Strengthening phosphate shale briquettes
AssigneeFMC Corporation
InventorJames A. Robertson
Life of this patent
Estimating the term…
Abstract
The strength of phosphate shale agglomerates or briquettes is enhanced by adding to and mixing with crushed phosphate shale ore tempering water and a water-soluble alkali metal or ammonium phosphate. The water-soluble phosphate salt is preferably dissolved in the tempering water and the solution sprayed onto the crushed shale ore. The tempering water is added in an amount to bring the moisture content of the mixture between about 9 and 12%. The phosphate salt is added in an amount up to 0.1%. The mixture is compacted into desired size and the compacts calcined.
Claims8
The method of producing phosphate shale agglomerates of enhanced strength which comprises adding to and mixing with crushed phosphate shale ore, the crushed ore containing from about 20% to about 30% by weight P.sub.2 O.sub.5 and including particles varying in size from fines up to about 3/4 inch, tempering water and a water-soluble alkali metal or ammonium phosphate, the amount of water being sufficient to bring the moisture content of the mixture between 9 and about 12%, the water-soluble phosphate being added in an amount up to about 0.1% by weight of the phosphate shale, compacting the mixture to form green briquettes, calcining the green briquettes at a temperature of from about 2,000.degree. F. (1,095.degree. C.) to about 2,500.degree. F. (1,375.degree. C.) and recovering the calcined briquettes.
Dependencies are inferred from the claim text.