X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hi...X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hindering widespread technology adoption.Accurate classification models are crucial to determine if actual grade exceeds the sorting threshold using localized XRF signals.Previous studies mainly used linear regression(LR)algorithms including simple linear regression(SLR),multivariable linear regression(MLR),and multivariable linear regression with interaction(MLRI)but often fell short attaining satisfactory results.This study employed the particle swarm optimization support vector machine(PSO-SVM)algorithm for sorting porphyritic copper ore pebble.Lab-scale results showed PSO-SVM out-performed LR and raw data(RD)models and the significant interaction effects among input features was observed.Despite poor input data quality,PSO-SVM demonstrated exceptional capabilities.Lab-scale sorting achieved 93.0%accuracy,0.24%grade increase,84.94%recovery rate,57.02%discard rate,and a remarkable 39.62 yuan/t net smelter return(NSR)increase compared to no sorting.These improvements were achieved by the PSO-SVM model with optimized input combinations and highest data quality(T=10,T is XRF testing times).The unsuitability of LR methods for XRF sensor-based sorting of investigated sample is illustrated.Input element selection and mineral association analysis elucidate element importance and influence mechanisms.展开更多
The application of pressure leaching technology in the treatment of high-copper and high-arsenic dust was studied.The pressure leaching technique was determined as follows:the liquid to solid ratio(mL/g)of 5:1,the lea...The application of pressure leaching technology in the treatment of high-copper and high-arsenic dust was studied.The pressure leaching technique was determined as follows:the liquid to solid ratio(mL/g)of 5:1,the leaching temperature of 453 K,the retention time of 2 h,the initial sulfuric acid concentration of 0.74 mol/L,the oxygen partial pressure of 0.7 MPa,and the agitation speed of 500 r/min.Under these conditions,95%of copper and 99%of zinc and only 6%of iron in the dust were leached,while about 20%of arsenic was also leached.The leaching technique was optimized further to restrain the leaching of arsenic by adding a small quantity of ferrous iron into the leaching system(c(Fe2 +)=0.036 mol/L).Copper and zinc can be effectively separated from arsenic and iron in the leach.The optimal pressure leaching technique of high-copper and high-arsenic smelter dust is proved to be effective.展开更多
A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arse...A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.展开更多
This paper describes the structure and function of the intelligent decision support system (IDSS) on the process of nickel matte smelter. The knowledge and model base system based on fuzzy-decision rules ale specially...This paper describes the structure and function of the intelligent decision support system (IDSS) on the process of nickel matte smelter. The knowledge and model base system based on fuzzy-decision rules ale specially suggested. The IDSS possesses the self-learning and adaptive properties, andhas been used for managing and analyzing the production information, optimizing the composition of the charge mixture, and deciding the optimal operational conditions. Electric energy consumption has been reduced remarkably and the yield of nickel has been increased.展开更多
The preparation of granulated adsorption material of water-quenched slag/rectorite composite and the treatment of Cu （ Ⅱ ）-containing copper smelter wastewater with the adsorption material were studied. The experim...The preparation of granulated adsorption material of water-quenched slag/rectorite composite and the treatment of Cu （ Ⅱ ）-containing copper smelter wastewater with the adsorption material were studied. The experimental results showed that under the conditions with the mass ratio of water-quenched slag to rectorite of 1：1, 10% additive of industrial starch （IS）, and 50% water, and a calcination temperature of 400 ℃, the granulated adsorption material prepared had a density of 1.06 kg/m^3, a porosity of 62.29%, water absorption rate of 58.82%, and compressive strength of 2.22 MPa. The efficiency of wastewater treatment was the best, whereas the rate of spallation loss was low. Under the conditions of natural pH, with the addition of the granulated adsorption material of 0.05 g/mL, a reaction time of 40 minutes, and temperature of 25 ℃, the efficiency of the granulated adsorption material for the removal of Cu （ Ⅱ ） ions from the copper smelter wastewater attained 98.2%, and the quality indexes of the wastewater after treatment conformed with the first level of integrated wastewater discharge standard （GB8978-1996）. The reclamation of the used granulated adsorption material was carried out by de-sorption of the Cu （ Ⅱ） ions from the surface with 1 mol/L sodium chloride solution. The de-sorption rate was 96.4%, and the adsorption material can be reused many times to treat copper smelter wastewater.展开更多
The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature...The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature were investigated in desulfurization experiments. The X-ray diffraction(XRD) and X-ray fluorescence(XRF) analyses show that the optimum conditions are LSS:ISS of 3:7 and temperature of 1350°C. The composition of desulfurization products is mainly Zn Fe2O4, and the desulfurization rate of 99.66% is obtained under optimum conditions. The thermogravimetric(TG) and differential scanning calorimeter(DSC) analyses demonstrate that reductant is necessary for decomposition and reduction of zinc ferrite in desulfurization product. The effects of reductant, temperature and feeding modes on iron enrichment were investigated in reduction experiments. The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) determination show that the iron content of reduction product is up to 99.36% under optimum conditions of coke as reductant, reduction temperature of 1450°C and the feeding mode of premixing.展开更多
This work describes the experimental results of pyrometallurgical removing of arsenic from the dust collected in the electrostatic copper precipitators within the gas cleaning system of a Copper Flash Smelting Furnace...This work describes the experimental results of pyrometallurgical removing of arsenic from the dust collected in the electrostatic copper precipitators within the gas cleaning system of a Copper Flash Smelting Furnace. The generation of dust in the copper smelting worldwide ranges from 2 - 15 wt% per ton of a copper concentrate. In Chile, copper smelters produce approximately 110 kt/y of dust with a concentration of arsenic between 1 and 15 wt%. The dust is a complex of metals oxides and sulfurs with copper concentrations greater than 10 wt% and relatively high silver concentrations. Since its high arsenic concentration, it is difficult to recover valuable metals through hydrometallurgical processes or by direct recirculation of the dust in a smelting furnace. Thus, the development of pyrometallurgical processes aimed at reducing the concentration of arsenic in the dust (<0.5 wt%) is the main objective of this study, giving particular attention to the production of a suitable material to be recirculated in operations of copper smelting. The work provides a detailed characterization of the dust including the Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN), Scanning Electron Microscope-Energy Dispersive X-ray Analysis (SEM/EDS), X-Ray Diffraction (XRD), the elemental chemical analysis using Atomic Adsorption (AAS), and X-Ray Fluorescence (X-RF). By considering that arsenic volatilization requires a process of sulfidation-decomposition-oxidation, this work seeks to explore the roasting of mixtures of copper concentrate/dust, sulfur/dust, and pyrrhotite/dust. By the elemental chemical analysis of the mixture after and before the roasting process, the degree of arsenic volatilization was determined. The results indicated the effects of parameters such as roasting temperature, gas flow, gas composition, and the ratio of mixtures (concentrate/dust, sulfur/dust, or pyrrhotite/dust) on the volatilization of arsenic. According to the findings, the concentration of arsenic in the roasted Flash Smelting dust can be reduced to a relatively low level (<0.5 wt%), which allows its recirculation into an smelting process.展开更多
Case reports of indium-related lung disease in workers have raised public concern to the human toxicity of indium （In） and its compounds. However, studies evaluating the exposure or health of workers in In smelting ...Case reports of indium-related lung disease in workers have raised public concern to the human toxicity of indium （In） and its compounds. However, studies evaluating the exposure or health of workers in In smelting plants are rare. Therefore, in this study, we focused on four In smelting plants, with the main objective of characterizing In in smelter plants in China and discussing the potential exposure biomarkers of In exposure.展开更多
Surface soil samples were collected from Sarcheshmeh Copper Smelter Plant and analyzed for 16 Polycyclic Aromatic Hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs), and heavy metals to determine t...Surface soil samples were collected from Sarcheshmeh Copper Smelter Plant and analyzed for 16 Polycyclic Aromatic Hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs), and heavy metals to determine their concentrations, distributions, and probable sources of contamination. The mean concentrations of ΣPAHs, As, Pb, Zn, Se, Cd, and Cr in the soil samples were 878.8, 850, 2185, 2455, 21, and 24 mg/kg, respectively. Besides, their Toxic Equivalents (TEQs) were calculated. The samples generally displayed elevated concentrations of heavy metals when finding the toxic values of dioxin/furan compounds in comparison to the limit values for industrial uses. The background concentrations, molecular indices, and ring classes of the heavy metals indicated that their sources and those of PAHs were both geogenic and pyrolitic. The mean concentrations of total PAHs, PCDD/Fs, and heavy metals were compared with the reports from industrial areas throughout the world and the contamination rates at Sarcheshmeh Copper Plant were found to be moderate.展开更多
The flow and heat transfer of the basalt melt in the boundary layer on a flat plate is considered. The conditions of formation of the layer and the intensity of heat transfer are determined. A self-similar analysis us...The flow and heat transfer of the basalt melt in the boundary layer on a flat plate is considered. The conditions of formation of the layer and the intensity of heat transfer are determined. A self-similar analysis using the symmetry method was used. A system of ordinary differential equations in self-similar form is obtained. The fluid flow and heat transfer of molten basalt at a laminar steady-state flow in the feeder furnaces are numerically researched. The term “protective layer” on the interface “basalt melt-lining” is introduced. The dependences for the calculation of dimensionless shear stresses and the Nusselt number on the lining surface are obtained. The conditions of rational organization of the technological process of basalt melt feeding in the furnace feeder are formulated.展开更多
Slag is waste from pyrometallurgical processing, usually stored in stacks or warehouses around or near smelters. Slag research has focused on potential environmental problems associated with slag weathering or process...Slag is waste from pyrometallurgical processing, usually stored in stacks or warehouses around or near smelters. Slag research has focused on potential environmental problems associated with slag weathering or processing for secondary metal recovery and/or other uses (construction, landscaping, etc.). Located in northern Mexico, the city of Chihuahua has a mining history that dates back to the eighteenth century. A lead smelter located southeast of Chihuahua City;closed in 1997, leaving behind a large pile of slag. In this study, a chemical analysis of smelter slag was carried out. The tailings contain Zn (15 - 35 wt%), Pb (0.5 - 4 wt%), As (0.6 wt%), Sn (888 ppb) and Hg (170 ppb). XRD identified several minerals such as hardystonite (Ca<sub>2</sub>ZnSi<sub>2</sub>O<sub>7</sub>), melanotekite (), kentrolite () and sphalerite (ZnS) in the glass. Major elements are present in phases such as monticellite (CaMgSiO<sub>4</sub>), kirschsteinite (CaFe<sup>2+</sup>SiO<sub>4</sub>), hedenbergite (CaFe<sup>2+</sup>Si<sub>2</sub>O<sub>6</sub>), babingtonite (Fe<sub>2</sub>Si<sub>3</sub>O<sub>9</sub>), magnetite (Fe<sub>3</sub>O<sub>4</sub>), and calcite (CaCO<sub>3</sub>). Whether the goal is reuse, recycling or remediation, research into the properties of slag and its environmental and health impacts (on vulnerable exposed populations) should continue to be relevant.展开更多
This paper describes the experimental results of removing arsenic from the dust collected in electrostatic precipitators of a fluidized bed roasting furnace (RP dust). The fluidized bed roasting process generates 600 ...This paper describes the experimental results of removing arsenic from the dust collected in electrostatic precipitators of a fluidized bed roasting furnace (RP dust). The fluidized bed roasting process generates 600 kilotons of copper concentrate per year with 3 - 6 wt% of concentration of arsenic, producing a roasted product with a low content of arsenic below 0.3 wt%. The process generates 27 kilotons of RP dust per year with a concentration of arsenic of the order of 5 wt% and copper concentration of around 20 wt%. Subsequently, the dust collected in the electrostatic precipitators is treated by hydrometallurgical methods allowing the recovery of copper, and the disposition of arsenic as scorodite. This work proposes to use a pyrometallurgy process to the volatilization of arsenic from RP dust. The obtained material can be recirculated in copper smelting furnaces allowing the recovery of valuable metals. The set of experiments carried out in the roasting of the mixture of copper concentrate/RP dust and sulfur/RP dust used different ratios of mixtures, temperatures and roasting times. By different techniques, the characterization of the RP dust determined its size distribution, morphology, and chemical and mineralogical composition. RP dust is a composite material of small particles (<5 μm) in 50 μm agglomerates, mostly amorphous, with a complex chemical composition of sulfoxides. The results of the roasting experiments indicated that for a 75/25 weight ratio of the mixture of the copper concentrate/PR dust under 700℃, 15 minutes of roasting time with injection of air, the volatilization of arsenic reached 96% by weight. The arsenic concentration after the roasting process is less than 0.3% by weight. For a 5/95 mixture of sulfur/RP dust, at 650℃, the volatilization of arsenic reached a promissory result of 67%. Even that this study was carried out for a particular operation, the results have the potential to be extended to dust produced in the roasting of concentrates of nickel, lead-zinc, and gold.展开更多
The Shenyang Smelter,which is located in Shenyang,the well-known industrialcity of northeastern China,is one of the most important non-ferrous metallurgicalplants in the people’s Republic of China.Shenyang is the cap...The Shenyang Smelter,which is located in Shenyang,the well-known industrialcity of northeastern China,is one of the most important non-ferrous metallurgicalplants in the people’s Republic of China.Shenyang is the capital of Liaoning Provin-ce,where transportation is very convenient by the railway,and it is connected direc-tly with the famous seaports-Dalian and Tianjin.展开更多
The abandoned smelters present a substantial pollution threat to the nearby soil and groundwater.In this study,63 surface soil samples were collected from a zinc smelter to quantitatively describe the pollution charac...The abandoned smelters present a substantial pollution threat to the nearby soil and groundwater.In this study,63 surface soil samples were collected from a zinc smelter to quantitatively describe the pollution characteristics,ecological risks,and source apportionment of heavy metal(loid)s(HMs).The results revealed that the average contents of Zn,Cd,Pb,As,and Hg were 0.4,12.2,3.3,5.3,and 12.7 times higher than the risk screening values of the construction sites,respectively.Notably,the smelter was accumulated heavily with Cd and Hg,and the contribution of Cd(0.38)and Hg(0.53)to ecological risk was 91.58%.ZZ3 and ZZ7 were the most polluted workshops,accounting for 25.7%and 35.0%of the pollution load and ecological risk,respectively.The influence of soil parent materials on pollution was minor compared to various workshops within the smelter.Combined with PMF,APCS-MLR and GIS analysis,four sources of HMs were identified:P1(25.5%)and A3(18.4%)were atmospheric deposition from the electric defogging workshop and surface runoff from the smelter;P2(32.7%)and A2(20.9%)were surface runoff of As-Pb foul acid;P3(14.5%)and A4(49.8%)were atmospheric deposition from the leach slag drying workshop;P4(27.3%)and A1(10.8%)were the smelting process of zinc products.This paper described the distribution characteristics and specific sources of HMs in different process workshops,providing a new perspective for the precise remediation of the smelter by determining the priority control factors.展开更多
A large amount of solid waste has been produced by the antimony smelting process in the＂World Capital of Antimony＂, Xikuangshan area in China. This study comprehensively investigated the physical and chemical charac...A large amount of solid waste has been produced by the antimony smelting process in the＂World Capital of Antimony＂, Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag,arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 104 and 3.16 × 105mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste.展开更多
Env ironmental pollution is currently identified as one of the major drivers of rapid decline of insect populations,and this finding has revitalized interest in insect responses to pollution.We tested the hypothesis t...Env ironmental pollution is currently identified as one of the major drivers of rapid decline of insect populations,and this finding has revitalized interest in insect responses to pollution.We tested the hypothesis that the pollution-induced decline of insect populations can be predicted from phenotypic stress responses expressed as morphological differences between populations inhabiting polluted and unpolluted sites.We explored populations of the brassy tortrix Eulia ministrana in subarctic forests along an environmental disturbance gradient created by long-lasting severe impacts of aerial emissions of the copper-nickel smelter in Monchegorsk,northwestern Russia.We used pheromone traps to measure the population densities of this leafrolling moth and to collect specimens for assessment of three morphological stress indices:size,forewing melanization,and fluctuating asymmetry in wing venation.Wing length of E.ministrana increased by 10%,and neither forewing melanization nor fluctuating asymmetry changed from the unpolluted forest to the heavily polluted industrial barren.However,the population density of E.ministrana decreased 5 to 10 fold in the same pollution gradient.Thus,none of the studied potential morphological stress indicators signaled vulnerability of E.ministrana to environmental pollution and/or to pollution-induced environmental disturbance.We conclude that insect populations can decline without any visible signs of stress.The use of morphological proxies of insect fitness to predict the consequences of human impact on insect populations is therefore risky until causal relationships between these proxies and insect abundance are deciphered.展开更多
Stable flow of off-gas dust from dust collector hoppers and storage silos is important for smooth operation. Flow properties of the collected off-gas dust are critical to achieve suitable flow. Various dust samples co...Stable flow of off-gas dust from dust collector hoppers and storage silos is important for smooth operation. Flow properties of the collected off-gas dust are critical to achieve suitable flow. Various dust samples collected from secondary copper smelter off-gases were studied. The median diameter of the fine-grained dusts varied from 0.8 to 1.4 μm and the flowability ranged from ＂cohesive＂ to ＂very cohesive＂. The flowa- bility of shaft and anode furnace dust improved slightly with increasing consolidation stress and their wall friction angles decreased, which is a typical behavior. In contrast, the flowability of converter dust decreased with increasing consolidation stress and its wall friction angles increased. Pre-shear treatment of converter dust worsened its flowability, increased the wall friction angle, and improved the flowabil- ity with increasing consolidation stress. This is believed to occur because pre-shear treatment fragments small agglomerates in the dust that improve flowability. The presence of such agglomerates was con- firmed by sieving tests. A diagrammatic representation of the flowability showing that the unconfined yield strength is dependent on consolidation stress can be improved by using logarithmically scaled axes.展开更多
It is reported that Zhuzhou Smelter Group officially launched its zinc-based material project in Nanzhou Industrial Park, Luzhou District, Zhuzhou, Hunan on March, 7. This project includes zinc alloy product line,galv...It is reported that Zhuzhou Smelter Group officially launched its zinc-based material project in Nanzhou Industrial Park, Luzhou District, Zhuzhou, Hunan on March, 7. This project includes zinc alloy product line,galvanizing zinc residue treating system and zinc particle and zinc ball manufacturing system.展开更多
基金supported by State Key Laboratory of Mineral Processing (No.BGRIMM-KJSKL-2022-16)China Postdoctoral Science Foundation (No.2021M700387)+1 种基金National Natural Science Foundation of China (No.G2021105015L)Ministry of Science and Technology of the People’s Republic of China (No.2022YFC2904502)。
文摘X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hindering widespread technology adoption.Accurate classification models are crucial to determine if actual grade exceeds the sorting threshold using localized XRF signals.Previous studies mainly used linear regression(LR)algorithms including simple linear regression(SLR),multivariable linear regression(MLR),and multivariable linear regression with interaction(MLRI)but often fell short attaining satisfactory results.This study employed the particle swarm optimization support vector machine(PSO-SVM)algorithm for sorting porphyritic copper ore pebble.Lab-scale results showed PSO-SVM out-performed LR and raw data(RD)models and the significant interaction effects among input features was observed.Despite poor input data quality,PSO-SVM demonstrated exceptional capabilities.Lab-scale sorting achieved 93.0%accuracy,0.24%grade increase,84.94%recovery rate,57.02%discard rate,and a remarkable 39.62 yuan/t net smelter return(NSR)increase compared to no sorting.These improvements were achieved by the PSO-SVM model with optimized input combinations and highest data quality(T=10,T is XRF testing times).The unsuitability of LR methods for XRF sensor-based sorting of investigated sample is illustrated.Input element selection and mineral association analysis elucidate element importance and influence mechanisms.
文摘The application of pressure leaching technology in the treatment of high-copper and high-arsenic dust was studied.The pressure leaching technique was determined as follows:the liquid to solid ratio(mL/g)of 5:1,the leaching temperature of 453 K,the retention time of 2 h,the initial sulfuric acid concentration of 0.74 mol/L,the oxygen partial pressure of 0.7 MPa,and the agitation speed of 500 r/min.Under these conditions,95%of copper and 99%of zinc and only 6%of iron in the dust were leached,while about 20%of arsenic was also leached.The leaching technique was optimized further to restrain the leaching of arsenic by adding a small quantity of ferrous iron into the leaching system(c(Fe2 +)=0.036 mol/L).Copper and zinc can be effectively separated from arsenic and iron in the leach.The optimal pressure leaching technique of high-copper and high-arsenic smelter dust is proved to be effective.
基金Project(2011AA061001)supported by the National High Technology Research and Development Program of ChinaProject(51304251)supported by the National Natural Science Foundation of China+1 种基金Project(2013M542141)supported by China Postdoctoral FoundationProject(K1201010-61)supported by Planned Program of Science and Technology of Changsha,China
文摘A field study was conducted to determine the behavior and distribution of arsenic during the pyrometallurgy process in a typical SKS(Shuikoushan) lead smelter in Hunan province, China. Environmental influences of arsenic in selected samples were evaluated. Arsenic contents in all input and output samples vary from 0.11% in raw lead to 6.66% in collected dust-2. More arsenic is volatilized in blast furnace and fuming furnace(73.02% of arsenic input) than bottom blowing furnace(10.29% of arsenic input).There are 78.97%, 13.69%, 7.31% of total arsenic distributed in intermediate materials, stockpiled materials and unorganized emissions, respectively. Matte slag-2, collected dust-1 and secondary zinc oxide are hazardous based on the arsenic concentrations of toxicity characteristic leaching procedure. According to risk assessment code(RAC) guideline, arsenic in collected dust-1 poses a very serious risk to the surrounding environment, arsenic in speiss, matte slag-2, water-quenched slag and secondary zinc oxide show low risk, while arsenic in matte slag-1, collected dust-2 and post dust has no risk to the environment.
文摘This paper describes the structure and function of the intelligent decision support system (IDSS) on the process of nickel matte smelter. The knowledge and model base system based on fuzzy-decision rules ale specially suggested. The IDSS possesses the self-learning and adaptive properties, andhas been used for managing and analyzing the production information, optimizing the composition of the charge mixture, and deciding the optimal operational conditions. Electric energy consumption has been reduced remarkably and the yield of nickel has been increased.
基金National"973"Plan Research Project(No.2004CB619204)Educational Ministry Scientific and Technological Research Key Project(No.02052)
文摘The preparation of granulated adsorption material of water-quenched slag/rectorite composite and the treatment of Cu （ Ⅱ ）-containing copper smelter wastewater with the adsorption material were studied. The experimental results showed that under the conditions with the mass ratio of water-quenched slag to rectorite of 1：1, 10% additive of industrial starch （IS）, and 50% water, and a calcination temperature of 400 ℃, the granulated adsorption material prepared had a density of 1.06 kg/m^3, a porosity of 62.29%, water absorption rate of 58.82%, and compressive strength of 2.22 MPa. The efficiency of wastewater treatment was the best, whereas the rate of spallation loss was low. Under the conditions of natural pH, with the addition of the granulated adsorption material of 0.05 g/mL, a reaction time of 40 minutes, and temperature of 25 ℃, the efficiency of the granulated adsorption material for the removal of Cu （ Ⅱ ） ions from the copper smelter wastewater attained 98.2%, and the quality indexes of the wastewater after treatment conformed with the first level of integrated wastewater discharge standard （GB8978-1996）. The reclamation of the used granulated adsorption material was carried out by de-sorption of the Cu （ Ⅱ） ions from the surface with 1 mol/L sodium chloride solution. The de-sorption rate was 96.4%, and the adsorption material can be reused many times to treat copper smelter wastewater.
基金Project(2011AA061003)supported by the National High Technology Research and Development Program of China
文摘The recovery of iron from iron sinking slag and lead smelter slag was investigated by desulfurization-reduction bath smelting. The effects of lead smelter slag(LSS) to iron sinking slag(ISS) mass ratio and temperature were investigated in desulfurization experiments. The X-ray diffraction(XRD) and X-ray fluorescence(XRF) analyses show that the optimum conditions are LSS:ISS of 3:7 and temperature of 1350°C. The composition of desulfurization products is mainly Zn Fe2O4, and the desulfurization rate of 99.66% is obtained under optimum conditions. The thermogravimetric(TG) and differential scanning calorimeter(DSC) analyses demonstrate that reductant is necessary for decomposition and reduction of zinc ferrite in desulfurization product. The effects of reductant, temperature and feeding modes on iron enrichment were investigated in reduction experiments. The scanning electron microscope(SEM) and energy dispersive spectrometer(EDS) determination show that the iron content of reduction product is up to 99.36% under optimum conditions of coke as reductant, reduction temperature of 1450°C and the feeding mode of premixing.
文摘This work describes the experimental results of pyrometallurgical removing of arsenic from the dust collected in the electrostatic copper precipitators within the gas cleaning system of a Copper Flash Smelting Furnace. The generation of dust in the copper smelting worldwide ranges from 2 - 15 wt% per ton of a copper concentrate. In Chile, copper smelters produce approximately 110 kt/y of dust with a concentration of arsenic between 1 and 15 wt%. The dust is a complex of metals oxides and sulfurs with copper concentrations greater than 10 wt% and relatively high silver concentrations. Since its high arsenic concentration, it is difficult to recover valuable metals through hydrometallurgical processes or by direct recirculation of the dust in a smelting furnace. Thus, the development of pyrometallurgical processes aimed at reducing the concentration of arsenic in the dust (<0.5 wt%) is the main objective of this study, giving particular attention to the production of a suitable material to be recirculated in operations of copper smelting. The work provides a detailed characterization of the dust including the Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN), Scanning Electron Microscope-Energy Dispersive X-ray Analysis (SEM/EDS), X-Ray Diffraction (XRD), the elemental chemical analysis using Atomic Adsorption (AAS), and X-Ray Fluorescence (X-RF). By considering that arsenic volatilization requires a process of sulfidation-decomposition-oxidation, this work seeks to explore the roasting of mixtures of copper concentrate/dust, sulfur/dust, and pyrrhotite/dust. By the elemental chemical analysis of the mixture after and before the roasting process, the degree of arsenic volatilization was determined. The results indicated the effects of parameters such as roasting temperature, gas flow, gas composition, and the ratio of mixtures (concentrate/dust, sulfur/dust, or pyrrhotite/dust) on the volatilization of arsenic. According to the findings, the concentration of arsenic in the roasted Flash Smelting dust can be reduced to a relatively low level (<0.5 wt%), which allows its recirculation into an smelting process.
基金supported by the Public Welfare Special Projects of National Health and Family Planning Commission of the People’s Republic of China(No.201402021)The ‘Twelfth Five-Year Plan’ of the National Science and Technology Support(No.2014BAI12B01)
文摘Case reports of indium-related lung disease in workers have raised public concern to the human toxicity of indium （In） and its compounds. However, studies evaluating the exposure or health of workers in In smelting plants are rare. Therefore, in this study, we focused on four In smelting plants, with the main objective of characterizing In in smelter plants in China and discussing the potential exposure biomarkers of In exposure.
文摘Surface soil samples were collected from Sarcheshmeh Copper Smelter Plant and analyzed for 16 Polycyclic Aromatic Hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs), and heavy metals to determine their concentrations, distributions, and probable sources of contamination. The mean concentrations of ΣPAHs, As, Pb, Zn, Se, Cd, and Cr in the soil samples were 878.8, 850, 2185, 2455, 21, and 24 mg/kg, respectively. Besides, their Toxic Equivalents (TEQs) were calculated. The samples generally displayed elevated concentrations of heavy metals when finding the toxic values of dioxin/furan compounds in comparison to the limit values for industrial uses. The background concentrations, molecular indices, and ring classes of the heavy metals indicated that their sources and those of PAHs were both geogenic and pyrolitic. The mean concentrations of total PAHs, PCDD/Fs, and heavy metals were compared with the reports from industrial areas throughout the world and the contamination rates at Sarcheshmeh Copper Plant were found to be moderate.
文摘The flow and heat transfer of the basalt melt in the boundary layer on a flat plate is considered. The conditions of formation of the layer and the intensity of heat transfer are determined. A self-similar analysis using the symmetry method was used. A system of ordinary differential equations in self-similar form is obtained. The fluid flow and heat transfer of molten basalt at a laminar steady-state flow in the feeder furnaces are numerically researched. The term “protective layer” on the interface “basalt melt-lining” is introduced. The dependences for the calculation of dimensionless shear stresses and the Nusselt number on the lining surface are obtained. The conditions of rational organization of the technological process of basalt melt feeding in the furnace feeder are formulated.
文摘Slag is waste from pyrometallurgical processing, usually stored in stacks or warehouses around or near smelters. Slag research has focused on potential environmental problems associated with slag weathering or processing for secondary metal recovery and/or other uses (construction, landscaping, etc.). Located in northern Mexico, the city of Chihuahua has a mining history that dates back to the eighteenth century. A lead smelter located southeast of Chihuahua City;closed in 1997, leaving behind a large pile of slag. In this study, a chemical analysis of smelter slag was carried out. The tailings contain Zn (15 - 35 wt%), Pb (0.5 - 4 wt%), As (0.6 wt%), Sn (888 ppb) and Hg (170 ppb). XRD identified several minerals such as hardystonite (Ca<sub>2</sub>ZnSi<sub>2</sub>O<sub>7</sub>), melanotekite (), kentrolite () and sphalerite (ZnS) in the glass. Major elements are present in phases such as monticellite (CaMgSiO<sub>4</sub>), kirschsteinite (CaFe<sup>2+</sup>SiO<sub>4</sub>), hedenbergite (CaFe<sup>2+</sup>Si<sub>2</sub>O<sub>6</sub>), babingtonite (Fe<sub>2</sub>Si<sub>3</sub>O<sub>9</sub>), magnetite (Fe<sub>3</sub>O<sub>4</sub>), and calcite (CaCO<sub>3</sub>). Whether the goal is reuse, recycling or remediation, research into the properties of slag and its environmental and health impacts (on vulnerable exposed populations) should continue to be relevant.
文摘This paper describes the experimental results of removing arsenic from the dust collected in electrostatic precipitators of a fluidized bed roasting furnace (RP dust). The fluidized bed roasting process generates 600 kilotons of copper concentrate per year with 3 - 6 wt% of concentration of arsenic, producing a roasted product with a low content of arsenic below 0.3 wt%. The process generates 27 kilotons of RP dust per year with a concentration of arsenic of the order of 5 wt% and copper concentration of around 20 wt%. Subsequently, the dust collected in the electrostatic precipitators is treated by hydrometallurgical methods allowing the recovery of copper, and the disposition of arsenic as scorodite. This work proposes to use a pyrometallurgy process to the volatilization of arsenic from RP dust. The obtained material can be recirculated in copper smelting furnaces allowing the recovery of valuable metals. The set of experiments carried out in the roasting of the mixture of copper concentrate/RP dust and sulfur/RP dust used different ratios of mixtures, temperatures and roasting times. By different techniques, the characterization of the RP dust determined its size distribution, morphology, and chemical and mineralogical composition. RP dust is a composite material of small particles (<5 μm) in 50 μm agglomerates, mostly amorphous, with a complex chemical composition of sulfoxides. The results of the roasting experiments indicated that for a 75/25 weight ratio of the mixture of the copper concentrate/PR dust under 700℃, 15 minutes of roasting time with injection of air, the volatilization of arsenic reached 96% by weight. The arsenic concentration after the roasting process is less than 0.3% by weight. For a 5/95 mixture of sulfur/RP dust, at 650℃, the volatilization of arsenic reached a promissory result of 67%. Even that this study was carried out for a particular operation, the results have the potential to be extended to dust produced in the roasting of concentrates of nickel, lead-zinc, and gold.
文摘The Shenyang Smelter,which is located in Shenyang,the well-known industrialcity of northeastern China,is one of the most important non-ferrous metallurgicalplants in the people’s Republic of China.Shenyang is the capital of Liaoning Provin-ce,where transportation is very convenient by the railway,and it is connected direc-tly with the famous seaports-Dalian and Tianjin.
基金This work was supported by the National Key Research and Development Program of China(No.2019YFC1803603).
文摘The abandoned smelters present a substantial pollution threat to the nearby soil and groundwater.In this study,63 surface soil samples were collected from a zinc smelter to quantitatively describe the pollution characteristics,ecological risks,and source apportionment of heavy metal(loid)s(HMs).The results revealed that the average contents of Zn,Cd,Pb,As,and Hg were 0.4,12.2,3.3,5.3,and 12.7 times higher than the risk screening values of the construction sites,respectively.Notably,the smelter was accumulated heavily with Cd and Hg,and the contribution of Cd(0.38)and Hg(0.53)to ecological risk was 91.58%.ZZ3 and ZZ7 were the most polluted workshops,accounting for 25.7%and 35.0%of the pollution load and ecological risk,respectively.The influence of soil parent materials on pollution was minor compared to various workshops within the smelter.Combined with PMF,APCS-MLR and GIS analysis,four sources of HMs were identified:P1(25.5%)and A3(18.4%)were atmospheric deposition from the electric defogging workshop and surface runoff from the smelter;P2(32.7%)and A2(20.9%)were surface runoff of As-Pb foul acid;P3(14.5%)and A4(49.8%)were atmospheric deposition from the leach slag drying workshop;P4(27.3%)and A1(10.8%)were the smelting process of zinc products.This paper described the distribution characteristics and specific sources of HMs in different process workshops,providing a new perspective for the precise remediation of the smelter by determining the priority control factors.
基金supported by the Environment Protection Specific Project (Nos. 201409096, 201009037-06)the National Natural Science Foundation of China (Nos. 41273105, 41371440)
文摘A large amount of solid waste has been produced by the antimony smelting process in the＂World Capital of Antimony＂, Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag,arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 104 and 3.16 × 105mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste.
基金the Academy of Finland(projects 276671 and 311929).
文摘Env ironmental pollution is currently identified as one of the major drivers of rapid decline of insect populations,and this finding has revitalized interest in insect responses to pollution.We tested the hypothesis that the pollution-induced decline of insect populations can be predicted from phenotypic stress responses expressed as morphological differences between populations inhabiting polluted and unpolluted sites.We explored populations of the brassy tortrix Eulia ministrana in subarctic forests along an environmental disturbance gradient created by long-lasting severe impacts of aerial emissions of the copper-nickel smelter in Monchegorsk,northwestern Russia.We used pheromone traps to measure the population densities of this leafrolling moth and to collect specimens for assessment of three morphological stress indices:size,forewing melanization,and fluctuating asymmetry in wing venation.Wing length of E.ministrana increased by 10%,and neither forewing melanization nor fluctuating asymmetry changed from the unpolluted forest to the heavily polluted industrial barren.However,the population density of E.ministrana decreased 5 to 10 fold in the same pollution gradient.Thus,none of the studied potential morphological stress indicators signaled vulnerability of E.ministrana to environmental pollution and/or to pollution-induced environmental disturbance.We conclude that insect populations can decline without any visible signs of stress.The use of morphological proxies of insect fitness to predict the consequences of human impact on insect populations is therefore risky until causal relationships between these proxies and insect abundance are deciphered.
文摘Stable flow of off-gas dust from dust collector hoppers and storage silos is important for smooth operation. Flow properties of the collected off-gas dust are critical to achieve suitable flow. Various dust samples collected from secondary copper smelter off-gases were studied. The median diameter of the fine-grained dusts varied from 0.8 to 1.4 μm and the flowability ranged from ＂cohesive＂ to ＂very cohesive＂. The flowa- bility of shaft and anode furnace dust improved slightly with increasing consolidation stress and their wall friction angles decreased, which is a typical behavior. In contrast, the flowability of converter dust decreased with increasing consolidation stress and its wall friction angles increased. Pre-shear treatment of converter dust worsened its flowability, increased the wall friction angle, and improved the flowabil- ity with increasing consolidation stress. This is believed to occur because pre-shear treatment fragments small agglomerates in the dust that improve flowability. The presence of such agglomerates was con- firmed by sieving tests. A diagrammatic representation of the flowability showing that the unconfined yield strength is dependent on consolidation stress can be improved by using logarithmically scaled axes.
文摘It is reported that Zhuzhou Smelter Group officially launched its zinc-based material project in Nanzhou Industrial Park, Luzhou District, Zhuzhou, Hunan on March, 7. This project includes zinc alloy product line,galvanizing zinc residue treating system and zinc particle and zinc ball manufacturing system.
