Process of treating dust containing zinc and lead and derived in an iron or steel making process
AssigneeEstel Hoogovens B.V.
InventorsCornelis P. Heijwegen, Willem Kat
Life of this patent
Estimating the term…
Abstract
Zinc and lead are separated together out of dust derived from a gas-cleaning installation in iron or steel making by a flotation-separation treatment. In order economically to provide a good separation of these metals and to leave a residue which is re-usable in an ore-preparation process in the iron and steel industry, the flotation-separation treatment is at a pH of 7 to 9 and is effective to achieve a separation, according to size of the dust particles, of a floated component in which the zinc and lead are concentrated and a non-floated component which is suitable for re-use.
Claims2
A process of treating dust containing zinc and lead oxides of size less than 0.02 mm and derived from a gas cleaning installation in an iron or steel-making process, comprising the steps of
- (i) subjecting said dust to a flotation separation treatment in a bath of pH in the range 7 to 9 containing a frother selected from the group consisting of short chain alcohol polyglycol ethers, branched hexanols and branched decanols such that the dust is separated according to dust particle size into a floated component in which the zinc and lead are concentrated and non-floated component,
- (ii) feeding said non-floated component to an ore-preparation process for a reduction furnace,
- (iii) treating said floated component with HCl to dissolve at least 90% of the zinc and lead components present,
- (iv) separating residual solid material from said dissolved components and
- (v) feeding said residual solid material to said ore preparation process.
Dependencies are inferred from the claim text.