Silver sulfide leaching with a copper-thiosulfate solution in the absence of ammonia

Leaching from silver sulfide.using a copper-thiosulfate solution in the absence of ammonia was investigated. It is found that silver sulfide could be effectively dissolved in the copper-thiosulfate system without ammonia. The effects of thiosulfate concentration, cop- per-to-thiosulfate ratio, agitation vigorousness, pH values, and dissolved gases on the leaching of silver sulfide with the copper-thiosulfate solution were studied. A maximum extraction of 95.1% was achieved with the 0.12 mol/L thiosulfate and the 0.048 rnol/L copper sulfate. It is shown that copper-to-thiosulfate ratio is an important factor in silver sulfide dissolution and oxygen is not needed to leach silver sulfide, which leads to the instability of the leaching system at high copper-to-thiosulfate ratio. On the other hand, the silver extraction is not affected by the pulp pH values.

Investigation of copper sulfate pentahydrate dehydration by terahertz time-domain spectroscopy

Copper sulfate pentahydrate is investigated by terahertz time-domain spectroscopy. It is shown that the terahertz absorption coefficients are correlated with the particle size of the samples, as well as the heating rates of the ambient temperature. Furthermore, the water molecules of copper sulfate pentahydrate can be quantitatively characterized due to the high sensitivity of the terahertz wave to water molecules. Based on such results, the status of water incorporated in mineral opal is also characterized using terahertz time-domain spectroscopy. It indicates that terahertz technology can be considered as an efficient method to detect the dehydration of minerals.

Integrated transcriptome and physiology analysis of Microcystis aeruginosa after exposure to copper sulfate

Copper sulfate(CuSO4)is widely used in controlling the Microcystis aeruginosa blooms.Many studies reported the toxicity mechanisms of Cu^2+to M.aeruginosa at the physiological level,but little is known about a transcriptomic basis of these mechanisms.In the present study,M.aeruginosa was treated by 0.5 mg/L Cu^2+(half of the 96-h EC50)for 72 h.The results show that CH2+content in M.aeruginosa increased after 72 h Cu^2+exposure,whereas the Fv/Fm chlorophyll fluorescence value and chlorophyll a content in M.aeruginosa sharply decreased.Reactive oxygen species concentration and activity of antioxidant enzymes(superoxide dismutase,catalase and peroxidase)were all increased.These physiological data confirmed toxicity of Cu^2+to m.aeruginosa.The RNA-seq analysis showed that 6646725 and 7880291 clean reads were obtained for the Cu-treated and control libraries,respectively.The 595 genes(252 downward trend and 343 upward trend)with the Gene Ontology(GO)annotations were divided into three main functional categories:cellular component,molecular function,and biological process.In the Cluster of Orthologous Groups(COG)annotation,418 differentially expressed genes with 25 functional definitions were obtained.Among them,‘replication,recombination and repair’,‘energy production and conversion’,and‘general function prediction only’were the largest three groups of transcripts.In the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,genes involved in photosynthesis and oxidative phosphorylation were present at the highest percentages.In addition,the genes involved in photosynthesis and oxidative phosphorylation were identified,and then confirmed using real-time PCR.This study reported the first transcriptome of M.aeruginosa.Photosynthesis and oxidative phosphorylation were severely affected by Cu^2+toxicity,which may have contributed to cell death.These data provide the potential mechanism to explain the CuSO4 effect on the harmful M.aeruginosa.

Recovery of copper sulfate after treating As-containing wastewater by precipitation method

The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2：1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide. The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4：1 and copper arsenite was reduced by SO2 at 60℃ for 1 h. The white powder was gained after the arsenious acid solution was evaporated and cooled. Copper sulfate solution was obtained after the red residue was leached by H2SO4 solution under the action of air. The results show that red residue is Cu3（SO3）2·2H2O and the white powder is As2O3. The leaching rate of Cu reaches 99.00% when the leaching time is 1.5 h, molar ratio of H2SO4 to Cu is 1.70, H2SO4 concentration is 24% and the leaching temperature is 80 ℃. The direct recovery rate of copper sulfate is 79.11% and the content of CuSOa·5H2O is up to 98.33% in the product after evaporating and cooling the copper sulfate solution.

Proteomic analysis of acute responses to copper sulfate stress in larvae of the brine shrimp,Artemia sinica

Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica.Fourteen differentially displayed protein spots were detected and seven of them were identified.Three spots were up-expressed and identified:actin, heat shock protein 70,and chaperone subunit 1;three down-regulated proteins were identified:arginine kinase,elongation factor-2,and glycine-rich protein;and a newly expressed protein was identified as peroxiredoxin.The study indicates the involvement of all the differentially expressed proteins in the early responses of protein expression,and in the survival of A.sinica in the presence of copper and other heavy metals;the findings improve understanding of the organism’s adaptive responses and resistance.

Separation and recovery of Ni from copper electrolyte by crystallization of nickel ammonium sulfate double salt

The separation and recovery of Ni from the copper electrolyte by crystallization of nickel ammonium sulfate double salt were studied.It is found that the solubility of copper sulfate at the same temperature is less than that of nickel sulfate,while the solubility of copper ammonium sulfate is greater than that of nickel ammonium sulfate.So,by adding(NH_(4))_(2)SO_(4),the Ni can be selectively crystallized from the copper electrolyte.By adding(NH_(4))_(2)SO_(4)at the molar ratio of(NH_(4))_(2)SO_(4)/NiSO_(4)≤0.8,and crystallizing at−15℃for 10 h,the Ni in the copper electrolyte can be crystallized in the form of Ni(NH_(4))_(2)(SO_(4))_(2)×6H_(2)O.The qualified product of NiSO_(4)×6H_(2)O can be obtained by pyrolyzing the crystals,dissolving the pyrolysis product in water,and then concentrating the dissolved solution for crystallization.The method of double salt crystallization is a clean,environmentally-friendly,cost-effective and efficient method for separating and recovering nickel from copper electrolyte.

Deep removal of copper from cobalt sulfate electrolyte by ion-exchange

SP-C was applied for the removal of Cu^2＋ from simulated cobalt sulfate electrolyte containing Co2＋ 50 g/L and Cu2＋ 0.5-2.0 g/L. Experimental conditions included pH of 2-4, temperature of 20-60℃ and contact time of 10-40 min. The investigation demonstrated that SP-C had recommendable efficiency in adsorbing Cu2＋ from the electrolyte with 25- to 100-fold of Co2＋ The optimal adsorption conditions of SP-C were pH of 4, contact time of 30 min and ambient temperature. The study also showed that the loaded resin could be effectively eluted with 2.0 mol/L H2SO4 solution at a contact time of 40 min; the peak concentration of Cu2＋ in the eluate was about 35 g/L. The sorption characteristics of Cu2＋ by SP-C could be described by Langrnuir isotherm and the pseudo second-order kinetic equation. Infrared spectra showed that nitrogen atoms in the functional group coordinated with Cu2＋ to form coordination bands.

Effect of Preparations of Bamboo Vinegar and Copper Sulfate on Green Algae and Tobacco Seedling Growth

To provide theoretical and technical basis for the application of preparations of bamboo vinegar and copper sulfate in the prevention of green algae in floating system for tobacco seeding,the soaking and spraying methods were employed to study the effect of different concentrations of preparations of bamboo vinegar and copper sulfate on green algae and tobacco seedling growth. The results showed that the preparations of bamboo vinegar and copper sulfate of different concentrations played a strong role in inhibiting green algae growth and had better effect than copper sulfate. Spraying 1∶ 200 preparations of bamboo vinegar and copper sulfate could significantly promote tobacco seedling growth,and the leaf fresh weight increased by 15. 80% compared with CK,with significant difference; spraying 1∶ 50 preparations was not conducive to tobacco seedling growth. It was recommended to spray 1∶ 200 preparations of bamboo vinegar and copper sulfate in floating system for tobacco seeding,which could promote tobacco seedling growth and reduce green algae to varying degrees.

One step synthesis and characterization of copper doped sulfated titania and its enhanced photocatalytic activity in visible light by degradation of methyl orange

This paper reports on the synthesis of copper doped sulfated titania nano-crystalline powders with varying （2.0%-10.0%, by mass） by single step sol gel method. The synthesized photo catalyst has been characterized by employing various techniques like X-ray Diffraction （XRD）, Ultraviolet-Visible Diffuse Reflection Spectroscopy （UV-Vis DRS）, X-ray Photoelectron Spectroscopy （XPS）, Scanning Electron Microscopy （SEM）, Energy Dispersive Spectrometry （EDS）, Fourier Transform Infrared Spectroscopic Studies （FT-IR）, and Transmission Electron Microscopy （TEM）. From the XRD and TEM results, all the samples were reported in anatase phase with reduction in particle size in the range of 7 to 12 nm. SEM indicated the change in morphology of the particles. The presence of copper in titania lattice was evidenced by XPS. From UV-Vis DRS and FT-IR studies indicated that prominent absorption shift is observed towards visible region （red shift）, the entry ofCu2 ＋ into Ti02 lattice as a substitution- al dopant and S042- ions were covalently bonded with Ti4＋ on the surface of the copper doped titania respectively. The photocatalytic activity studies were investigated by considering methyl orange （MO） as dye pollutant in the presence of the visible light. The effect of various parameters like effect of dosage of the catalyst, dopant concentration, pH of the solution, and concentration of the dye was studied in detail.

Separation of halogens and recovery of heavy metals from secondary copper smelting dust

The separation of halogens and recovery of heavy metals from secondary copper smelting(SCS)dust using a sulfating roasting−water leaching process were investigated.The thermodynamic analysis results confirm the feasibility of the phase transformation to metal sulfates and to gaseous HF and HCl.Under the sulfating roasting conditions of the roasting temperature of 250℃ and the sulfuric acid excess coefficient of 1.8,over 74 wt.%of F and 98 wt.%of Cl were volatilized into flue gas.Approximately 98.6 wt.%of Zn and 96.5 wt.%of Cu in the roasting product were dissolved into the leaching solution after the water leaching process,while the leaching efficiencies of Pb and Sn were only 0.12%and 0.22%,respectively.The mechanism studies indicate the pivotal effect of roasting temperature on the sulphation reactions from various metal species to metal sulfates and the salting out reactions from various metal halides to gaseous hydrogen halides.

Sulfate-Reducing Bacteria Impact on Copper Corrosion Behavior in Natural Seawater Environment

In this study, the electrochemical corrosion behavior of copper was investigated in seawater collected from four different marine zones of Agadir coastal. These zones are different by the degree of pollution in order to study the effect of this pollution on the copper corrosion, especially the microbial pollution by sulfate reducing-bacteria (SRB). So, to prove this relationship, the microbiological analyses researching the SRB are realized. In parallel, the electrochemical impedance measurement and atomic absorption analysis are established to compare the microbiological evolution cycles with the electrochemical behavior of copper during the immersion period. In the results, we found a good correlation between the growth cycle of marine sulfate-reducing bacteria and the copper corrosion rate by the sulfur and extracellular polymeric substances (EPS) produced as bacteria metabolites. Additionally, this corrosion rate depends on the immersed time: it is maximal after the first or second month depending on the marine zone.

Formation of arsenic−copper-containing particles and their sulfation decomposition mechanism in copper smelting flue gas

The heat recovery steam generator(HRSG)of copper smelting generates a large number of arsenic−coppercontaining particles,and the in-situ separation of arsenic and copper is of importance for cutting off environmental risk and realizing resource recovery.The formation of arsenic−copper-containing particles was simulated,the method of in-situ decomposition of arsenic−copper-containing particles by pyrite was proposed,and the decomposition mechanism was confirmed.It was found that particles with high arsenic content were formed in the simulated HRSG,and copper arsenate was liable for the high arsenic content.Pyrite promoted the sulfation of copper,leading to the in-situ decomposition of copper arsenate.In this process,gaseous arsenic was released,and thus the separation of arsenic and copper was realized.

Recovery of Copper from Copper Sulfide Concentrate by Sulfation Roasting

Sulfation roasting was studied to extract copper from the copper sulfide concentrate. Sodium sulfite was added as sulfation agent to the copper sulfide concentrate during roasting in this study. Sulfur removal rate at different roasting temperatures was investigated, and the effects of roasting temperature, roasting time, and the amount of sodium sulfite on copper extraction were studied. Copper extraction higher than 96% was achieved at optimum roasting conditions.

硫酸铜对黑豆种子萌发和幼苗生长的影响

用水培法探究了硫酸铜对黑豆种子萌发、幼苗生长和生理指标的影响。结果显示,高浓度的硫酸铜抑制了黑豆种子的发芽势、发芽率、发芽指数和幼苗的鲜重、根长和苗高。随着硫酸铜处理浓度的增加,黑豆幼苗中的SOD活性呈上升趋势,POD和CAT活性先升高后降低,MDA含量逐渐升高,可溶性蛋白含量先增高后下降。结果表明,高浓度硫酸铜可以改变抗氧化酶活性,显著提高MDA含量和降低可溶性蛋白含量,从而抑制了黑豆种子的萌发和幼苗的生长。硫酸铜对黑豆幼苗根的抑制作用明显强于对地上部分的抑制。

4种水产常用药物对华鳈鱼苗的急性毒性试验

采用静态急性毒性试验法,开展了硫酸铜、敌百虫、甲苯咪唑、聚维酮碘等4种水产常用药物,对华鳈鱼苗的急性毒性试验。结果表明,硫酸铜对华鳈24,48和96 h的半致死浓度(LC_(50))分别为0.63,0.41和0.29 mg/L,安全浓度(SC)为0.05 mg/L;敌百虫对华鳈鱼苗24,48和96 h的LC_(50)分别为58.73,25.58和13.98 mg/L,SC为1.44 mg/L;甲苯咪唑对华鳈鱼苗24,48和96 h的LC_(50)分别为4.89,3.11和2.57 mg/L,SC为0.38 mg/L;聚维酮碘对华鳈24,48和96 h的LC_(50)分别为11.58,10.43和10.31 mg/L,SC为2.54 mg/L。指出,硫酸铜慎用于试验规格的华鳈鱼苗,敌百虫、甲苯咪唑、聚维酮碘可用于试验规格华鳈鱼苗的疾病防治。

甲酰胺萃取-卡尔·费休容量法测定硫酸铜中总水含量

建立卡尔·费休联合甲酰胺萃取法测定硫酸铜中的总水含量。采用甲酰胺与甲醇混合作为萃取剂提取硫酸铜中的游离水及结合水,卡尔·费休容量法测定硫酸铜中水分含量。结果表明甲酰胺与甲醇体积比为4∶6作为提取溶液,萃取时间为1 min时,卡尔·费休容量法可以全部检出硫酸铜中的水分,因此采用卡尔·费休联合甲酰胺萃取法测定硫酸铜的水分含量,可以完全检出硫酸铜中的游离水和结晶水,且精密度良好,经验证可以作为硫酸铜中总水含量的可靠检测方法。

低浓度硫酸铜对化学镀Ni-P镀层微观结构及性能的影响

为改善镍磷(Ni-P)镀层的表面质量、提高Ni-P镀层的性能,在化学镀Ni-P镀液中加入少量的硫酸铜(CuSO_(4)·5H_(2)O)制备Ni-P镀层。利用扫描电镜、能谱仪、X射线衍射仪分析了镀层的表面形貌、成分和结构,研究了CuSO_(4)·5H_(2)O浓度对镀层的微观结构、表面粗糙度、光泽度、硬度、耐磨性和耐蚀性的影响。研究表明:当CuSO_(4)·5H_(2)O浓度为0.1 g/L时,镀层为致密的非晶态节瘤状组织,具有最佳的耐蚀性;当CuSO_(4)·5H_(2)O浓度为0.2 g/L时,镀层表面质量最好,硬度高、耐磨性优异,但镀层中出现少量微晶态Ni-Cu固溶体,耐蚀性下降;当CuSO_(4)·5H_(2)O浓度超过0.2 g/L后,镀层为混晶态菜花状组织,镀层表面的质量和耐蚀性随CuSO_(4)·5H_(2)O浓度的增加不断恶化。

Separation and recovery of Cu and As during purification of copper electrolyte

Cu, As, Sb and Bi in copper electrolyte could be efficiently removed by reducing with SO2 followed by evaporative crystallization. As2O3 and CuSO4·5H2O were obtained after crystallized product was treated by dissolution, oxidation, neutralization, sedimentation, filtration and evaporative crystallization. The removal rates of Cu, As, Sb and Bi are 87.1%, 83.9%, 21.0% and 84.7%, respectively, when As （Ⅴ） in copper electrolyte is fully reduced to As （Ⅲ） by SO2, and the H2SO4 in concentrated copper electrolyte is 645 g/L. The removal rate of As is 92.81% when 65 g crystallized product is dissolved in 200 mL water at 30 ℃. The CuSO4·5H2O content is 98.8% when the filtrate is purified under the conditions that n（Fe）：n（As） is 1.2, the dosage of H2O2 is 19 times the stoichiometric needed, temperature is 45 ℃, time is 40 min, pH is 3.7, and then is evaporation crystallized.

硫酸盐还原菌修复四川某典型铜矿选冶渣复合重金属污染研究

为实现铜矿选冶渣复合重金属污染的修复治理,以四川某铜矿选冶渣为研究对象,采用硫酸盐还原菌为固化/稳定化微生物,探讨了其生长特性、溶液中重金属离子变化规律及修复效果。结果表明,硫酸盐还原菌在修复铜矿选冶渣时生长迅速,适合作为修复复合重金属污染的微生物;由于铁、锌、铜、铅等重金属活性差异较大,因此其固化效果亦有显著差异;修复30 d时,重金属Cu、Pb、Zn、Fe的最佳接种量分别为5%、10%、15%和15%,生物有效性降低率分别为72.36%、98.37%、43.01%和79.31%;随着固化时间的增加,溶液中重金属离子的浓度先增后减,但并不影响其修复效果。因此,硫酸盐还原菌可同时修复多种重金属离子,有效解决某铜矿选冶渣中铁锌铜铅的复合重金属污染。

三种药剂对水绵控制效果的比较分析

选择硫酸铜、扑草净以及肉桂酸为控藻药剂,以常见的丝状藻-水绵为受试对象,比较了三种药剂的控藻效果。研究结果表明,三种药剂的施用对水绵生长、代谢及抗逆功能均造成了影响,但影响程度因药剂类型、药剂浓度及施用时间而异。相同浓度条件下,硫酸铜、扑草净的控藻效果均优于肉桂酸,但硫酸铜的施用会造成环境累积和生物放大等危害。结合控藻有效性、安全性和经济性,选择1 mg/L扑草净为最优方案。