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据澳大利亚西部耶尔加恩布洛克(Yilgarn Block)天然产出的金—银矿块的矿物学观察表明,沿着矿块的边部,特别当附近有氧化铁存在时,经常发生银和/或金的溶解作用。在红土剖面中常发现很纯的小金晶体(Ag<0.4%)与氧化铁紧密伴生。这种情况表明金和银在红土化过程中曾被溶解、搬运和再沉积。实验证据表明,在红土剖面中,由铁解作用(铁的氧化作用和水解作用)产生的酸度很高的氯化物溶液可以促使金和银的溶解。随后由于AuCl_4~-离子被Fe~(+2)离子还原,金被再次沉淀了下来。而络合物AgCl~o由于Fe~(+2)/Fe~(+3)和Ag/AgCl~o的相对氧化还原电位不同,不发生类似的还原作用,因此在红土化期间金起了化学提纯作用。在红土风化剖面中,低pH值的发育和金、银的再分配似乎更多见于花岗岩和片麻岩基岩之上,而在基性岩层的风化带中,由于碳酸盐的存在,这种作用可能受到抑制。
Mineralogical observations of naturally occurring gold-silver ore blocks from the Yilgarn Block in western Australia show that silver and / or silver are often present along the edges of the nuggets, particularly in the presence of iron oxide nearby, Or gold dissolution. Very pure small gold crystals (Ag <0.4%) are often found in the laterite profile in close association with iron oxide. This situation indicates that gold and silver were dissolved, transported and redeposited during the later stage of the later. Experimental evidence indicates that the highly acidic chloride solution produced by ironysis (iron oxidation and hydrolysis) can promote the dissolution of gold and silver in the laterite profile. Then AuCl_4 ~ - ion is Fe ~ (+2) ion reduction, gold was precipitated again. However, due to the different redox potential of Fe ~ (+2) / Fe ~ (+3) and Ag / AgCl ~ o, the complex AgCl ~ o did not undergo similar reduction, Purification effect. In the laterite weathering profile, the development of low pH value and the redistribution of gold and silver appear to be found more on granite and gneiss bedrock, whereas in the weathered belt of basement rock, due to the presence of carbonate, The role of species may be inhibited.