Sphalerite in the Niujiaotang Cd rich zinc deposit, Duyun, Guizhou is characteristically light yellow in color with significant enrichment of cadmium which ranges from 0.83% to 1.97% (averaging 1.38%) in concentration...Sphalerite in the Niujiaotang Cd rich zinc deposit, Duyun, Guizhou is characteristically light yellow in color with significant enrichment of cadmium which ranges from 0.83% to 1.97% (averaging 1.38%) in concentration in the mineral, corresponding to an enrichment coefficient as high as 30.47 to 72.96. In comparison with other major Pb Zn deposits in the world (the Mississippi Valley deposits, and the Fankou and Jinding deposits in China) the Niujiaotang deposit is n-n×10 times richer in cadmium. Sphalerite in the deposit is also rich in Ga and Ge, but poor in In, Mn and Fe, suggesting some special mechanisms that govern the geochemical behavior of these trace elements. Except for a minor amount of independent minerals like greenockite, cadmium occurs mainly as isomorphous impurity in the crystal lattice of sphalerite. During weathering and leaching under supergene condition, cadmium was separated from Zn, resulting in some secondary minerals of Cd, including oxides and otavite.展开更多
CADMIUN is a dispersed element and has long been explored and utilized as a by-product of Pb-Zn ores.Current research on Cd is focused on the following aspects: (i) environmental effects due to the migration and enric...CADMIUN is a dispersed element and has long been explored and utilized as a by-product of Pb-Zn ores.Current research on Cd is focused on the following aspects: (i) environmental effects due to the migration and enrichment of Cd as a heavy metal poisonous element in water (rivers, lakes, industrially discharged waste water), sediments and soils. The research paper concerned can be seen in variousjournals of environmental science; and (ii) exploration of the existing forms of Cd and its independentminerals and ordinary geological problems. However, many researchers have paid little attention tothe geochemical behavior of Cd and its environmental effects under supergene weathering-leaching conditions in Cd-bearing Pb-Zn deposits. Cd can be separated from Zn in the supergene weathering processand its sulfate CdS0-4 is easy to dissolve in water. Our preliminary studies showed that Cd can be enrichedto some extent under supergene weathering conditions in Niujiaotang deposit. The stronger the extent展开更多
As a dispersed element, cadmium is difficult to enrich and mineralize. As the Cd tetrahedron is similar tothat of Zn in covalent radius and crystal structure, both the elements possess similar geochemical habits.Cd is...As a dispersed element, cadmium is difficult to enrich and mineralize. As the Cd tetrahedron is similar tothat of Zn in covalent radius and crystal structure, both the elements possess similar geochemical habits.Cd is present mainly as isomorphous impurity in sphalerite. So Cd, as an associated element, occurslargely in Pb-Zn deposits. Current research both at home and abroad is focused on the environmental effect of Cd, but little work has been done on the mechanism of enrichment and mineralization of Cd. Theresearch papers available are mostly restricted to the ordinary geochemical characteristics of CdFrom the end of 1980s to the early 1990s, independent ore deposits of Te, Tl and other dispersed elements were discovered in the region of Southwest China. Prof. Tu Guangzhr proposed that dispersed elements can form their independent ore deposits. It has been realized that the dispersed展开更多
为了解安徽贵池地区富硒土壤特征与潜力,服务当地富硒土地资源开发,选择贵池西部开展土壤地球化学测量试验,探讨Se、I等有益元素的富集特征、成因及潜力,Cd、As等有害元素的超标特征及成因等,结合研究区土壤中有益、有害元素特征,讨论...为了解安徽贵池地区富硒土壤特征与潜力,服务当地富硒土地资源开发,选择贵池西部开展土壤地球化学测量试验,探讨Se、I等有益元素的富集特征、成因及潜力,Cd、As等有害元素的超标特征及成因等,结合研究区土壤中有益、有害元素特征,讨论富硒土地资源及其开发优势。发现表层和深层土壤中Se等有益元素含量总体较高,其中Se含量达到富硒土地标准的表层土壤点位占全部样品点位的76%;表层土壤中Cd含量超标的点位占48%,其他有害元素仅个别点位超标,Cd是制约该地区富硒土地资源开发的主要不利因素。在研究区圈定了61.4 km 2的富硒土地资源,认为研究区东部土壤富硒的物质来源是二叠系灰岩,可以利用当地灰岩提升富硒土地资源品质,降低生态风险。展开更多
文摘Sphalerite in the Niujiaotang Cd rich zinc deposit, Duyun, Guizhou is characteristically light yellow in color with significant enrichment of cadmium which ranges from 0.83% to 1.97% (averaging 1.38%) in concentration in the mineral, corresponding to an enrichment coefficient as high as 30.47 to 72.96. In comparison with other major Pb Zn deposits in the world (the Mississippi Valley deposits, and the Fankou and Jinding deposits in China) the Niujiaotang deposit is n-n×10 times richer in cadmium. Sphalerite in the deposit is also rich in Ga and Ge, but poor in In, Mn and Fe, suggesting some special mechanisms that govern the geochemical behavior of these trace elements. Except for a minor amount of independent minerals like greenockite, cadmium occurs mainly as isomorphous impurity in the crystal lattice of sphalerite. During weathering and leaching under supergene condition, cadmium was separated from Zn, resulting in some secondary minerals of Cd, including oxides and otavite.
文摘CADMIUN is a dispersed element and has long been explored and utilized as a by-product of Pb-Zn ores.Current research on Cd is focused on the following aspects: (i) environmental effects due to the migration and enrichment of Cd as a heavy metal poisonous element in water (rivers, lakes, industrially discharged waste water), sediments and soils. The research paper concerned can be seen in variousjournals of environmental science; and (ii) exploration of the existing forms of Cd and its independentminerals and ordinary geological problems. However, many researchers have paid little attention tothe geochemical behavior of Cd and its environmental effects under supergene weathering-leaching conditions in Cd-bearing Pb-Zn deposits. Cd can be separated from Zn in the supergene weathering processand its sulfate CdS0-4 is easy to dissolve in water. Our preliminary studies showed that Cd can be enrichedto some extent under supergene weathering conditions in Niujiaotang deposit. The stronger the extent
文摘As a dispersed element, cadmium is difficult to enrich and mineralize. As the Cd tetrahedron is similar tothat of Zn in covalent radius and crystal structure, both the elements possess similar geochemical habits.Cd is present mainly as isomorphous impurity in sphalerite. So Cd, as an associated element, occurslargely in Pb-Zn deposits. Current research both at home and abroad is focused on the environmental effect of Cd, but little work has been done on the mechanism of enrichment and mineralization of Cd. Theresearch papers available are mostly restricted to the ordinary geochemical characteristics of CdFrom the end of 1980s to the early 1990s, independent ore deposits of Te, Tl and other dispersed elements were discovered in the region of Southwest China. Prof. Tu Guangzhr proposed that dispersed elements can form their independent ore deposits. It has been realized that the dispersed
文摘为了解安徽贵池地区富硒土壤特征与潜力,服务当地富硒土地资源开发,选择贵池西部开展土壤地球化学测量试验,探讨Se、I等有益元素的富集特征、成因及潜力,Cd、As等有害元素的超标特征及成因等,结合研究区土壤中有益、有害元素特征,讨论富硒土地资源及其开发优势。发现表层和深层土壤中Se等有益元素含量总体较高,其中Se含量达到富硒土地标准的表层土壤点位占全部样品点位的76%;表层土壤中Cd含量超标的点位占48%,其他有害元素仅个别点位超标,Cd是制约该地区富硒土地资源开发的主要不利因素。在研究区圈定了61.4 km 2的富硒土地资源,认为研究区东部土壤富硒的物质来源是二叠系灰岩,可以利用当地灰岩提升富硒土地资源品质,降低生态风险。
