This invention relates to a method for producing geothermal power using geothermal brines while producing a reduced silica and iron brine having improved injectivity. The resulting compositions include a composition with reduced silica, iron, and lithium having reduced quantity of total suspended solids.

This invention relates to a method for producing geothermal power using geothermal brines while producing a reduced silica and iron brine having improved injectivity. The resulting compositions include a composition with reduced silica, iron, and lithium having reduced quantity of total suspended solids.

This invention relates to a method for producing geothermal power using geothermal brines while producing a reduced silica and iron brine having improved injectivity. The resulting compositions include a composition with reduced silica, iron, and lithium having reduced quantity of total suspended solids.

This invention relates to a method for producing geothermal power using geothermal brines while producing a reduced silica and iron brine having improved injectivity. The resulting compositions include a composition with reduced silica, iron, and lithium having reduced quantity of total suspended solids.

A process for simultaneously removing silica and reducing total hardness of a natural or waste water containing silica and scale-forming ions is described. The process comprises adding (i) magnesium hydroxide or a precursor of magnesium hydroxide and (ii) a soluble aluminate compound or a precursor of aluminate to said water while maintaining the pH of said stream at pH>8 to produce a layered double hydroxide in situ, wherein the layered double hydroxide contains the scale-forming ions in a lattice of the layered double hydroxide and silica is incorporated in the lattice of the layered double hydroxide as an interlayer anion and/or bound by the layered double hydroxide via one or more binding modes.

A process for simultaneously removing silica and reducing total hardness of a natural or waste water containing silica and scale-forming ions is described. The process comprises adding (i) magnesium hydroxide or a precursor of magnesium hydroxide and (ii) a soluble aluminate compound or a precursor of aluminate to said water while maintaining the pH of said stream at pH>8 to produce a layered double hydroxide in situ, wherein the layered double hydroxide contains the scale-forming ions in a lattice of the layered double hydroxide and silica is incorporated in the lattice of the layered double hydroxide as an interlayer anion and/or bound by the layered double hydroxide via one or more binding modes.

The present invention relates to a process that uses one or more evaporators to treat produced water containing silica. To address silica scaling, a crystallizing reagent is mixed with the produced water upstream of the evaporator. The crystallizing reagent is designed to precipitate a silica adsorbing compound such as magnesium hydroxide. The feedwater with the adsorbed silica is directed to an evaporator that produces a distillate and a concentrate containing the adsorbed silica. At least a portion of the concentrate having the silica adsorbing compound is directed to a separator that separates the silica adsorbing compound from the concentrate and recycles it back to where it is mixed with the produced water.

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.

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.

A slurry product is shown for treating water to both soften the water and to remove silica. The slurry is prepared by blending, in an aqueous medium, hydrated lime under the form of a slurry or of a powder with at least partly hydrated dolime, or magnesium hydroxide or magnesium oxide particles or a combination thereof under the form of a slurry or of a powder, to form an aqueous slurry where the amounts of the dolime, magnesium hydroxide or magnesium oxide particles or the combination thereof are provided such that the solid content of the slurry is up to 60% by weight of the slurry. The slurry also maintains a stable and pumpable viscosity for over a month.