Dolomitwerke Gmbh

Rheinische Kalksteinwerke Gmbh

Alfred Roeder

Herbert Richrath

Max Chmiel

Heinzjosef Poggenpohl

Dieter Opitz

Thomas Hammer

Rainer Prange

Friedrich Schmitz

Rudiger Oberste-Padtberg

Wolfgang Munchberg

Karlheinz Rosener

Karl H Zepter

Dietrich Gruschka

Heinz Bestek

Werner Ewald

Hans-Peter Hennecke

Method for the production of sintered dolomite, wherein at least carbonate material is ground into particles, formed into a predetermined shape, such as briquettes, deacidified and then heated to a predetermined temperature.

Method of thermal treatment of mineral raw material

Production of sintered dolomite in a rotary kiln

This invention relates to a process for the production of a usable or storable product with a low susceptibility to elutriation by water. This product is produced from residues containing halides obtained from a waste gas cleaning process. The halide containing residues as components of a crude dust having a CaO/SiO.sub.2 ratio between 1.7 and 3.4, are subjected to a thermal treatment to produce chlorosilicates. The waste gases formed during the thermal treatment for chlorosilicate production are subjected to a preliminary cleaning, and are then transported to the waste gas cleaning system of a refuse incineration plant. The residues occurring during the preliminary cleaning can be added to the crude dust.

Process for the production of chlorosilicates

A process is provided for producing dry calcium hydroxide by slaking finely divided or ground, softly burnt lime by carrying out the blending of slaking liquid consisting of 30 to 50 parts by volume water and 70 to 50 parts by volume organic solvent with the lime at a temperature below 45.degree. C. in a mixing vessel, subsequently transferring the reaction mixture into a main reaction vessel where the mixture is heated by means of a heating device to a temperature of from 50.degree. to 70.degree. C., and carrying out the final reaction in another reaction vessel. In the mixing vessel, the ratio of lime to slaking liquid is selected in a way such that a final reaction temperature of 85.degree. to 110.degree. C. is reached in the final reaction vessel.

Process for producing calcium hydroxide

In a method of manufacturing sintered dolomite having raw densities exceeding about 3.0 grams per cubic centimeter in a shaft kiln from ground raw dolomite briquetted or pelletized into shaped bodies, the steps include deacidifying and heating the shaped bodies to a temperature of at least 1000.degree. C. in an upper region of the shaft kiln in a preheating and deacidifying zone heated with fuels of a low thermal content, thereafter sintering the shaped bodies in a lower sintering zone heated with fuels of high thermal content, so as to heat the shaped bodies to a temperature of about 1600.degree. C. to about 2000.degree. C., and subsequently passing the sintered bodies into a lower cooling zone, cooling the bodies therein, and, thereafter, discharging the sintered bodies from the shaft kiln.

Method of manufacturing a sintered dolomite in a shaft kiln

To produce a dolomite sinter with a low porosity and a good hydration stability made of difficult-to-sinter raw dolomite, the dolomite is milled and caustic burnt dolomite, dolomite hydrate or semi-burnt dolomite in quantities between 3 and 20% by weight relative to the total mixture is added to the raw dolomite powder and is calculated as oxide, as well as foreign oxide, such as Fe.sub.2 O.sub.3, Al.sub.2 O.sub.3 or SiO.sub.2, in such quantities that the total content of the foreign oxide mixture is 1 to 3% by weight.

Method for making sintered dolomite with a low porosity and a good

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Duisburg, Germany

Alfred Roeder