Process for removing uranium in copper concentrate via magnetic separation
The present invention describes a process for removing uranium from a copper concentrate by magnetic separation (low and high field) to reduce the uranium content to commercially acceptable levels.
1. A process for removing uranium from copper concentrates via magnetic separation comprising the steps of:
i. magnetically separating the copper concentrates to provide a magnetic fraction and a non-magnetic fraction with a size distribution of about 15 micron to about 40 micron (P 80 ), the magnetic fraction having a uranium content of about 20 ppm to about 100 ppm, and obtaining about 75% to about 99.99% non-magnetic copper;
ii. grinding the magnetic fraction to produce a magnetic copper concentrate having a fine size distribution of about 5 micron to about 15 micron (P 80 ) and a uranium content of about 100 ppm to about 300 ppm;
iii. fine flotation of the magnetic copper concentrate to produce a recovered copper concentrate having about 0.01% to about 25% by weight copper and a uranium content of about 100 ppm to about 300 ppm; and
iv. mixing the non-magnetic fraction with the recovered copper concentrate of step iii to produce a final concentrate having a uranium content of about 40 ppm to about 150 ppm and about 65% to about 99.99% copper.
2. The process for removing uranium from copper concentrates via magnetic separation, according to claim 1 , wherein the uranium comprises uranium oxides, copper sulfides, magnetite and other oxides.
3. The process for removing uranium from copper concentrates via magnetic separation, according to claim 1 , wherein the non-magnetic fraction comprises a uranium content of about 20 ppm to about 100 ppm.
4. The process for removing uranium from copper concentrates via magnetic separation, according to claim 1 , wherein the final concentrate has a uranium content below about 100 ppm.
5. The process for removing uranium from copper concentrates via magnetic separation, according to claim 1 , wherein the magnetic separation is performed by a wet high intensity magnetic separator (WHIMS).
6. The process for removing uranium from copper concentrates via magnetic separation, according to claim 2 , wherein the copper sulphides, magnetite, and other oxides make up 54%, 14%, and 7%, respectively, of the uranium.