Treatment of phosphate rock on soil in situ with sulfuric acid
AssigneeChemsoil Corporation
InventorDwight D. Collins
Life of this patent
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Abstract
A layer of bare, untreated phosphate rock granules is applied to the soil, and concentrated sulfuric acid is supplied thereto. The sulfuric acid is sufficiently concentrated so as to be containable by cold-rolled carbon steel, and sufficiently viscous to cling to the granules to react therewith. Sulfuric acid in excess of the amount needed for reaction with the phosphate rock can be added to correct alkaline conditions in the underlying soil. The reaction of sulfuric acid with the phosphate rock produces substantial quantities of available phosphate and gypsum.
Claims14
The method of providing available phosphate and gypsum to soil comprising:
- (a) applying bare granules of pulverized phosphate rock which has not been previously treated by sulfuric acid to the top of the soil exposed to the air without mixing the granules into the soil or otherwise covering the granules, whereby to form a layer of granules the top of which is exposed to the air and whose area covers the top of the soil to an appreciable extent;
- and
- (b) applying to the top of said layer, sulfuric acid of such concentration as to be containable by equipment made of cold-rolled carbon steel without substantial corrosion, more viscous than water, and deliquescent, said concentration being above about 75% H.sub.2 SO.sub.4, whereby that portion of the sulfuric acid which contacts the granules tends to remain adherently in contact with the granules and attract water for reaction with said granules, without substantial penetration of the acid into the soil beneath the granules.
Dependencies are inferred from the claim text.