Process for purifying zinc oxide
AssigneeCanadus Chemical LLC
InventorsMichel Laurin, Stephen C. Paspek
Life of this patent
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Abstract
A process for separating zinc from a feedstock containing a mixture of metals and metal compounds. The process includes leaching a zinc-containing feedstock with a concentrated basic solution, optionally diluting the slurry with an amount of water sufficient to reduce the viscosity of the slurry thereby facilitating separation of a pregnant liquor containing dissolved zinc from insoluble materials, separating the insoluble materials from the pregnant liquor, and precipitating zinc oxide from the pregnant liquor by adding an anti-solvent to the pregnant liquor. The described process also provides for recycling of the basic solution and the anti-solvent.
Claims31
A process for separating zinc oxide from a feedstock containing a mixture of metals and metal compounds comprising the following steps:
- a. leaching, and oxidizing if zinc metal is present, a zinc-containing feedstock with a concentrated inorganic basic solution containing more than 25 wt % base, wherein the base contains a cation that does not form a complex with zinc, to form a slurry comprising a pregnant liquor containing dissolved zinc and insoluble materials;
- b. optionally, diluting the slurry with an amount of water sufficient to reduce the viscosity of the slurry thereby facilitating separation of the pregnant liquor containing dissolved zinc from insoluble materials;
- c. separating the insoluble materials from the pregnant liquor;
- and
- d. precipitating zinc oxide from the pregnant liquor by adding an anti-solvent to the pregnant liquor.
A process for separating zinc from a zinc-containing feedstock comprising the following steps:
- a. contacting a zinc-containing feedstock with a concentrated inorganic basic solution comprising a base, wherein the base contains a cation that does not form a complex with zinc, to form a slurry, wherein the slurry comprises undissolved materials and a pregnant liquor containing a super saturated amount of dissolved zinc;
- b. separating the pregnant liquor containing a super-saturated amount of dissolved zinc from insoluble materials;
- c. purifying the pregnant liquor to remove non-zinc materials soluble in the basic solution;
- and
- d. precipitating zinc oxide from the purified pregnant liquor by adding an anti-solvent to the pregnant liquor.
Dependencies are inferred from the claim text.