摘要 |
Processes are disclosed for recovering solid wastes containing elemental phosphorus. The wastes may cause serious environmental problems at phosphorus furnaces because elemental phosphorus is toxic to marine animals. Recovery of the wastes was considered for the following. 1. At phosphorus furnace plants making phosphoric acid as one of the products, when the objective is to produce only high-quality phosphoric acid. 2. At phosphorus furnace plants making elemental phosphorus as a final product, and the objective is to provide only high-quality phosphorus. 3. At plant sites where neither phosphoric acid nor phosphorus is produced. The processes include recycling the wastes to phosphorus furnaces. All of the phosphoric acid produced in 1 can be highly concentrated with low impurities content. In 2, all the low-quality phosphorus is recycled to the phosphorus furnaces and all the produce is high grade. In 3, phosphorus furnaces are not available at the plant site and recycling the solid wastes is impractical. In this case processes are disclosed for recovering the elemental phosphorus from the waste, converting the residue to granular fertilizer, and making suspension fertilizer from water containing elemental phosphorus.
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