Pub Date : 2021-08-04DOI: 10.11648/J.IJMPEM.20210603.12
Abel Monele Mokadze, S. Ndlovu, A. Shemi, M. Dworzanowski
The South African platinum industry has advanced into an era of predominantly mining and processing Upper Group Two (UG-2) ore to extract Platinum Group Metals (PGMs). Flotation concentrates derived from processing UG-2 ore are typically characterized by high chrome contents (>3 wt.%) which are not amenable to conventional PGM smelters. The net effect of high chrome, inter alia, includes increased smelting energy requirements and the reduction of effective furnace capacity. Various interventions ranging from the redesign and modification of existing physical and pyrometallurgical operations have been introduced and these have yielded no sustainable solutions. In this study, a hydrometallurgical process was investigated as an alternative route to reduce chrome in UG-2 concentrates. The parameters initially considered for investigation were acid concentration, leaching time, temperature and oxygen flowrate while keeping solid to liquid ratio and agitation rate constant. Results showed that oxygen flowrate and an interaction of temperature, time and acid concentration had a positive but minimal effect on Cr extraction. The highest Cr extraction obtained was 7.0%. Further test work entailed exploring the effect of solid to liquid ratio using optimized conditions. The results showed a substantial increase of Cr extraction of up to 37%. This represents 1.33% decrease in chrome content, from 3.63% to 2.30%, in UG-2 concentrate.
{"title":"The Reduction of Chrome in UG-2 Flotation Concentrate by Hydrometallurgical Means","authors":"Abel Monele Mokadze, S. Ndlovu, A. Shemi, M. Dworzanowski","doi":"10.11648/J.IJMPEM.20210603.12","DOIUrl":"https://doi.org/10.11648/J.IJMPEM.20210603.12","url":null,"abstract":"The South African platinum industry has advanced into an era of predominantly mining and processing Upper Group Two (UG-2) ore to extract Platinum Group Metals (PGMs). Flotation concentrates derived from processing UG-2 ore are typically characterized by high chrome contents (>3 wt.%) which are not amenable to conventional PGM smelters. The net effect of high chrome, inter alia, includes increased smelting energy requirements and the reduction of effective furnace capacity. Various interventions ranging from the redesign and modification of existing physical and pyrometallurgical operations have been introduced and these have yielded no sustainable solutions. In this study, a hydrometallurgical process was investigated as an alternative route to reduce chrome in UG-2 concentrates. The parameters initially considered for investigation were acid concentration, leaching time, temperature and oxygen flowrate while keeping solid to liquid ratio and agitation rate constant. Results showed that oxygen flowrate and an interaction of temperature, time and acid concentration had a positive but minimal effect on Cr extraction. The highest Cr extraction obtained was 7.0%. Further test work entailed exploring the effect of solid to liquid ratio using optimized conditions. The results showed a substantial increase of Cr extraction of up to 37%. This represents 1.33% decrease in chrome content, from 3.63% to 2.30%, in UG-2 concentrate.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"28 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75445222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-31DOI: 10.1080/25726641.2021.1959882
X. Goso, J. Petersen, M. Tangstad, J. Safarian
ABSTRACT Smelting production of a limestone-fluxed titaniferous slag with low MgO content for subsequent beneficiation using the modified Upgraded Slag (UGS) process was investigated, with the aim of producing a marketable titania product. Smelting of titaniferous magnetite (titanomagnetite) with a carbon reductant and limestone flux was conducted in a water-cooled copper crucible in an iron-suscepting induction furnace under argon. The resulting titaniferous slag contained high residual iron (from the susceptor and incomplete iron reduction in the titanomagnetite), which caused crystallization of an ulvospinel. The slag was beneficiated using the modified UGS process, an industrial roast–leach process used for beneficiation of low-titania slag to a feedstock suitable for production of titania pigment. The upgraded product contained 90.5 mass% TiO2, with a recovery of 83%. Although the TiO2 grade met the feedstock specification for pigment production via the chloride route, SiO2, Al2O3, CaO, and Cr2O3 concentrations exceeded the specification and the particle size distribution was too fine.
{"title":"Beneficiation of fluxed titaniferous slag to a marketable titania product using the modified upgraded slag process","authors":"X. Goso, J. Petersen, M. Tangstad, J. Safarian","doi":"10.1080/25726641.2021.1959882","DOIUrl":"https://doi.org/10.1080/25726641.2021.1959882","url":null,"abstract":"ABSTRACT Smelting production of a limestone-fluxed titaniferous slag with low MgO content for subsequent beneficiation using the modified Upgraded Slag (UGS) process was investigated, with the aim of producing a marketable titania product. Smelting of titaniferous magnetite (titanomagnetite) with a carbon reductant and limestone flux was conducted in a water-cooled copper crucible in an iron-suscepting induction furnace under argon. The resulting titaniferous slag contained high residual iron (from the susceptor and incomplete iron reduction in the titanomagnetite), which caused crystallization of an ulvospinel. The slag was beneficiated using the modified UGS process, an industrial roast–leach process used for beneficiation of low-titania slag to a feedstock suitable for production of titania pigment. The upgraded product contained 90.5 mass% TiO2, with a recovery of 83%. Although the TiO2 grade met the feedstock specification for pigment production via the chloride route, SiO2, Al2O3, CaO, and Cr2O3 concentrations exceeded the specification and the particle size distribution was too fine.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"131 1","pages":"239 - 249"},"PeriodicalIF":1.2,"publicationDate":"2021-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49165896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1080/25726641.2021.1948319
J. Cuevas, W. Bruckard, M. Pownceby, G. Sparrow, A. Torpy
ABSTRACT High-arsenic copper flotation concentrates, in which the major arsenic-bearing mineral was tennantite, were leached with an alkaline sulphide system. At a pulp density of 5 wt% solids with 100–150 g/L Na2S and 50 g/L NaOH, over 91 wt% As was dissolved within 2 h at 100°C. From concentrates containing 3.4–4.9 wt% As, leach residues containing <0.5 wt% As were obtained making them suitable as a smelter feed without a penalty for arsenic. Copper dissolution ranged from 16 to 22 wt% Cu, with significant amounts of calcium, iron and sulphur also dissolved. In a leach at 34.0 wt% solids, excellent arsenic extraction was obtained (97.9 wt% As), but the levels of copper, calcium, and iron dissolution were 0.5, 1.1, and 0.2 wt%, respectively, meaning excellent selectivity for arsenic was achieved. X-ray diffraction and electron probe microanalyses indicated the mechanism for arsenic dissolution from tennantite, and bornite abundance in the residue.
{"title":"Alkaline sulphide leaching of tennantite in copper flotation concentrates to selectively dissolve arsenic","authors":"J. Cuevas, W. Bruckard, M. Pownceby, G. Sparrow, A. Torpy","doi":"10.1080/25726641.2021.1948319","DOIUrl":"https://doi.org/10.1080/25726641.2021.1948319","url":null,"abstract":"ABSTRACT High-arsenic copper flotation concentrates, in which the major arsenic-bearing mineral was tennantite, were leached with an alkaline sulphide system. At a pulp density of 5 wt% solids with 100–150 g/L Na2S and 50 g/L NaOH, over 91 wt% As was dissolved within 2 h at 100°C. From concentrates containing 3.4–4.9 wt% As, leach residues containing <0.5 wt% As were obtained making them suitable as a smelter feed without a penalty for arsenic. Copper dissolution ranged from 16 to 22 wt% Cu, with significant amounts of calcium, iron and sulphur also dissolved. In a leach at 34.0 wt% solids, excellent arsenic extraction was obtained (97.9 wt% As), but the levels of copper, calcium, and iron dissolution were 0.5, 1.1, and 0.2 wt%, respectively, meaning excellent selectivity for arsenic was achieved. X-ray diffraction and electron probe microanalyses indicated the mechanism for arsenic dissolution from tennantite, and bornite abundance in the residue.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"131 1","pages":"229 - 238"},"PeriodicalIF":1.2,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44106068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-27DOI: 10.1080/25726641.2021.1942752
W. Bruckard, D. Brew, E. Vance, G. Sparrow
ABSTRACT Immobilisation of AsIII and AsV using alkali- and acid-bonded low temperature ceramics (LTCs), respectively, has been investigated. Arsenic was loaded into these matrices as solubilised arsenic or as a solid via precipitation with a metal nitrate. Where appropriate, samples were heated to 1000°C to consolidate their microstructure and reduce their open porosity. Samples were assessed according to microstructural characterisation and standard leaching protocols. Alkali-bonded LTCs, even after the application of a thermal treatment, did not bind arsenic sufficiently to pass a TCLP protocol, whereas acid bonded LTCs showed better potential for immobilising As. At a loading of 5 wt% As2O5, a TCLP leach test on an acid bonded LTC resulted in As levels of 7 ppm, close to the regulatory limit of 5 ppm As.
{"title":"Retention of arsenic using alkali- and acid-bonded low temperature ceramics","authors":"W. Bruckard, D. Brew, E. Vance, G. Sparrow","doi":"10.1080/25726641.2021.1942752","DOIUrl":"https://doi.org/10.1080/25726641.2021.1942752","url":null,"abstract":"ABSTRACT Immobilisation of AsIII and AsV using alkali- and acid-bonded low temperature ceramics (LTCs), respectively, has been investigated. Arsenic was loaded into these matrices as solubilised arsenic or as a solid via precipitation with a metal nitrate. Where appropriate, samples were heated to 1000°C to consolidate their microstructure and reduce their open porosity. Samples were assessed according to microstructural characterisation and standard leaching protocols. Alkali-bonded LTCs, even after the application of a thermal treatment, did not bind arsenic sufficiently to pass a TCLP protocol, whereas acid bonded LTCs showed better potential for immobilising As. At a loading of 5 wt% As2O5, a TCLP leach test on an acid bonded LTC resulted in As levels of 7 ppm, close to the regulatory limit of 5 ppm As.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"131 1","pages":"220 - 228"},"PeriodicalIF":1.2,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46262361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-03DOI: 10.1080/25726641.2021.1933722
M. Valenzuela, J. Becker, F. Parada, E. Balladares, I. Wilkomirsky
ABSTRACT Copper reduction to metallic copper from dilute acid solutions containing Cu+2 was studied by means of sawdust from Radiata Pine as a reducing agent. Influence of the temperature, copper concentration and reaction time on the reduction of copper was investigated using an autoclave reactor. Furthermore, maximum reduction capacity of the sawdust was calculated through consecutive reductions. Results obtained show that diluted acid solutions containing Cu+2 can be effectively reduced to metallic copper by sawdust from Radiata Pine above 120°C. For a 0.5 g L−1 Cu+2 solution at 120°C and in 60 min, close to 90% of the copper can be reduced to metallic copper, which crystalises on the surface of the wood particles. At 120°C and for 90 min reaction time up to 95% of the copper can be reduced, generating an effluent with 0.02 g L−1 of copper. This value is similar to those obtained using activated carbon. Consecutive steps of reductions of the sawdust with fresh solutions with 0.5 g L−1 Cu+2 indicate that for 6 steps, the copper load of the sawdust is about 11.9 kg Cu/ton sawdust (dry basis) while for more concentrated solutions of 16.7 gL−1 Cu+2 the copper load reaches 15.0 kg Cu/ton sawdust. These results indicate that this process could be an alternative to conventional electrowinning.
以辐射松木屑为还原剂，研究了铜在含Cu+2稀酸溶液中还原为金属铜的反应。采用高压釜反应器研究了温度、铜浓度和反应时间对铜还原的影响。此外，通过连续还原计算了锯末的最大还原能力。结果表明，在120°C以上，辐射松木屑能有效地将含Cu+2的稀酸溶液还原为金属铜。对于0.5 g L−1 Cu+2溶液，120°C和60 至少，接近90%的铜可以被还原为金属铜，金属铜在木材颗粒的表面结晶。在120°C和90 最短反应时间可减少高达95%的铜，产生0.02的流出物 g L−1铜。该值与使用活性炭获得的值相似。用0.5的新鲜溶液连续减少锯末的步骤 g L−1 Cu+2表明，对于6个步骤，锯末的铜负荷约为11.9 kg铜/吨锯末（干基），而对于浓度更高的16.7 gL−1 Cu+2铜负载达到15.0 kg铜/吨锯末。这些结果表明，该工艺可以替代传统的电积法。
{"title":"Reduction of copper from dilute acid solutions by hydrolysis of wood carbohydrates","authors":"M. Valenzuela, J. Becker, F. Parada, E. Balladares, I. Wilkomirsky","doi":"10.1080/25726641.2021.1933722","DOIUrl":"https://doi.org/10.1080/25726641.2021.1933722","url":null,"abstract":"ABSTRACT Copper reduction to metallic copper from dilute acid solutions containing Cu+2 was studied by means of sawdust from Radiata Pine as a reducing agent. Influence of the temperature, copper concentration and reaction time on the reduction of copper was investigated using an autoclave reactor. Furthermore, maximum reduction capacity of the sawdust was calculated through consecutive reductions. Results obtained show that diluted acid solutions containing Cu+2 can be effectively reduced to metallic copper by sawdust from Radiata Pine above 120°C. For a 0.5 g L−1 Cu+2 solution at 120°C and in 60 min, close to 90% of the copper can be reduced to metallic copper, which crystalises on the surface of the wood particles. At 120°C and for 90 min reaction time up to 95% of the copper can be reduced, generating an effluent with 0.02 g L−1 of copper. This value is similar to those obtained using activated carbon. Consecutive steps of reductions of the sawdust with fresh solutions with 0.5 g L−1 Cu+2 indicate that for 6 steps, the copper load of the sawdust is about 11.9 kg Cu/ton sawdust (dry basis) while for more concentrated solutions of 16.7 gL−1 Cu+2 the copper load reaches 15.0 kg Cu/ton sawdust. These results indicate that this process could be an alternative to conventional electrowinning.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"131 1","pages":"203 - 210"},"PeriodicalIF":1.2,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25726641.2021.1933722","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49088289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-03DOI: 10.1080/25726641.2021.1935163
S. Barakan, Mehdi Noroozi Ayaluey, S. Shayanfar, V. Aghazadeh
ABSTRACT The polythermal crystallization method has been used to extract sodium and potassium carbonate salts as valuable by-products. The salt production was carried out using an alkaline carbonate solution from the Azarshar nepheline syenite pilot plant in Iran. The optimum conditions were obtained by comparison between the results of thermodynamic modelling and experiments. To better understand the properties of the carbonate salts, thermal analysis, chemical analysis, and X-ray diffraction methods were also utilised. The optimum density and temperature for sodium carbonate crystallization were found to be 1.50 g/cm3 and 115–120°C, respectively, and for hydrated potassium carbonate crystallization to be 1.68 g/cm3 and 130°C at the first stage, and 1.70 g/cm3 and 135°C at the second stage, respectively. The thermodynamic modelling showed good agreement with experimental data for the carbonate salts.
{"title":"Production and characterisation of sodium and potassium carbonate salts from carbonation alkaline aluminate liquor","authors":"S. Barakan, Mehdi Noroozi Ayaluey, S. Shayanfar, V. Aghazadeh","doi":"10.1080/25726641.2021.1935163","DOIUrl":"https://doi.org/10.1080/25726641.2021.1935163","url":null,"abstract":"ABSTRACT The polythermal crystallization method has been used to extract sodium and potassium carbonate salts as valuable by-products. The salt production was carried out using an alkaline carbonate solution from the Azarshar nepheline syenite pilot plant in Iran. The optimum conditions were obtained by comparison between the results of thermodynamic modelling and experiments. To better understand the properties of the carbonate salts, thermal analysis, chemical analysis, and X-ray diffraction methods were also utilised. The optimum density and temperature for sodium carbonate crystallization were found to be 1.50 g/cm3 and 115–120°C, respectively, and for hydrated potassium carbonate crystallization to be 1.68 g/cm3 and 130°C at the first stage, and 1.70 g/cm3 and 135°C at the second stage, respectively. The thermodynamic modelling showed good agreement with experimental data for the carbonate salts.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"131 1","pages":"211 - 219"},"PeriodicalIF":1.2,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25726641.2021.1935163","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45607876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-14DOI: 10.11648/J.IJMPEM.20210601.13
Ibrahima Camara, Jiang Deyi, Li Lin
Mining exploration has left many communities in deplorable conditions, ranging from low levels of livelihood sustenance to poor health facilities and poor road networks. This study examined the impact of mining exploration on sustainable development of a community in Guinea, West Africa. The paper reviews literature published on mining and exploration and its impact on community environments.’ However, this study employed descriptive quantitative and correlational methods, which facilitated the gathering, classification and presentation of data that led to analysis, description and conclusion of the study. In this study, 300 questionnaires were distributed to community inhabitants, which enhanced the compilation of first-hand information. Data was analysed using descriptive statistics. The results disclosed numerous problems, ranging from health to education and poor road networks. It was revealed that, exploration activities have damaged lands utilised for agricultural purposes, and deposits of toxic substances have damaged soil nutrients, which caused degradation of the land tenure system. Such problems have left lands to be unproductive. Because of the foregoing problems discovered as negative impact, it is fitting for government and mining corporations to pay considerable attention to Sangaredi community and address such problems. This study identified issues bothering Sangaredi and other communities where mining explorations are conducted. It descriptively explained issues of exploration and established the negative impact mining activities have caused in the community. However, such impact adversely affects the community at large. In addition, academics and mining consultants will use this information as a source for further investigation on the subject matter.
{"title":"The Impact of Mining Exploration on Sangaredi Community’s Sustainable Development: Inhabitants Perspectives on Livelihood","authors":"Ibrahima Camara, Jiang Deyi, Li Lin","doi":"10.11648/J.IJMPEM.20210601.13","DOIUrl":"https://doi.org/10.11648/J.IJMPEM.20210601.13","url":null,"abstract":"Mining exploration has left many communities in deplorable conditions, ranging from low levels of livelihood sustenance to poor health facilities and poor road networks. This study examined the impact of mining exploration on sustainable development of a community in Guinea, West Africa. The paper reviews literature published on mining and exploration and its impact on community environments.’ However, this study employed descriptive quantitative and correlational methods, which facilitated the gathering, classification and presentation of data that led to analysis, description and conclusion of the study. In this study, 300 questionnaires were distributed to community inhabitants, which enhanced the compilation of first-hand information. Data was analysed using descriptive statistics. The results disclosed numerous problems, ranging from health to education and poor road networks. It was revealed that, exploration activities have damaged lands utilised for agricultural purposes, and deposits of toxic substances have damaged soil nutrients, which caused degradation of the land tenure system. Such problems have left lands to be unproductive. Because of the foregoing problems discovered as negative impact, it is fitting for government and mining corporations to pay considerable attention to Sangaredi community and address such problems. This study identified issues bothering Sangaredi and other communities where mining explorations are conducted. It descriptively explained issues of exploration and established the negative impact mining activities have caused in the community. However, such impact adversely affects the community at large. In addition, academics and mining consultants will use this information as a source for further investigation on the subject matter.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"1140 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72684519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-14DOI: 10.11648/J.IJMPEM.20210602.11
Sun Yanwen, Yuan Chaoxin, Guo Chihao, Li Dajiang, Li Yibin, Mu Liangzhao
Cyanide tailings produced in gold smelting process contain a large number of heavy metals and cyanides, which are more and more harmful to the environment. In order to reduce environmental pollution, valuable metals from cyanide tailings are recovered. The amount of calcium chloride, chlorination time, the way of adding calcium chloride and other factors on the influence of gold and silver extraction by chlorination were studied by using the raw material of cyanide tailings with melting chlorination process in this paper, and how to reduce the melting chlorination temperature was explored, and a comprehensive experiment was carried out under the best conditions. The results showed that when the chlorination temperature is 1500°C, the chlorination time is 1 h, and the addition amount of CaCl2 is 7%, the volatilization rate of gold is 85.38%, the content of gold in slag is 1.83 g/t, the volatilization rate of silver is 77.36%, and the content of silver in slag is 4.12 g/t; when the chlorination temperature is 1500°C, 7% CaCl2 is added, and the chlorination time is 15 min, the volatilization rate of gold is 87.78%, the content of gold in slag is 1.23 g/t, the volatilization rate of silver is 59.40%, and the content of silver in slag is 7.39 g/t; the addition of 5% CaO can change the slag type, reduce the chlorination temperature by 50~100°C, increase the volatilization rate of gold and silver slightly, and decrease the content of gold and silver in slag; when CaCl2 is added in five times, the volatilization rate of gold increases to 95.53%, the content of gold in slag decreases to 0.56g/t, the volatilization rate of silver increases to 77.80%, and the content of silver in slag decreases to 4.04 g/t; 7% CaCl2 was added in five times, and the melting chlorination time was 15 min. the amount of CaO was 5%, and the melting chlorination temperature was 1450°C, the gold volatilization rate is 95.69%, and the gold content of slag is 0.54 g/t, the silver volatilization rate is 77.06% and the silver content of slag is 4.20 g/t.
{"title":"Experiment of Gold and Silver Extraction from Cyanide Tailings by Melting Chlorination","authors":"Sun Yanwen, Yuan Chaoxin, Guo Chihao, Li Dajiang, Li Yibin, Mu Liangzhao","doi":"10.11648/J.IJMPEM.20210602.11","DOIUrl":"https://doi.org/10.11648/J.IJMPEM.20210602.11","url":null,"abstract":"Cyanide tailings produced in gold smelting process contain a large number of heavy metals and cyanides, which are more and more harmful to the environment. In order to reduce environmental pollution, valuable metals from cyanide tailings are recovered. The amount of calcium chloride, chlorination time, the way of adding calcium chloride and other factors on the influence of gold and silver extraction by chlorination were studied by using the raw material of cyanide tailings with melting chlorination process in this paper, and how to reduce the melting chlorination temperature was explored, and a comprehensive experiment was carried out under the best conditions. The results showed that when the chlorination temperature is 1500°C, the chlorination time is 1 h, and the addition amount of CaCl2 is 7%, the volatilization rate of gold is 85.38%, the content of gold in slag is 1.83 g/t, the volatilization rate of silver is 77.36%, and the content of silver in slag is 4.12 g/t; when the chlorination temperature is 1500°C, 7% CaCl2 is added, and the chlorination time is 15 min, the volatilization rate of gold is 87.78%, the content of gold in slag is 1.23 g/t, the volatilization rate of silver is 59.40%, and the content of silver in slag is 7.39 g/t; the addition of 5% CaO can change the slag type, reduce the chlorination temperature by 50~100°C, increase the volatilization rate of gold and silver slightly, and decrease the content of gold and silver in slag; when CaCl2 is added in five times, the volatilization rate of gold increases to 95.53%, the content of gold in slag decreases to 0.56g/t, the volatilization rate of silver increases to 77.80%, and the content of silver in slag decreases to 4.04 g/t; 7% CaCl2 was added in five times, and the melting chlorination time was 15 min. the amount of CaO was 5%, and the melting chlorination temperature was 1450°C, the gold volatilization rate is 95.69%, and the gold content of slag is 0.54 g/t, the silver volatilization rate is 77.06% and the silver content of slag is 4.20 g/t.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"67 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79845704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-03DOI: 10.1080/25726641.2021.1919375
S. Sineva, T. Hidayat, A. Fallah-Mehrjardi, R. Starykh, P. Hayes, E. Jak
ABSTRACT Experimental measurements have been undertaken of the gas-matte-spinel and gas-slag-matte-spinel equilibria in the Cu–Fe–O–S–Si system at 1200°C and of 0.1 and 0.6 bar. The technique involved high temperature equilibration of sulfide-oxide mixtures on iron spinel support substrates, preservation of the equilibrium phases by rapid quenching, and direct compositional analysis of the phases using microanalysis techniques. The results, combined with previous data obtained at = 0.25 bar show the effects of sulphur dioxide partial pressure on the gas-matte-spinel and gas-slag-matte-spinel equilibria at fixed temperature and as a function of matte grade. For a given matte grade the concentration of dissolved copper in slag is found to decrease with increasing SO2 partial pressure.
{"title":"Experimental investigation of gas-matte-spinel and gas-slag-matte-spinel equilibria in the Cu-Fe-O-S-Si system at 1200°C: effect of SO2 partial pressure","authors":"S. Sineva, T. Hidayat, A. Fallah-Mehrjardi, R. Starykh, P. Hayes, E. Jak","doi":"10.1080/25726641.2021.1919375","DOIUrl":"https://doi.org/10.1080/25726641.2021.1919375","url":null,"abstract":"ABSTRACT Experimental measurements have been undertaken of the gas-matte-spinel and gas-slag-matte-spinel equilibria in the Cu–Fe–O–S–Si system at 1200°C and of 0.1 and 0.6 bar. The technique involved high temperature equilibration of sulfide-oxide mixtures on iron spinel support substrates, preservation of the equilibrium phases by rapid quenching, and direct compositional analysis of the phases using microanalysis techniques. The results, combined with previous data obtained at = 0.25 bar show the effects of sulphur dioxide partial pressure on the gas-matte-spinel and gas-slag-matte-spinel equilibria at fixed temperature and as a function of matte grade. For a given matte grade the concentration of dissolved copper in slag is found to decrease with increasing SO2 partial pressure.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"131 1","pages":"195 - 202"},"PeriodicalIF":1.2,"publicationDate":"2021-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25726641.2021.1919375","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42084068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-26DOI: 10.11648/J.IJMPEM.20210601.12
Mohammad Mohayminul Islam, Mosammat Shamima Shirin, Tausif Rahman Tonoy, Sanzit Ahmed Sweet
Proper disposal of plastics and its derivatives is one of the biggest challenges all over the globe. Due to the improper management of plastic product environment is being polluted. Plastic waste generation and plastic waste-based pollution in Bangladesh is leaping at a high pace. Among numerous ways of disposal of waste plastics, one can be using it in flexible pavement construction. According to the Bangladesh Waste Database 2014, Dhaka city alone produces 25.44% (5,925.51 tons/ day) of waste, of which 8.45% is plastic. In the construction of bituminous pavement, plastics, as well as construction debris, are being used in the form of aggregate and filler materials popularly. This study focusses on the improvement of properties of bitumen by blending it with LDPE (Low-density polyethylene) and PP (Polypropylene) at a different proportion. Three cases were considered in the study for plastic waste addition, Case-01:- only LDPE; Case-02:- LDPE: PP=3:1; Case-03:- LDPE: PP=1:1. For each case, 3%, 6%, 9%, 12%, and 15% of plastic waste was mixed with bitumen. It was found that the penetration value and ductility decrease with the increasing proportion of plastic waste in bitumen, whereas the softening point increases for every case. Loss on heating, flash & fire point also been improved with the plastic addition. The performance of Case- 03 (LDPE: PP=1:1) is better than others. Minimum penetration value, 11 and maximum softening point, 90°C, is found for this case, which indicates a 90% improvement compared to virgin bitumen. Due to the addition of plastic waste, the ductility always gets affected. But overall, a significant improvement in the properties of bitumen is noticeable.
{"title":"Modification of Bitumen Properties Using Waste Polymer in Context of Bangladesh","authors":"Mohammad Mohayminul Islam, Mosammat Shamima Shirin, Tausif Rahman Tonoy, Sanzit Ahmed Sweet","doi":"10.11648/J.IJMPEM.20210601.12","DOIUrl":"https://doi.org/10.11648/J.IJMPEM.20210601.12","url":null,"abstract":"Proper disposal of plastics and its derivatives is one of the biggest challenges all over the globe. Due to the improper management of plastic product environment is being polluted. Plastic waste generation and plastic waste-based pollution in Bangladesh is leaping at a high pace. Among numerous ways of disposal of waste plastics, one can be using it in flexible pavement construction. According to the Bangladesh Waste Database 2014, Dhaka city alone produces 25.44% (5,925.51 tons/ day) of waste, of which 8.45% is plastic. In the construction of bituminous pavement, plastics, as well as construction debris, are being used in the form of aggregate and filler materials popularly. This study focusses on the improvement of properties of bitumen by blending it with LDPE (Low-density polyethylene) and PP (Polypropylene) at a different proportion. Three cases were considered in the study for plastic waste addition, Case-01:- only LDPE; Case-02:- LDPE: PP=3:1; Case-03:- LDPE: PP=1:1. For each case, 3%, 6%, 9%, 12%, and 15% of plastic waste was mixed with bitumen. It was found that the penetration value and ductility decrease with the increasing proportion of plastic waste in bitumen, whereas the softening point increases for every case. Loss on heating, flash & fire point also been improved with the plastic addition. The performance of Case- 03 (LDPE: PP=1:1) is better than others. Minimum penetration value, 11 and maximum softening point, 90°C, is found for this case, which indicates a 90% improvement compared to virgin bitumen. Due to the addition of plastic waste, the ductility always gets affected. But overall, a significant improvement in the properties of bitumen is noticeable.","PeriodicalId":43710,"journal":{"name":"Mineral Processing and Extractive Metallurgy-Transactions of the Institutions of Mining and Metallurgy","volume":"6 1","pages":"6"},"PeriodicalIF":1.2,"publicationDate":"2021-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45224478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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