The enrichment mechanisms of precious metals by base metals or their mattes in pyro-metallurgical processes are discussed at the atomic level in this paper.The reasons brought forward for a trace amount of precious me...The enrichment mechanisms of precious metals by base metals or their mattes in pyro-metallurgical processes are discussed at the atomic level in this paper.The reasons brought forward for a trace amount of precious metals to be trapped into base metals or mattes are that the melted slag phases possess different chemical structures and properties from that of the melted base metal or matte phases.As for the melted slag phase,its formation is thought to depend on the covalent bonds and the ionic bonds between Si,O atoms and Ca2+,Mg2+,Fe2+ ions to tie up each other.Because the bridging electrons in the slag phase are all thought as the localized electrons,the precious metal atoms are not stable among them.However,as for the metal phase,its formation is thought depend on the metal bonds to bind up the metal atoms.Because the electrons in the metal phases can move freely among the atoms,the precious metal atoms that enter the metal phase can cause the system's free energy to decrease.For the melted mattes phase,because it has high electrical conductivities(between 103～104 s·cm-1) at higher temperatures,and its temperature coefficients presents the negative values,its conductance mechanism belongs with the electronic conduction.The property of the mattes is in fact similar to that of the metal at their melted state,so the precious metal atoms will enter the matte phase instead of the slag phase in a matte-smelting process.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
Based on the facts that cations and anions of molten salts and binary basic oxide solid solutions do not separate from each other as well as that the electric conductivities of mattes are greater than that of salts an...Based on the facts that cations and anions of molten salts and binary basic oxide solid solutions do not separate from each other as well as that the electric conductivities of mattes are greater than that of salts and basic oxide solid solutions, the calculating models of mass action concentrations for binary and ternary mattes involving eutectic have been formulated. The results of calculation agree well with the values measured;this in turn shows that the calculating models can reftect the structural characteristics of the mattes concerned.展开更多
Based on the properties of antimony(Sb)and arsenic(As),a method was proposed to enhance gold recovery during iron matte smelting.The impact of Sb and As on gold enhancement capture was investigated using an exclusion ...Based on the properties of antimony(Sb)and arsenic(As),a method was proposed to enhance gold recovery during iron matte smelting.The impact of Sb and As on gold enhancement capture was investigated using an exclusion method.The results demonstrated that both Sb and As significantly improved the gold recovery rate.As the Sb or As content increased,the gold recovery rate increased.The enhancement effect of Sb was better than that of As,and the optimal results were achieved through the synergistic effects of Sb and As.Under optimized conditions,the gold recovery rate reached 97.12%,whereas the gold content in the slag decreased to 1.70 g/t.Sb captured and aggregated free gold as an Au-Sb alloy,whereas As-Fe alloy also captured free gold.The growth of the gold-captured phase size enhanced the settling velocity,thereby promoting gold recovery.展开更多
在After Effects中合成水墨效果一直是人们关注的热点。该软件强大的合成功能及众多第三方插件的支持,为我们实现水墨效果提供了可能。本文主要通过Track Mattes和Cycore FX HD CC、Genarts Sapphire这两组插件包的综合应用,探讨了一种...在After Effects中合成水墨效果一直是人们关注的热点。该软件强大的合成功能及众多第三方插件的支持,为我们实现水墨效果提供了可能。本文主要通过Track Mattes和Cycore FX HD CC、Genarts Sapphire这两组插件包的综合应用,探讨了一种实现动态水墨效果所需要的可行性方法。展开更多
Fine nickel ferrite precursors NiFe2（C204）3·6H2O were obtained via co-precipitation method with low grade nickel matte as the raw material. Thermodynamic analysis of NiClz-FeC12-（NH4）2C204-H20 system for prec...Fine nickel ferrite precursors NiFe2（C204）3·6H2O were obtained via co-precipitation method with low grade nickel matte as the raw material. Thermodynamic analysis of NiClz-FeC12-（NH4）2C204-H20 system for precipitation identified that the theoretical optimum co-precipitation pH value is 2, and C2O2 has strong complexation with Ni2＋ and Fe2＋ ions. Based on these theoretical considerations, the effects of parameters on the precipitation rates and precursors size were investigated systematically. The results show that the optimum co-precipitation conditions are pH=2, temperature 45 ℃, 1.2 times theoretical amount of （NH4）2C204 dosage and 3% PEG400 addition. Under these conditions, the precipitation rates of Ni2＋ and Fe2＋ are both over 99.8%, with the precursors size of 1-2 urn. Furthermore, X-ray diffraction （XRD） and thermogravimetry-differential thermal analysis （TG-DTA） demonstrate that the precursors are single-phase solid solution, wherein the nickel/iron atoms are replaced by the iron/nickel atoms reciprocally.展开更多
The change of iron composition as well as the removal of copper from iron was investigated in the reduction process, and a new way to deal with copper slag was proposed. The iron in copper slag exists mainly in the fo...The change of iron composition as well as the removal of copper from iron was investigated in the reduction process, and a new way to deal with copper slag was proposed. The iron in copper slag exists mainly in the form of fayalite, and the copper sulfide content accounts for just about 50%. Therefore, the magnetic separation as well as grinding floatation method is not suitable, and a pyrogenic treatment on copper slag is necessary. The carhurization and desulfurization process is restricted to a degree within the carbon composite pellets, and copper matte phase pre- cipitates from copper slag in the reduction process, which is immiscible with molten iron and slag. The copper con- tent decreases to 0.4% as the carbon content in molten iron reaches 3.84%, and the removal ratio of copper from molten iron approaches to 80%. The reduction and sulfurization process can be eompleted in one step, and the copper is separated from iron based on the ternary system of iron-matte-slag.展开更多
In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research resu...In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research results concerning the relationship between the Cu content of the matte and slag in the SKS process; the results are based on actual industrial production in the Dongying Fangyuan copper smelter. The results show that the matte grade strongly influences Cu losses in slag. The dissolved and entrained losses account for 10%–20% and 80%–90% of the total SKS industrial Cu losses in slag, respectively. With increasing matte grade, the dissolved and entrained Cu losses in the SKS slag both increase continuously. When the matte grade is greater than 68%, the content of Cu in the smelting slag increases much more dramatically. To obtain a high direct recovery of copper, the matte grade should be less than 75% in industrial SKS copper production.展开更多
A calcified roasting-acid leaching process was developed as a highly effective method for the extraction of valuable metals from low nickel matte in the presence of CaO additive. The influences of process parameters o...A calcified roasting-acid leaching process was developed as a highly effective method for the extraction of valuable metals from low nickel matte in the presence of CaO additive. The influences of process parameters on the metal extraction were studied, including the roasting temperature, roasting time, addition of CaO, H2SO4 concentration and liquid-solid ratio. Under the optimum condition, 94.2% of Ni, 98.1% of Cu, 92.2% of Co and 89.3% of Fe were recovered. Additionally, 99.6% of Fe was removed from the leachate as goethite by a subsequent goethite iron precipitation process. The behavior and mechanism of CaO additive in the roasting process was clarified. The role of CaO is to prevent the formation of nonferrous metal ferrite phases by a preferential reaction with Fe2O3 during the roasting process. The metal oxides(Cu O and NixCu1-xO) remained stable during high-temperature roasting and were subsequently efficiently leached using a sulfuric acid solution.展开更多
Nickel leaching from low-grade nickel matte(LGNM) using aqueous ferric chloride solution was studied.The influence of factors such as leaching temperature and concentration of ferric chloride on the nickel leaching ra...Nickel leaching from low-grade nickel matte(LGNM) using aqueous ferric chloride solution was studied.The influence of factors such as leaching temperature and concentration of ferric chloride on the nickel leaching ratio was investigated.The results show that increasing leaching temperature and concentration of ferric chloride increases the nickel leaching ratio.The overall nickel leaching process follows the unreacted shrinking core model,and the surface chemical reaction is the rate-controlling step.The activation energy and the reaction order of the nickel leaching process,controlled by the surface chemical reaction,were calculated to be 52.96 kJ mol^(-1)and 0.5,respectively.Therefore,the kinetics equation for the nickel leaching was found to be 1-(1-α)^(1/3)=7.18×10~4C^(0.5)exp[-52,960/(RT)]t.展开更多
文摘The enrichment mechanisms of precious metals by base metals or their mattes in pyro-metallurgical processes are discussed at the atomic level in this paper.The reasons brought forward for a trace amount of precious metals to be trapped into base metals or mattes are that the melted slag phases possess different chemical structures and properties from that of the melted base metal or matte phases.As for the melted slag phase,its formation is thought to depend on the covalent bonds and the ionic bonds between Si,O atoms and Ca2+,Mg2+,Fe2+ ions to tie up each other.Because the bridging electrons in the slag phase are all thought as the localized electrons,the precious metal atoms are not stable among them.However,as for the metal phase,its formation is thought depend on the metal bonds to bind up the metal atoms.Because the electrons in the metal phases can move freely among the atoms,the precious metal atoms that enter the metal phase can cause the system's free energy to decrease.For the melted mattes phase,because it has high electrical conductivities(between 103～104 s·cm-1) at higher temperatures,and its temperature coefficients presents the negative values,its conductance mechanism belongs with the electronic conduction.The property of the mattes is in fact similar to that of the metal at their melted state,so the precious metal atoms will enter the matte phase instead of the slag phase in a matte-smelting process.
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.
文摘Based on the facts that cations and anions of molten salts and binary basic oxide solid solutions do not separate from each other as well as that the electric conductivities of mattes are greater than that of salts and basic oxide solid solutions, the calculating models of mass action concentrations for binary and ternary mattes involving eutectic have been formulated. The results of calculation agree well with the values measured;this in turn shows that the calculating models can reftect the structural characteristics of the mattes concerned.
基金financially supported from the National Natural Science Foundation of China(No.52274358)the Natural Science Foundation of Hunan Province,China(No.2020JJ4718)+2 种基金the Major Science and Technology Projects of Gansu Province,China(No.22ZD6GC017)the Young Scientists Fund of National Natural Science Foundation of China(No.51404296)the National Key Research and Development Program of China(No.2018YFC1901604).
文摘Based on the properties of antimony(Sb)and arsenic(As),a method was proposed to enhance gold recovery during iron matte smelting.The impact of Sb and As on gold enhancement capture was investigated using an exclusion method.The results demonstrated that both Sb and As significantly improved the gold recovery rate.As the Sb or As content increased,the gold recovery rate increased.The enhancement effect of Sb was better than that of As,and the optimal results were achieved through the synergistic effects of Sb and As.Under optimized conditions,the gold recovery rate reached 97.12%,whereas the gold content in the slag decreased to 1.70 g/t.Sb captured and aggregated free gold as an Au-Sb alloy,whereas As-Fe alloy also captured free gold.The growth of the gold-captured phase size enhanced the settling velocity,thereby promoting gold recovery.
文摘在After Effects中合成水墨效果一直是人们关注的热点。该软件强大的合成功能及众多第三方插件的支持,为我们实现水墨效果提供了可能。本文主要通过Track Mattes和Cycore FX HD CC、Genarts Sapphire这两组插件包的综合应用,探讨了一种实现动态水墨效果所需要的可行性方法。
基金Project(2012BAB10B04) supported by National Key Technology R&D Program of ChinaProject supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘Fine nickel ferrite precursors NiFe2（C204）3·6H2O were obtained via co-precipitation method with low grade nickel matte as the raw material. Thermodynamic analysis of NiClz-FeC12-（NH4）2C204-H20 system for precipitation identified that the theoretical optimum co-precipitation pH value is 2, and C2O2 has strong complexation with Ni2＋ and Fe2＋ ions. Based on these theoretical considerations, the effects of parameters on the precipitation rates and precursors size were investigated systematically. The results show that the optimum co-precipitation conditions are pH=2, temperature 45 ℃, 1.2 times theoretical amount of （NH4）2C204 dosage and 3% PEG400 addition. Under these conditions, the precipitation rates of Ni2＋ and Fe2＋ are both over 99.8%, with the precursors size of 1-2 urn. Furthermore, X-ray diffraction （XRD） and thermogravimetry-differential thermal analysis （TG-DTA） demonstrate that the precursors are single-phase solid solution, wherein the nickel/iron atoms are replaced by the iron/nickel atoms reciprocally.
基金Item Sponsored by National Natural Science Foundation of China(51404075)
文摘The change of iron composition as well as the removal of copper from iron was investigated in the reduction process, and a new way to deal with copper slag was proposed. The iron in copper slag exists mainly in the form of fayalite, and the copper sulfide content accounts for just about 50%. Therefore, the magnetic separation as well as grinding floatation method is not suitable, and a pyrogenic treatment on copper slag is necessary. The carhurization and desulfurization process is restricted to a degree within the carbon composite pellets, and copper matte phase pre- cipitates from copper slag in the reduction process, which is immiscible with molten iron and slag. The copper con- tent decreases to 0.4% as the carbon content in molten iron reaches 3.84%, and the removal ratio of copper from molten iron approaches to 80%. The reduction and sulfurization process can be eompleted in one step, and the copper is separated from iron based on the ternary system of iron-matte-slag.
基金financially supported by the National Natural Science Foundation of China (No. 51620105013)Dongying Fangyuan Nonferrous Metals Co., Ltd.
文摘In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research results concerning the relationship between the Cu content of the matte and slag in the SKS process; the results are based on actual industrial production in the Dongying Fangyuan copper smelter. The results show that the matte grade strongly influences Cu losses in slag. The dissolved and entrained losses account for 10%–20% and 80%–90% of the total SKS industrial Cu losses in slag, respectively. With increasing matte grade, the dissolved and entrained Cu losses in the SKS slag both increase continuously. When the matte grade is greater than 68%, the content of Cu in the smelting slag increases much more dramatically. To obtain a high direct recovery of copper, the matte grade should be less than 75% in industrial SKS copper production.
基金Projects(U1860203,U1860108,51574164) supported by the National Natural Science Foundation of China
文摘A calcified roasting-acid leaching process was developed as a highly effective method for the extraction of valuable metals from low nickel matte in the presence of CaO additive. The influences of process parameters on the metal extraction were studied, including the roasting temperature, roasting time, addition of CaO, H2SO4 concentration and liquid-solid ratio. Under the optimum condition, 94.2% of Ni, 98.1% of Cu, 92.2% of Co and 89.3% of Fe were recovered. Additionally, 99.6% of Fe was removed from the leachate as goethite by a subsequent goethite iron precipitation process. The behavior and mechanism of CaO additive in the roasting process was clarified. The role of CaO is to prevent the formation of nonferrous metal ferrite phases by a preferential reaction with Fe2O3 during the roasting process. The metal oxides(Cu O and NixCu1-xO) remained stable during high-temperature roasting and were subsequently efficiently leached using a sulfuric acid solution.
基金financially supported by the National Basic Research Program of China (No.2014CB6434085)
文摘Nickel leaching from low-grade nickel matte(LGNM) using aqueous ferric chloride solution was studied.The influence of factors such as leaching temperature and concentration of ferric chloride on the nickel leaching ratio was investigated.The results show that increasing leaching temperature and concentration of ferric chloride increases the nickel leaching ratio.The overall nickel leaching process follows the unreacted shrinking core model,and the surface chemical reaction is the rate-controlling step.The activation energy and the reaction order of the nickel leaching process,controlled by the surface chemical reaction,were calculated to be 52.96 kJ mol^(-1)and 0.5,respectively.Therefore,the kinetics equation for the nickel leaching was found to be 1-(1-α)^(1/3)=7.18×10~4C^(0.5)exp[-52,960/(RT)]t.
