Ostara Nutrient Recovery Technologies Inc.

Donald R Clark

Ahren Thomas Britton

Dan Michael Froehlich

Pierre Lucien Cote

Ram Prasad Melahalli Sathyanarayana

Rhonda Maria Hyslop

A method for treating phosphate-containing wastewater, such as phosphogypsum pond water. The method includes the steps of: (a) adding a first cation to the wastewater to precipitate fluorosilicate from the wastewater; (b) adding a second cation to the wastewater to precipitate fluoride from the wastewater; (c) raising the pH of the wastewater to precipitate the second cation from the wastewater; (d) removing residual silica from the wastewater; and (e) precipitating phosphate from the wastewater. The precipitated fluorosilicate may be sodium fluorosilicate. The precipitated phosphate may be struvite.

Treatment of phosphate-containing wastewater with fluorosilicate and phosphate recovery

A homogeneous fertilizer granule comprises slow-release (e.g. struvite) and fast release sources of phosphorus (P). The homogeneous fertilizer granule may further contain other essential nutrients and micronutrients required by plants. A number of methods may be used to make such granules. One method includes introducing a struvite slurry or fines and a liquid supply of water soluble P into a granulator. Alternatively, dry raw materials can be mixed with water/steam and/or another binder prior to being fed into a granulator. In another embodiment, pre-mixed dry raw materials are mechanically compacted and crushed to yield homogeneous fertilizer particles.

Slow and fast release fertilizer composition and methods for making same

Methods and apparatus for precipitating dissolved materials from a solution involve reduction of fines. In an embodiment, the method comprises: introducing a solution into a reactor, causing the dissolved materials in the solution to precipitate into crystals under a first reaction condition, adjusting the reaction condition from the first reaction condition to a second reaction condition, maintaining the reaction condition in the second reaction condition to cause a sub-population of the crystals to dissolve, and adjusting the reaction condition from the second reaction condition to the first reaction condition. In an embodiment, the apparatus comprises a reaction tank, a recycling path and at least an acid injector which is configured for dosing an acid into solution flow in the recycling path.

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Lutz, FL, United States of America

Donald R Clark