一体。众多现代散文名家对徐志摩的散文给予了高度评价。试从写作风格、意境和人生感受等三方面阐述徐志摩散文特色。     

昆钢铁矿粉烧结特性试验研究

为研究昆钢目前使用的3种粉矿的成矿性能,针对其原料特点设计正交试验方案,进行大量系统的烧结杯试验。通过试验数据分析,得到每种矿混合料平均粒度以及烧结矿转鼓强度表达式。利用单因素分析法和极差法研究了配碳量和碱度对烧结矿FeO、转鼓强度、成品率以及利用系数的影响。试验结果得到每种矿的最佳配碳量和碱度配比。分析发现,配碳量对3种矿烧结指标的影响大于碱度的影响。     

电镀锌机组铅系合金阳极电化学行为的研究

为了防止铅系合金阳极引发电镀锌钢板黑变,对不同成分及不同制造方法得到的阳极进行了电化学性能研究。发现在组成上Pb-In-Ag、Pb-Ag阳极性能良好,Pb-Sn阳极性能较差;在制备方法上真空扩散焊的阳极性能要比铸造阳极性能好。     

司家营精粉烧结特性试验研究

基于唐钢原料条件,进行了司家营精粉烧结特性的试验研究.主要研究了司家营精粉配比(50%～100%)变化对烧结矿品位、强度及冶金性能的影响规律.     

Toxicity of metal extraction and flotation chemicals to Sulfolobus metallicus and chalcopyrite bioleaching

The effect of chemicals used in preparation of mineral concentrates and subsequent extraction of metals to the thermophilic, acidophilic microorganism Sulfolobus metallicus has been tested. The chemicals tested included collectors and frothers employed during flotation of the ore to produce a mineral concentrate, solvent extraction reagents used to remove metals after leaching, and thiocyanate produced as a decomposition product during cyanidation for gold recovery. The effect of these chemicals to S. metallicus depends on the conditions and time frame that the experiments were carried out due to their mode of toxicity and stability in acid pH. The metal extraction chemical that had the least effect on bioleaching was potassium amyl xanthate that increased the leaching rate, possibly due to solubilization of sulfur that can form passivation layers on the surface of minerals. The frother Flotanol C-7 decreased the chalcopyrite leaching rate, despite having no effect on Fe²⁺ oxidation by S. metallicus resting cells. This is probably due to inhibition of oxygen transfer during bioleaching that had little effect on Fe²⁺ oxidation over 20 min. Solvent extraction chemicals inhibited both Fe²⁺ oxidation and bioleaching suggesting their mode of inhibition is due to Fe²⁺ oxidation. The results suggest that relevant concentrations of metal extraction and flotation chemicals can be toxic to chalcopyrite bioleaching by S. metallicus.