Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

The invention relates to multi-stage cement calcining plant suspension preheater of the kind mentioned in the introduction, wherein the preheater comprises a top separator comprising a central tube entering the top separator in a lowermost part of the separator housing whereas the central tubes of the bottom separators enters the separator housing in an upper part of the separator housing.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods makes use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

The disclosure discloses a method for preparing calcium oxide using multistage suspension preheater kiln. The steps of the method are: (1) the limestone powder is fed to the multistage suspension preheater kiln for preheating to 800 C. to 900 C.; (2) A preheated material is fed to a decomposition furnace, and calcined at 900 C. to 1100 C. for 25 s to 35 s; (3) A calcined material is fed to a rotary kiln, and calcined at 1100 C. to 1300 C. for 25 to 35 minutes, and finally cooled to obtain calcium oxide.

The present invention relates to apparatus for thermal treatment of a mineral starting material, wherein the apparatus comprises a calciner, wherein the calciner comprises at least a first calciner section and a second calciner section, wherein the first calciner section is arranged vertically, wherein the second calciner section is arranged at an incline, wherein the second calciner section has an angle ? between the horizontal and the flow direction of the second calciner section, wherein the angle ? is between 20? and 80?, wherein the first calciner section has a first hydraulic diameter d.sub.h,1, wherein the second calciner section has a second hydraulic diameter d.sub.h,2, wherein the second hydraulic diameter d.sub.h,2 is less than or equal to the first hydraulic diameter d.sub.h,1 multiplied by the sine of the angle ?.

An apparatus for calcination of gypsum includes a gypsum calciner having an interior wall surface with a circular or annular configuration as seen in its plan view, and a tubular combustor positioned at a center part of a body of the calciner. Raw gypsum is calcined or dehydrated by a high temperature gas spouting flow (Hg) ejected from a lower portion of the combustor. The calciner has a stationary-vane-type or movable-vane-type auxiliary device, which circumferentially energizes the raw gypsum in the vicinity of the interior wall surface toward a circumferential direction of the calciner. The auxiliary device has a plurality of stationary vanes circumferentially arranged in an outer peripheral zone of a lower portion of the combustor and spaced apart from each other at an angular interval, or an agitator extending through a conical or inner circumferential surface defined by the interior wall surface.

An apparatus for calcination of gypsum includes a gypsum calciner having an interior wall surface with a circular or annular configuration as seen in its plan view, and a tubular combustor positioned at a center part of a body of the calciner. Raw gypsum is calcined or dehydrated by a high temperature gas spouting flow (Hg) ejected from a lower portion of the combustor. The calciner has a stationary-vane-type or movable-vane-type auxiliary device, which circumferentially energizes the raw gypsum in the vicinity of the interior wall surface toward a circumferential direction of the calciner. The auxiliary device has a plurality of stationary vanes circumferentially arranged in an outer peripheral zone of a lower portion of the combustor and spaced apart from each other at an angular interval, or an agitator extending through a conical or inner circumferential surface defined by the interior wall surface.

Apparatus for the production of carbon dioxide from limestone includes a nuclear reactor (10) for generating heat and a rotary kiln (12). The rotary kiln (12) has an inlet (28) for the introduction of limestone and an outlet (30) for the release of carbon dioxide. A heat transfer arrangement is provided for transferring heat from the nuclear reactor (10) to the interior of the rotary kiln (12). The heat transfer arrangement includes feed and return primary conduits (17,18) for passing a heat transfer fluid (14) through the nuclear reactor (10) so that heat may be extracted from the nuclear reactor (10) for transfer to the interior of the rotary kiln (12). Limestone in the rotary kiln (12) is thereby heated to a temperature sufficient for the release of carbon dioxide.

Apparatus for the production of carbon dioxide from limestone includes a nuclear reactor (10) for generating heat and a rotary kiln (12). The rotary kiln (12) has an inlet (28) for the introduction of limestone and an outlet (30) for the release of carbon dioxide. A heat transfer arrangement is provided for transferring heat from the nuclear reactor (10) to the interior of the rotary kiln (12). The heat transfer arrangement includes feed and return primary conduits (17,18) for passing a heat transfer fluid (14) through the nuclear reactor (10) so that heat may be extracted from the nuclear reactor (10) for transfer to the interior of the rotary kiln (12). Limestone in the rotary kiln (12) is thereby heated to a temperature sufficient for the release of carbon dioxide.