Abstract:
Brazil hosts a significant number of deposits bearing different metallic and industrial minerals. Some deposits are so rich that only comminution and sizing operations are sufficient to yield final products. In other cases, sophisticated concentration operations are required.
Iron ore concentrates and pellets are the major product of the mining segment. Two major areas, the Iron Quadrangle, Minas Gerais state, and Carajas, in Para state, are known worldwide. The currently mined reserves in Carajas represent an outstanding example of ore that does not require concentration stages. On the other hand, most of the ore mined in the Iron Quadrangle and adjacent areas consists of itabirite rock, a banded formation of quartz and hematite. WHIMS and froth flotation are used in the concentration of itabirites.
Brazil holds the largest world reserves of niobium ores. A unique flotation reagents scheme is used in the production of pyrochlore concentrate.
Another important mineral resource addressed is phosphate rock. The Brazilian phosphate deposits that are currently mined are from igneous origin and the concentration requires a technology different from that applied to ores from sedimentary origin. The utilization of distinct flotation circuits for coarse and fine particles and for slimes, combined with the development of reagents schemes from local raw materials are some of the features that will be addressed.
The gold head grade at Kinross operation is 0.40 g/metric ton. The gold annual production is 500,000 ounces and the annual ROM extraction reaches 56,000,000 tons.
Sulfide mines are not as widespread as oximinerals operations, but they are still worth mentioning. VALE operates two sulfide copper mines in the Carajas mineral province. Mirabela operates a nickel mine in Bahia state.
This plenary paper will make a detailed overview of the technologies used in the above mentioned sites.
|
