Lead-zinc sulphide ore contains lead sulphide (galena), and zinc sulphide (sphalerite). In the first flotation stage, galena is rendered hydrophobic with an organic collector such as xanthate, while sphalerite is kept...Lead-zinc sulphide ore contains lead sulphide (galena), and zinc sulphide (sphalerite). In the first flotation stage, galena is rendered hydrophobic with an organic collector such as xanthate, while sphalerite is kept from floating by depressants, and in the second flotation stage, activator was used to activated zinc flotation. Since the organic regent used are different in the two flotation stage, wastewater from the second zinc flotation stage can’t be directly recycled to the first lead flotation stage. Wastewater from flotation process for concentrating lead-zinc sulphide ore often containing organic compounds such as diethyldithiocarbamate(DDTC), xanthate, terpenic oil(2# oil) and thionocarbamate esters (Z-200), are environmentally hazardous. Their removal from contaminated water and the reuse of the water is one of the main challenges facing lead-zinc sulphide ore processing plants. In this study, synthetic wastewater containing DDTC, xanthate, 2# oil and Z-200 at concentrations ranging from 21 to 42 mg/L was fed into an Ozone/Biological activated carbon (BAC) reactor. Analyses of the effluent indicated a chemical oxygen demand (COD) removal over 86.21% and Total organic carbon (TOC) removal over 90.00% were achieved under Hydraulic retention time (HRT) of 4h and O3 feeding concentration of 33.3mg/L. The effluent was further recycled to the lab scale lead concentrating process and no significant difference was found in compare with fresh water. Furthermore, lead-zinc sulphide mineral concentrating process was carried out at lab scale. The produced wastewater was treated by Ozone/BAC reactor at O3 feeding concentration of 16.7mg/L and HRT of 4h. The effluent analysis showed that TOC removal was 74.58%. This effluent was recycled to the lab scale lead-zinc sulphide mineral concentrating process and the recovery of lead was not affected. The results showed that by using Ozone/BAC technology, the lead-zinc sulphide mineral processing wastewater could be recycled.展开更多
With the aim of controlling the problem of fine particles in the flue gas of lead-zinc smelting,a low-temperature plasma-electrocoagulation and electric bag composite dedusting experimental platform was designed by co...With the aim of controlling the problem of fine particles in the flue gas of lead-zinc smelting,a low-temperature plasma-electrocoagulation and electric bag composite dedusting experimental platform was designed by combining electrocoagulation and electric bag composite dust removal technology based on the research of low-temperature plasma technology.Firstly,the properties of fine particles in flue gas from lead-zinc smelting were analyzed,and the effects of input voltage,filter wind speed,dust concentration,and pulse-jet ash-cleaning cycle on the dust collection efficiency of the integrated device were studied.Then,the energy efficiency of the integrated technology was analyzed,and the control mechanism of the fine particles was revealed.The experimental results show that the integrated technology of low-temperature plasma-electrocoagulation and electric bag composite dust removal achieves a fine particle removal efficiency of more than 99.99%and the energy consumption per unit mass of the dust is only 0.008 k W·h/g.The integrated technology has broad application prospects and farreaching practical significance for the lead-zinc smelting industry to achieve ultra-low emission targets for flue gas and achieve energy-saving and emission reduction effects.展开更多
Electrochemical technology was introduced to study the floatability of galena in some wastewater samples from different processes of mineral processing plant in Fankou Lead-Zinc Mine. It is shown that the residual col...Electrochemical technology was introduced to study the floatability of galena in some wastewater samples from different processes of mineral processing plant in Fankou Lead-Zinc Mine. It is shown that the residual collector molecules in the wastewater from the thickening of lead and zinc concentrates can benefit the formation of lead xanthanate onto the surface of galena, yet, some special chemical components in the wastewater from zinc tailings and effluent may induce some surface reactions on galena, and herewith the direct reuse of this water may bring disadvantageous influence on galena flotation.展开更多
The contamination of heavy metal(loid)s at mining&metallurgical sites has been a major environmental challenge worldwide[1].Typically,large amounts of metal(loid)s-bearing wastes are generated at these sites,such ...The contamination of heavy metal(loid)s at mining&metallurgical sites has been a major environmental challenge worldwide[1].Typically,large amounts of metal(loid)s-bearing wastes are generated at these sites,such as smelting slag,combustion residues,mine tailings,wastewater,and exhaust gas[2].Due to their high mobility in the environment,the released heavy metal(loid)s can easily enter the soil and water environment,posing long-term and widespread threats to ecological and human health[3].展开更多
Coagulation is commonly applied to treat Zn-bearing wastewater from smelting industries(smelting wastewater),and thus the Zn-bearing sludge was considerably produced,which should be solidified before safety disposal.H...Coagulation is commonly applied to treat Zn-bearing wastewater from smelting industries(smelting wastewater),and thus the Zn-bearing sludge was considerably produced,which should be solidified before safety disposal.Herein,we demonstrated a novel approach to recycle Zn effectively from smelting wastewater via an integrated Fe coagulation and hematite precipitation method.First,smelting wastewater was coagulated by adding ferric chloride to generate Fe/Zn-bearing sludge(sludge for short).Secondly,the sludge was dissolved to generate an acid solution containing 2.2 g/L of Zn and 39.2 g/L of Fe.Thirdly,the Fe/Zn-bearing solution was hydrothermally treated,and 89%of Fe was eliminated to highly purified hematite block,whereas the percentage of Zn lost was below 1.1%.Finally,the hematite precipitates were collected,and the supernatant was hydrothermally treated again with the addition of glucose.When the molar ratio of glucose to Fe in the supernatant was 1.5,over 99.5%of Fe was precipitated in hematite nanoparticles with a diameter of 10-100 nm,and the residual Fe was 21.5 mg/L.The loss of Zn was below 0.4%,and the residual Zn in the solution was 2169 mg/L,290 times of that in the smelting wastewater.The major mechanism for Fe removal was the hydrolysis of ferric nitrate into hematite,which was promoted by nitrate consumption in glucose oxidation.This paper is the first report of an environment-friendly method for enriching Zn without generating any waste.展开更多
文摘Lead-zinc sulphide ore contains lead sulphide (galena), and zinc sulphide (sphalerite). In the first flotation stage, galena is rendered hydrophobic with an organic collector such as xanthate, while sphalerite is kept from floating by depressants, and in the second flotation stage, activator was used to activated zinc flotation. Since the organic regent used are different in the two flotation stage, wastewater from the second zinc flotation stage can’t be directly recycled to the first lead flotation stage. Wastewater from flotation process for concentrating lead-zinc sulphide ore often containing organic compounds such as diethyldithiocarbamate(DDTC), xanthate, terpenic oil(2# oil) and thionocarbamate esters (Z-200), are environmentally hazardous. Their removal from contaminated water and the reuse of the water is one of the main challenges facing lead-zinc sulphide ore processing plants. In this study, synthetic wastewater containing DDTC, xanthate, 2# oil and Z-200 at concentrations ranging from 21 to 42 mg/L was fed into an Ozone/Biological activated carbon (BAC) reactor. Analyses of the effluent indicated a chemical oxygen demand (COD) removal over 86.21% and Total organic carbon (TOC) removal over 90.00% were achieved under Hydraulic retention time (HRT) of 4h and O3 feeding concentration of 33.3mg/L. The effluent was further recycled to the lab scale lead concentrating process and no significant difference was found in compare with fresh water. Furthermore, lead-zinc sulphide mineral concentrating process was carried out at lab scale. The produced wastewater was treated by Ozone/BAC reactor at O3 feeding concentration of 16.7mg/L and HRT of 4h. The effluent analysis showed that TOC removal was 74.58%. This effluent was recycled to the lab scale lead-zinc sulphide mineral concentrating process and the recovery of lead was not affected. The results showed that by using Ozone/BAC technology, the lead-zinc sulphide mineral processing wastewater could be recycled.
基金supported by the State Key Laboratory of Organic Geochemistry,GIGCAS(No.SKLOG-201909)the Fundamental Research Funds for the Central Universities(2009QH03)funded by the Open Foundation of Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation(under planning).
文摘With the aim of controlling the problem of fine particles in the flue gas of lead-zinc smelting,a low-temperature plasma-electrocoagulation and electric bag composite dedusting experimental platform was designed by combining electrocoagulation and electric bag composite dust removal technology based on the research of low-temperature plasma technology.Firstly,the properties of fine particles in flue gas from lead-zinc smelting were analyzed,and the effects of input voltage,filter wind speed,dust concentration,and pulse-jet ash-cleaning cycle on the dust collection efficiency of the integrated device were studied.Then,the energy efficiency of the integrated technology was analyzed,and the control mechanism of the fine particles was revealed.The experimental results show that the integrated technology of low-temperature plasma-electrocoagulation and electric bag composite dust removal achieves a fine particle removal efficiency of more than 99.99%and the energy consumption per unit mass of the dust is only 0.008 k W·h/g.The integrated technology has broad application prospects and farreaching practical significance for the lead-zinc smelting industry to achieve ultra-low emission targets for flue gas and achieve energy-saving and emission reduction effects.
文摘Electrochemical technology was introduced to study the floatability of galena in some wastewater samples from different processes of mineral processing plant in Fankou Lead-Zinc Mine. It is shown that the residual collector molecules in the wastewater from the thickening of lead and zinc concentrates can benefit the formation of lead xanthanate onto the surface of galena, yet, some special chemical components in the wastewater from zinc tailings and effluent may induce some surface reactions on galena, and herewith the direct reuse of this water may bring disadvantageous influence on galena flotation.
基金the financial support by the National Key Research and Development Program of China and the Natural Science Foundation of Hunan Province (2019YFC18 03600, 2019YFC1803500, 2019YFC1805200, 2020YFC1807700, 2020YFC1808300, 2021YFC29 02600, 2022YFC2904400, 2023YFC3707700, 2024JJ1012)
文摘The contamination of heavy metal(loid)s at mining&metallurgical sites has been a major environmental challenge worldwide[1].Typically,large amounts of metal(loid)s-bearing wastes are generated at these sites,such as smelting slag,combustion residues,mine tailings,wastewater,and exhaust gas[2].Due to their high mobility in the environment,the released heavy metal(loid)s can easily enter the soil and water environment,posing long-term and widespread threats to ecological and human health[3].
基金This work was sponsored by the National Natural Science Foundation of China(Grant Nos.5157811&51878134,51678273 and 51878133)the Science and Technology Program of Jilin Province(Grant No.20190303001SF).
文摘Coagulation is commonly applied to treat Zn-bearing wastewater from smelting industries(smelting wastewater),and thus the Zn-bearing sludge was considerably produced,which should be solidified before safety disposal.Herein,we demonstrated a novel approach to recycle Zn effectively from smelting wastewater via an integrated Fe coagulation and hematite precipitation method.First,smelting wastewater was coagulated by adding ferric chloride to generate Fe/Zn-bearing sludge(sludge for short).Secondly,the sludge was dissolved to generate an acid solution containing 2.2 g/L of Zn and 39.2 g/L of Fe.Thirdly,the Fe/Zn-bearing solution was hydrothermally treated,and 89%of Fe was eliminated to highly purified hematite block,whereas the percentage of Zn lost was below 1.1%.Finally,the hematite precipitates were collected,and the supernatant was hydrothermally treated again with the addition of glucose.When the molar ratio of glucose to Fe in the supernatant was 1.5,over 99.5%of Fe was precipitated in hematite nanoparticles with a diameter of 10-100 nm,and the residual Fe was 21.5 mg/L.The loss of Zn was below 0.4%,and the residual Zn in the solution was 2169 mg/L,290 times of that in the smelting wastewater.The major mechanism for Fe removal was the hydrolysis of ferric nitrate into hematite,which was promoted by nitrate consumption in glucose oxidation.This paper is the first report of an environment-friendly method for enriching Zn without generating any waste.
