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 μm 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 μm to 50.0 μm, 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 present invention refers to the use of a surface-reacted calcium carbonate having a volume median particle size d.sub.50 from 0.1 to 90 μm as skin appearance modifier in a cosmetic and/or skin care composition.

A method for sequestering carbon by spraying an aqueous solution containing calcium ions into a reactor containing supercritical carbon dioxide to form a slurry of calcium carbonate, and collecting the calcium carbonate from the bottom of the reactor.

Compositions comprising highly reflective microcrystalline/amorphous materials are provided. In some instances, the highly reflective materials are microcrystalline or amorphous carbonate materials, which may include calcium and/or magnesium carbonate. In some instances, the materials are CO.sub.2 sequestering materials. Also provided are methods of making and using the compositions, e.g., to increase the albedo of a surface, to mitigate urban heat island effects, etc.

A process includes converting hydrocarbons to at least one molecular energy carrier and carbon dioxide, reacting said carbon dioxide with a divalent metal-containing silicate to form solid divalent metal carbonate and silicate and utilizing at least one of said carbonate and silicate in the production of construction and/or chemical material.

The present invention relates to a method for continuous removal of carbon dioxide, the method comprising the steps of: a) preparing an aqueous solution containing an amine-based compound and an acidic calcium compound; b) bringing a gas containing carbon dioxide to be treated into contact with the aqueous solution to prepare a calcium carbonate precipitate; and c) recovering the calcium carbonate and then adding a basic calcium compound to the residual aqueous solution, wherein after step c), step b) and step c) are repeatedly performed. The removal of carbon dioxide by the method of the present invention has advantages of requiring low energy and being capable of mineralizing and removing carbon dioxide at a fast rate without a separate time for induction.

A method for making a calcium hydroxide solution for use in a carbonation reactor containing supercritical carbon dioxide to form calcium carbonate particles of a selected size.

The present application pertains to methods for making metal oxides and/or citric acid and/or capturing carbon dioxide. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth sulfite or bisulfate and an aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.

A method of treating a metal carbonate salt includes hydrolyzing a metal halide salt to form a hydrohalic acid and a hydroxide salt of the metal in the metal halide salt. The metal includes an alkaline earth metal or an alkali metal. The method includes reacting the hydrohalic acid with the metal carbonate salt, wherein the metal carbonate salt is a carbonate salt of the alkaline earth metal or alkali metal, to form CO.sub.2 and the metal halide salt. At least some of the metal halide salt formed from the reacting of the hydrohalic acid with the metal carbonate salt is recycled as at least some of the metal halide salt in the hydrolyzing of the metal halide salt to form the hydrohalic acid and the hydroxide salt.