Hydrometallurgical test results have demonstrated exceptionally fast leaching rates with high nickel and cobalt recoveries from Mindoro Resources' Agata nickel laterite project in northern Mindanao.
High pressure acid leach (HPAL) testing extracted about 98% of the nickel and 95-96% of the cobalt from limonitic material within 20 minutes. This leaching rate is 50% faster for HPAL processing than previously assumed in the scoping study announced on October 2, 2010.
With half the leaching time, the HPAL circuit throughput could be doubled, with higher nickel extraction than previously reported and resulting in significantly lower processing cost projections. Testing also demonstrated faster processing times and higher nickel recoveries for Atmospheric Leach (AL) processing than assumed in the scoping study.
Testing was conducted on a total of nine samples representing the grade ranges in the deposit from limonite, saprolite and transition material.
Mindoro's president and chief executive officer Jon Dugdale says, “We are extremely pleased with these metallurgical results which advance our investigations into establishing a low-cost integrated processing operation at Agata.
“These results justify commencing a larger scale and more systematic metallurgical testing program in early 2011 as a precursor to commencing a pre-feasibility study.”
The program investigated HPAL processing a limonite and transition composite, as well as atmospheric leaching (AL) of saprolite. Beneficiation potential - the process of upgrading ore through crushing/scrubbing and screening - and slurry settling properties were also investigated.
Tests are also under way to evaluate using saprolite to neutralize the acid and CCD (leach discharge) settling properties.
Meanwhile, Mindoro began trading on the Australian Securities Exchange (ASX) on December 7, 2010, after raising Aus$8 million from the sale of 40 million CHESS Depository Interests (CDIs).
In addition the company also raised Can$2 million through the sale of 10 million shares to the IFC, a member of the World Bank Group.
Mindoro will use the funds to advance pre-feasibility and feasibility studies into a staged and integrated nickel processing operation at Agata and continue regional drilling in an effort to increase its nickel laterite resource. The company also plans to advance its outstanding portfolio of gold and copper-gold projects in the Philippines.