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: 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 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: 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: In a process for a selective flotation of a copper-lead-zinc sulfide ore the raw ore is ground and slurried with water and the resulting suspension is aerated with air to adjust a certain oxidation-reduction potential and is subsequently successively conditioned with SO.sub.2, Ca(OH).sub.2, and collecting and frothing agents, whereafter a flotation of Cu is effected. An oxidation-reduction potential which is 70 to 90% of the oxidation-reduction potential desired for the flotation of Cu is adjusted by the aeration of the suspension with air before the flotation of Cu, the desired oxidation-reduction potential of 60 to 340 mV is adjusted during the flotation of Cu by the aeration with air, the flotation of Cu is effected at a pH of 8.5 to 10.5 and Cu is removed from the flotation process with the froth.

Abstract: The iron content of the TiO.sub.2 -containing precursor is subjected to a direct reduction to effect a metallization of at least 90%. The reduced product is separated into magnetic and nonmagnetic fractions by magnetic separation. To oxidize the metallic iron, the magnetic fraction is subjected to an oxidation in an acid medium with agitation at a pH value below 2, under a pressure of 12 to 24 bars, and at a temperature from 150.degree. to 210.degree. C. with a supply of an oxygen-containing gas that contains at least 90% oxygen. When the suspension has been pressure-relieved, the hematite which has been formed is separated from the TiO.sub.2 concentrate.