Dia Bras Exploration Inc.

Dia Bras Exploration Inc.

October 06, 2011 10:00 ET

Dia Bras's New Piedras Verdes Mill Starts Up and Triples Its Bolivar Property Throughput

TORONTO, ONTARIO--(Marketwire - Oct. 6, 2011) - Dia Bras Exploration Inc. (TSX VENTURE:DIB) ("Dia Bras" or the "Company") is pleased to announce that it has commissioned its new Piedras Verdes mill at the Bolivar Property in Chihuahua, Mexico, which currently has a capacity to process 1,000 tonnes per day ("tpd"). The mill is presently operating at 850 tpd, more than doubling the prior production of 360 tpd when using the old Malpaso mill and production will be ramped up to the full 1,000 tpd by late October. The Company plans to increase the Piedras Verdes mill's capacity to 2,000 tpd in the third quarter of 2012. The new Piedras Verdes mill is only 5 km from the Bolivar property, and eliminates the need to transport rock for 287km through the Sierra Madre from the Bolivar property to the Malpaso mill.

"Dia Bras has completed a significant milestone, since the mining activity started at Bolivar" stated Daniel Tellechea, President and CEO. "The Piedras Verdes mill is taking the Company to a new level of operating efficiency, processing rates and profitability, since we will be tripling our daily production from Bolivar while reducing our overall production costs by 45%. Our new water reservoir has a capacity of 1.5 million cubic meters and is presently 67% filled, ensuring a reliable source of water for operations during dry seasons. The Company now has three, fully-paid-for, operational mills with total capacity of 4,350 tpd: 1) the Piedras Verde mill with start-up capacity of 1,000 tpd; 2) the Malpaso mill, with a capacity of 850 tpd; and 3) the Chumpe mill in Peru with a capacity of 2,500 tpd, which will greatly improve the cost efficiency of its mining assets and hence optimizes its NAV".

Shipping of mineralized rock from Bolivar to the Malpaso mill will be stopped on October 7 and the mill will complete processing its stockpiled rock by October 17. From that date, the Malpaso mill will be dedicated to processing rock from the Cusi silver district and other sources.


The new Piedras Verdes Mill will process mineralized rock mined from the Bolivar Alta Ley, El Gallo, Increíble, and Narizona mines. During September, the combined mine production from Bolivar totalled 23,603 tonnes, of which 16,560 tonnes were shipped to the Piedras Verdes mill and 7,043 tonnes were shipped to Malpaso. There are presently 20,000 tonnes stockpiled at the Piedras Verde mill, which has a patio capacity for 40,000 tonnes. Development of the mines continues and their combined output will be increased to 2,000 tpd over the next few months.

Rock being processed at Piedras Verdes during these first days has averaged 0.63% copper and 2.07% zinc as low grade material is being processed so that mill circuits can be tuned and optimized, thereby minimizing losses of copper, zinc, silver and gold. Once mill tune-up is complete, the grades planned to be fed to the mill are 1.20% copper, 2.70% zinc and 29 gpt silver. Metallurgical recoveries are still being determined, but initial bench tests at the Malpaso mill yielded 87.2% recovery for copper, 85.5% recovery for zinc and 60.0% recovery for silver. Recoveries at the Malpaso mill for Bolivar rock through September 30 have averaged 86.9% for copper, 88.3% for zinc and 70.0% for silver. The difference in the recoveries at the Piedras Verdes mill compared to the Malpaso mill is the result of lower head grades of the rock that is being fed through the Piedras Verdes mill.


Crushing and Screening Circuits: Rock is fed to the mill through a coarse-screen grizzly with spacing of 14 x 18", with the undersize reporting to a primary Cedar Rapids 25 x 40" jaw crusher with a capacity of 120 tonnes per hour ("tph"). The crusher output is sent to a Terex 5 x 16 feet double-deck screen with a 200 tph capacity, with upper 2" and lower 3/4" screens. The -3/4" rock is sent to two fine ore bins, each with a capacity of 1,000 tonnes. The oversize reports by closed circuit to a secondary Sandvik model 6800 cone crusher with a capacity of 160 tph, and its output reports back to the Terex screen.

Ball Mills: Rock from the fine ore bins reports to a Dominion 9.5 x 14 feet ball mill with a capacity of 1,000 tpd. It runs at 19 rpm and is powered by a 600 horsepower motor. The foundation for a second ball mill of the same make, size and capacity is in place. This second Dominion 9.5 x 14 ball mill has already been purchased, is scheduled to arrive at Piedras Verde in late October and be installed during November. However this second mill will be operational in the third quarter of 2012 when the Piedras Verdes mill has been completely upgraded to 2,000 tpd capacity.

Flotation Circuits: The Piedras Verdes mill has 2 flotation circuits for copper and zinc concentrates. The copper circuit includes: 3 rougher cells with a total of 900 cubic feet capacity ("cfc"); 4 scavenger cells totaling 1200 cfc; 2 primary cleaner cells totaling 600 cfc; 5 secondary cleaner cells totaling 500 cfc. The zinc circuit includes: 3 rougher cells totaling 900 cfc; 5 scavenger cells totaling 1500 cfc; 2 primary cleaner cells totaling 900 cfc; and 6 secondary cleaner cells totaling 600 cfc.

Thickeners: The Piedras Verdes Mill has separate copper and zinc thickeners. The copper thickener is 40 feet in diameter and has capacity to process 150 tpd of copper concentrates. The zinc thickener is 50 feet in diameter and has capacity to process 200 tpd of zinc concentrates. Concentrates from both thickeners report to separate JWI model 800-G32 filters, each with 31.5 x 31.5" frames and capacity of 22 ft3 (cake).


The construction to increase capacity of the mill to 2,000 tpd will be initiated in the first quarter of 2012 and will take 8 months to complete, with an expected start-up in the third quarter of 2012. The cost of the 1,000 tpd increase in capacity is expected to be US $8.2 million, of which US $3.7 million will be for a new power line of 11 kilometers from Tubares to Mesa Colorada, Chihuahua to guarantee a constant and consistent power supply for the 2,000 tpd Piedras Verdes mill, plus US $4.5 million for additional flotation cells, installation of the second ball mill, various equipment and labor cost.

About Dia Bras

Dia Bras Exploration Inc. is a Canadian listed mining company focused on precious and base metals in Peru and Mexico. The Company owns and operates the Yauricocha Mine (Ag-Cu-Zn-Pb) in Central Peru and the Bolivar Property (Cu-Zn-Ag) in Chihuahua State, Mexico. Dia Bras is also pursuing the development and exploration of the Cusi Property (Ag) and exploring several base and precious metals targets in Peru and Mexico.

The Company's shares trade on the TSX Venture Exchange under the symbol "DIB".

For further information on Dia Bras Exploration Inc. visit www.diabras.com

Forward-looking Statements

Except for statements of historical fact, all statements in this news release without limitation regarding new projects, acquisitions, future plans and objectives are forward-looking statements which involve risks and uncertainties. There can be no assurance that such statements will prove to be accurate; actual results and future events could differ materially from those anticipated in such statements.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.

Contact Information

  • Daniel Tellechea
    President & CEO
    Dia Bras Exploration Inc.
    1 (866) 493-9646

    Robert Hirsh
    Director, Corporate Development
    Dia Bras Exploration Inc.
    1 (866) 493-9646