Method for the beneficiation of iron ore streams
A method of beneficiating iron ore streams, the method comprising the steps of sizing an iron ore stream to provide a fines fraction of less than 3.0 mm diameter particle size and contacting the fines fraction with a magnetic field and magnetically separating the fines fraction into a concentrate stream and a tailings stream.
1. A method of beneficiating iron ore streams, the method comprising the steps of:
sizing an iron ore stream to provide a wet fines fraction of less than 3.0 mm diameter particle size;
contacting the wet fines fraction of less than 3.0 diameter particle size with a magnetic field directly, so that the fines fraction is magnetically separated into a concentrate stream and a tailings stream; and
contacting the tailings stream with a second magnetic field and magnetically separating the tailings stream into a second concentrate stream and a second tailings stream;
wherein the iron ore stream is a comminuted iron ore stream comprising about 40-66 w/w % iron and the concentrate stream has an iron concentration of at least 55 w/w % iron, wherein the tailings stream is an untreated tailings stream, and the second magnetic field is of higher intensity than the magnetic field.
2. A method of beneficiating iron ore streams according to claim 1 , wherein the step of:
contacting the tailings stream with a second magnetic field and magnetically separating the tailings stream into a second concentrate stream and a second tailings stream is repeated by contacting the second tailings stream with a third magnetic field to provide a third concentrate stream and a third tailings stream.
3. A method of beneficiating iron ore streams according to claim 1 , wherein the step of contacting the fines fraction with a magnetic field and separating the fines fraction into a concentrate stream and a tailings stream comprises contacting the fines fraction with at least one of a high intensity magnetic field, a medium intensity magnetic field and a low intensity magnetic field.
4. A method of beneficiating iron ore streams according to claim 1 , wherein the step of contacting the fines fraction with a high intensity magnetic field comprises contacting the fines fraction with a magnetic field of 500 to 18000 Gauss.
5. A method of beneficiating iron ore streams according to claim 1 , wherein the step of contacting the fines fraction with a high intensity magnetic field comprises contacting the fines fraction with a magnetic field of 2000 to 10000 Gauss.
6. A method of beneficiating iron ore streams according to claim 1 , wherein the step of contacting the fines fraction with a high intensity magnetic field comprises contacting the fines fraction with a magnetic field of 1600 to 6000 Gauss.
7. A method of beneficiating iron ore streams according to claim 1 , wherein the step of contacting the fines fraction with a high intensity magnetic field comprises contacting the fines fraction with a magnetic field of 3000 to 6000 Gauss.
8. A method of beneficiating iron ore streams according to claim 1 , wherein the fines fraction is split into a plurality of fractions and each one of the plurality of fines fractions is fed independently to a different magnetic separator or plurality of magnetic separators operating in parallel.
9. A method of beneficiating iron ore streams according to claim 1 , wherein the iron ore stream comprises about 44-55 w/w % iron or about 55-58 w/w % iron or about 58-66 w/w % iron.
10. A method of beneficiating iron ore streams according to claim 1 , wherein the second concentrate stream has an iron concentration of at least 55 w/w % iron.
11. A method of beneficiating iron ore streams according to claim 1 , wherein the concentrate stream has an iron concentration of at least 60 w/w % iron.
12. A method of beneficiating iron ore streams according to claim 1 , wherein the second concentrate stream has an iron concentration of at least 55 w/w % iron.
13. A method of beneficiating iron ore streams according to claim 1 , wherein the second concentrate stream has an iron concentration of at least 60 w/w % iron.
14. A method of beneficiating iron ore streams according to claim 1 , wherein the concentrate stream and the second concentrate stream are combined to form a combined concentrate stream and stockpiled.
15. A method of beneficiating iron ore streams according to claim 14 , wherein the combined concentrate stream has an iron concentration of at least 55 w/w % iron.
16. A method of beneficiating iron ore streams according to claim 14 , wherein the combined concentrate stream has an iron concentration of at least 60 w/w % iron.
17. A method of beneficiating iron ore streams according to claim 2 , wherein the third concentrate stream has an iron concentration of at least 55 W/% iron.
18. A method of beneficiating iron ore streams according to claim 2 , wherein the third concentrate stream has an iron concentration of at least 60 w/w % iron.
19. A method of beneficiating iron ore streams according to claim 2 , wherein the concentrate stream and the second concentrate stream and the third concentrate stream are combined to form a second combined concentrate stream and stockpiled.
20. A method of beneficiating iron ore streams according to claim 19 , wherein the second combined concentrate stream has an iron concentration of at least 55 w/w % iron.
21. A method of beneficiating iron ore streams according to claim 19 , wherein the second combined concentrate stream has an iron concentration of at least 60 w/w % iron.