从铼的地球化学性质看我国铼找矿前景

Rhenium resource exploration prospects in China based on its geochemical properties

铼是生产涡轮发动机耐高温超级合金的核心元素,被誉为改变航空业的金属。斑岩铜矿伴生的辉钼矿和还原性沉积岩中的硫化物是铼的主要赋存矿物。从目前铼的产量来看,全球近一半的铼产出于智利的斑岩铜钼矿床。据美国地质调查局估计,智利的铼探明储量在1300吨。其他国家依次是美国、俄罗斯、秘鲁等国,均在300吨左右。从现有的数据估算我国目前的铼储量约为250吨,以辉钼矿伴生为主。从地球化学的角度来看,铼是地球上最稀有的金属之一;作为中度不相容的亲铜、亲铁元素,铼倾向于在岩浆中富集;铼对硫逸度、氧逸度敏感,在表生过程中可以通过氧化还原过程富集于黑色页岩等还原性沉积物中。封闭、半封闭的海湾是其常见的富集位置。在埃迪卡拉纪和寒武纪,大气中的氧气含量大幅度上升,是表生过程中铼迁移、富集的最佳时期。我国华南广泛分布形成于近海环境的埃迪卡拉纪寒武纪黑色页岩,仅鄂西分布范围就有数千平方千米,厚度可以达到200m,其中铼的含量达到0.1×10^-6~0.6×10^-6,远景资源量在万吨以上,是寻找铼矿的最佳选区之一。

Rhenium(Re)is the crucial element in the production of heat resistant superalloys for turbine engines,and it is known as the aviation industry transforming metal.The rhenium deposits predominantly occurred in molybdenites of porphyry coppermolybdenum deposits and sulfides in the reducing sedimentary rocks.At present,nearly half of the rhenium reserves in the world were contained by the porphyry coppermolybdenum deposits in Chile.The total rhenium reserves in Chile estimated by the United States Geological Survey are ca.1300 tons.The following countries include United States,Russia,Peru and other countries,totaling 300 tons.It is estimated from the available data that the proved rhenium reserves in China are about 250 tons,mainly associated with molybdenites.In geochemical perspective,rhenium is one of the rarest metals on the Earth.As a moderately incompatible chalcophile and siderophile element,rhenium is enriched in magmas.Rhenium is sensitive to sulfur fugacity and oxygen fugacity,which prefer to be enriched in sediments under the reducing conditions,e.g.black shale,during the surface process.Enclosed and semienclosed bays are the common places for rhenium concentration.During the Ediacaran and Cambrian periods,the atmospheric oxygen increased greatly,which was the most favorable period for the migration and enrichment of rhenium during the Earth\s surface processes.The EdiacaranCambrian black shales,formed in offshore environments,are widely distributed in South China.The western Hubei has included several thousand square kilometers of black shale,of which the thicknesses is up to 200 meters and the rhenium concentration reaches 0.1×10^-6~0.6×10^-6.The predicted resource of contained rhenium in this area is more than 10,000 tons,which is potential to be one of the best target for rhenium exploration.