Interphase migration and enrichment of lead and zinc during copper slag depletion

An interphase migration and enrichment model of lead and zinc during molten copper slag depletion was established.The occurrence of various components in copper slag was predicted using sulfur-oxygen potential calculations and confirmed through high-temperature experiments.The recovery rate of copper can reach 90.13%under the optimal conditions of 1200°C,an iron to silicon mass ratio of 1.0,3 wt.%ferrous sulfide,and a duration of 45 min.Lead(54.07 wt.%)and zinc(17.42 wt.%)are found in the flue dust as lead sulfate,lead sulfide,and zinc oxide,while copper matte contains lead(14.44 wt.%)and zinc sulfide(1.29 wt.%).The remaining lead and zinc are encapsulated as oxides within the fayalite phase.

Selective separation of copper and cadmium from zinc solutions by low current density electrolysis

Copper and cadmium ions were selectively separated from zinc sulphate aqueous solution or zinc ammonia/ammonium sulphate aqueous solution by low current density electrolysis.It was shown that the concentration of cadmium ion in zinc sulphate solution decreased from 4.56 g/L to 0.18 g/L in an electrolysis time of 8.5 h,whilst it decreased from 5.16 g/L to lower than 0.005 g/L in zinc ammonia/ammonium sulphate aqueous solution.On the other hand,the deposition rate of copper was so low that it was difficult to separate copper and cadmium ions from the zinc ammonia/ammonium sulphate aqueous solution during electrolysis.But copper ion could be decreased to 0.002 g/L in this solution through solvent extraction by using kerosene diluted LIX984N as extractant.Therefore,it is favorable to recover cadmium ion from the zinc ammonia/ammonium sulphate solution by electrolysis after solvent extraction of copper.

Removal of Cadmium, Copper, and Zinc from Aqueous Solution by Activated Carbon Impregnated with 8-Hydroxyquinoline

The removal of cadmium, copper, and zinc from aqueous solution using activated carbon impregnated with 8-Hydroxyquinoline （oxine） was investigated in this study. The study was conducted using a completely mixed batch technique. Quantitative evaluation of the experimental results showed that the adsorption capacity of oxine impregnated activated carbon was higher than that of the virgin activated carbon for the three heavy metals. For oxine impregnated activated carbon, the Freundlieh distribution coefficient, kd , values were 23, 100, and 104 times larger than those of the virgin activated carbon for cadmium, copper, and zinc, respectively. Moreover, for oxine impregnated activated carbon, the kd values followed the sequence Cu 〉 Zn 〉 Cd which aggress well with the stability constants reported in the literature for the complexation of the three heavy metals with 8-Hydroxyquinoline.

Electrolytic Removal of Cadmium, Lead and Copper from Wastewater

The respective compounds of copper, cadmium and lead, owing to their strong toxic potential, as a result of industrial effluent, have left a trail of contamination in humans and the environment. This paper aimed to study the electrode position on the removal of aqueous solutions of cadmium, lead and copper, using an electrolytic cell with a metallic screen cathode of carbon steel and platinum anode. Removal efficiencies were obtained by analysis of the solutions before and after treatment, using the methodology of cathodic-stripping voltammetry with a mercury drop electrode to quantify the concentrations of Cd2+, Pb22+ and Cu2+. Removal efficiencies were obtained of 94.07% for cadmium, 94.71% for lead and 96.19% for copper, demonstrating that electrolytic removal is an effective technique for the removal of these metals from simulated industrial wastewater.

Effects of field application of phosphate fertilizers on the availability and uptake of lead, zinc and cadmium by cabbage (Brassica chinensis L.) in a mining tailing contaminated soil

A field trial was conducted to evaluate the reduction of bioavailability of heavy metals including lead (Pb), zinc (Zn) and cadmium (Cd) in a soil contaminated by mining tailings in Shaoxing, Zhejiang, China. Three commercial phosphate (P) fertilizers including phosphate rock (PR), calcium magnesium phosphate (CMP), and single superphosphate (SSP) were applied to the plot at three P application rates, 50, 300, and 500 g/m2 with 9 treatments and control (CK). Plants, water soluble and exchangeable (WE) extra...

Effects of Cadmium, Lead, and Zinc on Size of MicrobialBiomass in Red Soil

A laboratory incubation experiment was conducted to study the influence of cadmium (Cd), lead (Pb)and zinc (Zn) on the size of the microbial biomass in red soil. All the three metals were applied, separately,at five different levels that were: Cd at 5, 15, 30, 60 and 100 μg g-1; Pb at 100, 200, 300, 450 and 600 μg g-1 and Zn at 50, 100, 150, 200 and 250 μg g-1 soil. In comparison to uncontaminated soil, the microbial biomass carbon and biomass nitrogen decreased sharply in soils contaminated with Cd, Ph and Zn. A more considerable increase in the microbial biomass C: N ratio was observed in the metal contaminated soils than the non-treated control. Among the tested metals, Cd displayed the greatest biocidal effect followed by Zn and Pb, showing their relative toxicity in the order of Cd > Zn > Pb.

Study on the response of wheat to lead, cadmium and zinc

The effect of lead, cadmium and zinc on the transcriptions and structures of 5 DNA fragments was studied by RNA slot blot hybridization and the analysis of restriction fragment length polymorphism (RFLP). The seeds of three wheat strains (Yunmai29, 1257, 5118) which had grown in contaminated area, Huize Lead Zinc Mine, Yunnan Province of China and in uncontaminated area were taken as the experimental materials. No obvious change of DNA structure was detected, but there were many differences in the DNA transcription levels. These results implied that lead, cadmium and zinc might inhibit DNA transcription and had much more effect on gene expression than structure in wheat, which might acclimate to metal pollution after having grown in pollution area for a long time and the interference of these metal ions in gene expression might be one of main mechanisms of metal toxicity and plant adaptation. The results also showed the microevolution of wheat in the lead zinc mine.

METALLOGENIC ANALYSIS OF THE DEXING COPPER-GOLD-LEAD-ZINC POLYMETALLIC DEPOSITS, JIANGXI PROVINCE, CHINA

The paper discusses the tectonic setting of the fortnation of the Dexing giant copper-gold-lead-zinc deposit and its geological features and demonstrates in detail the polygenetic compound mechanism of its formation.

Does copper reduce cadmium uptake by different rice genotypes?

A hydroponics experiment was conducted to investigate the effect of copper （Cu） on cadmium （Cd）, calcium （Ca）, iron （Fe）, and zinc （Zn） uptake by several rice genotypes. The experiment was carried out as a 2×2×4 factorial with four rice genotypes and two levels of Cu and Cd in nutrient solution. Plants were grown in a growth chamber with controlled environment. The results showed a significant difference between the biomass of different rice genotypes （P 〈 0.001）. The Cd and Cu concentration in the solution had no significant effect on the biomass. The addition of Cu significantly decreased Cd uptake by shoots and roots of rice （P 〈 0.001）. The Cd concentration did not significantly influence Ca uptake by plants, whereas the Cu concentration did （P = 0.034）. There was a significant influence of Cd on Fe uptake by shoots and roots （P 〈 0.001, P = 0.003, respectively）. Zn uptake decreased significantly as the addition of Cd and Cu increased in shoots. We concluded that Cu had significant influence on Cd uptake. The possible mechanisms were discussed.

Simultaneous determination of trace Cu^(2+), Cd^(2+), Ni^(2+) and Co^(2+) in zinc electrolytes by oscillopolarographic second derivative waves

Simultaneous determination of impurity metal ions in high concentration zinc solution is very important for zinc hydrometallurgy,and the purpose is to establish a method for determining the trace Cu^2+,Cd^2+,Ni^2+and Co^2+in zinc electrolytes at the same time using the second derivative waves of single sweep oscillopolarography.Factors affecting the derivative waves of the ions were researched in a medium of dimethylglyoxime(DMG)-sodium citrate-sodium tetraborate.The results indicated that the interferences of a high concentration of Zn^2+and most other coexisting ions on the determination can be eliminated;when the Cu^2+,Cd^2+,Ni^2+and Co^2+are in the ranges of1×10^-7-3×10^-4,6×10^-7-2×10^-4,2×10^-8-1×10^-5and1×10^-8-3×10^-5mol/L,respectively,the relationships between the peak currents of the second derivative waves and the concentrations are linear;the detection limits to determine the Cu^2+,Cd^2+,Ni^2+and Co^2+are8×10^-8,2×10^-7,6×10^-9and4×10^-9mol/L,respectively.Without any sample pretreatment,the method was used to directly determine the trace Cu^2+,Cd^2+,Ni^2+and Co^2+in actual zinc electrolytes with satisfactory results.The method is simple,sensitive and rapid.

Mass transfer process in replacement-column purification device in zinc hydrometallurgy

It is important to remove the impurities, such as copper and cadmium, from leaching solution in zinc hydrometallurgy. To improve purification efficiency, a replacement-column purification device was proposed and its mass transfer characteristics and purification efficiency were experimentally studied. The results show that purification efficiency increases with the decrease of the zinc powder diameter and decreases with the increase of solution velocity. If appropriate structure and operation parameters are used, it is possible to make purification efficiency more than 99%, but the diameter of zinc powder should be larger than 0.45 mm. For the velocity of 0.05-0.7 cm/s, mass transfer coefficient kc is in the range of 3.94×10-7-2.76×10-6 m/s, and increases with the decrease of zinc powder diameter and the increase of solution velocity. Moreover, it can be derived by mass transfer correlations of Sherwood number:Sh=0.1069Re0.5Sc0.33, for 0.3<Re<6.

Toxicity of copper,lead,and cadmium on the motility of two marine microalgae Isochrysis galbana and Tetraselmis chui

Computer assisted movement tracking was used to characterize the motility of two marine microalgae, lsochrysis galbana and Tetraselmis chui, and to investigate the toxicity of Cu, Pb, and Cd on motile percentage, curvilinear velocity, average path velocity, straight line velocity, linearity, straightness, and wobble. Except for motile percentage, all other motility parameters differed significantly between L galbana and T. chui. Based on relative motile percentage data, the median effective concentration （ECs0） of Cu on the motility of L galbana and T. chui was 31.4 and 1.3 gmol/L, respectively, while for Pb it was 37.8 and 10.9 ~tmol/L and for Cd it was 12 1.6 and 37.8 ~tmol/L, respectively. Compared to L galbana, T. chui was more sensitive to all tested metals. The toxic effect of the heavy metals on motility exhibited the following decreasing order for both species： Cu 〉 Pb 〉 Cd. Our results indicate that L galbana and T. chui motility is sensitive to heavy metals and can be used as an indicator for toxicology bioassays.

Phytoremediation potential of charophytes:Bioaccumulation and toxicity studies of cadmium,lead and zinc

The ability for usage of common freshwater charophytes,Chara aculeolata and Nitella opaca in removal of cadmium （Cd）,lead （Pb） and zinc （Zn） from wastewater was examined.C.aculeolata and N.opaca were exposed to various concentrations of Cd （0.25 and 0.5 mg/L）,Pb （5 and 10 mg/L） and Zn （5 and 10 mg/L） solutions under hydroponic conditions for 6 days.C.aculeolata was more tolerant of Cd and Pb than N.opaca.The relative growth rate of N.opaca was drastically reduced at high concentrations of Cd and Pb although both were tolerant of Zn.Both macroalgae showed a reduction in chloroplast,chlorophyll and carotenoid content after Cd and Pb exposure,while Zn exposure had little effects.The bioaccumulation of both Cd and Pb was higher in N.opaca （1544.3 μg/g at 0.5 mg/L Cd,21657.0 μg/g at 10 mg/L Pb） whereas higher Zn accumulation was observed in C.aculeolata （6703.5 μg/g at 10 mg/L Zn）.In addition,high bioconcentration factor values （〉 1000） for Cd and Pb were observed in both species.C.aculeolata showed higher percentage of Cd and Pb removal （〉 95%） than N.opaca and seemed to be a better choice for Cd and Pb removal from wastewater due to its tolerance to these metals.

Physiological and Biochemical Responses of Perennial Ryegrass Mixed Planting with Legumes under Heavy Metal Pollution

In artificially controlled pot experiments,perennial ryegrass was mixed with other leguminous plants(white clo-ver and alfalfa)and treated with lead,zinc and cadmium(337 mg·kg^(-1),648 mg·kg^(-1),and 9 mg·kg^(-1),respectively)to simulate compound pollution conditions.The results showed that the concentrations of heavy metals,trans-port factors,and bioconcentration factors in mixed planting of ryegrass decreased compared with those in mono-culture.Regardless of whether heavy metal pollution was introduced,mixed planting increased the aboveground and underground biomasses of ryegrass.The different mixed planting treatments had no significant impact on the chlorophyll concentration of ryegrass.The mowing time,mixed planting treatment,and heavy metal treatment had impacts on antioxidant and osmotic adjustment substances,and there were some interactions.The mixed planting treatment did not significantly affect glutathione concentration,cysteine concentration,or nonprotein thiol.Mixed planting generally increased the nitrogen and phosphorus concentrations of ryegrass while reducing the stoichiometric ratio of carbon,nitrogen,and phosphorus.These results suggest that the mixed planting of ryegrass with legumes promotes the growth of ryegrass in the presence of high concentrations of heavy metal pollution.However,it does not enhance the ability of ryegrass to remediate heavy metal pollution in the soil.

Assessing the Metal Recovery Value of Municipal Solid Waste Incineration Residues: Impact of Pretreatment on Fly Ash and Bottom Ash

This paper focuses on evaluating the metal recovery potential of Municipal Solid Waste Incineration (MSWI) residues, with particular emphasis on the influence of pretreatment methods on MSWI fly ash and bottom ash. We assess the effectiveness of these pretreatments in enhancing the concentration of valuable metals and compare the metal content before and after treatment. Our findings reveal that water washing significantly enhances fly ash’s zinc and copper content, surpassing the minimum industrial-grade requirements. Mechanical sieving is an efficient pretreatment method for bottom ash, with the zinc concentration inversely related to particle size. Additionally, copper content peaks in the 1 - 2 mm particle size range for both bottom ash samples. These results provide valuable insights into the potential for metal recovery from MSWI residues. They hold significance for relevant research, engineering practices, and policy formulation.

高频燃烧红外吸收法测定铜铅锌多金属矿中的碳、硫

铜铅锌多金属矿中的碳、硫元素对矿产开采、钢铁冶炼及环境保护等方面有着重要的影响,对碳、硫的准确、快速定量检测至关重要,但未见有对铜铅锌多金属矿中的碳、硫同时测定的研究。将铜铅锌多金属矿中碳、硫含量科学分为C1、C2、S1、S2四段,并分别对样品称样量、助熔剂加入比例及种类等因素进行探究,建立了高频燃烧红外吸收法测定铜铅锌多金属矿中的碳、硫的方法,并通过标准物质验证了方法的准确度、精密度与再现性。结果表明,C1、C2、S1、S2称样量分别为0.200 0、0.100 0、0.100 0、0.100 0 g,助熔剂组合方式为Fe+W=(0.6000+0.6000)、(0.6000+0.6000)、(0.9000+0.6000)、(0.6000+0.600 0) g为最佳实验条件。C1、C2、S1、S2曲线的相关系数分别为0.999 4、0.995 9、0.999 9、0.998 9,测定结果的相对标准偏差(RSD,n=11)分别为1.3%、1.5%、1.3%、1.3%,使用3种不同型号的红外碳硫仪进行对比实验,相对标准偏差(RSD,n=11)为0.56%~6.5%。结果均显示,方法准确、可靠,满足铜铅锌多金属矿中碳、硫的同时、准确快速定量检测的要求。

青海某铜铅锌多金属矿选矿工艺研究

针对青海某铜铅锌多金属矿,进行了不同类型捕收剂对铜铅锌浮选分离影响的试验,重点考察了新型捕收剂4037B、P5100C、QBSC的选别效果。结果表明:P5100C和QBSC更有利于铜、铅分离,在最佳条件下,采用铜快速浮选—铜铅混选—铜铅再磨分离—锌浮选流程,获得铜品位35.56%、铜回收率75.23%的铜精矿;铅品位45.02%、铅回收率71.92%的铅精矿;锌品位41.49%、锌回收率72.58%的锌精矿;含铜20.14%、含铅8.90%、含锌28.38%,铜回收率11.93%、铅回收率6.77%、锌回收率11.81%的混合精矿。全流程铜总回收率97.94%,铅总回收率96.62%,锌总回收率92.64%。

螯合锌肥对小白菜生长、品质、吸收镉铅及土壤酶活性的影响

以小白菜为供试作物,研究了不同螯合锌肥及螯合锌添加量(1%、3%和5%)对Cd和Pb复合污染土壤上小白菜的生长、品质及吸收镉铅的影响。结果表明,乙二胺四乙酸二钠螯合锌肥(EDTA-Zn)和聚天门冬氨酸螯合锌肥(PASP-Zn)均明显促进了小白菜的生长和品质(维生素C、可溶性糖和叶绿素含量均提高),而三聚磷酸钾螯合锌肥(KTPP-Zn)则抑制了小白菜的生长和品质。除PASP-Zn1、PASP-Zn3外,其余处理的小白菜硝酸盐含量均显著增加,增幅为3.23%~16.27%。大部分处理的小白菜根部和地上部中Cd和Pb含量均增加,其中EDTA-Zn5和PASP-Zn5处理显著增加了小白菜根部Pb含量,增幅分别为44.65%和35.29%。3种螯合锌肥均表现为螯合锌添加量为5%时的小白菜根和地上部的Cd和Pb含量最高,说明螯合锌肥添加量越高促进了小白菜对土壤中重金属Cd和Pb的富集。此外,总体上3种螯合锌肥均促进了土壤过氧化氢酶、蔗糖酶、脲酶和酸性磷酸酶活性,其中PASPZn和KTPP-Zn对土壤酶活性的促进作用要大于EDTA-Zn。本研究为螯合肥在重金属污染土壤上的施用提供了重要的指导意义。

铜熔炼渣的火法回收工艺与铅锌锑富集规律

铜精矿火法冶金后产生的熔炼渣经浮选回收铜后,尾渣含Pb、Zn和Sb,仍具有一定回收经济价值。浮选法对铜熔炼渣中Pb、Zn和Sb的回收率低,而火法熔炼通过高温和碳热还原可以有效分离这些元素。对直接还原熔炼、造锍还原熔炼和氧化-还原熔炼3种典型的火法回收工艺进行了对比中试试验。结果表明:火法回收工艺可达到理想的铜回收率,但不同工艺对Pb、Zn和Sb的回收效果不同;直接还原熔炼提高了Pb的回收率;造锍还原熔炼提高了Zn的回收率;熔炼法需消耗大量还原剂和能源,经济性需慎重考虑。火法熔炼适合作为铜回收的备用工艺进行研究。

从铁矾渣侧吹熔炼—烟化法烟灰中回收锌镉及其净化除杂

研究了采用酸性浸出—硫化除杂法从铁矾渣侧吹熔炼—烟化法产出的烟灰中回收锌、镉,并选择性除去浸出液中的铜,产物用以制备镉掺杂硫化锌;在热力学分析基础上,探明了硫酸体系下锌浸出率影响因素及其浸出动力学;通过正交试验明确了各参数对硫化钠选择性除杂的影响。结果表明:烟灰中锌主要以氧化锌形式存在,其浸出过程符合混合控制,表观活化能为73.70 kJ/mol;在最佳条件下,锌浸出率达98.99%。以Na_(2)S用量为理论添加量的3.2倍,控制体系pH=2.0,铜去除率可达95.97%,同时有效保留锌、镉,实现了铜与锌、镉的选择性分离。