The present invention aims to provide techniques for efficiently synthesizing inorganic microparticles. According to the present invention, inorganic carbonate microparticles can be synthesized by generating ultrafine bubbles containing carbonic acid gas by injecting a gas containing carbonic acid gas and a liquid into a reaction vessel through a nozzle to deposit an inorganic carbonate having an average primary particle size of 300 nm or less in the presence of the ultrafine bubbles.

Disclosed herein are system and methods to effectively leach coal ash with hydrochloric acid and separate an insoluble silica product and then selectively precipitate, from the leachate, a number to value-added, strategic, marketable products using a hydroxide reagent. The resulting precipitated products include iron, aluminum, magnesium, calcium, and a mixture of rare earth elements and transition metals. These can be separated as hydroxides or converted to oxides or carbonates. Using hydrochloric acid for leaching and converting the chloride to sodium chloride in the final step results in practically no waste for this process. The silica can be further purified using sodium hydroxide fusion or caustic leach methods and some minor streams from this process are recycled to minimize any waste stream. These systems and methods can be applied to a number of other industrial waste products such as red mud from the aluminum process, slag from steel furnaces, mine tailings, and other metal-bearing waste streams.

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 invention provides a new method for fixing carbon dioxide. The method for fixing carbon dioxide of the present invention includes a contact step of bringing a mixed liquid containing sodium hydroxide and further containing at least one of a chloride of a Group 2 element or a chloride of a divalent metal element into contact with a gas containing carbon dioxide.

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.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving limestone 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.

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.

Disclosed is a method for fast and cost-efficient preparation of ikaite crystals. The method comprises contacting an alkaline aqueous solution, which comprises carbonate and bicarbonate ions, with a water solution, which comprises Ca.sup.2+, at a temperature not exceeding 15° C., wherein contact between the alkaline aqueous solution and the water solution takes place at a permeable or porous surface, through which either solution is fed to the other at a flow rate facilitating formation of ikaite crystals. Also disclosed is system for carrying out the ikaite preparation process. The process and system provides a cost efficient and effective means for capture and storage of carbon dioxide.

Method for preparing lithium concentrate from natural lithium-bearing brines was developed. The brine is first subjected to purification from the suspended solids, then filtered through a static layer of the granulated sorbent based on the LiCl-2Al(OH)3-mH20, where m=3-5, to obtain primary lithium concentrate. The process is carried out in sorption-desorption units consisting of 4 columns, two of which are in the process of lithium chloride from the brine, one column is in the process of washing the sorbent saturated with lithium chloride from the brine, and one column is in the process of lithium chloride desorption. Primary lithium concentrate is converted to a secondary lithium concentrate by concentration in evaporative pools or reverse-osmotic concentration-desalination. Secondary lithium concentrate is used for further production of lithium chloride or lithium carbonate. Invention increases recovery of lithium chloride during sorption enrichment of natural lithium brines, improves the quality of lithium chloride and lithium carbonate obtained, widens the range of lithium-bearing hydromineral raw materials suitable for the production of lithium compounds, by using lithium-bearing natural brines containing suspended particles.

A method for ship ballasting includes receiving, at a carbon negative energy storage system, input comprising calcium oxide and water and reacting, within a reaction chamber of the carbon negative energy storage system, the calcium oxide and water to release energy and generate calcium hydroxide. The method includes directing, by the carbon negative energy storage system, the released energy to a requesting end user and providing, by the carbon negative energy storage system, the calcium hydroxide to a marine vessel ballasting system. The method includes releasing a mixture of the calcium hydroxide and ballast water from the marine vessel ballasting system into the ocean to sequester atmospheric COCO.sub.2.