Extension Project for Fortaleza de Minas Mine

Extension Project for

Fortaleza de Minas Mine

Votorantim Metais:

Miguel S. Kato

Thiago N. Teixeira

Silvia M. Santana

• 1983 – The deposit is discovered;

• 1995 – Project approval and construction start;

• 1997 – Beginning open pit operation and

concentration;

MINE HISTORY

• 1998 – Beginning underground mine access;

• 2003 – Announcement of the closure of the mine;

• 2004 – Votorantim Metais buys Fortaleza de Minas;

• 2009 – Beginning the extension project;

INTRODUTION

• LOM estimated middle 2011;

• Because of the rock host quality the actual mining method

has;

� High dilution;� High dilution;

� Mining cost is very expensive;

� Low recoveries;

• Necessity to change the mining method;

FORTALEZA DE MINAS MINE

ZONA NORTE

AREA CENTRALZONA FORMIGA

• NSR (Net Smelter Return) methodology:

� The cut-off consider:

� Mining costs;

� Royalties;

RESERVE ESTIMATION

� Royalties;

� G&A;

� The process cost is included in the NSR calculation.

• Sublevel-Stope (AVOCA)

Actual Mining Method

REMAINING AVOCA STOPES

CUT AND FILL SCENARIO

CUT AND FILL SCENARIO

• Development section from 4m to 3m;

• Cut and fill still has high dilution;

CUT AND FILL SCENARIO

• Low production rates;

• Necessary to study a different scenario

UP HOLE SCENARIO

UP HOLE SCENARIO

UP HOLE PRODUCTION SEQUENCE

• The proposed method is very selective and with low dilution;

• The filling will provide greater stability to the rock mass;

• The mine has already made two experimental mining and the results demonstrate alignment with the rates adopted in the project;

CONCLUSION

• For the unit the continued operation of the mine has an important impact on the smelter. Because the nickel concentrate produced by the mine itself is cheaper than those concentrated acquires from other companies, it has also an important role in the concentrates blending, for being the most energetic and least contaminated of all.

QUESTIONS

THANK YOU