Silver and gold producer Great Panther Mining has released updated mineral resource estimates for the Guanajuato and San Ignacio underground mines within its wholly owned Guanajuato mine complex (GMC) in Mexico.
Combined measured and indicated resources increased by 17%, to 10.2 million silver-equivalent oz. these ounces are within 821,851 tonnes, grading 199 g/t silver and 2.07 g/t gold (385 g/t silver-equivalent).
Total inferred resources more than doubled, to 18.1 million oz. of silver-equivalent. The inferred resources total 1.5 million tonnes, at 185 g/t silver and 2.25 g/t gold (388 g/t silver-equivalent).
“We are pleased to have completed another productive drilling campaign at GMC, successfully outlining new resources and demonstrating the quality of the orebody. GMC has been in our portfolio since 2005 and has cumulatively produced nearly 30 million silver equivalent ounces for Great Panther,” Rob Henderson, Great Panther’s president and CEO, said in a release.
Henderson added that the company expects to provide an updated resource and reserve estimate for its Tucano gold mine in Brazil before the end of the year.
Within the above resource totals, the San Ignacio mine holds 387,898 measured and indicated tonnes, at 377 g/t silver-equivalent, and 992,835 inferred tonnes, at 384 g/t silver-equivalent. Guanajuato contributes 433,953 measured and indicated tonnes, at 396 g/t silver-equivalent; and 460,174 inferred tonnes, grading 407 g/t silver-equivalent.
The resources are based on net smelter return cut-offs between US$89 and US$125 per tonne. The two mines at GMC feed the 1,000 t/d Cata processing plant on-site. Since the Jul. 31 resource cut-off, the company has drilled 9,560 metres. Three rigs are working at the Guanajuato mine and one drill is active at San Ignacio.
On the permitting front, Great Panther is looking to permit an expansion of the GMC tailings storage facility (TSF), to increase capacity beyond January 2021. It has received approval from SEMANART, the environmental permitting authority and is waiting for approval from the national water authority, CONAGUA. In conjunction with this permitting, the company has also been seeking a permit from SEMANART for a one-metre raise of the existing TSF, to increase tailings capacity beyond April 2021, and to allow more time for the CONAGUA approval – SEMANART has advised Great Panther that the one-metre raise will not be approved.
The company is looking into alternatives for tailings storage to continue processing beyond January – these could extend the tailings capacity for two to five months, to allow more time till the CONAGUA permit is received. The release notes that “if the CONAGUA approval of expansion of the TSF has not been received and an alternative tailing storage solution does not get resolved prior to January 2021 , the Company may need to cease milling operations at the GMC until receipt of the CONAGUA expansion approval.”
Last year, the GMC generated 1.5 million silver-equivalent oz. and is expected to churn out 1.2 to 1.3 million silver-equivalent oz. in 2020.
In its portfolio, the company also holds the Topia silver mine in Mexico, in addition to Tucano and the GMC.
(This article first appeared in the Canadian Mining Journal)