铬铁矿是生产不锈钢不可替代的原材料,中国目前是世界最大不锈钢消费国。铬铁矿一直是中国的短缺矿种,几乎完全依靠进口。铬铁矿床分为层状和豆荚状两种类型矿床。中国已知的铬铁矿床均属于豆荚状铬铁矿床,主要分布在西藏、新疆和内蒙古等地。该类矿床主要产于蛇绿岩型地幔橄榄岩或相关的堆晶杂岩中。最近在西藏罗布莎和俄罗斯乌拉尔豆荚状铬铁矿中发现深部地幔矿物,认为铬铁矿来自深部地幔,不是产自浅部地幔橄榄岩。认为深部来源的铬铁矿可以成大矿,小岩体也可以成大矿,因此,十分有必要对中国境内的蛇绿岩地幔橄榄岩开展新一轮的调查。
Chromite is an essential component of stainless steel,and China is the largest consumer of stainless steel in the world.However,only a few chromite deposits have been discovered in China,so China must rely almost entirely on imports for this strategic metal.Chromite forms two types of deposits,namely layered and podiform deposits.Chromite deposits in China are all of the podiform type and occur mainly in Tibet,Xinjiang and Inner Mongolia,where they are hosted in mantle peridotites and cumulates sequences in ophiolites.Deep mantle minerals have recently been discovered in-situ in chromite deposits in Tibet and the Polar Urals,which strongly suggests that chromite was formed in the deep mantle rather than in shallow mantle peridotite as suggested by previous researchers.It is held that large chromite deposits can be formed deep in the mantle and be hosted even in small bodies of mantle peridotite.It is thus necessary to reevaluate the current models for chromite formation and to undertake a new investigation into the ophiolite peridotites and chromite deposits in China.