Over View of iron ore mining in Brazil
Brazil is the one of the world’s largest iron ore producers and exporters. Iron ore has traditionally been country’s largest export product, accounting for 82 % of the total iron ore production of the country. Iron ore production during 2006 was 300 Mt and exported 246.6 Mt. Japan, Germany, China and South Korea were the main importers of Brazilian iron ore. CVRD and MBR (Mineracao Brasileiras Reunidas) are Brazil’s largest iron ore exporters. Other major iron ore producers include Samitri, Ferteco, Samarco Mineracao and CSN (Companhia Siderurgica Nacional). Ferteco is Brazil’s third largest iron ore producer – and was purchased by CVRD in mid 2001. Ferteco operates the Fabrica and Feijao mines that are located in the Iron Quadrangle of the State of Minas Gerais. Annual production capacity from the two facilities amounts to around 15 Mt with mineable reserves estimated at 260 Mt.
Samarco Mineracao is a joint venture between BHP Billiton and CVRD that operates the Alegria opencast mine and the Germano concentrator. Alegria has measured reserves containing 701 Mt grading at an iron ore content of 47%. The Samarco project produced 10.4 Mt of pellets and has a capacity to produce 12 Mt/year. Rio Tinto own 80% of the Corumba mine located in the State of Mato Grosso do Sul. The mine produces 1Mt of lumpy destined for markets in Argentina.
BHP Billiton – Through its 49% interest in Samarco Mineracao S.A. (Samarco), BHP Billiton operates the Alegria iron ore complex in Brazil.
Companhia Vale do Rio Doce – CVRD is on of the world’s largest iron ore producers with several large scale operations in Brazil.
Rio Tinto – Rio Tinto produce iron ore from the 80% owned Corumba mine in the state of Mato grosso do Sul.
The methodology of extraction of Iron ore and over burden being adopted in Brazil is Open Cast mining methods either by shovel – dumper combination or Shovel – Dumper- conveyor transport systems. The bench heights are being maintained varies from 15 m to 17m and the mines are deploying wide variety of HEMM. Drilling is done by Bucyrus Eric and Tamrock’s rotary drills (microprocessor based) having bit diameter 380 mm or 445 mm with sound proof temperature controlled operator’s cabin and wet drilling arrangements. For excavation high capacity electric rope shovels (22yd3 capacity), Demag H485 hydraulic excavators, high capacity electric wheel loaders and caterpillar 9920 wheel loaders. Note worthy technologies are Global Positioning System (GPS) monitoring for HEMM used in high precision, three applications on a board a variety of mining machines, blast whole drills, shovels and dozers etc. At present 240 tonne, 2 axles, six wheeled 2400 H.P diesel – electric (Electric Wheel) trucks with air-conditioned sound proof operator’s cabin are in use in Brazil. All the truck movements are controlled by a modular mining dispatch system.
To cope with the need of higher production of Iron Ore, blasting materials are also being developed/manufactured at the same pace. Use of slurry, emulsions, ANFO & HANFO in bulk explosive systems have been well established with considerable benefit to the Brazilian Iron Ore industries. In the field of blasting accessories, the introduction and adoption of “non-electric delay initiation system “contributed significantly to the improvement in blasting results and reducing the levels of blast induced ground vibration and air blast noise. Post blast analysis is also being done through high speed video camera.
As few opencast Iron ore mines have gone deep more than 200m in Brazil, In-pit crushing-conveying transportation (using mobile crusher /semi-mobile crushers with High angle belt conveyors) of Iron ore and Over burden materials are already in use successfully. A significant technological development was the application of WHIMS for treating hematite and limonatic ores in order to produce concentrate. At CVRD, 28 Jones separators (WHIMS) have been installed to treat > 25 Mt/y to produce 10 Mt/Y concentrate.