Disclosed herein are processes for producing precipitated calcium carbonate. In one embodiment, the process comprises the steps of a) providing an aqueous slurry of calcium hydroxide; b) adding a polysaccharide to the slurry of calcium hydroxide; and c) carbonating the slurry of calcium hydroxide. The polysaccharide comprises poly alpha-1,3-glucan, a poly alpha-1,3-glucan ester compound as disclosed herein, or a poly alpha-1,3-glucan ether compound as disclosed herein. The precipitated calcium carbonate produced by the process can be useful in making paper.

Methods and systems for capturing and storing carbon dioxide are disclosed. In some embodiments, the methods include the following: mixing materials including magnesium or calcium with one or more acids and chelating agents to form a magnesium or calcium-rich solvent; using the organic acids derived from biogenic wastes as acids or chelating agents; generating carbonate ions by reacting a gas including carbon dioxide with a carbonic anhydrase biocatalyst; reacting the solvent with the carbonate ions to form magnesium or calcium carbonates; recycling a solution containing the biocatalyst after forming magnesium or calcium carbonates for re-use in the generating step; using the magnesium and calcium carbonates as carbon neutral filler materials and using the silica product as green filler materials or inexpensive absorbents.

A process for treating a sulfurous fluid to form gypsum and magnesium carbonate, whereby the sulfurous fluid is scrubbed with a sequestrating agent to yield a scrubbed fluid, gypsum and magnesium sulfate. The flue gas desulfurized gypsum is isolated from the magnesium sulfate solution by filtration or centrifugation. The magnesium sulfate is reacted with a carbonate salt to produce a magnesium carbonate whereby the reaction conditions are controlled to control the properties of the magnesium carbonate produced.

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.

Provided are carbon dioxide capture composite particles which contribute to carbon neutrality by fixing carbon dioxide in seawater or an aqueous solution in which calcium ions are dissolved through mineralization, and a method of producing the same. More particularly, provided are carbon dioxide capture composite particles which capture carbon dioxide in seawater to form calcium carbonate particles, preferably aragonite type calcium carbonate, and a method of producing the same. In an exemplary embodiment, a method of producing carbon dioxide capture composite particles including: immersing polyamidoamine particles in seawater or an aqueous solution in which calcium ions are dissolved and maintaining the solution at room temperature under normal pressure to produce carbon dioxide capture composite particles in which aragonite type calcium carbonate particles are formed on a surface of the polyamidoamine particles is provided.

The invention relates to a method for producing an implant which contains a composite powder comprising microstructured particles, obtainable by a method in which large polymer particles are bonded to small spherical calcium carbonate particles. Said calcium carbonate particles can be obtained by a method with the following steps: a) providing a calcium hydroxide suspension, b) introducing carbon dioxide or a carbon dioxide-containing gas mixture into the suspension from step a), and c) separating the calcium carbonate particles formed, while adding 0.3 wt.-% to 0.7 wt.-% of at least one amino trialkylene phosphonic acid.

A composite powder containing microstructured particles obtainable by means of a method in which large particles are combined with small particles, wherein the large particles have an average particle diameter within the range from 0.1 m to 10 mm, the large particles comprise at least one polymer, the small particles are arranged on the surface of the large particles and/or distributed inhomogeneously within the large particles, the small particles comprise sphere-shaped precipitated calcium carbonate particles having an average diameter within the range from 0.05 m to 50.0 m, wherein the sphere-shaped calcium carbonate particles are obtainable by means of a method in which
a. a calcium hydroxide suspension is initially charged,
b. carbon dioxide or a carbon dioxide-containing gas mixture is introduced into the suspension from step a. and
c. resultant calcium carbonate particles are separated off,
with 0.3% by weight to 0.7% by weight of at least one aminotrisalkylenephosphonic acid being further added.

Preferred application areas of the composite powder encompass its use as additive, especially as polymer additive, as additive substance or starting material for compounding, for the production of components, for applications in medical technology and/or in microtechnology and/or for the production of foamed articles.

The invention therefore also provides components obtainable by selective laser sintering of a composition comprising a composite powder according to the invention, except for implants for uses in the field of neurosurgery, oral surgery, jaw surgery, facial surgery, neck surgery, nose surgery and ear surgery as well as hand surgery, foot surgery, thorax surgery, rib surgery and shoulder surgery.

The invention also provides the sphere-shaped calcium carbonate particles which can advantageously be used to produce the composite particles according to the invention, and the use thereof.

The invention relates to a method for producing an implant by means of a composite powder having micro structured particles having inhibiting calcium carbonate, wherein the composite powder is obtained by a method in that large polymer particles are joined to small calcium carbonate particles, wherein the calcium carbonate particles are obtained by a method in that calcium carbonate particles are coated with a composition which, in each case based on the total weight thereof, comprises a mixture of at least 0.1 wt % of at least one calcium complexing agent and/or at least one conjugated base which is an alkaline metal or calcium salt of a weak acid, together with at least 0.1 wt % of at least one weak acid.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof, b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

Organic-inorganic composite particles that can be dispersed in a solvent and/or a resin as primary particles having an organic group on the surface of inorganic particles, the organic-inorganic composite particles having negative birefringence.