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最近6年来俄罗斯的白垩开采量增加了42．4％,2005年白垩的开采量超过2 530万t。俄罗斯开采的白垩原料有91％用于生产水泥,有4％～5％用于
In the past six years, the amount of chalk extraction in Russia has increased by 42.4%. In 2005, chalk production exceeded 25.3 million tons. 91% of the chalk material extracted from Russia is used to produce cement and 4% to 5% are used