Abstract: A method for the heat treatment of granular solids includes initially introducing solids into a first reactor configured as a flash reactor or fluidized bed reactor where they are brought into contact with hot gases at temperatures in the range 500° C. to 1500° C. Next, the solids are passed through a residence time reactor in which they are fluidized. The residence time reactor is configured in a manner such that it has various regions which are separated from one another, from which the solid can be withdrawn in a manner such that it is provided with a variety of residence times in the residence time reactor.

Abstract: A method for the heat treatment of granular solids includes initially introducing solids into a first reactor configured as a flash reactor or fluidized bed reactor where they are brought into contact with hot gases at temperatures in the range 500° C. to 1500° C. Next, the solids are passed through a residence time reactor in which they are fluidized. The residence time reactor is configured in a manner such that it has various regions which are separated from one another, from which the solid can be withdrawn in a manner such that it is provided with a variety of residence times in the residence time reactor.

Abstract: A process for purifying red mud including reduction of the red mud to reduced material, and traversing the reduced material with an oxygen-containing gas in the presence of a catalyst suitable for iron oxidation.

Abstract: A process for production of calcined petroleum coke includes combusting, in a fluidized bed reactor, green petroleum coke as a fuel with a substoichiometric amount of oxygen at a temperature of between 900 and 1,400° C. so as to provide a required amount of energy to evaporate volatile matter included in the green petroleum coke. An air-to-fuel ratio in the reactor is less than 1 and retention time is less than 40 minutes. Calcined petroleum coke and flue gas is obtained. The flue gas comprises at least 80 wt-% of the volatile matter contained in the green petroleum coke. The flue gas is at least partially recycled to the reactor as an additional fuel.

Abstract: A process for purifying red mud, comprises the following steps: 1. reduction of the red mud to reduced material, and 2. traversing the reduced material with an oxygen-containing gas in the presence of a catalyst suitable for iron oxidation.

Abstract: A plant for chemical or physical treatment of granular solids includes a fluidized-bed reactor, a solids supply conduit and a central gas supply tube. A cooling tube is disposed relative to the gas supply tube so as to form an annular cooling duct, which is configured to cool the gas supply tube and the process gas and is connected with a coolant source configured to supply a coolant with a temperature of below about 400° C. Outlet openings are disposed in the cooling tube. The fluidized-bed reactor is a Venturi reactor in which the cooling tube opens into a flared portion with the outlet openings connecting the annular cooling duct with the reactor interior. The cooling tube adjoins the gas supply tube and extends substantially parallel to the flared portion of the reactor.

Abstract: A method for producing a clinker substitute for use in cement production includes predrying clay with an iron content >1.5 wt-% in a form of iron oxides and a kaolinite content <40 wt-% to a moisture <10 wt-%. The clay is comminuted to a grain size <2 mm. The clay is calcined by thermal treatment in a furnace at a temperature of 600 to 1000° C. The clay is thermally treated under reducing conditions at a temperature of 600 to 1000° C. so as to form a reduction product. The reduction product is intermediately cooled to a temperature <300° C. and finally cooled.

Abstract: A process for at least one of a chemical and a physical treatment of fluidizable substances in a reactor includes introducing a hot gas into an interior of the reactor through a gas supply tube and cooling at least one of the hot gas and the gas supply tube with a coolant. The cooling is performed by contacting the hot gas with the coolant so as to provide a temperature of a wall of the gas supply tube at least 50° C. lower than a temperature of the gas at an inlet of the gas supply tube facing away from the interior of the reactor.

Abstract: A process for at least one of a chemical and a physical treatment of fluidizable substances in a reactor. The process includes introducing a hot gas into an interior of the reactor through a gas supply tube and cooling at least one of the hot gas and the gas supply tube with a coolant. The cooling is performed by contacting the hot gas with the coolant so as to provide a temperature of a wall of the gas supply tube at least 50° C. lower than a temperature of the gas at an inlet of the gas supply tube facing away from the interior of the reactor.

Abstract: A method for producing a clinker substitute for use in cement production includes predrying clay with an iron content >1.5 wt-% in a form of iron oxides and a kaolinite content <40 wt-% to a moisture <10 wt-%. The clay is comminuted to a grain size <2 mm. The clay is calcined by thermal treatment in a furnace at a temperature of 600 to 1000° C. The clay is thermally treated under reducing conditions at a temperature of 600 to 1000° C. so as to form a reduction product. The reduction product is intermediately cooled to a temperature <300° C. and finally cooled.

Abstract: A process for producing a geopolymer includes combusting at least one of oil shale and mineral residues originating from a production of oil using the oil shale so as to produce a combustion product. The combustion product is ground. An alkaline activator is added to the combustion product to form a geopolymer mixture. Water is added to the geopolymer mixture. The geopolymer mixture is adjusted so as to obtain a mol ratio of Si:Al of 2 to 5, a mol ratio of K:Al of 0.6 to 0.7, a mol ratio of Si:K of 3 to 10, a mol ratio of Ca:Al of 0.1 to 0.4, and a mol ratio of Si:CA of 4.9 to 41. The geopolymer mixture is hardened.

Abstract: The present invention relates to the production of geopolymers from oil shale and/or mineral residues, which originate from the production of oil by means of oil shale. To use the residues left in the combustion of oil shale for the production of geopolymers, the oil shale and/or also mineral residues, which originate from the production of oil by means of shale are burnt and subsequently ground, before they are mixed with an alkaline activator and water and cured.

Abstract: A process for heat treatment of fine-grained mineral solids includes passing fine-grained mineral solids through a flash reactor so as to contact the fine-grained mineral solids with hot gases in the flash reactor at a temperature of 450 to 1500° C. so as to obtain hot solids. The hot solids arc passed through a residence time reactor at a temperature of 500 to 890° C. The hot solids are withdrawn from the residence time reactor after a residence time of 1 to 600 minutes. A waste gas of the residence time reactor is recirculated to at least one of the flash reactor and a preheating stage.

Abstract: A process for at least one of a chemical and a physical treatment of fluidizable substances in a reactor. The process includes introducing a hot gas into an interior of the reactor through a gas supply tube and cooling at least one of the hot gas and the gas supply tube with a coolant. The cooling is performed by contacting the hot gas with the coolant so as to provide a temperature of a wall of the gas supply tube at least 50° C. lower than a temperature of the gas at an inlet of the gas supply tube facing away from the interior of the reactor.