PROCESS TO THERMALLY UPGRADE METAL-CONTAINING LIMONITE OR SAPROLITE ORES VIA MAGNETIC SEPARATION AND THE USE OF THE MAGNETIC CONCENTRATE AS SEEDS

摘要

This invention provides a process to thermally upgrade metal-containing ores comprising the following steps: (1) mixing: (i) ore, (ii) from 4 and up to 15% by weight relative to the ore of reducing agent, (iii) sulphur bearing agent, (iv) metallic-bearing seeding agent, and optionally (v) low temperature binder agent to produce a blend; (2) agglomeration and dry, if required, of the blend formed in step 1 to produce agglomerates; (3) calcination the agglomerates formed in step 2 at reducing atmosphere from a partial pressure of oxygen of Log10(pO2)=−12 to Log10(pO2)=−15) and at temperature between 950-1150° C. to produce a liquid metallic phase that growth and concentrate into metallic particles within the agglomerates; (4) cooling the agglomerates after step 3 to ambient temperature in reducing or inert atmosphere; (5) crushing and grinding the calcine produced in step 4 to a size amenable for magnetic separation of metallic particles, typically represented by a p80 equal or below 25 μm; and (6) magnetic concentration of metallic particles by known techniques of magnetic separation including but not limited to magnetic separation by wet or dry means, dewatering and drying.;The invention also refers to the magnetic concentrate produced by the process and to the use of the magnetic concentrate to produce a ferronickel or highly metalized nickel containing matte for the production of stainless steel.

主权项

1. A process to thermally upgrade metal-containing ores, comprising the following steps:
(1) mixing: (i) ore, (ii) from 4 up to 15% by weight relative to the ore of reducing agent, (iii) sulphur bearing agent, (iv) metallic-bearing seeding agent, and optionally (v) low temperature binder agent to produce a blend; (2) agglomeration and dry, if required, of the blend formed in step 1 to produce agglomerates; (3) calcination the agglomerates formed in step 2 at reducing atmosphere (from a partial pressure of oxygen of Log10(pO2)=−12 to Log10(pO2) =−15) and at temperature between 950-1150° C. to produce a liquid metallic phase that growth and concentrate into metallic particles within the agglomerates; (4) cooling the agglomerates after step 3 to ambient temperature in reducing or inert atmosphere; (5) crushing and grinding the calcine produced in step 4 to a size amenable (p80≦25 μm) for magnetic separation of metallic particles; and (6) magnetic concentration of metallic particles by known techniques of magnetic separation, including but not limited to magnetic separation by wet or dry means, dewatering and drying.