The present invention is directed to a process for producing precipitated calcium carbonate with improved resistance to structural breakdown, wherein the milk of lime is carbonated in the presence of at least one gas other than carbon dioxide, or the carbonation is carried out in the presence of a static gas bubble comminution unit as well as to precipitated calcium carbonate obtained by such a process.

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.

The present invention relates to a process for preparing an aqueous suspension comprising precipitated calcium carbonate. The invention further relates to an aqueous suspension comprising precipitated calcium carbonate as well as a partially dewatered or essentially completely dried precipitated calcium carbonate obtainable by the process and the use of the aqueous suspension comprising precipitated calcium carbonate and/or the partially dewatered or essentially completely dried precipitated calcium carbonate in paper making, paper coating, plastic, agricultural, adhesives, sealants and/or paint applications.

The present invention relates to a process for the preparation of precipitated calcium carbonate allowing for a more sustainable and cost-efficient use of milk of lime. The obtainable products show good optical properties as well as fine particle size distributions.

Implant comprising composite powder with microstructured particles, obtained by a process in which large particles are bonded to small particles, wherein the large particles have a mean particle diameter in the range from 10 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 are non-homogeneously spread within the large particles, the small particles comprise a calcium salt, the small particles have a mean particle size in the range from 0.01 m to 1.0 mm,
wherein the particles of the composite powder have a mean particle size d50 in the range from 10 m to less than 200 m and the fine fraction of the composite powder is less than 50 vol %.

Therefore, the subject matter of the invention further are implants obtained by selective laser sintering of a composition comprising a composite powder, especially as an implant for applications in the field of neuro, oral, maxillary, facial, ear, nose and throat surgery as well as of hand, foot, thorax, costal and shoulder surgery.

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.

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.

A process, apparatus, and cyclopropenimine (CPI) material for generating metal carbonates are disclosed. Generating the metal carbonates comprises reacting carbon dioxide (CO.sub.2) with CPI. Generating the metal carbonates also comprises forming a reaction mixture comprising water, metal cations, and a product of the reacting.

Effluent water is combined with carbon dioxide sourced from a carbon dioxide-containing emission stream to produce a reaction solution. The pH of the reaction solution is controlled to induce precipitation of a carbonate salt from the reaction solution.

The present invention relates to a process for producing an aqueous suspension of precipitated calcium carbonate, an aqueous suspension of precipitated calcium carbonate and a precipitated calcium carbonate obtained by the process, a process comprising the precipitated calcium carbonate and its use.