Fe2(SO4)3溶液细菌辅助浸出高砷金精矿

利用摇瓶实验对纯Fe2(SO4)3溶液浸出高砷金精矿进行了研究,考察了温度及Fe3+浓度的影响,并与细菌直接浸矿进行了对比. 同时,在Fe2(SO4)3溶液中加入高密度嗜中温氧化亚铁硫杆菌、嗜中温氧化硫硫杆菌、中度嗜热西伯利亚硫杆菌,考察其对Fe2(SO4)3溶液的辅助浸出作用. 结果表明,Fe3+溶液化学浸出可迅速溶解高砷金精矿,随温度升高,浸出率先升后降,80℃时达最大;浸出前期Fe3+浓度的积累对浸出速率影响不大,初始Fe3+浓度越高As的浸出率越高,但当Fe3+浓度高于40 g/L,由于沉淀严重,浸出率降低;连续浸出情况下,Fe3+浓度可维持恒定,10 g/L的Fe3+可保持较快的矿物浸出速率. 对照实验表明,较高的矿浆浓度对浸矿菌生长繁殖有显著影响. 高密度浸矿菌可维持Fe2(SO4)3溶液中较高的Fe3+浓度并及时消除反应产生的S层的阻碍,有利于Fe2(SO4)3溶液对矿物的浸出.     

氧化亚铁硫杆菌浸出镍黄铁矿机理的初步分析

对生物浸出镍黄铁矿的过程进行了研究,得到以下一些结论：(1) 吸附在矿物表面的细菌对矿物的溶解起着最重要的作用,溶液中游离菌的作用较小,而Fe3+对镍黄铁矿的化学溶解作用较弱;(2) Fe2+主要是被溶液中的游离菌氧化的;(3) 硫的不完全氧化将导致溶液pH的升高.     

混合铜矿的高压氨浸工艺

对新疆某地混合铜矿采用高压氨浸工艺, 考了NH3·H2O浓度、NH4+盐用量、氧压、浸出温度、浸出时间及固液比等因素对浸出过程的影响. 结果表明, 在适宜的工艺条件下,铜浸出率可达98%以上.     

铁闪锌矿细菌浸出过程中亚铁和细菌初始浓度的影响

利用摇瓶浸出研究了氧化亚铁硫杆菌在35℃下生物浸出铁闪锌矿的过程,探讨了铁含量和细菌接种量等因素对细菌在矿浆中的生长以及对锌浸出的影响,并对细菌浸出铁闪锌矿的机理进行了分析. 发现在不添加铁的情况下,即使细菌接种量达到40 mL,矿浆的氧化还原电位提高仍然非常缓慢,细菌无法在矿浆中正常生长,证明不存在直接浸出;而在添加FeSO4×7H2O的矿浆中,随接种量的增加细菌浸出铁闪锌矿的速度加快. 结果表明,铁闪锌矿的浸出需要一定量的Fe3+作为氧化浸出剂以提高浸出速度,因此必须预先添加部分Fe2+作为细菌氧化生成Fe3+的来源. 通过分析浸出过程中矿浆Eh和铁浓度的变化,认为Eh的高低与细菌浸出速度直接相关. 并且根据实验和电镜分析证明氧化亚铁浸出铁闪锌矿的过程是pH值上升的耗酸过程.     

Fe0价铁催化Fenton法降解酸性橙Ⅱ的研究

以Fe0作为H2O2的催化剂,建立了Fe0催化Fenton法(Fe0-Fenton)处理染料酸性橙Ⅱ(AOⅡ)模拟废水.Fe0的添加保证了溶液中较高的Fe2+含量,促进了H2O2的分解并提高了Fenton反应的降解效率.同时考察了初始pH、铁屑投加量、H20:投加量、铁屑粒径和染料初始含量等因素对降解效果的影响,结果表明,在溶液初始pH为3、铁屑投加量为10g·L-1、H2O2投加量为10mmol·L-I,铁屑粒径为0.84～0.42mm的最佳处理条件下,初始质量浓度200mg·L-1的AOII溶液在120 min内脱色率达到100%.     

富铁菌液浸出硫化铜精矿中砷的实验初探

以含砷2.5%的硫化铜精矿为原料，采用含Fe浓度较高的细菌驯化后液为浸出剂浸出矿中的As、Cu元素，研究了浸出过程中浸出剂pH值、精矿粒度、初始Fe3+浓度、液固比、温度、时间、细菌生长情况等因素对浸出率的影响. 结果表明，精矿粒度范围50~75 mm、浸出剂的初始Fe3+浓度5.0~30.0 g/L、液固比20:1~30:1、浸出时间10 d左右、体系初始pH值1.5左右、温度30℃时，浸出效果较好，As与Cu2+的最高浸出率分别达到52.16%和30%；通过含菌和纯化学氧化的对比浸出实验，发现细菌的存在改善了浸出效果，提高了浸出率.     

Ag+对含砷金精矿生物浸出的影响

研究了Ag+对含砷金精矿生物浸出的影响,测量了浸出液中铁、银、砷浓度及氧化还原电位(Eh)的变化,考察了Ag+对细菌密度的影响,并对浸渣进行了光谱表征. 结果表明,Ag+对含砷金精矿的生物浸出有一定的促进作用且在高浓度Fe3+条件下催化作用明显;低Ag+浓度下含砷金精矿的生物浸出率提高约10%,但Ag+浓度过高将影响细菌生长,导致浸出速率下降. Ag+催化含砷金精矿生物浸出是Ag+取代矿物表面的砷并生成Ag2S,之后被Fe3+氧化分解,重新产生Ag+,从而加速矿物的氧化分解.     

粉煤灰协同非均相Fenton法处理焦化废水的研究

建立了粉煤灰协同非均相Fenton法处理焦化废水,两者协同处理对COD的去除率高于其单独处理之和.通过粉煤灰对废水中有机物的吸附和铁离子的富集,是提高COD去除率的重要因素.考察了粉煤灰投加量、初始pH、H2O2添加量和Fe2+2 质量浓度等因素对降解效果的影响.结果表明,粉煤灰投加量30 g·L-1,初始pH=3,H2O2添加量100mmol·L-1,Fe2+质量浓度280mg·L-1的最佳条件下,经过180min的处理,焦化废水中H2O2分解率达到86.6%,COD去除率达到90.17%.     

某含砷硫金精矿酸性氧化预处理机理及其反应动力学

针对国内某金精矿中金嵌布粒度细且大部分被黄铁矿、毒砂包裹,难以浸出的现状,采用HCl?H2O2体系对其进行酸性氧化预处理,分析了氧化预处理的机理和动力学. 结果表明,在盐酸浓度0.7 mol/L、矿浆浓度40 g/L、金精矿粒度小于48 μm占90%以上、搅拌速度400 r/min、温度60℃和H2O2浓度0.5 mol/L的条件下,金精矿中Fe和As的溶解率分别达45.9%和99.6%,利于包裹金释放和浸出. 酸性条件下,金精矿中的黄铁矿和毒砂可被H2O2氧化分解,符合产物层扩散为速率控制的固相反应收缩核模型.     

微污染水中微囊藻毒素去除方法研究

比较了UV/H2O2,H2O2/Fe2+(Fenton反应)两种实验方法对微囊藻毒素-LR的降解效果,通过改变H2O2浓度或者Fe2+浓度,寻找微囊藻毒素-LR最佳降解效果。实验表明,UV/H2O2条件下随着H2O2浓度的增加,微囊藻毒素-LR降解效果先增加后减少。在Fenton体系中H2O2或Fe2+浓度的增加,MC-LR降解效果均逐渐上升,当Fe2+浓度为1.0 mmol/L,H2O2浓度为10 mmol/L时,降解5 min,MC-LR降解率能达到93%。     

废杂铜的回收与利用

介绍了我禺铜的需求及资源状况,提出了我国废杂铜回收利用的必要性。总结了国惠废杂铜的分类方法和废杂铜回收利用的现状以及废杂铜的回收处理方法,并针对国内废杂铜的回收利用情况提出了意见与建议,希望能够为我国废杂铜的回收利用提供参考。     

熔融铜渣回收铜及铜铁合金工艺研究

本文根据某炼铜熔融炉渣的矿物特性和选矿工艺特点,提出了一种"两步法"新工艺分别回收铜和铜铁合金,即低温阶段回收铜,高温阶段回收铜铁合金。该工艺对铜和铜铁合金提取比较充分,回收率均在90%以上。回收铜的品位可达99%,可直接送去火法精炼;产出的铜铁合金有害杂质少,可作为耐候钢的理想原料,其价值比纯铁高。此工艺用粉状或粒状非焦煤代替焦炭作还原剂,不用烧结,可以充分利用铜厂现有的设备,节省投资成本。该工艺简单易行,操作方便,有效实现了铜渣的资源化利用,具有良好的经济、社会和环境效益,是一种应用前景广阔的铜渣再利用工艺。     

Copper removal during formation of corrosion resistant alkaline oxide coatings on Al–Cu–Mg alloys

The performance of corrosion resistant inorganic oxide coatings formed on Al–Cu–Mg alloys is often degraded by Cu enrichment that occurs during oxide formation. This is particularly true of coating processes conducted in basic solutions. A modification to an alkaline oxide coating process has been made that simultaneously eliminates Cu enrichment and forms a corrosion resistant coating. In this paper, the modified process is described and the resulting coating morphology, structure and composition are reported. Results from electrochemical and exposure corrosion tests show that useful gains in corrosion resistance are achieved. Cu removal during the modified process is rationalized using an argument based on the increase in Cu solubility that occurs in solutions with a pHgreater than the solubility minimum for Cu (9.8), and the effect of Cu complexing by carbonate.     

Copper nucleation on titanium for thin film applications

Copper nucleation and growth on titanium substrates from concentrated acidic copper sulfate solutions was studied at 45 and 65C and high cathodic potentials. Electrochemical experiments allied to SEM examination were performed to characterize the mechanism of nucleation and its evolution with time. Particular emphasis was given to the influence of potential and agitation on the initial stages of nucleation and growth. Results indicated that most of copper nucleation on titanium from a 83g dm^–3 Cu²⁺ solution, at 65 C, is achieved in a matter of milliseconds. As expected, the initial stages of the copper nucleation and growth is strongly dependent of potential and temperature, and the influence of agitation is only evident at very high potentials. The calculated diffusion coefficients for Cu²⁺ at 45 and 65 C, under the experimental conditions, were found to be 9.16 × 10^–6 and 1.62 × 10^–5cm² s^–1, respectively.     

An Analysis of Contemporary Copper Recycling in China

Copper consumption increased very quickly in China in recent years, which could not be met by inland copper industry. In order to achieve a sustainable development of copper industry, an analysis of copper recycling in China was necessary. For the life cycle of copper products a copper-flow diagram with time factor was worked out and the contemporary copper recycling in China was analyzed, from which the following data were obtained. The average life cycle of copper products was 30 years. From 1998 to 2002, the use ratio of copper scraps in copper production, the use ratio of copper scraps in copper manufacture, the materials self-support ratio in copper production, and the materials self-support ratio in copper manufacture were 26.50%, 15.49%, 48.05% and 59.41%, respectively. The materials self-support ratios in copper production and manufacture declined year by year in recent years on the whole, and the latter dropped more quickly. The average index of copper ore and copper scrap from 1998 to 2002 were 0.8475 t/t and 0.0736 t/t, respectively; and copper resource efficiency was 1.1855 t/t. Some efforts should be paid to reduce copper ores consumption and promote copper scraps regeneration. Copper scraps were mostly imported from foreign countries because of shortage in recent years in China. Here the reasons related to copper scraps deficiency were also demonstrated. But we can forecast: when copper production was in a slow rise or in a steady state in China, the deficiency of copper scraps may be mitigated; when copper production was in a steady state for a very long time, copper scraps may become relatively abundant. According to the status of copper industry in China, the raw materials of copper production and manufacture have to depend on oversea markets heavily in recent years, and at the same time, the copper scraps using proportion and efficiency in copper industry should be improved.     

铜及铜合金着色

简述了铜及铜合金着色的原理.总结了铜及铜合金着黑色、褐色、绿色、蓝色的工艺配方及操作条件,介绍了手工点涂铜绿(铜锈)、双色点蚀(先着黑色再点蚀铜绿)、套色、着土黄铜绿色等多种特殊的着色工艺.     

液相空气氧化法制取硫酸铜工艺的研究

对液相空气氧化法制取硫酸铜的生产条件进行了研究。在实验基础上，提出了中酸度高温空气氧化法生产硫酸铜的新工艺。     

Comments on “The effect of ZnO in methanol synthesis catalysts on Cu dispersion and the specific activity” [by T. Fujitani and J. Nakamura]

Fujitani and Nakamura recently reported on the effect of ZnO on Cu/ZnO methanol synthesis catalysts (Catal. Lett. 56 (1998) 119). Having measured the methanol synthesis activity of a series of Cu/ZnO catalysts of different Cu/ZnO ratios, they reported a linear relationship between the copper metal area and the methanol yield (implying a fixed value of the copper specific activity) and paradoxically they also reported a volcano-type relationship between the copper specific activity in methanol synthesis and the ZnO content. This paradox is resolved by showing that their Cu/ZnO catalysts fall into two groups: (i) the low-surface-area copper catalysts which have a specific activity of 10 mg CH₃OH/m²-Cu h and (ii) the high-surface-area copper catalysts which have specific activity of 14.8 mg CH₃OH/m²-Cu h. These different specific activities derive from different surface morphologies of the copper in these catalysts. This revised version was published online in November 2006 with corrections to the Cover Date.     

某铜矿选矿实验研究

为了开发某铜矿资源,对其进行了可行性实验研究.根据矿石物相分析结果,采用硫化铜与氧化铜混合浮选工艺,并选用新型高效浮选药剂,可获得铜精品位20.29%,收率70.68%的铜精矿.