In the presented study the flotation process has been proposed as a method of enrichment of silver-bearing jewellery waste. This method, traditionally used for the enrichment of non-ferrous metal ores, is based on differences in wettability between individual minerals. Flotation concentrate, enriched with Ag, was subjected to further processing by the pyrometallurgical method in order to produce silver from these wastes

A. Blacha-Grzechnik

B. Oleksiak

G. Siwiec

J. Wieczorek

English

Hrčak - Portal of scientific journals of Croatia

605METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK, G. SIWIEC, A. BLACHA-GRZECHNIK, J. WIECZOREKTHE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL PROCESSINGReceived – Prispjelo: 2014-01-20Accepted – Prihvaćeno: 2014-05-20Preliminary Note – Prethodno priopćenjeISSN 0543-5846METABK 53(4) 605-608 (2014)UDC – UDK 661.185:669.22:671-12=111G. Siwiec, B. Oleksiak, J. Wieczorek - Silesian University of Technol-ogy, Katowice, PolandA. Blacha-Grzechnik - Silesian University of Technology, Gliwice, Po-landIn the presented study the flotation process has been proposed as a method of enrichment of silver-bearing jewel-lery waste. This method, traditionally used for the enrichment of non-ferrous metal ores, is based on differences in wettability between individual minerals. Flotation concentrate, enriched with Ag, was subjected to further process-ing by the pyrometallurgical method in order to produce silver from these wastes.Key words: flotation concentrate, silver, jewellery wastes, pyrometallurgical methodINTRODUCTIONFlotation is a well-known method of separation, which is most commonly used for the beneficiation processes of non-ferrous metal ores and coal. In Poland it is used for enrichment of sulphide copper ores, sul-phide zinc-lead ores as well as in hard coal preparation processes. Flotation can also be used to separate metal from some grain size oxides and carbides. This is confirmed through research on recovery of native gold from poly-metallic copper ores, presented by Allan and Woodcock [1]. Promising results were obtained by the application of xanthogenates (e.g. NaC2H5OCSS), dithiophosphates (DTP) and monothiophosphates (MTP) as collectors, with coaction of activators (Na2CO3, CuSO4) and depres-sors (sodium sulphide). Pine oil and cresol acid were used as frothers and H2SO4 was used as a regulator.The results of research performed by Łuszczkiewicz [2] also indicate the potential application of flotation for enrichment of fractions in gold. He subjected landfilled waste from the area of the decommissioned mine Złoty Stok to flotation. Having used sodium isobutyl xantho-genate as a collector, α-terpineol as a frother and H2SO4 as a regulator, he obtained yields of gold at a maximum level of 40 %.Soto and Toguri [3] conducted research on the appli-cation of flotation for the recovery of Al from waste slag from aluminium works; the concentration of this metal being too low for profitable pyro-metallurgical path processing. Milling the slag and introducing it to a water solution of sulphuric acid and CuSO4, as well as the ap-plication of collectors in the form of diisobutyl dithio-phosphate or amyl xanthogenate, yielded concentrate with aluminium contents reaching 80 % by weight.Until now flotation’s most important application has been in the processing of waste materials in copper pro-duction. Slags from suspension-based processes for the production of copper matte with the application of tech-nology Inco and Outokumpu with copper content over 0,5 % by weight are commonly processed by this meth-od. After slow cooling and size reduction these are sub-jected to a flotation process with the use of flotation reagents, which are traditionally used for producing copper concentrates from sulphide ores [4, 5].TEST RESULTSA wide cycle of tests was conducted using synthetic mixtures in order to determine whether or not flotation in systems like ceramics - metallic fraction, polymer - metallic fraction, ceramics-polymer-metallic fraction can be used to process jewellery waste containing pre-cious metals. The composition of these mixtures is col-lated in Table 1. Table 1 Types of synthetic mixtures used in the researchMixture type Percentages of individual constituents / wt. % Ag SiO2 Al2O3 Epoxy resinAl2O3-Ag 10 ------ 90 -------SiO2-Ag 10 90 ----- -----epoxy resin-Ag 1 ----- ----- 99SiO2- epoxy resin-Ag 5 50 ----- 45The purpose of the tests was to determine the correct conditions in which to conduct the flotation of materials present in actual wastes.The following factors, which were held to influence the outcome of the flotation process, were subjected to analysis: rotational speed of rotor, flow rate of gas (air), duration of the process,606  METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK et al.: THE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL... type and quantity of flotation reagents.Tests on synthetic systems were conducted with ro-tor speeds of 300, 500, 700 and 900 rpm and a gas flow rate from 2 to 8 dm3/min.An analysis of test results from synthetic mixtures, indicates that maximum concentrations of silver in flo-tation concentrate for individual systems are apprecia-bly higher from initial ones and amount to: Al2O3-Ag - 60 wt. %,  SiO2-Ag - 53 wt. %, epoxy resin-Ag – 7,5 wt. %, SiO2-epoxy resin-Ag - 26 wt. %.This significant degree of beneficiation of flotation concentrate was achieved while using Corflot (2 cm3), amyl sodium xanthogenate (0,25 cm3) and CuSO4 as flotation reagents. The best results of silver recovery were obtained at pH=6 for epoxy resin - Ag and at pH=8 for the remaining systems. Too low or too high pH cor-related with a significant reduction of silver content in flotation concentrate.The following reagents also offered promising re-sults during the course of flotation process:  frothers: pine oil, sodium sulphide(II) (water so-lution), α-terpineol,  collectors: polyacrylonitryle, naphtha, oleinic acid, ethyl sodium xanthogenate and X-23.Similarly to Corflot, the optimum amount of frother was 2 cm3. This amount in all cases ensured the forma-tion of durable and stable foam during the whole proc-ess. 0,25 cm3 of collector was used as for amyl xantho-genate. Too low an amount of collecting reagents re-sulted in the reduction of silver content in flotation con-centrate, whilst an excess did not increase the efficiency of the process. In order to perform a more complete analysis of the test results, yield values for useful constituent in con-centrate (εAg) and non-useful constituent in tailing (εN) were determined on the basis of the results of silver concentration in flotation concentrate [6 - 8].Graphical interpretation of changes of silver yield in the flotation process under analysis is also presented in form of enrichment curves of εAg- εN relation in exem-plary Figure 1. Enrichment curves are described with the relation (1) [9]:  )()100(AgAgN aa−−⋅=  (1)Values of coefficient a in equation (1) are between the 100,18 to 136 range indicate good floatability of sil-ver from the synthetic mixtures being analysed [9].An analysis of test results for synthetic mixtures in-dicates a regular increase of flotation concentrate mass over time. In the first minutes of the process, the mass of flotate sludge increases significantly and then stabi-lizes.Flotation process research results and the evolution of silver enrichment curves indicate that the best results from the flotation process were achieved with rotor speeds of 500 rpm and 700 rpm and an air flow rate in the range of 2 - 6 dm3/min. Optimum parameters for the flotation process were determined through research using synthetic systems and used in the enrichment process of materials origi-nating from the surface treatment of silver semi-prod-ucts and jewellery. PROCESSING OF FLOTATION CONCENTRATES WITH PYROMETALLURGICAL METHODSilver sludges originating from the process of sur-face treatment of silver semi-products and jewellery in wet conditions, after prior drying, were subjected to fur-ther pyrometallurgical processing in order to obtain semi-product for the production of silver or its alloys. The average composition of flotation concentrate sub-jected to further treatment is collated in Table 2.Table 2  Average composition of flotation concentrates subjected to pyrometallurgical treatmentType of concentrateContent of main components of concentrate / wt. %Ag Cu SiO2 Al2O3Concentrate after sludge fl otation (jewellery processing) 41,8 2,7 49,6 4,9Concentrate after sludge fl otation (silver semi –products processing) 39,2 3,2 50,4 6,2Below 4 wt. % copper content in the concentrates allows the direct processing of these materials in order to obtain Dore metal without additional decoppering.The whole cycle of tests had three main objectives:  to determine the optimum smelting temperature (range 1 273 K – 1 373 K),  to determine the optimum smelting duration (range 30 – 150 minutes),  to select the composition of the charging mix that yielded the maximum amount of silver.Figure 1  Silver beneficiation curves for synthetic materials (flow rate 4 dm3/min, rotor speed 700 rpm)607METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK et al.: THE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL...Borax, as a slag-forming addition (sodium tetrabo-rate decahydrate), was used mainly to form liquid slag with a low viscosity, absorbing impurities contained in the concentrate being smelted. With this type of slag silver, being heavier, accumulated on the bottom of melting pot after smelting. In the course of each experi-ment the weighed quantities of charging materials were placed in magnesite melting pots and mixed thoroughly. Flotation concentrate and borax were introduced in var-ious weight ratios. Then the melting pots were heated to the required temperatures, after which they were soaked over a period of 30 to 150 minutes. Liquid charge was continually purged with air at a flow rate of 2 dm3/min. The lance supplying air was made of Al2O3. Metallic phase, separated from slag after the process, was weighed and subjected to chemical analysis. Test results (with ad-dition of borax 2:1 as compared to mass of the concen-trate) are presented in Table 3 and in Figures 2- 3. The results of research into the possibility of using the pyrometallurgical method to process beneficiated sludges from the surface treatment of silver jewellery and semi-products indicate that if appropriate condi-tions are maintained during the process, it is possible to obtain silver with purity near to that of Dore metal (pro-duced using traditional metallurgical technologies such as smelting silver from sludges that originate from cop-per electrorefining), The optimum smelting conditions are:  temperature of the process – 1 373 K,  time of heat – 120 minutes,  addition of borax – 2:1 in relation to the mass of concentrate.SUMMARY  The flotation process can be applied successfully for the beneficiation of silver-bearing jewellery wastes (sludges from surface treatment) prior to their further pyrometallurgical processing.  Research on flotation in synthetic systems – Al2O3 –Ag, SiO2 – Ag, SiO2-epoxy resin-Ag, epoxy res-in-Ag – indicates a possibility for the beneficia-tion of concentrates with silver to concentration Table 3  Test results for silver smelting from flotation concentratesType of concentrate being smeltedProcess parametersAg /wt. %ε Ag/ %Temp/ KTime/ minConcentrate after sludge fl ota-tion from jewellery processing1 273 30 62,12 58Concentrate after sludge fl ota-tion from jewellery processing1 273 60 79,30 68Concentrate after sludge fl ota-tion from jewellery processing1 273 90 83,77 74Concentrate after sludge fl ota-tion from jewellery processing1 273 120 94,64 79Concentrate after sludge fl ota-tion from jewellery processing1 373 30 67,12 68Concentrate after sludge fl ota-tion from jewellery processing1 373 60 82,35 75Concentrate after sludge fl ota-tion from jewellery processing1 373 90 96,09 82Concentrate after sludge fl ota-tion from jewellery processing1 373 120 98,96 87Concentrate after sludge fl ota-tion from silver semi-products processing1 273 30 56,59 53Concentrate after sludge fl ota-tion from silver semi-products processing1 273 60 77,45 61Concentrate after sludge fl ota-tion from silver semi-products processing1 273 90 79,54 72Concentrate after sludge fl ota-tion from silver semi-products processing1 273 120 81,60 77Concentrate after sludge fl ota-tion from silver semi-products processing1 373 30 65,89 68Concentrate after sludge fl ota-tion from silver semi-products processing1 373 60 83,23 75Concentrate after sludge fl ota-tion from silver semi-products processing1 373 90 97,11 84Concentrate after sludge fl ota-tion from silver semi-products processing1 373 120 97,94 84Figure 2  Impact of smelting parameters of flotation concentrates on yield of silver (the concentrate after sludge flotation from jewellery processing)Figure 3  Impact of smelting parameters of flotation concentrates on yield of silver (the concentrate after sludge flotation from silver semi-products processing)608  METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK et al.: THE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL...as high as 60 wt. % with initial concentration not exceeding 10 wt. %. In some systems a silver yield εAg of over 90 % was obtained from the con-centrate.  Silver concentrate obtained from the flotation proc-ess can be an excellent raw material for the produc-tion of both silver and its alloys. This was con-firmed by smelting this material with sodium tetra-borate decahydrate (borax). The final product of smelting contained between 87 - 98 wt. % Ag. REFERENCES[1] G. C. Allan, J. T. Woodcock: Minerals Engineering 14 (2001), 9, 931-962.[2] A. Łuszczkiewicz: Prace Naukowe Instytutu Górnictwa Politechniki Wrocławskiej 32 (2006), 179-185.[3] H. Soto, J. M. Toguri: Conservation & Recycling 9 (1986), 1, 45-54.[4] M. Kucharski: Pirometalurgia miedzi, Wyd. AGH, Kraków (2003).[5] R. Burdzik, P. Folęga, B. Łazarz, Z. Stanik, J. Warczek: Archives of Metallurgy and Materials 57 (2012), 4, 987-993.[6] J. Drzymała: Physicochemical Problems of Mineral Pro-cessing 40 (2006), 19-29.[7] J. Drzymała, H. A. M. Ahmed: International Journal of Mineral Processing 76 (2005), 1-2, 55-65.[8] J. Drzymała, A. Łuszczkiewicz, D. Foszcz: Mineral Pro-cessing and Ectraxtive Metall. Rev. 31 (2010), 3, 165-175.[9] F. Hernainz, M. Calero: Chemical Engineering and Pro-cessing 40 (2001), 269-275.Note: Nowak P. is responsible for English language, Katowice, Poland

The obtained of concentrates containing precious metals for pyrometallurgical processing

HRČAK - Portal of Croatian Scientific and Professional Journals

Directory of Open Access Journals

605 METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK, G. SIWIEC, A. BLACHA-GRZECHNIK, J. WIECZOREKTHE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL PROCESSINGReceived – Prispjelo: 2014-01-20Accepted – Prihvaćeno: 2014-05-20Preliminary Note – Prethodno priopćenjeISSN 0543-5846METABK 53(4) 605-608 (2014)UDC – UDK 661.185:669.22:671-12=111G. Siwiec, B. Oleksiak, J. Wieczorek - Silesian University of Technol-ogy, Katowice, PolandA. Blacha-Grzechnik - Silesian University of Technology, Gliwice, Po-landIn the presented study the flotation process has been proposed as a method of enrichment of silver-bearing jewel-lery waste. This method, traditionally used for the enrichment of non-ferrous metal ores, is based on differences in wettability between individual minerals. Flotation concentrate, enriched with Ag, was subjected to further process-ing by the pyrometallurgical method in order to produce silver from these wastes.Key words: flotation concentrate, silver, jewellery wastes, pyrometallurgical methodINTRODUCTIONFlotation is a well-known method of separation, which is most commonly used for the beneficiation processes of non-ferrous metal ores and coal. In Poland it is used for enrichment of sulphide copper ores, sul-phide zinc-lead ores as well as in hard coal preparation processes. Flotation can also be used to separate metal from some grain size oxides and carbides. This is confirmed through research on recovery of native gold from poly-metallic copper ores, presented by Allan and Woodcock [1]. Promising results were obtained by the application of xanthogenates (e.g. NaC2H5OCSS), dithiophosphates (DTP) and monothiophosphates (MTP) as collectors, with coaction of activators (Na2CO3, CuSO4) and depres-sors (sodium sulphide). Pine oil and cresol acid were used as frothers and H2SO4 was used as a regulator.The results of research performed by Łuszczkiewicz [2] also indicate the potential application of flotation for enrichment of fractions in gold. He subjected landfilled waste from the area of the decommissioned mine Złoty Stok to flotation. Having used sodium isobutyl xantho-genate as a collector, α-terpineol as a frother and H2SO4 as a regulator, he obtained yields of gold at a maximum level of 40 %.Soto and Toguri [3] conducted research on the appli-cation of flotation for the recovery of Al from waste slag from aluminium works; the concentration of this metal being too low for profitable pyro-metallurgical path processing. Milling the slag and introducing it to a water solution of sulphuric acid and CuSO4, as well as the ap-plication of collectors in the form of diisobutyl dithio-phosphate or amyl xanthogenate, yielded concentrate with aluminium contents reaching 80 % by weight.Until now flotation’s most important application has been in the processing of waste materials in copper pro-duction. Slags from suspension-based processes for the production of copper matte with the application of tech-nology Inco and Outokumpu with copper content over 0,5 % by weight are commonly processed by this meth-od. After slow cooling and size reduction these are sub-jected to a flotation process with the use of flotation reagents, which are traditionally used for producing copper concentrates from sulphide ores [4, 5].TEST RESULTSA wide cycle of tests was conducted using synthetic mixtures in order to determine whether or not flotation in systems like ceramics - metallic fraction, polymer - metallic fraction, ceramics-polymer-metallic fraction can be used to process jewellery waste containing pre-cious metals. The composition of these mixtures is col-lated in Table 1. Table 1 Types of synthetic mixtures used in the researchMixture type Percentages of individual constituents / wt. % Ag SiO2 Al2O3 Epoxy resinAl2O3-Ag 10 ------ 90 -------SiO2-Ag 10 90 ----- -----epoxy resin-Ag 1 ----- ----- 99SiO2- epoxy resin-Ag 5 50 ----- 45The purpose of the tests was to determine the correct conditions in which to conduct the flotation of materials present in actual wastes.The following factors, which were held to influence the outcome of the flotation process, were subjected to analysis:  rotational speed of rotor,  flow rate of gas (air),  duration of the process,606   METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK et al.: THE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL...  type and quantity of flotation reagents.Tests on synthetic systems were conducted with ro-tor speeds of 300, 500, 700 and 900 rpm and a gas flow rate from 2 to 8 dm3/min.An analysis of test results from synthetic mixtures, indicates that maximum concentrations of silver in flo-tation concentrate for individual systems are apprecia-bly higher from initial ones and amount to:  Al2O3-Ag - 60 wt. %,   SiO2-Ag - 53 wt. %,  epoxy resin-Ag – 7,5 wt. %,  SiO2-epoxy resin-Ag - 26 wt. %.This significant degree of beneficiation of flotation concentrate was achieved while using Corflot (2 cm3), amyl sodium xanthogenate (0,25 cm3) and CuSO4 as flotation reagents. The best results of silver recovery were obtained at pH=6 for epoxy resin - Ag and at pH=8 for the remaining systems. Too low or too high pH cor-related with a significant reduction of silver content in flotation concentrate.The following reagents also offered promising re-sults during the course of flotation process:    frothers: pine oil, sodium sulphide(II) (water so-lution), α-terpineol,    collectors: polyacrylonitryle, naphtha, oleinic acid, ethyl sodium xanthogenate and X-23.Similarly to Corflot, the optimum amount of frother was 2 cm3. This amount in all cases ensured the forma-tion of durable and stable foam during the whole proc-ess. 0,25 cm3 of collector was used as for amyl xantho-genate. Too low an amount of collecting reagents re-sulted in the reduction of silver content in flotation con-centrate, whilst an excess did not increase the efficiency of the process. In order to perform a more complete analysis of the test results, yield values for useful constituent in con-centrate (εAg) and non-useful constituent in tailing (εN) were determined on the basis of the results of silver concentration in flotation concentrate [6 - 8].Graphical interpretation of changes of silver yield in the flotation process under analysis is also presented in form of enrichment curves of εAg- εN relation in exem-plary Figure 1. Enrichment curves are described with the relation (1) [9]:  ) () 100 (AgAgN aa−−⋅ =  (1)Values of coefficient a in equation (1) are between the 100,18 to 136 range indicate good floatability of sil-ver from the synthetic mixtures being analysed [9].An analysis of test results for synthetic mixtures in-dicates a regular increase of flotation concentrate mass over time. In the first minutes of the process, the mass of flotate sludge increases significantly and then stabi-lizes.Flotation process research results and the evolution of silver enrichment curves indicate that the best results from the flotation process were achieved with rotor speeds of 500 rpm and 700 rpm and an air flow rate in the range of 2 - 6 dm3/min. Optimum parameters for the flotation process were determined through research using synthetic systems and used in the enrichment process of materials origi-nating from the surface treatment of silver semi-prod-ucts and jewellery. PROCESSING OF FLOTATION CONCENTRATES WITH PYROMETALLURGICAL METHODSilver sludges originating from the process of sur-face treatment of silver semi-products and jewellery in wet conditions, after prior drying, were subjected to fur-ther pyrometallurgical processing in order to obtain semi-product for the production of silver or its alloys. The average composition of flotation concentrate sub-jected to further treatment is collated in Table 2.Table 2   Average composition of flotation concentrates subjected to pyrometallurgical treatmentType of concentrateContent of main components of concentrate / wt. %Ag Cu SiO2 Al2O3Concentrate after sludge fl  otation (jewellery processing)41,8 2,7 49,6 4,9Concentrate after sludge fl  otation (silver semi –products processing)39,2 3,2 50,4 6,2Below 4 wt. % copper content in the concentrates allows the direct processing of these materials in order to obtain Dore metal without additional decoppering.The whole cycle of tests had three main objectives:     to determine the optimum smelting temperature (range 1 273 K – 1 373 K),     to determine the optimum smelting duration (range 30 – 150 minutes),    to select the composition of the charging mix that yielded the maximum amount of silver.Figure 1   Silver beneficiation curves for synthetic materials (flow rate 4 dm3/min, rotor speed 700 rpm)607 METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK et al.: THE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL...Borax, as a slag-forming addition (sodium tetrabo-rate decahydrate), was used mainly to form liquid slag with a low viscosity, absorbing impurities contained in the concentrate being smelted. With this type of slag silver, being heavier, accumulated on the bottom of melting pot after smelting. In the course of each experi-ment the weighed quantities of charging materials were placed in magnesite melting pots and mixed thoroughly. Flotation concentrate and borax were introduced in var-ious weight ratios. Then the melting pots were heated to the required temperatures, after which they were soaked over a period of 30 to 150 minutes. Liquid charge was continually purged with air at a flow rate of 2 dm3/min. The lance supplying air was made of Al2O3. Metallic phase, separated from slag after the process, was weighed and subjected to chemical analysis. Test results (with ad-dition of borax 2:1 as compared to mass of the concen-trate) are presented in Table 3 and in Figures 2- 3. The results of research into the possibility of using the pyrometallurgical method to process beneficiated sludges from the surface treatment of silver jewellery and semi-products indicate that if appropriate condi-tions are maintained during the process, it is possible to obtain silver with purity near to that of Dore metal (pro-duced using traditional metallurgical technologies such as smelting silver from sludges that originate from cop-per electrorefining), The optimum smelting conditions are:    temperature of the process – 1 373 K,    time of heat – 120 minutes,    addition of borax – 2:1 in relation to the mass of concentrate.SUMMARY    The flotation process can be applied successfully for the beneficiation of silver-bearing jewellery wastes (sludges from surface treatment) prior to their further pyrometallurgical processing.   Research on flotation in synthetic systems – Al2O3 –Ag, SiO2 – Ag, SiO2-epoxy resin-Ag, epoxy res-in-Ag – indicates a possibility for the beneficia-tion of concentrates with silver to concentration Table 3   Test results for silver smelting from flotation concentratesType of concentrate being smeltedProcess parametersAg /wt. %ε Ag/ %Temp/ KTime/ minConcentrate after sludge fl  ota-tion from jewellery processing1 273 30 62,12 58Concentrate after sludge fl  ota-tion from jewellery processing1 273 60 79,30 68Concentrate after sludge fl  ota-tion from jewellery processing1 273 90 83,77 74Concentrate after sludge fl  ota-tion from jewellery processing1 273 120 94,64 79Concentrate after sludge fl  ota-tion from jewellery processing1 373 30 67,12 68Concentrate after sludge fl  ota-tion from jewellery processing1 373 60 82,35 75Concentrate after sludge fl  ota-tion from jewellery processing1 373 90 96,09 82Concentrate after sludge fl  ota-tion from jewellery processing1 373 120 98,96 87Concentrate after sludge fl  ota-tion from silver semi-products processing1 273 30 56,59 53Concentrate after sludge fl  ota-tion from silver semi-products processing1 273 60 77,45 61Concentrate after sludge fl  ota-tion from silver semi-products processing1 273 90 79,54 72Concentrate after sludge fl  ota-tion from silver semi-products processing1 273 120 81,60 77Concentrate after sludge fl  ota-tion from silver semi-products processing1 373 30 65,89 68Concentrate after sludge fl  ota-tion from silver semi-products processing1 373 60 83,23 75Concentrate after sludge fl  ota-tion from silver semi-products processing1 373 90 97,11 84Concentrate after sludge fl  ota-tion from silver semi-products processing1 373 120 97,94 84Figure 2   Impact of smelting parameters of flotation concentrates on yield of silver (the concentrate after sludge flotation from jewellery processing)Figure 3   Impact of smelting parameters of flotation concentrates on yield of silver (the concentrate after sludge flotation from silver semi-products processing)608   METALURGIJA 53 (2014) 4, 605-608B. OLEKSIAK et al.: THE OBTAINED OF CONCENTRATES CONTAINING PRECIOUS METALS FOR PYROMETALLURGICAL...as high as 60 wt. % with initial concentration not exceeding 10 wt. %. In some systems a silver yield εAg of over 90 % was obtained from the con-centrate.   Silver concentrate obtained from the flotation proc-ess can be an excellent raw material for the produc-tion of both silver and its alloys. This was con-firmed by smelting this material with sodium tetra-borate decahydrate (borax). The final product of smelting contained between 87 - 98 wt. % Ag. REFERENCES[1]  G. C. Allan, J. T. Woodcock: Minerals Engineering 14 (2001), 9, 931-962.[2] A.  Łuszczkiewicz:  Prace  Naukowe  Instytutu  Górnictwa Politechniki Wrocławskiej 32 (2006), 179-185.[3]  H. Soto, J. M. Toguri: Conservation & Recycling 9 (1986), 1, 45-54.[4] M.  Kucharski:  Pirometalurgia  miedzi,  Wyd.  AGH,  Kraków (2003).[5]  R. Burdzik, P. Folęga, B. Łazarz, Z. Stanik, J. Warczek: Archives of Metallurgy and Materials 57 (2012), 4, 987-993.[6] J.  Drzymała:  Physicochemical  Problems  of  Mineral  Pro-cessing 40 (2006), 19-29.[7]  J. Drzymała, H. A. M. Ahmed: International Journal of Mineral Processing 76 (2005), 1-2, 55-65.[8]  J. Drzymała, A. Łuszczkiewicz, D. Foszcz: Mineral Pro-cessing and Ectraxtive Metall. Rev. 31 (2010), 3, 165-175.[9]  F. Hernainz, M. Calero: Chemical Engineering and Pro-cessing 40 (2001), 269-275.Note: Nowak P. is responsible for English language, Katowice, Poland

The obtained of concentrates containing precious metals for pyrometallurgical processing

Abstract

Similar works

Full text

Available Versions

Hrčak - Portal of scientific journals of Croatia

HRČAK - Portal of Croatian Scientific and Professional Journals

Directory of Open Access Journals