摘要 |
Raw phosphate material is calcined to remove pollutants, such as organic compounds and sulphides, by heat treatment in two suspension calciners (3,5) arranged in series. Fuel supplied at burners (8) is burnt in the calciners with air, supplied in parallel through pipes (9) from a cooler (7) for the treated material. The material is preheated in a preheater, for instance a pipe (13) and cyclone (2) by exit gases from the calciner before entering the calciners and, after leaving the calciners, is separated from the gas streams in separators (4,6).
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