The effect of calcite and dolomite on the oxidation of pyrite was studied using batch-leaching experiments complemented with chemical modeling, solution analysis and solid characterization techniques. Leaching tests c...The effect of calcite and dolomite on the oxidation of pyrite was studied using batch-leaching experiments complemented with chemical modeling, solution analysis and solid characterization techniques. Leaching tests conducted at 80℃ and p（O2）=1.013×105 Pa and pH〉13 showed that pyrite alkaline oxidation rate decreased in the presence of both calcite and dolomite, while more detrimental effect was observed in the case of calcite. FE-SEM/EDS analysis exhibited a surface layer containing Ca（in the case of calcite） and Mg（in the case of dolomite） on the pyrite surface, which justified the slowdown in pyrite leaching rate. This surface layer was formed due to partial dissolution of carbonate minerals, which was affected dominantly by the p H and temperature of the leaching solution based on the chemical modeling data. The surface layer was characterized as Ca or Mg hydroxide using XRD and FTIR analysis. It was also found that this layer was thin and continuous in the case of calcite while it was thick and discontinuous in the presence of dolomite.展开更多
The dissolution of pyrite was studied with Phanerochaete chrysosporium(P.chrysosporium).This fungus resulted in the dissolution of 18%iron and 33%sulfur.The oxidization layer was formed on the pyrite surface,which pro...The dissolution of pyrite was studied with Phanerochaete chrysosporium(P.chrysosporium).This fungus resulted in the dissolution of 18%iron and 33%sulfur.The oxidization layer was formed on the pyrite surface,which probably consisted of iron oxide,iron oxy-hydroxide,iron sulfate,elemental sulfur and mycelia.The electrochemical characteristics of pyrite were studied in the systems without and with P.chrysosporium.P.chrysosporium could accelerate the dissolution of pyrite by decreasing pitting potential and polarization resistance plus improving polarization current,corrosion potential and corrosion current density.The dissolution of pyrite is the combined effect of enzymes,hydrogen peroxide,ferric iron and organic acids.Enzymes attack the chemical bonds by free radicals.Organic acids dissolve pyrite by acidolysis and complexolysis.Enzymes and hydrogen peroxide play an essential role in this process.展开更多
Based on the accumulated data for the gold deposits in the central Jilin Province in recent years and our understanding of the gold metallogenic province,the Haigou gold metallogenic province is delineated and the den...Based on the accumulated data for the gold deposits in the central Jilin Province in recent years and our understanding of the gold metallogenic province,the Haigou gold metallogenic province is delineated and the denudation degree of gold deposits in this province is discussed. The potential and the ore-searching direction of the province are also considered. The Haigou gold metallogenic province occurs as an independent province with low denudation degree and high ore-producing potential. Regional fault belts and small basic intrusions are two ore-constrains and could serve as the ore-searching indictors in the province.展开更多
Lode 28 is the largest gold-bearing quartz vein in Haigou gold deposit, and the lode itself contains more than 301 of gold. Geochemical study shows that 12 trace elements related gold mineralization can be divided int...Lode 28 is the largest gold-bearing quartz vein in Haigou gold deposit, and the lode itself contains more than 301 of gold. Geochemical study shows that 12 trace elements related gold mineralization can be divided into 5 metallogenic factors （element assemblages）. The high values of F1 , F2 and F4 together indicate overlapped of multiple stages of gold mineralization, revealing high potential of gold mineralization at depth ; the single high value of F4 represents the root of an existing ore body while high values of F3 and F4 show the intervals of barton sectors in the lode. Comprehensive geochemical studies show the high prospeetion potential below the 14^th level and between lines 39-71. It is also prospective to look for blind ore-bodies between lines 15-29 and below the 10^th level.展开更多
Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusio...Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusions,of which most of them are CO2-bearing inclusions. The fluid salinity is 1. 43%- 9. 08%,mainly concentrated in the range of 4. 69%- 5. 41%,the density of CO2 is 0. 69- 0. 80 g / cm3,indicating that the mineralization fluid is low-medium salinity and low density fluid. A series of studies on gold-bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi-neralization and the amount of CO2 in the inclusions,which means the more CO2-bearing inclusions there are,the higher the content of gold is. CO2 is mainly derived from mantle fluid,and the ore-forming fluid should be derived from mantle fluid and the crust shallow fluid. The conclusions have important denotative meaning on the metallogenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit.展开更多
The authors presented geochronology and geochemical data of diorites from Nancha gold deposit in Tonghua region, with the aim to constraining its formation age, magma source and tectonic setting. LA-ICP-MS U-Pb dating...The authors presented geochronology and geochemical data of diorites from Nancha gold deposit in Tonghua region, with the aim to constraining its formation age, magma source and tectonic setting. LA-ICP-MS U-Pb dating results of zircons from the diorites indicate that the rocks were formed in the Middle Jurassic （171 ±2 Ma, MSWD = 1. 19）. Geochemically, these rocks have Si02 concentrations of 52. 52%-54. 90%,K20 of 2. 14%-3.84% , Na20 of 3. 17%-3. 35% , MgO of 7. 43%-9. 34% and high Mg# of 68. 57-72. 57. These rocks are characterized by enrichment in large ion lithophile elements（ LILE,such as K, Ba, Rb and Sr） and light rare earth elements （ LREE） , relatively depletion in high field strength elements （ HFSE, such as Ta, Nb, Ti and Zr） , and heavy rare earth elements （HREE）. These characteristics suggest that primary magma of the rocks were derived from the partial melting of mantle with miner crustal contamination, which may related to partial melting of mantle wedge by addition of sediment melt from subducting oceanic crust. Based on former and present studies, the authors consider that the Nancha ore deposit high-Mg diorites were formed in compres- sional structural setting which is similar to volcanic arc. It could be related to the subduction of the Paleo-Paci- fic plate beneath the Eurasian continent.展开更多
基金the support of IMIDRO,Iranian Mines & Mining Industries Development & Renovation,for providing the financial support to carry out this research
文摘The effect of calcite and dolomite on the oxidation of pyrite was studied using batch-leaching experiments complemented with chemical modeling, solution analysis and solid characterization techniques. Leaching tests conducted at 80℃ and p（O2）=1.013×105 Pa and pH〉13 showed that pyrite alkaline oxidation rate decreased in the presence of both calcite and dolomite, while more detrimental effect was observed in the case of calcite. FE-SEM/EDS analysis exhibited a surface layer containing Ca（in the case of calcite） and Mg（in the case of dolomite） on the pyrite surface, which justified the slowdown in pyrite leaching rate. This surface layer was formed due to partial dissolution of carbonate minerals, which was affected dominantly by the p H and temperature of the leaching solution based on the chemical modeling data. The surface layer was characterized as Ca or Mg hydroxide using XRD and FTIR analysis. It was also found that this layer was thin and continuous in the case of calcite while it was thick and discontinuous in the presence of dolomite.
基金Project(U1608254)supported by the National Natural Science Foundation of China
文摘The dissolution of pyrite was studied with Phanerochaete chrysosporium(P.chrysosporium).This fungus resulted in the dissolution of 18%iron and 33%sulfur.The oxidization layer was formed on the pyrite surface,which probably consisted of iron oxide,iron oxy-hydroxide,iron sulfate,elemental sulfur and mycelia.The electrochemical characteristics of pyrite were studied in the systems without and with P.chrysosporium.P.chrysosporium could accelerate the dissolution of pyrite by decreasing pitting potential and polarization resistance plus improving polarization current,corrosion potential and corrosion current density.The dissolution of pyrite is the combined effect of enzymes,hydrogen peroxide,ferric iron and organic acids.Enzymes attack the chemical bonds by free radicals.Organic acids dissolve pyrite by acidolysis and complexolysis.Enzymes and hydrogen peroxide play an essential role in this process.
基金Supported by Project of China Geological Survey(No.1212011085480)Key Scientific and Technological Development Project of Jilin Province(No.20090479)
文摘Based on the accumulated data for the gold deposits in the central Jilin Province in recent years and our understanding of the gold metallogenic province,the Haigou gold metallogenic province is delineated and the denudation degree of gold deposits in this province is discussed. The potential and the ore-searching direction of the province are also considered. The Haigou gold metallogenic province occurs as an independent province with low denudation degree and high ore-producing potential. Regional fault belts and small basic intrusions are two ore-constrains and could serve as the ore-searching indictors in the province.
文摘Lode 28 is the largest gold-bearing quartz vein in Haigou gold deposit, and the lode itself contains more than 301 of gold. Geochemical study shows that 12 trace elements related gold mineralization can be divided into 5 metallogenic factors （element assemblages）. The high values of F1 , F2 and F4 together indicate overlapped of multiple stages of gold mineralization, revealing high potential of gold mineralization at depth ; the single high value of F4 represents the root of an existing ore body while high values of F3 and F4 show the intervals of barton sectors in the lode. Comprehensive geochemical studies show the high prospeetion potential below the 14^th level and between lines 39-71. It is also prospective to look for blind ore-bodies between lines 15-29 and below the 10^th level.
基金Supported by Project of National Natural Science Foundation of China(No.41172072)
文摘Haigou gold deposit is a typical orogenic gold deposit. There are a reasonable amount of fluid inclusions in the gold deposit,including three types: CO2-H2O-Na Cl inclusions,pure CO2 inclusions and Na Cl-H2 O inclusions,of which most of them are CO2-bearing inclusions. The fluid salinity is 1. 43%- 9. 08%,mainly concentrated in the range of 4. 69%- 5. 41%,the density of CO2 is 0. 69- 0. 80 g / cm3,indicating that the mineralization fluid is low-medium salinity and low density fluid. A series of studies on gold-bearing quartz vein and fluid inclusions show that there exists a positive correlation between the degree of the gold mi-neralization and the amount of CO2 in the inclusions,which means the more CO2-bearing inclusions there are,the higher the content of gold is. CO2 is mainly derived from mantle fluid,and the ore-forming fluid should be derived from mantle fluid and the crust shallow fluid. The conclusions have important denotative meaning on the metallogenic mechanism of orogenic gold deposit and the deep prospecting on metal deposit.
文摘The authors presented geochronology and geochemical data of diorites from Nancha gold deposit in Tonghua region, with the aim to constraining its formation age, magma source and tectonic setting. LA-ICP-MS U-Pb dating results of zircons from the diorites indicate that the rocks were formed in the Middle Jurassic （171 ±2 Ma, MSWD = 1. 19）. Geochemically, these rocks have Si02 concentrations of 52. 52%-54. 90%,K20 of 2. 14%-3.84% , Na20 of 3. 17%-3. 35% , MgO of 7. 43%-9. 34% and high Mg# of 68. 57-72. 57. These rocks are characterized by enrichment in large ion lithophile elements（ LILE,such as K, Ba, Rb and Sr） and light rare earth elements （ LREE） , relatively depletion in high field strength elements （ HFSE, such as Ta, Nb, Ti and Zr） , and heavy rare earth elements （HREE）. These characteristics suggest that primary magma of the rocks were derived from the partial melting of mantle with miner crustal contamination, which may related to partial melting of mantle wedge by addition of sediment melt from subducting oceanic crust. Based on former and present studies, the authors consider that the Nancha ore deposit high-Mg diorites were formed in compres- sional structural setting which is similar to volcanic arc. It could be related to the subduction of the Paleo-Paci- fic plate beneath the Eurasian continent.
