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US 4,710,219 AGranted
Production method of combined phosphorus fertilizer and soil conditioner
OwnerArvo Wahlberg, deceased, by Anna-Maija Wahlberg, heiressinventors
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Abstract
A method for producing combined phosphorus fertilizer and soil conditioner in which phosphate rock and, as reaction matter, organic acidic matter are used. In a method according to the invention, the acidic mass is organic, for instance, bark waste, peat, peat mud or waste fibre from a cellulose production plant or the solid component of communal sewage.
Claims13
A method for producing a combined phosphate fertilizer and soil conditioner without employing a mineral acid, which consists essentially of the steps of:
- (a) grinding a moist, acidic, organic waste material having a pH less than 5, a water content of at least 40% and lower calcium and phosphorous contents than the calcium and phosphorous contents of phosphate rock;
- (b) heating the acidic, organic waste material ground during step (a) to a temperature of 40.degree. to 120.degree. C. and at a pressure of 16 to 22 bar;
- (c) grinding phosphate rock to a particle size of 0.02 to 1 mm;
- (d) heating the phosphate rock ground during step (c) to a temperature of 50 to 800.degree. C.;
- (e) combining the ground, acidic, organic waste material obtained during step (b) as the sole acidic reactant with the ground phosphate rock obtained during step (d) at a pressure of 20 to 55 bar to permit the ground, acidic, organic waste material and the ground phosphate rock to collide, to cause disintegration of the phosphate rock;
- and
- (f) cooling the mixture obtained during step (e) to 20.degree. to 40.degree. C. to obtain the desired product which contains almost all nutrient elements of phosphate rock.
4 more elements
Dependencies are inferred from the claim text.