Provided is a medical calcium carbonate composition that highly satisfies 1) tissue affinity, 2) in vivo resorbability, 3) reactivity, and 4) mechanical strength required for medical materials to be implanted in vivo, a medical calcium phosphate composition, a medical carbonate apatite composition, a medical calcium hydroxide porous structure, a medical calcium sulfate setting granules, and a bone defect regeneration kit related to the medical calcium carbonate composition, and methods for producing these. The medical composition calcium carbonate that highly satisfies the above described elements, and related medical compositions can be produced by controlling the polymorph or structure of calcium carbonate.

Provided is a medical calcium carbonate composition that highly satisfies 1) tissue affinity, 2) in vivo resorbability, 3) reactivity, and 4) mechanical strength required for medical materials to be implanted in vivo, a medical calcium phosphate composition, a medical carbonate apatite composition, a medical calcium hydroxide porous structure, a medical calcium sulfate setting granules, and a bone defect regeneration kit related to the medical calcium carbonate composition, and methods for producing these. The medical composition calcium carbonate that highly satisfies the above described elements, and related medical compositions can be produced by controlling the polymorph or structure of calcium carbonate.

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.

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.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

A method of increasing the strength of a carbonate rock is described. The carbonate rock may be located within a subterranean carbonate formation or may be located on a building exterior. The method involves contacting the carbonate rock with a composition comprising a zinc salt or a silicon alkoxide. This may increase the hardness of the carbonate rock by 10% or more.

The present disclosure relates to processes for treating wastewater such as acid rock drainage. The processes may, for example, comprise subjecting the wastewater to a microbial fuel cell process, neutralizing the acid with a base comprising calcium to produce an aqueous composition comprising calcium ions and subjecting the aqueous composition comprising calcium ions to a biological precipitation process to precipitate the calcium ions as calcium carbonate.

Lithium recovery processes are described using concentration and conversion techniques. A vaporizer or membrane can be used to concentrate lithium and precipitate impurities. A conversion process can be used to replace anions in lithium bearing streams by adding a second anion and precipitating lithium in a salt with the second anion. Rotary separation can be used to separate the precipitated lithium salt.

A carbonate microfluidic model with controllable nanoscale porosity and methods are described. The method for fabricating a carbonate nanofluidic micromodel with controllable nanoscale porosity for studying fluid behaviors in an underground oil-reservoir environment includes: disposing a plurality of polymer spheres into a transparent flow cell; initiating crystallization of the plurality of polymer spheres to form a template with an opal structure; filling the transparent flow cell with a calcium-based solution and a carbonate-based solution to form nanocrystals in voids of the opal structure; and removing the template formed by crystallization of the plurality of polymer spheres from the transparent flow cell leaving an inverse opal structure with a plurality of nanoscale pores and a carbonate surface. The model includes: a transparent flow cell including a first end defining an inlet and a second end defining an outlet; and an inverse opal structure of carbonate inside the transparent flow cell.

A carbonate microfluidic model with controllable nanoscale porosity and methods are described. The method for fabricating a carbonate nanofluidic micromodel with controllable nanoscale porosity for studying fluid behaviors in an underground oil-reservoir environment includes: disposing a plurality of polymer spheres into a transparent flow cell; initiating crystallization of the plurality of polymer spheres to form a template with an opal structure; filling the transparent flow cell with a calcium-based solution and a carbonate-based solution to form nanocrystals in voids of the opal structure; and removing the template formed by crystallization of the plurality of polymer spheres from the transparent flow cell leaving an inverse opal structure with a plurality of nanoscale pores and a carbonate surface. The model includes: a transparent flow cell including a first end defining an inlet and a second end defining an outlet; and an inverse opal structure of carbonate inside the transparent flow cell.