Laporte Industries Limited

Scm Chemicals, Inc.

Scm Corporation

Scm Chemical Limited

Michael Robinson

James P Bonsack

David B Mobbs

Alan D Crosby

Harry B Wilson

Kirit Talati

Aluminium chloride contaminated with iron chloride is purified by contacting it in vapor form with a bed of particles of aluminium metal interspersed with particles of a chemically inert material. The efficiency of the process may be maintained by acid treating, drying and recycling the bed material. The process may be applied to aluminium chloride produced by the chlorination of a bauxite beneficiate.

Purification of aluminum chloride

The invention pertains to an entrained-downflow chlorination process of fine metalliferous ores particularly containing alkali and/or alkaline earth metals greater than about 0.3% by weight as the oxide. The process includes a quenching step following the chlorination step where the chlorinated products are quenched by liquid cooling fluid spray patterns adapted to prevent solidification of the alkali and/or alkaline earth materials onto the reactor walls. The chlorinator unit of this invention prevents disruption of the chlorination process due to presence of liquids or sticky particles and it contains a quenching spray means disposed below the chlorination zone in the entrained-downflow chlorinator unit, whereby the quenching sprays prevent reactor wall buildup.

Chlorination of ores containing alkali or alkaline earth values

Chlorine may be recovered from residues from the fluidized bed chlorination of iron-containing metalliferous oxidic materials, such as ilmenite, bauxite, chromite, wolframite, scheelite, tantalite or columbite, the residues containing condensed iron chloride and blow-over bed solids, by heating the residue to revolatalize the iron chloride and reacting it with oxygen. The quantity of iron chloride in the oxidic material is controlled relative to the quantity of blow-over carbon so that the quantity of carbon is sufficient on combustion to provide the required heat but is insufficient to cause undue dilution of the chlorine produced by virtue of its combustion products. Chlorine of a concentration suitable for direct recycle to a chlorination process, e.g. of 30% to 50% volume concentration is produced.

Recovery of chlorine

The process is directed to a fluidized bed chlorination of iron containing metaliferous materials to simultaneously produce a quantity of titanium beneficiate and a quantity of titanium tetrachloride. The process is controlled by maintaining the bed temperature between about 600.degree. C. and 1150.degree. C. while controlling the quantity of chlorine relative to the ratio of beneficiate to titanium tetrachloride desired.

Chlorination of iron-containing metaliferous material

A process for the beneficiation of an iron-containing material is carried out by first chlorinating the iron-containing material. Oxidation of ferrous chloride in the effluent gas from the chlorination is carried out under controlled conditions of oxygen supply so that more than 50% but less than 100% of the ferrous chloride is oxidized. In this way chlorine gas is separated from the process stream in a relatively pure form which can be utilized in a continuous process by recycle to another chlorination.

Process for beneficiating oxidic ores

In the fluidized bed chlorination of oxidic materials, for example minerals such as bauxite, tantalite, columbite, wolframite or scheelite, the separation of metal values giving vaporous chlorides at the reaction temperature is enhanced by maintaining a zone substantially free of chlorine in the fluidized bed, for example a zone at least 0.25 m in depth measured from the expanded bed surface. A high aspect ratio bed and counter current movement of the bed matter and the chlorine within the bed are preferably used.

Treatment of oxidic materials

In the fluidized bed chlorination of materials containing, for example, magnesium, manganese, calcium, iron or chromium oxides which tend to accumulate as chlorides in the bed leading to bed agglomeration, the hot partially chlorinated bed is treated with oxygen containing gas to strip out such chlorides as such or to convert them to oxides after which the chlorination may be continued. The invention may be applied, for example, to the production of titanium tetrachloride from titanium dioxide slag or the production of chromium chloride, from a chromite beneficiate.

Production of metal chlorides

Electrical insulation may be provided between two parts of a structure intended for exposure to high temperature radiation from a heat source, e.g. the interior wall of an electrical discharge furnace, by providing slot in the structure positioned so that the base of the slot cannot view the heat source directly. The slot may have flared lips, sides generally angled away from each other in the direction of increasing temperature, provision for a flow of gas in the same direction and provision for cooling the material bridging the base of the slot to a temperature at which it may be electrically insulating.

Electrical insulation device

Material containing iron in combination with chromium, such as chromite ore or sand, may be upgraded by removing at least some iron by a fluidized bed process in which iron is chlorinated to ferrous chloride in the presence of carbon and the ferrous chloride vapor removed. Selectivity of the process in reducing or avoiding the chlorination of the chromiUm content of the ore and in reducing or avoiding the formation of ferric chloride, with resulting increased chlorine usage efficiency, may be achieved by control of process parameters such as bed depth, chlorine concentration, and temperature. The invention may be used to produce a suitable raw material for the production of ferrochrome, which generally requires a chromium to iron ratio of at least 3:1, from an initial material in which the said ratio is below 2:1, either by upgrading the bulk of the material to the desired level or a portion to above the required level and blending the product with untreated material.

Process for upgrading iron-containing materials

Metal may be recovered from metal chlorides, for example a mixed metal chloride residue from the fluidized bed chlorination of a titaniferous ore in the presence of carbon to produce titanium tetrachloride by heating, in the presence of a scavenging agent, which may comprise a combination of titanium dioxide and carbon inherently present in a residue from the aforesaid fluidized bed chlorination process, to at least 1500.degree. C. and preferably to a temperature at which iron present is liquid. If the temperature is maintained at below 2200.degree. C. iron, vanadium and niobium may be recovered preferentially to certain lower value metals which remain in the form of chlorides giving the possibility for the recovery of a high value mixed metal product. Titanium trichloride may be formed and this may be chlorinated to titanium tetrachloride thereby increasing the efficiency of the original chlorination process.

Processing metal chlorides

Granular active carbon having satisfactory adsorbency and hardness characteristics and having a high proportion of its porosity in the below 2000 A range is produced from granules prepared from coal fluid energy milled until not more than 1% of the particles have diameters above 38 microns. The coal has a low ash and high carbon content and may have a British Standard Swelling number from 2 to 7 although it is preferred for the volatile matter content of the coal to be not more than 40% on a dry ash free basis. The granules may be produced by compacting milled particles having a temperature of from 50.degree. C to 250.degree. C between unheated pressure rolls.

Production of carbon from coal granules prepared in a fluid energy mill

The simultaneous chlorination of the iron and titanium values in an iron containing titaniferous ore such as ilmenite is advantageously conducted to convert the iron values to ferrous chloride but the resulting gaseous effluent is difficult to process to recover the titanium tetrachloride. The iron values in the effluent are partially oxidized according to the equation

Growing community of inventors

Wooton, United Kingdom

Michael Robinson