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根据美国内务部矿山局的评估,1992年世界兰晶石及其伴生矿物(美国除外)的产品增长了4%,其数据如下(万t):
According to the assessment of the Mines Administration of the U.S. Department of the Interior, products of the world’s cyanite and its associated minerals (excluding the U.S.) grew by 4% in 1992, with the following data (10,000 t):