Abstract: A plant for producing metal oxide from metal compounds includes a fluidized-bed reactor in which the metal compounds are heated by a combustion of a fuel to produce metal oxide. The fluidized-bed-reactor reactor includes at least one gas supply tube at least partly surrounded by an annular chamber in which a stationary annular fluidized bed is disposed, and a mixing chamber disposed above an orifice region of the gas supply tube. A gas flowing through the gas supply tube entrains solids from the stationary annular fluidized bed when passing through the orifice region.

Abstract: A plant for the heat treatment of solids containing titanium includes a fluidized bed reactor. The reactor includes at least one gas supply tube being at least partly surrounded by an annular chamber in which a stationary annular fluidized bed is located, and a mixing chamber being located above the upper orifice region of the gas supply tube. The gas flowing through the gas supply tube entrains solids from the stationary annular fluidized bed into the mixing chamber when passing through the upper orifice region of the gas supply system. The plant further includes a solids separator downstream of the reactor. The solids separator includes a solids conduit leading to the annular fluidized bed of the reactor.

Abstract: The present invention relates to a method for the heat treatment of fine-grained solids, in particular gypsum, in which the solids are heated to a temperature of 50 to 1000° C. in a fluidized bed reactor (1), and to a corresponding plant. To improve the energy utilization, it is proposed to introduce a first gas or gas mixture from below through a preferably central gas supply tube (3) into a mixing chamber (21) of the reactor (1), the gas supply tube (3) being at least partly surrounded by a stationary annular fluidized bed (2) which is fluidized by supplying fluidizing gas, and to adjust the gas velocities of the first gas or gas mixture as well as of the fluidizing gas for the annular fluidized bed (2) such that the particle Froude numbers in the gas supply tube (3) are between 1 and 100, in the annular fluidized bed (2) between 0.02 and 2 and in the mixing chamber (21) between 0.3 and 30.

Abstract: A plant for the heat treatment of solids containing titanium includes a fluidized bed reactor. The reactor includes at least one gas supply tube being at least partly surrounded by an annular chamber in which a stationary annular fluidized bed is located, and a mixing chamber being located above the upper orifice region of the gas supply tube. The gas flowing through the gas supply tube entrains solids from the stationary annular fluidized bed into the mixing chamber when passing through the upper orifice region of the gas supply system. The plant further includes a solids separator downstream of the reactor. The solids separator includes a solids conduit leading to the annular fluidized bed of the reactor.

Abstract: The present invention relates to a process for producing metal oxide from metal compounds, in particular metal hydroxide or metal carbonate, in which the metal compound is conveyed into a reactor (25) with fluidized bed, heated there to a temperature of 650 15 to 1150° C. by combustion of fuel, and metal oxide is generated, as well as to a corresponding plant. To improve the utilization of energy, it is proposed to introduce a first gas or gas mixture from below through a gas supply tube (26) into a mixing chamber (20) of the reactor (25), the gas supply tube (26) being at least partly surrounded by a stationary annular fluidized bed (27) which is fluidized by supplying fluidizing gas, and 20 to adjust the gas velocities of the first gas or gas mixture and of the fluidizing gas for the annular fluidized bed (27) such that the Particle-Froude numbers in the gas supply tube (26) lie between 1 and 100, in the annular fluidized bed (27) between 0.02 and 2, and in the mixing chamber (20) between 0.3 and 30.

Abstract: The present invention relates to a method and a plant for the heat treatment of solids containing titanium and possibly further metal oxides, in which fine-grained solids are heated to a temperature of 700 to 950° C. in a fluidized bed reactor (1). To improve the energy utilization, it is proposed to introduce a first gas or gas mixture from below through a gas supply tube (3) into a mixing chamber (7) of the reactor (1), the gas supply tube (3) being at least partly surrounded by a stationary annular fluidized bed (10) which is fluidized by supplying fluidizing gas. The gas velocities of the first gas or gas mixture as well as of the fluidizing gas for the annular fluidized bed (10) are adjusted such that the particle Froude numbers in the gas supply tube (3) are between 1 and 100, in the annular fluidized bed (10) between 0.02 and 2 and in the mixing chamber (7) between 0.3 and 30.

Abstract: A plant for producing metal oxide from metal compounds includes a fluidized-bed reactor in which the metal compounds are heated by a combustion of a fuel to produce metal oxide. The fluidized-bed-reactor reactor includes at least one gas supply tube at least partly surrounded by an annular chamber in which a stationary annular fluidized bed is disposed, and a mixing chamber disposed above an orifice region of the gas supply tube. A gas flowing through the gas supply tube entrains solids from the stationary annular fluidized bed when passing through the orifice region.

Abstract: The present invention relates to a process for producing metal oxide from metal compounds, in particular metal hydroxide or metal carbonate, in which the metal compound is conveyed into a reactor (25) with fluidized bed, heated there to a temperature of 650 15 to 1150° C. by combustion of fuel, and metal oxide is generated, as well as to a corre-sponding plant. To improve the utilization of energy, it is proposed to introduce a first gas or gas mixture from below through a gas supply tube (26) into a mixing chamber (20) of the reactor (25), the gas supply tube (26) being at least partly surrounded by a stationary annular fluidized bed (27) which is fluidized by supplying fluidizing gas, and 20 to adjust the gas velocities of the first gas or gas mixture and of the fluidizing gas for the annular fluidized bed (27) such that the Particle-Froude numbers in the gas supply tube (26) lie between 1 and 100, in the annular fluidized bed (27) between 0.02 and 2, and in the mixing chamber (20) between 0.3 and 30.

Abstract: The present invention relates to a method and a plant for the heat treatment of solids containing titanium and possibly further metal oxides, in which fine-grained solids are heated to a temperature of 700 to 950° C. in a fluidized bed reactor (1). To improve the energy utilization, it is proposed to introduce a first gas or gas mixture from below through a gas supply tube (3) into a mixing chamber (7) of the reactor (1), the gas supply tube (3) being at least partly surrounded by a stationary annular fluidized bed (10) which is fluidized by supplying fluidizing gas. The gas velocities of the first gas or gas mixture as well as of the fluidizing gas for the annular fluidized bed (10) are adjusted such that the particle Froude numbers in the gas supply tube (3) are between 1 and 100, in the annular fluidized bed (10) between 0.02 and 2 and in the mixing chamber (7) between 0.3 and 30.

Abstract: A process is disclosed for preparing anhydrous alumina from aluminum hydroxide which comprises feeding aluminum hydroxide into a first suspension preheater and partially dehydrating the aluminum hydroxide with a hot exhaust gas, transporting the partially dehydrated aluminum hydroxide with said exhaust gas to a first separating means and separately withdrawing the exhaust gas and the partially dehydrated aluminum hydroxide, and dividing the partially dehydrated aluminum hydroxide into a first and second partial stream of solids. The process uses a circulating fluidized bed comprising a fluidized bed reactor, a recycle separator connected to the upper portion of said fluidized bed reactor, and a return line for leading solids from said recycle separator to the lower portion of said fluidized bed reactor. The second partial stream of solids is fed into a second suspension preheater and contacted with hot exhaust gas from the recycle separator.

Abstract: A fluidized bed reactor is supplied with fuel, oxygen-containing gas, and kaolinite, which contains water of crystallization. At least 80% by weight of the kaolinite have particle sizes in the range from 0.1 to 3 mm. A fluidized bed at temperatures in the range from 850.degree. to 950.degree. C. is formed in the fluidized bed reactor. A meta-kaolin white pigment which contains water of crystallization not in excess of 2% by weight is withdrawn from the fluidized bed reactor.