Abstract Large-scale coal mining is being carried out in Tete province, Mozambique. This area is also being planned to become a large coal fired power production hub serving electricity to neighboring countries in southern Africa. Thus, huge amounts of coal will be burned, resulting in the generation of a large quantity of coal ash. High concentrations of hazardous elements are often released from coal and coal ash causing negative impacts to human health and the environment. Therefore, it is important to understand the possibility of hazardous elements leaching. Aqueous batch leaching experiments under ambient conditions were conducted using six coal samples and their ash. Most of the coal leached very low concentrations of hazardous elements. However, an absence of carbonate minerals gave rise to higher acidity levels. This resulted in elevated leaching concentrations of manganese and iron, regardless of their contents. Burning coal resulted in higher contents of hazardous elements in the ash. However, leaching concentrations of most of the elements from the ash samples were still lower than the environmental standards. Chromium and manganese were enriched in slightly acidic leachates regardless of their contents while higher arsenic than the permitted level was leached from the ash containing the highest arsenic content that generated neutral pH leachate. These findings highlight a possibility of hazardous elements contamination from Mozambican coal and coal ash. Therefore, the storage of coal and disposal of coal wastes and ash in Tete Province should be done carefully and monitored to avoid the contamination in the region.

中文翻译：

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莫桑比克煤和煤灰中有害元素的浸出

摘要 莫桑比克太特省正在进行大规模煤炭开采。该地区还计划成为一个大型燃煤发电中心，为南部非洲的邻国提供电力。因此，将燃烧大量的煤，从而产生大量的煤灰。高浓度的有害元素通常从煤和煤灰中释放出来，对人类健康和环境造成负面影响。因此，了解有害元素浸出的可能性非常重要。使用六个煤样及其灰分在环境条件下进行水分批浸出实验。大多数煤浸出的有害元素浓度非常低。然而，碳酸盐矿物的缺乏导致更高的酸度水平。这导致锰和铁的浸出浓度升高，无论其含量如何。燃烧煤炭导致灰烬中有害元素的含量更高。然而，灰样中大部分元素的浸出浓度仍低于环保标准。铬和锰在微酸性浸出液中富集，而不管其含量如何，而高于允许水平的砷从砷含量最高的灰烬中浸出，产生中性 pH 值的浸出液。这些发现凸显了莫桑比克煤炭和煤灰污染有害元素的可能性。因此，在太特省的煤炭储存和煤炭废弃物和灰烬的处置应谨慎进行并进行监控，以避免该地区受到污染。