Metallurgical Testwork Result
Bezant Resources Plc
('Bezant' or the 'Company')
Metallurgical Testwork Results from AMMTEC Laboratories
on Samples from the Mankayan Project, Philippines
Highlights:
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Independent laboratory testwork indicates 94% copper recovery.
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Independent laboratory testwork indicates 74% gold recovery
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Recoveries in the upper range of industry experience.
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High-grade, copper/gold concentrates produced.
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All impurities below penalty levels.
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Concentrates could be an attractive smelter feed.
Bezant (AIM: BZT), the AIM listed gold and copper exploration and development company operating in the Philippines and Tanzania, today announces metallurgical testwork results on samples from its Mankayan copper/gold Project, located 260km north of Manila in the Philippines.
Samples Tested
The samples tested were selected from the diamond drill core from the inclined exploration boreholes (BC-57 an BC-58). The lithologies encountered by these holes are considered to be broadly representative of the Mankayan porphyry as a whole. Details of the six samples tested are set out below.
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Borehole and Sample Number
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Lithology
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Description
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BC-57, 6156
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Sericite Chlorite Clay (SCC)
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Typical of the main body of the porphyry, excluding the extreme upper zones.
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BC-58, 6159
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BC-57, 6155
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Intense Sericitic Overprint (ISO)
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A thin shell of material between the main body of the porphyry and the upper zone.
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BC-58, 6158
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BC-57, 6154
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Advanced Argillic
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The upper zone where the porphyry alteration contacts the country rock.
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BC-58, 6157
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The lithology of the first two samples (6156 and 6159) is representative of the major part of the porphyry. The other samples represent relatively small portions, located in the outer margin of the porphyry where it contacts the country rock.
Testwork Summary and Interpretation
Excellent results were obtained from samples 6156 and 6159, representing the bulk of the porphyry mineralisation. The testwork indicates that copper and gold recoveries of around 94% and 74% respectively can be anticipated whilst producing a saleable concentrate with a grade in excess of 30% copper.
Acceptable results were obtained from samples 6154, 6155, 6157 and 6158, representing the outer margin of the porphyry mineralisation. However, recoveries and concentrate grades were more variable and lower than those achieved on the first two samples. Further testwork to optimise flotation conditions for this outer margin material is expected be able to improve the copper and gold recovery.
A bulk flotation test (rougher cleaner re-cleaner) was performed on a composite of all samples to produce a larger sample of concentrate for further evaluation. Semi quantitative X-Ray diffraction mineral analysis of the bulk concentrate indicated that its composition was 73% chalcopyrite, 25% pyrite and 2% quartz. Multi element analysis showed that all impurity elements were below penalty levels commonly quoted by smelters. Of particular interest was that cadmium and mercury were at exceptionally low levels by industry standards. Owing to the low proportion of silicates and problem impurities, this concentrate could be a very attractive smelter feed.
Objectives and Structure of the Testwork Programme
The objectives of this testwork were to obtain preliminary indications, for the purposes of a prefeasibility study, of:
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The response of the ore to the froth flotation process in terms of metals recovery and concentrate grade; and
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The quality of the concentrates produced.
In actual operations, ores mined from copper porphyry deposits are processed by concentrator facilities located near to each mine. The concentration process commences with crushing and grinding to reduce the ore to a fine slurry. This is followed by selective froth flotation to concentrate the copper and gold values to a copper sulfides concentrate, whilst rejecting most of the iron sulfides and other gangue minerals to a tailings stream.
Gold recovery is generally less than copper recovery as a portion of the gold is associated with the iron sulfides that go to tailings. Actual gold recovery depends on the mineralogy of the ore but in general a gold recovery of over 65% would be considered good in terms of industry experience.
The concentrate slurry is then dewatered to a filter cake product and shipped to a remote smelter. Charges levied by the smelter depend on the concentrate grade and on levels of problem impurity elements such as lead, arsenic, cadmium, mercury and fluorine. Copper and by-product (gold and silver) values are credited to the mine.
AMMTEC Laboratories of Perth, Western Australia, conducted the froth flotation testwork and all associated analyses. A programme of open-circuit rougher and rougher, cleaner, re-cleaner tests was undertaken to investigate the conditions required for flotation and the performance (concentrate grade and recovery) that could be achieved. The limited number of samples tested, and the relatively simplistic nature of the test program, is appropriate for the requirements of a prefeasibility study.
The work commenced with grind establishment tests on each sample to determine the milling time required to achieve a grind with an 80% passing size (P80) of 75 microns. A preliminary rougher flotation test was then conducted on each sample using a simple reagent suite to test the flotation response. One sample (6158) was then selected and a rougher, scavenger, cleaner, re-cleaner procedure which gave reasonable flotation performance was developed in a series of eight iterative tests. All of the samples were then tested using this procedure, with all product samples being assayed for copper, gold, arsenic and sulfur. All of these flotation tests were conducted at the grind P80 of 75 microns using one-kilogram portions of sample.
A bulk flotation test was then performed on a 20-kilogram composite of equal portions from the six samples. Portions of the re-cleaner concentrate from this test were then sent for semi-quantitative mineral analysis by X-Ray diffraction and multi element analysis.
Gerry Nealon, Executive Chairman, today commented:
'We are very satisfied with the results from our preliminary metallurgical test programme on samples from our copper/gold Mankayan deposit. Whilst only of a preliminary nature, the testwork has clearly demonstrated an excellent metallurgical response with the potential to produce clean high-grade concentrates, of smelter feed quality'.
Dr Bernard Olivier has reviewed and approved the technical information contained within this announcement in his capacity as a qualified person, as required under the AIM rules. Dr Olivier is Executive Director of the Company and a Member of the Australasian Institute of Mining and Metallurgy.
Dr Evan Kirby supervised the testwork programme and interpreted the results obtained. Dr Kirby has extensive experience with grinding and froth flotation testwork and full-scale operations. Dr Kirby is a Non-Executive Director of the Company and a Member of the Australasian Institute of Mining and Metallurgy.
For further information, please contact:
Gerry Nealon
Executive Chairman, Bezant Resources Plc
Tel: +61 41 754 1873
Bernard Olivier
Executive Director, Bezant Resources Plc
Tel: +61 40 894 8182
Evan Kirby
Non-Executive Director, Bezant Resources Plc
Tel: +61 41 221 2827
James Harris / Matthew Chandler
Strand Partners Limited
Tel: +44 (0)20 7409 3494
Laurence Read/Beth Harris
Threadneedle Communications (UK)
Email: Laurence.Read@threadneedlepr.co.uk
Tel: +44 (0)20 7936 9696
Mob: +44 (0)7979 955 923
or visit http://www.bezantresources.com
Notes for editors:
The Mineral and Production Sharing Agreement covers a total of 534 hectares in the Guinaoang area of the Philippines (the 'Mankayan Project'). This is located in the Mankayan-Lepanto mining district, an area of porphyry copper belts in the Philippines and is similar to several deposits that have already been developed, such as the St Thomas deposit near Baguio City. The site is adjacent to the copper/gold mine owned and run by Lepanto Consolidated Mining Company, with the Mankayan-Lepanto area having been mined for centuries and being readily accessible by both road and air. The Mankayan deposit was discovered in the early 1970s and since then has been extensively drilled, with four historical programmes being completed covering more than 45,000 metres of diamond drilling over 48 holes. Last year, the Company announced an independent JORC compliant Inferred Resource, reported by Snowden Mining Industry Consultants Pty Limited, of 277.7 million tonnes grading at 0.50% copper and 0.42 g/t gold. The independent Resource estimate serves to support the Company's belief that its Mankayan Project represents a world-class copper and gold deposit, containing approximately 3.06 billion pounds (1.39 million tonnes) of copper and 3.8 million ounces of gold.
This information is provided by RNS
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