Disclosed herein are systems and methods from processing flue gas desulfurization (FGD) gypsum feedstock and ash feedstocks, either separately or together. FGD gypsum conversion comprises reacting FGD gypsum (calcium sulfate) feedstock or phosphogypsum, in either batch or continuous mode, with ammonium carbonate reagent to produce commercial products comprising ammonium sulfate and calcium carbonate. A process to separate the impurities and convert the calcium carbonate to a pure precipitated calcium carbonate is disclosed. These impurities include a concentrate of valuable Rare Earth Elements, and radioactive thorium and uranium. A process to convert calcium sulfite to calcium sulfate using oxygen and a catalyst is also disclosed. Ash conversion comprises a leach process followed by a sequential precipitation process to selectively precipitate products at predetermined pHs resulting in metal hydroxides which may be converted to oxides or carbonates. The processes may be controlled by use of one or more processors.

The present document describes an oral care composition comprising a cuttlefish bone powder, comprising particles having more than 95% (w/w) calcium carbonate content, a specific surface area of at least 5 m.sup.2/g, a mechanical hardness about 4.75 to 6.87 GPa, and at least 20% of said particles of the powder have a particle size of from about 50 microns to about 70 microns and a mean of about 60 microns, and a suitable carrier, and uses of the composition for oral hygiene.

Disclosed herein are systems and methods from processing flue gas desulfurization (FGD) gypsum feedstock and ash feedstocks, either separately or together. FGD gypsum conversion comprises reacting FGD gypsum (calcium sulfate) feedstock or phosphogypsum, in either batch or continuous mode, with ammonium carbonate reagent to produce commercial products comprising ammonium sulfate and calcium carbonate. A process to separate the impurities and convert the calcium carbonate to a pure precipitated calcium carbonate is disclosed. These impurities include a concentrate of valuable Rare Earth Elements, and radioactive thorium and uranium. A process to convert calcium sulfite to calcium sulfate using oxygen and a catalyst is also disclosed. Ash conversion comprises a leach process followed by a sequential precipitation process to selectively precipitate products at predetermined pHs resulting in metal hydroxides which may be converted to oxides or carbonates. The processes may be controlled by use of one or more processors.

The present invention provides stabilized amorphous calcium carbonate (ACC) formulations, comprising ACC and a non-aqueous liquid carrier in which the ACC is dispersed. The present invention further provides cosmetic and pharmaceutical compositions comprising ACC.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

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.

A process for converting natural calcium carbonate into precipitated calcium carbonate, involving treating the natural calcium carbonate with a sulfate to produce a gypsum and reacting the gypsum with at least one carbonate source to produce precipitated calcium carbonate. The crystalline polymorph, particle size, and various other characteristics of the precipitated calcium carbonate are controlled by varying conditions during the reacting. Since the natural calcium carbonate is not calcined, the process relates to a low energy method of producing precipitated calcium carbonate of controlled polymorph and particle size with limestone, marble, or chalk as the calcium source.

A method is provided for producing functionally improved carbolime from carbolime and the use of the functionally improved carbolime as a filtering aid, as filler, as lime fertilizer or as adsorbent for the adsorption of dyes.

The present invention provides stabilized amorphous calcium carbonate (ACC) formulations, comprising ACC and a non-aqueous liquid carrier in which the ACC is dispersed. The present invention further provides cosmetic and pharmaceutical compositions comprising ACC.

The present disclosure generally relates to methods of preparing spherical salt particles for industrial, medical, and other uses. The methods can include combining the angular salt particles with a quantity of finishing media, for example, into a receptacle. Thereafter, the angular salt particles and the finishing media can be moved or agitated until the angular salt particles have a desired sphericity.