Premier African Minerals Limited / Ticker: PREM / Index: AIM / Sector: Mining
For immediate release
10 September 2014
Premier African Minerals Limited
("Premier" or the "Company")
RHA Tungsten Project Update
Process test work results confirm excellent recoveries and marketable end product,
Flow sheet and process equipment now detailed
Premier African Minerals Limited, the AIM-traded, multi-commodity natural resource company with mineral projects located in Western and Southern Africa, provides details of the process test work results including WO3 grades and recoveries of the Wolframite concentrates as well as plant design for its RHA Tungsten Project, in Zimbabwe.
Highlights
· -6mm +1mm Jig cleaner concentrate grading 62.7% WO3
· -1mm Wilfley table concentrate grading at 67% WO3
· Cumulative Wolframite concentrate grades ranging between 62.3% and 63.5% WO3
· Corresponding recoveries ranging between 82.9% and 77.3%
· Simple Flow Sheet with significant potential flexibility to increase concentration grade
· Free of any significant deleterious elements
George Roach, CEO, commented:
"Determination of the concentrate grade and process recovery is a significant milestone in the development of the RHA mine. The fact that these positive results were achieved on a mini pilot scale allows us to finalise the flow sheet and plant design and proceed to order. We are advancing discussions on off-take and marketing agreements. Premier will now update the economic model contained in our conceptual mining study released in September 2013 based on these results and our enhanced resource announced in May 2014."
Premier is pleased to release encouraging results from the metallurgical test programme being conducted simultaneously by Peacocke & Simpson in Harare and SGS in Johannesburg. The programme consists of investigative work on a 200kg bulk sample as well as a mini pilot run on 800kg of bulk sample both originating from seven separate locations within the historic underground workings. The sample head grade was 3.58% WO3.
The results announced today are based on the mini pilot run which consisted of crushing, scrubbing and screening the sample to a -6mm, +1mm and a -1mm fraction. The coarser fraction (-6mm) was jigged while the finer fraction was subject to spiral concentration followed by gravity treatment using Wilfley tables. The test flow sheet produced two different concentrates: -6mm +1mm at 62.7% WO3 and a -1mm at 67% WO3 at a cumulative recovery of 77.3%. The process flow has not been optimised at this stage and the simple flow sheet provides the flexibility to potentially increase the -6mm +1mm fraction concentrate grade through a shallower jig cut. In practice the Board expects that it is likely that Premier should get a higher grade at this same recovery as the full scale process plant operation is continuous and the cuts on the spirals and tables are easier to maintain.
In addition, investigative work conducted on a 200kg sample confirmed the ability to efficiently pre-concentrate the plant feed at -25mm +6mm by achieving a fourfold upgrade of feed grade at a 20% mass pull. These results provide the ability and flexibility for the plant to accommodate significantly higher run of mine feed rates with the simple addition of jigging capacity upfront.
The two grades of concentrate produced from a simple and low cost process may, in principle, be optimised to customer specifications in terms of material sizing by staged crushing, screening and gravity concentration. Premier should be able to meet material standards used in Ferro-tungstate production as well as normal APT specifications.
Flow Sheet and Process Equipment.
Most aspects of the proposed flow sheets and plant design have been finalised. Appropriate Process Technologies has provided the plant design at an instantaneous process rate of 16tph. The process flow sheet is set out schematically below. The quotation, which is at a considerable discount to the US$2.79m estimated in the concept study, is currently under review by the Board.
Qualified Person
Dr Nic Barcza has reviewed and approved this release to the extent that information contained herein relates to metallurgical test work and process development. Dr Barcza has a PhD in Metallurgical Engineering and is a registered Professional Engineer. Nic is an Executive Consultant to Mintek in South Africa. He was the Chairman of Mintek's wholly-owned subsidiary Mindev Pty (Ltd), until the end of 2005 and has served on a number of Boards such as Mogale Alloys (Pty) Ltd. He is a past-President and Honorary Life Fellow of the South African Institute of Mining and Metallurgy (SAIMM), chairman of the International Committee of INFACON, namely ICFA, a Fellow of the South African Academy of Engineering (SAAE) and has served on several academic advisory Boards and the Council of Wits University.
Werner Swanepoel, Chief Operating Officer of Premier, has reviewed and approved this release to the extent that information contained herein relates to mining and mine development. Mr Swanepoel has 20 years' experience in the southern African mining industry and holds a Master's degree in Mining Engineering, an MBA and Mine Manager's Certificates in both Metalliferous and Coal Mining. He is a registered Professional Engineer with the Engineering Council of South Africa.
The other technical information contained in this announcement has been reviewed and approved by Bruce Cumming. Mr. Cumming holds a Bachelor of Science (Honours) in Geology from the University of Cape Town and is accredited to the South African Counsel for Natural Scientific Professionals (SACNASP). Mr. Cumming has sufficient geological experience (over 35 years).
Forward Looking Statements
Certain statements in this announcement, are, or may be deemed to be, forward looking statements. Forward looking statements are identified by their use of terms and phrases such as ''believe'', ''could'', "should" ''envisage'', ''estimate'', ''intend'', ''may'', ''plan'', ''will'' or the negative of those, variations or comparable expressions, including references to assumptions. These forward looking statements are not based on historical facts but rather on the Directors' current expectations and assumptions regarding the Company's future growth, results of operations, performance, future capital and other expenditures (including the amount, nature and sources of funding thereof), competitive advantages, business prospects and opportunities. Such forward looking statements reflect the Directors' current beliefs and assumptions and are based on information currently available to the Directors. A number of factors could cause actual results to differ materially from the results discussed in the forward looking statements including risks associated with vulnerability to general economic and business conditions, competition, environmental and other regulatory changes, actions by governmental authorities, the availability of capital markets, reliance on key personnel, uninsured and underinsured losses and other factors, many of which are beyond the control of the Company. Although any forward looking statements contained in this announcement are based upon what the Directors believe to be reasonable assumptions, the Company cannot assure investors that actual results will be consistent with such forward looking statements.
Enquiries
Pamela Hueston |
Premier African Minerals Limited |
Tel: +44 (0) 755 778 3855 |
Michael Cornish / Roland Cornish |
Beaumont Cornish Limited (Nominated Adviser) |
Tel: +44 (0) 207 628 3396 |
Jerry Keen/ Edward Mansfield |
Shore Capital Stockbrokers Limited |
Tel: +44 (0) 207 408 4090 |
Tim Blythe/ Halimah Hussain |
Blytheweigh |
Tel: +44 (0) 207 138 3204 |
Notes
Premier African Minerals Limited (AIM: PREM) is a multi-commodity exploration and development company focused in Southern and West Africa. The Company has a diverse portfolio of multi-commodity projects which includes tungsten, rare earth elements, gold, lithium and tantalum in Zimbabwe and Togo, which span from brownfield projects with near-term production potential to grass-roots exploration. The Company holds 2m shares in Circum Minerals Limited, the owners of the Danakil Potash Project formerly held in part by AgriMinco Corp. At inception, those shares had a nominal value of $1.4m. Circum is fully funded to completion of feasibility study.
Glossary of Technical Terms
"Mineral resource" is a concentration or occurrence of diamonds, natural solid inorganic material or natural fossilized organic material including base and precious metals, coal, and industrial minerals in or on the Earth's crust in such form and quantity and of such a grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological characteristics and continuity of a mineral resource are known, estimated or interpreted from specific geological evidence and knowledge.
"Measured mineral resource" is that part of a mineral resource for which quantity, grade or quality, densities, shape, and physical characteristics are so well established that they can be estimated with confidence sufficient to allow the appropriate application of technical and economic parameters, to support production planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough to confirm both geological and grade continuity.
"Indicated Resource" is that part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed.
"Inferred Resource" is that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and sampling and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that may be limited or of uncertain quality and reliability.
"(Fe, Mn) WO4" is the chemical composition of wolframite.
"Jigging" is the process where a water stream is pulsed, or moved by pistons upward and downward, through the material bed.
"Mass pull" means the mass of material within which the Wolframite concentrate is contained, expressed as a percentage of total plant feed.
"Mineralisation" is the presence of a target mineral in a mass of host rock.
"Pegmatite" is a very coarse grained igneous rock, normally of granitic composition. Typically forms during the final states of magma chamber crystallization when the high water content solutions allow rapid crystal growth.
"Spiral concentration" means the use of a gravity based concentrating device that separates light density granular and sandy (10 mesh to 200 mesh (2 mm to 0.075 mm)) consistency material from heavier density material.
"Tungsten" is a metallic element known also as wolfram with the chemical symbol W and atomic number 74.
"thp" means metric ton per hour
"Wilfley table" means a sand table that separates heavy mineral particles from lighter gangue by means of longitudinal riffles impeding the downward flow and a horizontal reciprocating motion carrying the heavy particles off the end of the table
"Wolframite" is the mineral name for iron-manganese tungstate; (Fe, Mn)WO4, an ore of tungsten. The ratio of iron to manganese varies; iron-rich wolframite is known as ferberite FeWO4, manganese-rich wolframite is known as hubnerite MnWO4.
"Tungstic Oxide" is Tungsten Trioxide. WO3.
"APT" means ammonium para-tungstate.
"mtu" means metric ton unit, i.e. 10Kg of contained WO3 in concentrate.
ENDS
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