Feb 22 2018
Wolf Wiese, CEO of Golden Dawn Minerals Inc., (the “Company” or “Golden Dawn”), announces preliminary results from pre-concentration testing of samples from the Lexington property, part of the Greenwood Precious Metals Project.
Golden Dawn provided 140 kg of mineralized samples (originating from the Lexington Mine for pre-concentration testing using the Steinert multi-sensor sorting system (KSS). The samples were collected and prepared from oversized material that was remaining from the 2008 mining operation. The sorting test work was conducted at the facilities of Steinert US in Walton, Kentucky.
The purpose of the test work was to determine the sorting efficiency of a Steinert Combined Sensor Sorting System on the samples provided. This machine measures the X-ray attenuation of each rock particle and this is utilized to separate high density from low density particles. Typically, the denser material is better mineralized and the less-dense material is low-grade or waste material.
The sorted samples were weighed and sent for independent laboratory analyses by SGS, an ISO 17025 accredited laboratory located in Lakefield, Ontario.
RESULTS
Two size fractions (-70 +30mm and -30 +10mm) were tested separately using a combination of XRT and 3D Laser sensors. Both size fractions showed good results in terms of upgrade and recovery. The fine size fraction -30 +10mm showed slightly better upgrades and recoveries. For the -30mm +10mm particle size, the gold grade was upgraded from 8.0 grams per tonne (g/t) to 12.5 g/t with a 90 % gold recovery and a mass rejection of 42%. For the coarser -70mm +30mm sample, the gold grade was upgraded from 9.6 g/t to 11.6 g/t, with a gold recovery of 86% and a mass rejection of 29%. High mass rejection of low grade material, between 42% and 28% of the respective samples, was obtained while still achieving good gold recoveries of 85% to 90%. Copper upgrading was also observed but final analytical data is still pending for some products. Full details are described in the preliminary report, which will be posted on the Company website.
DISCUSSION
The positive sorting response shows that the gold and copper grade of material extracted from the Lexington mine can be upgraded prior to processing at the existing Greenwood Process Plant. This would indicate a potential to increase mining rates and/or improve mill head feed grades. The mine could extract a larger resource at a lower cut-off grade or alternatively, ore sorting could be utilized to counter the effect of excess mining dilution. Therefore, the sorting process provides an opportunity to improve the economics for the Greenwood Project. The Company will be conducting further evaluation, including additional sorting and related metallurgical test work on a bulk sample, to advance the procedure.
Meanwhile, work is progressing towards start-up of mining operations at the Lexington mine, with mine planning and geotechnical assessments underway to prepare for mine production. The Greenwood Processing Plant will be wet commissioned once the mining operation is underway. At the same time, a surface diamond drilling program is about to kick-off on the Golden Crown property aimed at increasing resources on the known gold zones. This program will be expanded along a 3.5 km corridor of gold soil anomalies into the JD area and will test new gold zones identified by chip sampling last year. Permits are also being sought for exploration drilling and trenching at selected areas on the Phoenix property.
Technical disclosure in this news release has been approved by Frank Wright, P.Eng., a Qualified Person as defined by National Instrument 43-101, and metallurgical consultant to the Company
Source: https://goldendawnminerals.com/pre-concentration-test-for-lexington-mine-samples-shows-increase-in-gold-grade-up-to-12-6-g-t-gold-from-8-0-g-t-gold/