Patent ID: 11180424

Abstract:
A phosphate fertilizer as described contains a blend of finely ground sulfur component, swelling agent and rock phosphate (for example, apatite). Preferably, the swelling agent is bentonite. The sulfur component, swelling agent and rock phosphate raw materials are preferably present as particles of less than about 500μ in size, more preferably between about 400-200μ, but more than 100μ. The sulfur component and swelling agent may be combined together before sizing as a composition of about 85 wt % sulfur sublimed onto/into or melted together with about 15 wt % bentonite. These components are present in the phosphate fertilizer at about 10 wt % for the sulfur, at about 5 wt % for the swelling agent and about 80 wt % for the rock phosphate. In addition, when the blend is pelletized, a granulation aid, like lignin, molasses, etc., is also present at about 5 wt % of the blend.