Iron pyrites cinders (haematite) is freed from arsenic and non-ferrous metals by reducing the cinders, using air and a carbonaceous fuel, at 850-950 C. with a contact time of 30-90 minutes to effect a 10-50% reduction of haematite to magnetite chlorinating the partially reduced cinders in a fluidized bed at 650-950 C. with a contact time of 30-120 minutes in an oxidizing atmosphere such that the oxygen content of the exhaust gases is at least 3% by volume and then leaching the chlorinated product with a 0À2-2% by wt. aqueous solution of a mineral acid, e.g. HC1 and/or H 2 SO 4 using a liquid/solid weight ratio of at least 2 : 1 and a contact time of 15-30 minutes. The fluidized bed chlorination may be effected in 2 or more stages. If the iron content of the chlorinated cinders is low, they may be subjected to a magnetizing reduction and magnetic concentration before the acid leach. The purified cinders may be pelleted.
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机译：通过在850-950℃下使用空气和碳质燃料，接触时间为30-90分钟以减少10-50％的还原量来减少铁灰渣中的铁渣（赤铁矿）中的砷和有色金属的含量将赤铁矿转化为磁铁矿，将部分还原的煤渣在氧化气氛中于650-950°C的接触时间为30-120分钟的氯气中氯化，以使废气中的氧气含量至少为3％（体积），然后用0-2-2％（重量）浸出氯化产物。无机酸的水溶液，例如HCl和/或H 2 SO 4的液/固重量比至少为2：1，接触时间为15-30分钟。流化床氯化可分两个或更多个阶段进行。如果氯化煤的铁含量低，则在酸浸之前可能会对它们进行磁化还原和磁浓缩。可以将纯化的煤渣造粒。
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