Abstract: An ore containing crystal water (bond water) is heated to dehydrate the crystal water in the form of water vapor, thereby rendering the ore porous to generate a porous ore. Next, the porous ore is forced into contact with a dry-distilled gas (organic gas) obtained by dry-distillation of an organic substance such as wood and the like or an organic liquid such as tar and the like. An organic compound such as tar and the like contained in the dry-distilled gas or organic liquid adheres to the surface of the porous ore. Next, the porous ore adhered with an organic compound is heated at 500° C. or higher, to generate an ore in which a part of an oxide of an element such as iron and the like contained is reduced by carbon in the organic compound.

Abstract: The present invention relates to a zero-waste process for extraction of alumina from different types of bauxite ores and red mud residues and of titanium dioxide from ilmenite. Iron oxide is first reduced to metallic iron above the melting point of C-saturated cast iron alloy which yields a high-C iron alloy and an Al and Ti metal oxide rich slag which is then treated with alkali carbonate to form alkali aluminates and titanates. The alkali aluminates are separated by water leaching from which the hydroxide of alumina is precipitated by bubbling C02. The residue from water leaching is treated with sulphuric acid and Ti02 is precipitated via a hydrolysis route. The process recovers most of the metal values and generates only small quantities of silicious residues at pH 4-5 which can be used for soil conditioning.

Abstract: A method for producing reduced iron in a layered furnace which includes several superimposed layers. Ore is continuously fed into the layered furnace, deposited on the uppermost layer, and gradually transferred to the lower layer. A reducing agent is deposited on the uppermost layer and/or layers thereunder and is reacted with the ore in order to form directly reduced iron. The directly reduced iron and reducing agent residues are discharged in the vicinity of the lowest layer of the furnace.

Abstract: This process comprises; mixing (1) the solid residues with a solid reducing agent; treating (2) the mixture in a furnace at a temperature above 1000.degree. C. to obtain (3) a vitrified product rendered poor in metals and an emission of gas enriched in metallic elements in a vapour phase; air quenching (4) the gases rich in metals; filtering (5) the products resulting from the air quenching to obtain secondary ashes rich in metallic salts; at the end of the filtering operation, washing the smoke (6) for discharging it to the atmosphere; and subjecting the secondary ashes rich in metallic salts to a treatment for producing a product rich in valuable metals (7 to 10).