Indium Enrichment in the Meng'entaolegai Ag-Pb-Zn Deposit, Inner Mongolia, China

Abstract

Abstract:The Meng'entaolegai In-rich Ag-Pb-Zn deposit is located in the eastern part of Inner Mongolia. It is one of the In-richest deposits in China. Large amounts of quartz and sulfide minerals constitute a hydrothermal quartz-sulfide vein deposit within a Hercynian acidic granite massif, which occupies an area of about 400 km 2 . Thirty-six orebodies, controlled strictly by the E-W trend faults, are found in the orefield of 6 km in length from east to west and 200 to 1,000 m in width from south to north. The ore minerals are mainly galena, sphalerite and pyrite, and subordinate chalcopyrite, arsenopyrite, cassiterite and stannite with many Ag-minerals. The gangue minerals are mainly quartz, calcite, sericite and chlorite. Economic components of the deposit are dominated by Pb and Zn (reserves of Pb and Zn are 0.17 Mt and 0.37 Mt, and their grades are 1 % and 2.3 %, respectively), with Ag, Sn, In and Cd (1,800 t Ag, >2,000 t Sn, >500 t In and 1,800 t Cd) as by-products. Indium is highly enriched in ores and its contents are 9 to 295 ppm in ores and 85 to 2,660 ppm in sphalerite. Analytical results show that the ore-forming fluid of this deposit contains 0.8-3.5 ppm In and 4-36 ppm Sn, and the two elements show a very good positive correlation with a correlation coefficient of 0.8672, while the correlation between In and Zn in the ore-forming fluids, with a correlation coefficient of 0.5723, is not as good as that between In and Sn. This indicates that indium has an affinity with tin in the ore-forming fluids. The authors think that this is probably the main reason why those In-rich deposits spread over the world are simultaneously enriched in tin.

Indium Mineralization in Copper–Tin Stratiform Skarn Ores at the Saishitang–Rilonggou Ore Field, Qinghai, Northwest China

“…During the past decade, the geology and the mineralogy of In‐bearing deposits in Japan, China, Bolivia, Canada and Germany have attracted a great deal of research interest (e.g., Ishihara et al, ; Murao et al, ; Zhang et al, ; Ishihara et al, ; Ishihara et al, ; Sinclair et al, ; Seifert & Sandmann ). China contains extensive In reserves and is a producer of primary indium, with major deposits in the Guangxi, Yunnan, Guangdong, and Inner Mongolia provinces (Zhang et al, ; Ishihara et al, ).…”

“…China contains extensive In reserves and is a producer of primary indium, with major deposits in the Guangxi, Yunnan, Guangdong, and Inner Mongolia provinces (Zhang et al, ; Ishihara et al, ). Well‐known indium deposits include the Dachang Sn–polymetallic deposit (Luo et al, ; Li et al, ; Ishihara et al, ), the Dulong Sn–Zn deposit (Ishihara et al, ) and the Gejiu Cu–Sn deposit (Li et al, ) in South China, and the Dajing Sn–polymetallic deposit (Ishihara et al, ) and the Meng'entaolegai Ag–Pb–Zn deposit (Zhang et al, ) in North China. These In‐bearing deposits are characterized by polymetallic Cu–Sn–Pb–Zn assemblages within the ores.…”

Indium and other trace elements in volcanogenic massive sulfide ores from the Kuroko, Besshi and other types in Japan

“…About the granite-related deposits, 6,000 tons In are estimated in the Northeast Japan Arc including the Toyoha veintype deposits, while 3,000 tons In may be possible in veins of the Southwest Japan Arc (Ishihara et al, 2006a). Larger tonnage of indium may be concentrated in the Southern China including Dachang (6,000 tons In), Dulong (4,000 tons In) and other some hundreds tons-class deposits, and middle size deposits are also known in the Inner Mongolia, China (Zhang et al, 2006;Ishihara et al, 2006b).…”

Indium Mineralization in a Sn-Poor Skarn Deposit: A Case Study of the Qibaoshan Deposit, South China

“…Although In occurs mainly in an isomorphic form in sphalerite, important resources are hosted in Sn-rich deposits. Examples include Sn-polymetallic deposits in south China [5][6][7], Bolivia [8], Japan [2,4], and some Sn-rich Cu-Zn deposits within the Iberian Pyrite Belt [9][10][11] and the Meng'entaolegai Ag-Pb-Zn deposit in north China [12]. Considering these associations with Sn-rich mineralization, could In-rich deposits also occur in Sn-poor environments?…”