Abstract: Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

Abstract: Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 less than 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.

Abstract: Methods and systems for producing calcium carbonate from calcium hydroxide and carbon dioxide are disclosed herein. In some embodiments, a method for producing calcium carbonate comprises (i) providing a first plurality of particles comprising solid-state calcium hydroxide, and (ii) introducing a gas stream comprising carbon dioxide to the first plurality of particles to produce a second plurality of particles comprising calcium carbonate. Individual ones of the first plurality of particles can include a specific surface area of at least 20 m2/g and a free moisture content of from 2% to 20%. The second plurality of particles comprising calcium carbonate are not produced via precipitation.

Abstract: Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 from about 8 to about 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.

Abstract: Methods and systems for producing calcium carbonate from calcium hydroxide and carbon dioxide are disclosed herein. In some embodiments, a method for producing calcium carbonate comprises (i) providing a first plurality of particles comprising solid-state calcium hydroxide, and (ii) introducing a gas stream comprising carbon dioxide to the first plurality of particles to produce a second plurality of particles comprising calcium carbonate. Individual ones of the first plurality of particles can include a specific surface area of at least 20 m2/g and a free moisture content of from 2% to 20%. The second plurality of particles comprising calcium carbonate are not produced via precipitation.

Abstract: Methods and systems for treating oil sands tailings streams at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises providing a tailings stream including 10-55% solids by total weight, increasing the pH of the tailings stream by combining the tailings stream with lime to produce a lime-tailings mixture having a pH of at least 11.0, and dewatering the lime-tailings mixture to produce a first stream having 10% or less solids by total weight and a second stream having 50% or more solids by total weight. The first stream can correspond to a release water stream, and the second stream can correspond to a cake. The lime slurry can include about 10% lime by total weight, and can comprise lime hydrate, quicklime, or a combination thereof. Dewatering the lime-tailings mixture can include routing the lime-tailings mixture to a centrifuge unit and/or a pressure or vacuum filtration unit.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 from about 8 to about 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.

Abstract: Methods and systems for treating oil sands tailings streams at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises providing a tailings stream including 10-55% solids by total weight, increasing the pH of the tailings stream by combining the tailings stream with lime to produce a lime-tailings mixture having a pH of at least 11.0, and dewatering the lime-tailings mixture to produce a first stream having 10% or less solids by total weight and a second stream having 50% or more solids by total weight. The first stream can correspond to a release water stream, and the second stream can correspond to a cake. The lime slurry can include about 10% lime by total weight, and can comprise lime hydrate, quicklime, or a combination thereof. Dewatering the lime-tailings mixture can include routing the lime-tailings mixture to a centrifuge unit and/or a pressure or vacuum filtration unit.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 from about 8 to about 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.

Abstract: Methods and systems for producing calcium carbonate from calcium hydroxide and carbon dioxide are disclosed herein. In some embodiments, a method for producing calcium carbonate comprises (i) providing a first plurality of particles comprising solid-state calcium hydroxide, and (ii) introducing a gas stream comprising carbon dioxide to the first plurality of particles to produce a second plurality of particles comprising calcium carbonate. Individual ones of the first plurality of particles can include a specific surface area of at least 20 m2/g and a free moisture content of from 2% to 20%. The second plurality of particles comprising calcium carbonate are not produced via precipitation.

Abstract: Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions. In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 from about 8 to about 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 from about 8 to about 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.

Abstract: Methods and systems for treating oil sands tailings streams using multiple dosages of lime are disclosed herein. In some embodiments, the method comprises providing a tailings stream including 3-40% solids by total weight, combining the tailings stream with a first dosage of lime to produce a first mixture having a pH of less than 12.0, and then combining the first mixture with a polymer to produce a second mixture. In some embodiments, the method can further include combining the second mixture with a second dosage of lime to produce a third mixture having a pH greater than 12.0, and dewatering the third mixture in a centrifuge unit and/or a pressure filtration unit to produce a product stream having 55% or more solids by weight.

Abstract: Calcium hydroxide-containing compositions can be manufactured by slaking quicklime, and subsequently drying and milling the slaked product. The resulting calcium hydroxide-containing composition can have a size, steepness, pore volume, and/or other features that render the compositions suitable for treatment of exhaust gases and/or removal of contaminants. In some embodiments, the calcium hydroxide-containing compositions can include a D10 from about 0.5 microns to about 4 microns, a D90 less than about 30 microns, and a ratio of D90 to D10 from about 8 to about 20, wherein individual particles include a surface area greater than or equal to about 25 m2/g.