The present disclosure provides a method of biocementation comprising contacting a granular, cohesionless soil with a solution, wherein the solution comprises urea, urease, a source of calcium ions, and a source of non-urease proteins, wherein the urea, urease, source of calcium ions, and source of non-urease proteins are provided in effective amounts suitable to cause crystallization of calcium carbonate.

Techniques for growing crystalline calcium carbonate solids such that the crystalline calcium carbonate solids include a volume of 0.0005 mm.sup.3 to 5 mm.sup.3, include a slaker to react quicklime (CaO) and a low carbonate content fluid to yield a slurry of primarily slaked lime (Ca(OH).sub.2); a fluidized-bed reactive crystallizer that encloses a solid bed mass and includes an input for a slurry of primarily slaked lime, an input for an alkaline solution and carbonate, and an output for crystalline calcium carbonate solids that include particles and an alkaline carbonate solution; a dewatering apparatus that includes an input coupled to the crystallizer and an output to discharge a plurality of separate streams that each include a portion of the crystalline calcium carbonate solids and alkaline carbonate solution; and a seed transfer apparatus to deliver seed material into the crystallizer to maintain a consistent mass of seed material.

The present invention relates to a method for the production of granules comprising surface-reacted calcium carbonate, as well as to the granules obtained thereby and their use.

Provided is a method for preparing a stable amorphous calcium carbonate (ACC), which can be obtained either in suspension or as a powder. The method comprises stepwise combination of a soluble calcium salt, a soluble carbonate, a first and second stabilizer, and a water miscible organic solvent as described herein. The present invention further relates to stable ACC suspensions and dry powders produced by the method of the present invention.

The present invention relates to a process for producing an aqueous suspension of precipitated calcium carbonate, an aqueous suspension of precipitated calcium carbonate and a precipitated calcium carbonate obtained by the process, a product comprising the aqueous suspension of precipitated calcium carbonate or the precipitated calcium carbonate as well as its use.

A method for preparing nano silica and nano calcium carbonate using rice hull ash and flue gas. The method includes: 1) adding rice hull ash to a sodium hydroxide solution, to yield a first mixed solution; stirring and heating the first mixed solution; then filtering the first mixed solution to yield a first filtrate; 2) adding the first filtrate to a reaction still, and diluting the first filtrate; adding polyethylene glycol as a dispersant to the reaction solution; introducing flue gas to the reaction solution; filtering the reaction mixture to yield a first filter cake and a second filtrate; washing the first filter cake to a neural pH, slurrying and drying the first filter cake to yield nano silica; and 3) mixing the second filtrate and a washing solution collected from 2); adding a calcium hydroxide solution to the reaction still, to yield nano calcium carbonate.

The invention relates to the use of copolymers obtained by the polymerisation of styrene maleic anhydride, functionalised or not, for producing an aqueous suspension of precipitated calcium carbonate (PCC) by slaking a material containing calcium oxide in water then by carbonation of the milk of lime thus produced.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving lime in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

The present invention relates to the use of at least one cationic polymer in a method for manufacturing a precipitated calcium carbonate aqueous suspension, in which a milk of lime is prepared by mixing water, a calcium oxide containing material, said at least one cationic polymer, optionally at least one slaking additive, said milk of lime being them carbonated to form a precipitated calcium carbonate aqueous suspension.

A process for converting gypsum into precipitated calcium carbonate including reacting a mixture comprising gypsum and a seed, a mineral acid, or both with at least one carbonate source, whereby precipitated calcium carbonate is produced in the form of calcite and/or aragonite directly without conversion from a vaterite polymorph. Also, a process for converting gypsum into precipitated calcium carbonate including providing a mixture comprising i) gypsum ii) a seed, a mineral acid, or both iii) at least one additive selected from the group consisting of ammonium sulfate, an organic acid, or an iron material, and reacting the mixture with at least one carbonate source to produce precipitated calcium carbonate in the form of vaterite. The precipitated calcium carbonates having desired and unique compositions, polymorph and crystal size characteristics formed by these processes.