Ilmenite coated pellet and process for reducing same
AssigneeICI Australia Limited
InventorsAnwyn Margaret Martin, Donald Fergusson Stewart, Andrew Baikie Swanson
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Abstract
A pyrometallurgical reductive process characterised in that firstly pellets comprising a mixture of ore and coke precursor are heated in the absence of air so that the coke precursor is converted to coke and secondly the so formed pellets are treated in a subsequent reductive step to obtain as product discrete pellets comprising reduced ore set in a matrix of coke. Preferably the matrix of coke is in the form of an external coating to the pellet.
Claims11
A coated pellet comprising a core consisting of a suitable mixture for a metallurgical reductive process and a coke matrix skin substantially surrounding the core, the core comprising an ilmenite ore, solid carbonaceous material capable of reducing the iron oxide in ilmenite to metallic iron and a flux chosen from the group consisting of alkali metal chlorides, alkaline earth metal chlorides and mixtures thereof;
- the weight ratio of ore to flux being in the range from about 5:1 to 1.2:1 the diameter of the core being in the range from 0.25 to 5 cms and the ratio of diameter of core to thickness of coke matrix skin being in the range from 10:1 to 10:3 said skin being in such a state that it does not crack or collapse under thermal stress thereby retaining its physical identity during reductive roasting, and the flux does not exude from the pellet.
In the process for reducing ilmenite ore by reductive heating of pellets containing the ore, the improvement which comprises utilizing, as the pellets, coated pellets comprising a core and a coke matrix skin substantially surrounding the core, said core comprising ore, solid carbonaceous material capable of reducing the iron oxide in ilmenite to metallic iron, and a flux chosen from the group consisting of alkali metal chlorides, alkaline earth metal chlorides and mixtures thereof;
- the weight ratio of ore to flux being in the range from about 5:1 to 1.2:1 the diameter of the core being in the range from 0.25 to 5 cms and the ratio of diameter of core to thickness of coke matrix skin being in the range from 10:1 to 10:3 said skin being in such a state that it does not crack or collapse under thermal stress thereby retaining its physical identity during reductive roasting, and the flux does not exude from the pellet, said pellets retaining their pellet form during said reductive heating and having a reduced tendency to be crushed or to coalesce.
Dependencies are inferred from the claim text.