As one of the coal mining wastes, coal gangue is the largest amount of emissivity in China mining districts.

煤矸石是我国矿山排放量最大的废渣之一。

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As one of the coal mining wastes, coal gangue is the largest amount of emissivity in China mining districts.

煤矸石是我国矿山排放量最大的废渣之一。

youdao