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.

A method for reducing metal oxide containing charge materials (1): reducing the metal oxide containing charge materials (1) in at least two fluidized bed units (RA,RE) by means of a reduction gas (2), wherein at least some of the resulting off-gas (3) is recycled and wherein the metal oxide containing charge materials (1) are conveyed into the fluidized bed unit RE by a propellant gas. Also, apparatus for carrying out the method according to the invention is disclosed.

A method for reducing metal oxide containing charge materials (1): reducing the metal oxide containing charge materials (1) in at least two fluidized bed units (RA,RE) by means of a reduction gas (2), wherein at least some of the resulting off-gas (3) is recycled and wherein the metal oxide containing charge materials (1) are conveyed into the fluidized bed unit RE by a propellant gas. Also, apparatus for carrying out the method according to the invention is disclosed.

A fluidized calciner is provided which allows a reduction in the rate of unburned fuel at an outlet of a fluidized calciner to enable sufficient calcination while preventing possible occlusion in a preheater, even when pulverized coal of coal or coke, which has low combustion quality, is used as fuel, based on calculations in accordance with computational fluid dynamics based on the shape of an actual furnace and operational conditions. The present invention provides a fluidized calciner including a tubular furnace body (2) in which an axial direction is an up-down direction, a pulverized coal blowing line (3) through which fuel is blown into the furnace body (2), a raw material chute (4) through which a cement raw material is loaded into the furnace body (2), at least one air introduction pipe (5) through which introduced air is sucked, the pulverized coal blowing line (3), the raw material chute (4), and the air introduction pipe (5) being connected to a side portion of the furnace body (2), and a fluidizing air blowing port (6) disposed at a bottom portion of the furnace body (2) and through which fluidizing air is blown into the furnace body (2), in which a blowing port of the pulverized coal blowing line (3) is disposed below a suction port of the air introduction pipe (5) and above the fluidizing air blowing port (6).

A fluidized calciner is provided which allows a reduction in the rate of unburned fuel at an outlet of a fluidized calciner to enable sufficient calcination while preventing possible occlusion in a preheater, even when pulverized coal of coal or coke, which has low combustion quality, is used as fuel, based on calculations in accordance with computational fluid dynamics based on the shape of an actual furnace and operational conditions. The present invention provides a fluidized calciner including a tubular furnace body (2) in which an axial direction is an up-down direction, a pulverized coal blowing line (3) through which fuel is blown into the furnace body (2), a raw material chute (4) through which a cement raw material is loaded into the furnace body (2), at least one air introduction pipe (5) through which introduced air is sucked, the pulverized coal blowing line (3), the raw material chute (4), and the air introduction pipe (5) being connected to a side portion of the furnace body (2), and a fluidizing air blowing port (6) disposed at a bottom portion of the furnace body (2) and through which fluidizing air is blown into the furnace body (2), in which a blowing port of the pulverized coal blowing line (3) is disposed below a suction port of the air introduction pipe (5) and above the fluidizing air blowing port (6).

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.

A system for fluidized bed reduction of powdered iron ore. Use of high-gas-velocity processing accelerates iron ore reduction speed and greatly improves the gas-treatment capabilities of a unit-cross-sectional fluidized bed. Use of parallel connections involving reduced coal gas lessens the volume of gas passing through a single-stage fluidized bed. Use of serial/parallel-connection processing involving reduced coal gas increases the coal gas utilization rate. The invention achieves the highly-effective reduction of powdered iron ore in a fluidized bed under near-atmospheric pressure. A reduction method based on the present system is also disclosed.

A system for fluidized bed reduction of powdered iron ore. Use of high-gas-velocity processing accelerates iron ore reduction speed and greatly improves the gas-treatment capabilities of a unit-cross-sectional fluidized bed. Use of parallel connections involving reduced coal gas lessens the volume of gas passing through a single-stage fluidized bed. Use of serial/parallel-connection processing involving reduced coal gas increases the coal gas utilization rate. The invention achieves the highly-effective reduction of powdered iron ore in a fluidized bed under near-atmospheric pressure. A reduction method based on the present system is also disclosed.