湘西新元古界—寒武系中锑砷存在相态研究

Experimental Geochemical Study on Sb and As Spedations in the Neoproterozoic-Cambrian Strata in Western Hunan

应用部分提取技术研究湘西地区新元古界—寒武系中锑和砷元素的存在相态表明,岩石中以可交换离子、与碳酸盐有关、与硫化物有关和赋存于硅酸盐矿物晶格中4种形式存在的锑元素分别占岩石中锑总量的18.65％、0.85％、31.41％和43.81％;砷则分别为7.05％、4.29％、56.11％和29.18％。呈易迁移相态存在的锑和砷分别为55.91％和67.45％。在含硫开放体系中,岩石中元素的淋滤率与其中易迁移相态所占百分数值呈正相关关系。这为该区存在锑、砷矿源层的认识提供了实验证据。

The speciations of antimony and arsenic in the Neoproterozoic-Cambrian strata in western Hunan have been studied with partial dissolution techniques. In rocks, Sb and As have four modes of occurrence: exchangeable, bound to sulfides, bound to carbonates and in silicate mineral lattice. The average percentages of the four fractions of antimony are 18. 65% , 0. 85% , 31. 41% and 43. 81%, respectively, and the average percentages of the four fractions of arsenic are 7. 05%, 4. 29%, 56. 11% and 29. 18%, respectively. The movable fractions of antimony and arsenic are 55. 91% and 67. 45%, respectively. The leaching rates of elements in the open sulfur-bearing system are approximately proportional to the percentages of movable fractions, which furnishes experimental evidence for the existence of source beds of antimony and arsenic in the region.