- Mintek to scope out processing options on 1,000 kg of HQ diameter core from Area 4
- Preliminary studies by Commodas Ultrasort indicate amenability to a variety of sorting options
- Mineralogical studies confirm xenotime as primary HREE mineral
- Metallurgical program to be completed in Q4, 2012
HALIFAX, July 3, 2012 /CNW/ - Namibia Rare Earths Inc. ("Namibia Rare Earths" or the "Company") (TSX: NRE) is pleased to report that it has engaged Mintek to carry out metallurgical test work on the Lofdal Rare Earth Project in northwestern Namibia. Mintek will examine a variety of upgrading and separation options and determine the amenability of the material to floatation and leaching. Composite samples from the recently completed drill program in Area 4 will be provided from HQ diameter core drilled expressly for this purpose.
The Mintek metallurgical program is being supported by detailed mineralogical studies carried out by Applied Petrographics of Camden, WA (United States), QEMSCAN studies by the Colorado School of Mines of Denver, CO (United States), and sorting and upgrading studies by Commodas Ultrasort of Delta, BC (Canada) and Wedel (Germany). The metallurgical program will be monitored by Specialised Metallurgical Projects Ltd. ("SMP") of South Africa. SMP has been involved with the development of new technologies pertaining to upgrading run of mine ores, particularly in the field of sensor based sorting and sophisticated gravity concentration methods. It is anticipated that results from the metallurgical program will be available in the fourth quarter 2012.
Don Burton, President of Namibia Rare Earths stated,
"We are very pleased to have Mintek taking the leading role in this aspect of the project. An early focus of the metallurgical program will be to determine what levels of upgrading might be achievable to produce higher grade, heavy-enriched pre-concentrates. The preliminary findings of Commodas Ultrasort with regards to the amenability of surface samples from Lofdal to DEXRT, XRF and radiometric sorting are very encouraging. No rare earth project is without processing challenges and we are confident in the capacity of Mintek to scope out the best processing options that will maximize the value in the heavy rare earth-enriched zones we have delineated at Lofdal. With the benefit of the on-going mineralogical studies being undertaken by Dr. Jim Clark at Applied Petrographics and the engagement of SMP to monitor and assist in evaluating process options, we believe that we have assembled the most competent and innovative groups available to the project."
Sorting Studies Completed to Date
Commodas Ultrasort was provided with samples from mineralized and unmineralized carbonatitic outcrops which were coarse crushed at the Actlabs preparation facility in Windhoek and then shipped to the Commodas Ultrasort facility in Canada for benchtop test work. Preliminary observations from Commodas Ultrasort are that the heavy rare earth enriched1 material from Area 4 is amenable to sorting by dual energy x-ray transmission ("DEXRT"), x-ray fluorescence ("XRF") and radiometric methods. The most effective sorting results were achieved with DEXRT which provided a near perfect sort between the mineralized and unmineralized samples. It must be noted that the samples provided to Commodas Ultrasort were not representative of grade distributions expected from Area 4 but were selectively taken in order to determine the amenability of potential ore from Lofdal to various sorting methods. The next stage of sorting test work will be carried out on representative samples of the mineralized zone as described below.
Metallurgical Test Samples
Heavy rare earth-enrichment at Lofdal occurs in both high grade (>1% TREO) and low grade (0.5% TREO) zones and it will be important to determine the mineralogical and metallurgical characteristics of both grade ranges. Two HQ diameter core holes were drilled in Area 4 to provide representative two separate samples of high grade and low grade heavy rare earth-enriched material (Figure 1). Both holes were oriented to drill down-dip through the Main Zone which is the principal focus of the initial resource estimation program being carried out by MSA Group. The two holes have collectively provided 1,000 kg of material that is available for test work.
The grade characteristics of the holes are provided in Table 1 and Table 2. Hole 4084 provided 79 meters of core with an average grade of 1.50% TREO with 94.7% heavy rare earth-enrichment (Table 1 and Figure 2) and hole 4085 provided 74 meters of core with an average grade of 0.26% TREO with 81.5% heavy rare earth-enrichment (Table 2 and Figure 3). It must be noted that these intercepts were drilled sub-parallel to the dip of the mineralized zone and are therefore providing exaggerated thicknesses but the average grades are representative of those sections of the mineralized zone. The true thickness of the mineralized zone in these areas is 10-12 meters. Highest grade attained in the high grade composite sample was 5.80% TREO with 99.2% heavy rare earth enrichment and the highest grade attained in the low grade composite sample was 1.31% TREO with 95.8% heavy rare earth enrichment.
The holes were cut in half with one half from every meter being submitted for analysis and one half from every second meter in the "ore zones" being provided to Mintek for metallurgical test work. The remaining pieces of half core have been retained at site for archive and possible future test work. Sample preparation and analytical work for the two holes was carried out by Activation Laboratories Ltd. (Windhoek, Namibia and Ancaster, Ontario) employing ICP-MS techniques suitable for rare earth element analyses and following strict internal QAQC procedures inserting blanks, standards and duplicates.
Mineralogical Studies Completed to Date
Detailed studies of Area 4 drill core by Applied Petrographics have confirmed that the principal heavy rare earth mineral at Lofdal is xenotime. The potential ore mineral assemblage is dominated by xenotime and subordinate zircon ± generally minor amounts of aeschynite, bastnasite group minerals (including synchysite-Y), thorite, and unidentified phases (Ca-Y silicate and Th-Zr silicate). In samples with high thorium (2,000-4,000 ppm) the potential ore mineral assemblage is dominated by xenotime and thorite. It should be noted that the average thorium content of the high grade metallurgical composite is 326 ppm and for the low grade metallurgical composite it is 674 ppm (Table 1). Grain size and habit are variable with ore minerals being generally fine- to very fine-grained with much of the potential ore mineral averaging 15-20 microns but locally reaching up to 150 microns. Recent examinations of core from deeper drill holes in Area 4 have identified much coarser xenotime in hand specimens.
Metallurgical Test Program
Samples from the two metallurgical HQ diameter drill holes will be shipped to Commodas Ultrasort in Germany where large scale sorting test work can be carried out on samples of up to 500 kg. The objective of this work will be to determine the optimum sorting technologies to upgrade the respective run of mine grades on a variety of crushes for the high grade and low grade samples. Subsequent metallurgical test work will be performed by Mintek in South Africa on the upgraded material to optimize concentrate grades and determine the optimum extraction flow sheet. The Mintek test work will undertake a broad scope of test work including but not necessarily limited to:
- Sorting test work (DEXRT, XRF, radiometric)
- Comminution test work (UCS, CWI, SMC, AI, BRWI and BBWI tests)
- Separation options (gravimetric, magnetic) and milling
- Mineralogy (XRD, SEM)
- Floatation test work
- Leaching test work
Mintek is South Africa's national mineral research organisation and it is one of the world's leading technology organisations specialising in mineral processing, extractive metallurgy and related areas with specific experience on a number of rare earth deposits in southern Africa. Mintek provides service test work, process development and optimisation, consulting and innovative products to clients worldwide. Mintek has about 780 permanent staff members, over half of whom are scientists, engineers and other technical R&D specialists.
Engagement of Investor Relations Specialist
The Company is also pleased to announce that it has engaged the services of Mr. Karim Gangji to assist with the development of a comprehensive marketing plan over the next 6-12 months. Mr. Gangji has over 20 years of experience in the field of finance and investor relations with a number of junior resource companies, most recently with Orko Silver Corp. from 2005-2010. Namibia Rare Earths has recently upgraded its website and readers are encouraged to visit the site at www.namibiarareearths.com
Donald M. Burton, P.Geo. and President of Namibia Rare Earths is the Company's Qualified Person and has reviewed and approved this press release.
About Namibia Rare Earths Inc.
Namibia Rare Earths Inc. is developing a portfolio of mineral exploration projects in Namibia and is currently focused on the accelerated development of the Lofdal Rare Earths Project. The Company completed a CDN$28.75 million initial public offering and Toronto Stock Exchange listing in April, 2011 and is well funded to carry out its development program. The common shares of Namibia Rare Earths Inc. trade on the Toronto Stock Exchange under the symbol "NRE".
Please click here for figures and tables: http://files.newswire.ca/961/Namibia_Rare_Earths.pdf
NO REGULATORY AUTHORITY HAS APPROVED OR DISAPPROVED
THE CONTENT OF THIS RELEASE
1 As per industry norms heavy rare earths ("HREE") and their oxide equivalents ("HREO") comprise europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and yttrium (Y). Light rare earths ("LREE") and their oxide equivalents ("LREO") comprise lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd) and samarium (Sm). Total rare earths ("TREE") and their oxide equivalent ("TREO") comprise HREE+LREE (HREO+LREO). "Heavy rare earth enrichment" is the ratio of HREE:TREE or HREO:TREO expressed as a percentage. Ratios are calculated from source data and may vary from use of rounded numbers in tables.
For further information: