A hydrometallurgical process for refractory gold-bearing arsenosulfide concentrates at ambient temperature and pressure was presented, including fine grinding with intensified alkali-leaching （FGIAL）, enhanced agita...A hydrometallurgical process for refractory gold-bearing arsenosulfide concentrates at ambient temperature and pressure was presented, including fine grinding with intensified alkali-leaching （FGIAL）, enhanced agitation alkali-leaching （EAAL）, thiosulfate leaching and displacement. Experimental results on a refractory gold concentrate showed that the total consumption of NaOH in alkaline leaching is only 41% of those theoretically calculated under the conditions of full oxidization for the same amount of arse- nides and sulfides transformed into arsenates and sulfates, and 72.3% of gold is synchro-dissoluted by thiosulfate self-generated during alkaline leaching. After alkaline leaching, thiosulfate leaching was carried out for 24 h. The dissolution of gold is increased to 91.9% from 4.6% by cyanide without the pretreatment. The displacement of gold by zinc powder in the solution gets to 99.2%. Due to an amount of thiosulfate self-generated during alkaline leaching, the reagent addition in thiosulfate leaching afterwards is lower than the normal.展开更多
Ultrafine Milling technology is used to treat gold-bearingsulphides and to investigate the effects of minerals size, millingtime, liquid/solid ratio, NaCN consumption and leaching aid onleaching rate of gold. The resu...Ultrafine Milling technology is used to treat gold-bearingsulphides and to investigate the effects of minerals size, millingtime, liquid/solid ratio, NaCN consumption and leaching aid onleaching rate of gold. The results indicate that shorter treatingtime, decrease of NaCN consumption of 60/100 and increase of goldleaching rate of 15/100 can be ob- tained by the ultrafine millingtechnology compared with traditional cyanide leaching. Potentialexists for the new pro- cess to form the basis for an economicallyprocess for treatment of gold-bearing sulphides.展开更多
The ore-bearing belts, specialized for precious metals, are substantia ted to exist in the south Far East of Russia. The longest of which is the Amursk y gold-bearing belt extended from the Amur River mouth to the Uss...The ore-bearing belts, specialized for precious metals, are substantia ted to exist in the south Far East of Russia. The longest of which is the Amursk y gold-bearing belt extended from the Amur River mouth to the Ussuri River lowe r course and further to the southwest on China territory, probably, to the Sungar i River head. The fact that we have distinguished the Amursky and other gold-be a ring belts, make it possible to reevaluate the perspectives of the South Far Eas t of Russia and North-East China for new deposits of precious metals.展开更多
The thiourea leaching of gold from the calcine of gold-bearing arsenical pyrite concentrate of Kangjiawan mine was studied.The effects of the leaching time,the concentrations of thiourea,hydrochloric acid and initial ...The thiourea leaching of gold from the calcine of gold-bearing arsenical pyrite concentrate of Kangjiawan mine was studied.The effects of the leaching time,the concentrations of thiourea,hydrochloric acid and initial ferric ion on the leaching recovery of gold were investigated,and a regressive model has been established,which showed that the concentrations of thiourea and hydrochloric acid were the most important factors,leaching time the second,and concentration of the initial ferric ion the least・Under the optimal conditions,that is,temperature 50℃,the ratio of liquid to solid 4:1,thiourea 12g/L,hydrochloric acid 1 mol/L,and initial ferric ion 1 g/L,the leaching recoveries of gold and silver were more than 81%and 73%,respectively.The increase of silver recovery and the reduction of thiourea consumption could be attained when sodium sulphite was added.展开更多
In central Inner Mongolia, five gold bearing formations (Xiajining, Dongwufenzi, Wulashan, Baiyunebo and Bainaimiao Groups) belong either to volcano sedimentation or clasolite sedimentation. They formed in different t...In central Inner Mongolia, five gold bearing formations (Xiajining, Dongwufenzi, Wulashan, Baiyunebo and Bainaimiao Groups) belong either to volcano sedimentation or clasolite sedimentation. They formed in different tectonic environments such as an Archean rift zone (Xiajining and Dongwufenzi Groups), an Early Proterozoic stable basin (Wulashan Group), a Middle to Late Proterozoic continental rift zone (Baiyunebo Group), and a Paleozoic island arc environment (Bainaimiao Group). Gold contents in the gold bearing formations in the area are higher than those of other gold bearing formations in the North China Craton. However, as most gold bearing formations in the area are limited, there are a few big gold deposits in central Inner Mongolia. Gold contents in all formations were strongly influenced by migmatization and ductile shearing, the former process prompting mobilization, and the latter process resulting in gold enrichment in ductile shear zones. During the development of Archean to Proterozoic gold bearing formations, gold migrated from the mantle to the crust, then through the crust, finally deposited at the earth’s surface.展开更多
1. Material composition of the geosynclinal tectonic LayerThe geosynclinal tectonic layer is mainly composed of the following two parts: sandyslate rocks of Precambrin and volcanic rocks inbeded within the sand-slate ...1. Material composition of the geosynclinal tectonic LayerThe geosynclinal tectonic layer is mainly composed of the following two parts: sandyslate rocks of Precambrin and volcanic rocks inbeded within the sand-slate rocks.The sandy-slate rocks embrace the chemical compositional characteristics of light metamorphic rocks: SiO<sub>2</sub>=54.56<sup>8</sup>1.63（Wt%）, with average of 63.96（wt%）（n=58, the same as following）; Al<sub>2</sub>O<sub>3</sub>=9.47<sup>1</sup>7.75（wt%）, with average of 15.36（wt%）, and Al<sub>2</sub>O<sub>3</sub>】K<sub>2</sub>O+Na<sub>2</sub>O+CaO; the content of （FeO+Fe<sub>2</sub>O<sub>3</sub>） varies greatly with FeO】Fe<sub>2</sub>O<sub>3</sub>; （CaO+MgO）=0.78<sup>9</sup>.22 （wt%）with average of 23 （wt%）, and MgO】CaO; the ratios of K<sub>2</sub>O/Na<sub>2</sub>O rang from 2 to 4（】1）. By comparing all this chemical data with that of the other kind rocks, We can know that the sand y-slate rocks were the eunic and /or bathyal sediments which formed under the strongly active eugeosynclinal tectonic setting.展开更多
Field and remote sensing studies reveal that Au-bearing quartz carbonate lodes in Romite deposit, in the extreme South Eastern Desert of Egypt, are controlled by NNE-striking shear zones that splay from the ca. 660--...Field and remote sensing studies reveal that Au-bearing quartz carbonate lodes in Romite deposit, in the extreme South Eastern Desert of Egypt, are controlled by NNE-striking shear zones that splay from the ca. 660--550 Ma Hamisana Zone. Quartz in releasing bends with sinistral shear geometry and abundant boudinaged quartz-carbonate lodes with serrate ribboned fabrics suggest vein formation throughout a transpressive wrench system. Ubiquitous hydrothermal quartz, carbonate, and subordinate chlorite and sericite within the shear zones and as slivers in veins, indicate that gold deposition and hydro- thermal alteration occurred under greenschist facies conditions. The AI （IV） in chlorite indicates a forma- tion temperature of - 300 ℃, comparable with temperatures estimated from arsenopyrite composition for grains intimately associated with gold in quartz veins. The new geological and geochemical data indicate that splays off the Hamisana Zone are potential gold exploration targets. Quartz veins along the high order （2nd or 3rd） structures of this crustal-scale shear zone are favorable targets. In the Romite deposit and in surrounding areas, a Au-As-Cu-Sb-Co-Zn geochemical signature characterizes mineralized zones, and particularly rock chips with 〉 1000 ppm As and high contents of Cu, Zn, and Co target the better mineralized areas. The carbonate δ13CpDB and δ18OsMow isotope signatures preclude an organic source of the ore fluid, but metamorphic and magmatic sources are still valid candidates. The intense deformation and lack of mag- matism in the deposit area argue for metamorphic dewatering of greenstone rocks as the most likely fluid source. The narrow ranges of δ13C （-4.6‰ to -3.1‰） and 6180 （11.9‰- 13.7‰） in carbonate minerals in lodes imply a corresponding uniformity to the ambient temperature and δ13CCO2 （δ13C∑C） of the ore fluids.The calculated δ18OH2O values of 6‰-7.9‰for ore fluids, based on 6180 values of vein quartz further suggest a likely metamorphic origin.展开更多
The convergence confinement methods are solutions employed to estimate convergence in circular tunnels. They are mostly based on constitutive equations governed by the Mohr-Coulomb and Hoek-Brown yield criteria. Howev...The convergence confinement methods are solutions employed to estimate convergence in circular tunnels. They are mostly based on constitutive equations governed by the Mohr-Coulomb and Hoek-Brown yield criteria. However, the solutions based on these criteria neglect the intermediate principal stress confining effect on the ground reaction estimation. Therefore, in this paper, a Drucker-Prager yield criterion governed solution integrated with the Lode angle parameter is employed. It considers the intermediate principal stress influence and the critical effect of the parameter on failure characterization.Subsequently, it is verified with results attained from numerical simulations which consider an elasticperfectly plastic constitutive law with a non-associative flow rule within FLAC3D. It was drawn from the results that the ground reaction and plastic evolution are influenced by the confining stress.Furthermore, considering a suitable yield criterion leads to realistic convergence and plastic evolution estimation. The circumscribed DP criterion governed solution with Lode angle parameter value(0.8) is considered appropriate for the realistic ground reaction estimation in the three-dimensional(3D) stress state rock mass. It estimates approximately 3.4% of tunnel convergence as compared to the classic solutions(5%) and plastic radius estimated to be approximately 2.45 m compared to 2.84 m.展开更多
基金This project was financially supported by the Natural Science Foundation of Liaoning Province of China (No.2001101015) and theFree Study Item of the Institute of Metal Research, Chinese Academy of Sciences (No.AM05-0866)
文摘A hydrometallurgical process for refractory gold-bearing arsenosulfide concentrates at ambient temperature and pressure was presented, including fine grinding with intensified alkali-leaching （FGIAL）, enhanced agitation alkali-leaching （EAAL）, thiosulfate leaching and displacement. Experimental results on a refractory gold concentrate showed that the total consumption of NaOH in alkaline leaching is only 41% of those theoretically calculated under the conditions of full oxidization for the same amount of arse- nides and sulfides transformed into arsenates and sulfates, and 72.3% of gold is synchro-dissoluted by thiosulfate self-generated during alkaline leaching. After alkaline leaching, thiosulfate leaching was carried out for 24 h. The dissolution of gold is increased to 91.9% from 4.6% by cyanide without the pretreatment. The displacement of gold by zinc powder in the solution gets to 99.2%. Due to an amount of thiosulfate self-generated during alkaline leaching, the reagent addition in thiosulfate leaching afterwards is lower than the normal.
基金This project is financially supported by the Excellent Doctoral Dissertation Foundation of Hunan Province(No.200114)
文摘Ultrafine Milling technology is used to treat gold-bearingsulphides and to investigate the effects of minerals size, millingtime, liquid/solid ratio, NaCN consumption and leaching aid onleaching rate of gold. The results indicate that shorter treatingtime, decrease of NaCN consumption of 60/100 and increase of goldleaching rate of 15/100 can be ob- tained by the ultrafine millingtechnology compared with traditional cyanide leaching. Potentialexists for the new pro- cess to form the basis for an economicallyprocess for treatment of gold-bearing sulphides.
文摘The ore-bearing belts, specialized for precious metals, are substantia ted to exist in the south Far East of Russia. The longest of which is the Amursk y gold-bearing belt extended from the Amur River mouth to the Ussuri River lowe r course and further to the southwest on China territory, probably, to the Sungar i River head. The fact that we have distinguished the Amursky and other gold-be a ring belts, make it possible to reevaluate the perspectives of the South Far Eas t of Russia and North-East China for new deposits of precious metals.
文摘The thiourea leaching of gold from the calcine of gold-bearing arsenical pyrite concentrate of Kangjiawan mine was studied.The effects of the leaching time,the concentrations of thiourea,hydrochloric acid and initial ferric ion on the leaching recovery of gold were investigated,and a regressive model has been established,which showed that the concentrations of thiourea and hydrochloric acid were the most important factors,leaching time the second,and concentration of the initial ferric ion the least・Under the optimal conditions,that is,temperature 50℃,the ratio of liquid to solid 4:1,thiourea 12g/L,hydrochloric acid 1 mol/L,and initial ferric ion 1 g/L,the leaching recoveries of gold and silver were more than 81%and 73%,respectively.The increase of silver recovery and the reduction of thiourea consumption could be attained when sodium sulphite was added.
文摘In central Inner Mongolia, five gold bearing formations (Xiajining, Dongwufenzi, Wulashan, Baiyunebo and Bainaimiao Groups) belong either to volcano sedimentation or clasolite sedimentation. They formed in different tectonic environments such as an Archean rift zone (Xiajining and Dongwufenzi Groups), an Early Proterozoic stable basin (Wulashan Group), a Middle to Late Proterozoic continental rift zone (Baiyunebo Group), and a Paleozoic island arc environment (Bainaimiao Group). Gold contents in the gold bearing formations in the area are higher than those of other gold bearing formations in the North China Craton. However, as most gold bearing formations in the area are limited, there are a few big gold deposits in central Inner Mongolia. Gold contents in all formations were strongly influenced by migmatization and ductile shearing, the former process prompting mobilization, and the latter process resulting in gold enrichment in ductile shear zones. During the development of Archean to Proterozoic gold bearing formations, gold migrated from the mantle to the crust, then through the crust, finally deposited at the earth’s surface.
文摘1. Material composition of the geosynclinal tectonic LayerThe geosynclinal tectonic layer is mainly composed of the following two parts: sandyslate rocks of Precambrin and volcanic rocks inbeded within the sand-slate rocks.The sandy-slate rocks embrace the chemical compositional characteristics of light metamorphic rocks: SiO<sub>2</sub>=54.56<sup>8</sup>1.63（Wt%）, with average of 63.96（wt%）（n=58, the same as following）; Al<sub>2</sub>O<sub>3</sub>=9.47<sup>1</sup>7.75（wt%）, with average of 15.36（wt%）, and Al<sub>2</sub>O<sub>3</sub>】K<sub>2</sub>O+Na<sub>2</sub>O+CaO; the content of （FeO+Fe<sub>2</sub>O<sub>3</sub>） varies greatly with FeO】Fe<sub>2</sub>O<sub>3</sub>; （CaO+MgO）=0.78<sup>9</sup>.22 （wt%）with average of 23 （wt%）, and MgO】CaO; the ratios of K<sub>2</sub>O/Na<sub>2</sub>O rang from 2 to 4（】1）. By comparing all this chemical data with that of the other kind rocks, We can know that the sand y-slate rocks were the eunic and /or bathyal sediments which formed under the strongly active eugeosynclinal tectonic setting.
基金supported by the Science and Technology Development Fund(STDF),Egypt
文摘Field and remote sensing studies reveal that Au-bearing quartz carbonate lodes in Romite deposit, in the extreme South Eastern Desert of Egypt, are controlled by NNE-striking shear zones that splay from the ca. 660--550 Ma Hamisana Zone. Quartz in releasing bends with sinistral shear geometry and abundant boudinaged quartz-carbonate lodes with serrate ribboned fabrics suggest vein formation throughout a transpressive wrench system. Ubiquitous hydrothermal quartz, carbonate, and subordinate chlorite and sericite within the shear zones and as slivers in veins, indicate that gold deposition and hydro- thermal alteration occurred under greenschist facies conditions. The AI （IV） in chlorite indicates a forma- tion temperature of - 300 ℃, comparable with temperatures estimated from arsenopyrite composition for grains intimately associated with gold in quartz veins. The new geological and geochemical data indicate that splays off the Hamisana Zone are potential gold exploration targets. Quartz veins along the high order （2nd or 3rd） structures of this crustal-scale shear zone are favorable targets. In the Romite deposit and in surrounding areas, a Au-As-Cu-Sb-Co-Zn geochemical signature characterizes mineralized zones, and particularly rock chips with 〉 1000 ppm As and high contents of Cu, Zn, and Co target the better mineralized areas. The carbonate δ13CpDB and δ18OsMow isotope signatures preclude an organic source of the ore fluid, but metamorphic and magmatic sources are still valid candidates. The intense deformation and lack of mag- matism in the deposit area argue for metamorphic dewatering of greenstone rocks as the most likely fluid source. The narrow ranges of δ13C （-4.6‰ to -3.1‰） and 6180 （11.9‰- 13.7‰） in carbonate minerals in lodes imply a corresponding uniformity to the ambient temperature and δ13CCO2 （δ13C∑C） of the ore fluids.The calculated δ18OH2O values of 6‰-7.9‰for ore fluids, based on 6180 values of vein quartz further suggest a likely metamorphic origin.
基金The author gratefully acknowledges the financial support and affiliation from the University of Adelaide.
文摘The convergence confinement methods are solutions employed to estimate convergence in circular tunnels. They are mostly based on constitutive equations governed by the Mohr-Coulomb and Hoek-Brown yield criteria. However, the solutions based on these criteria neglect the intermediate principal stress confining effect on the ground reaction estimation. Therefore, in this paper, a Drucker-Prager yield criterion governed solution integrated with the Lode angle parameter is employed. It considers the intermediate principal stress influence and the critical effect of the parameter on failure characterization.Subsequently, it is verified with results attained from numerical simulations which consider an elasticperfectly plastic constitutive law with a non-associative flow rule within FLAC3D. It was drawn from the results that the ground reaction and plastic evolution are influenced by the confining stress.Furthermore, considering a suitable yield criterion leads to realistic convergence and plastic evolution estimation. The circumscribed DP criterion governed solution with Lode angle parameter value(0.8) is considered appropriate for the realistic ground reaction estimation in the three-dimensional(3D) stress state rock mass. It estimates approximately 3.4% of tunnel convergence as compared to the classic solutions(5%) and plastic radius estimated to be approximately 2.45 m compared to 2.84 m.
