Deep Yellow Limited (ASX:DYL) Updates On Results Of Preliminary Assessment And Testwork Of Shiyela Iron Project In Namibia.
DYL's Managing Director, Greg Cochran welcomed the encouraging results. "We are becoming increasingly optimistic that DYL has discovered a magnetite deposit that undoubtedly has development potential. Given the project's inherent infrastructural advantages, it may offer an aspiring producer an early and rapid entry into the iron ore market."
Currently, the Shiyela project, which is operated by DYL's wholly-owned Namibian subsidiary Reptile Uranium Namibia (Pty) Ltd (RUN), comprises two shallow, extensive magnetite bodies (M62 and M63) with magnetite content of between 15% and 75%. A drill programme is underway for an initial Mineral Resource estimate due for completion in the second quarter of 2011. From the testwork to date it has been determined that Shiyela magnetite has:
- Excellent metallurgical characteristics with extremely low silica and low deleterious elements;
- Three ore types that are all considered to be coarse grained with the potential to produce excellent quality products; and
- Ore that could be beneficiated at the mine site by Dry Magnetic Separation (DMS) requiring no chemicals thus minimising the potential environmental impact.
The Shiyela project comprises an aeromagnetic anomaly some 18 kilometres in extent with two extensive magnetite bodies (M62 and M63) with magnetite content of between 15% and 75%. Mineralisation was discovered in 2008 when a prospect hole made a 340 metre magnetite intercept. Recently three 50 kilogram magnetite samples were submitted to AMMTEC (Perth) for laboratory testwork.
The samples, which consisted of a coarse grained ore type, a finer grained ore type and an oxidised hematite ore type with a grain size between the coarse and the fine, were subject to the following testwork:
- Optimum grinding curve and tailings rejection assessment;
- Coarse Dry Magnetic Separation on each of the samples;
- Crushing Work Index, Bond Work Index, Abrasion Index and Unconfined Compressive Strength; and
- Davis Tube Recovery Testwork.
ProMet conducted a review of the preliminary results to determine if there were any potential metallurgical issues with the deposit that may raise processing concerns. The testwork demonstrated that the three samples:
- Had excellent metallurgical characteristics with extremely low silica and low deleterious elements;
- Are all considered to be coarse grained with the potential to produce excellent quality products;
- Could generate ore that could be beneficiated at the mine site by Dry Magnetic Separation (DMS) requiring no chemicals thus minimising the potential environmental impact of the operation; and
- Had a relatively high abrasion index and that the Bond Work Index (BWI) is trending to high at 18 to 21 kWh/t (although fine grinding should not be required).
The coarse grained nature of the samples and relatively easy upgrading indicate that ore derived from these deposits will likely be very viable - depending on the cost of transport and providing infrastructure to site. The current preference would be to fully process ore at the mine site unless transport costs are very low. However this will be influenced by the cost of providing water and power to the site. The relatively high abrasion index results could result in higher operating costs in the High-Pressure Grinding Rolls circuit (HPGR). It was also noted that DMS of the hematite sample was not particularly successful and that it may have to by-pass the circuit.
Iron Versus Silica
The first analysis that ProMet undertook was plotting iron (Fe) versus silica (SiO2) on all the data provided (head and concentrate grades). This determines if there are any immediate unusual features or different types of ore.
The data shows that essentially there is only one Fe v SiO2 relationship which is linear for all three ore types tested.
Optimum Grind Tests
Three samples were tested - Sample A representing a coarse grained ore type, Sample B is a finer grained ore type - the precise ore split of these two types is currently being investigated. The third sample Sample C, was an oxidised hematite ore type - with a grain size between A and B.
Results for Sample A showed that a 4.5% silica content can be obtained at 80% passing 330 micron - a very coarse result - which has very positive implications for grinding costs. A Direct Reduction (DR) grade (
Copyright 2011 ABN Newswire
Provided by Syndigate.info an Albawaba.com company
|Printer friendly Cite/link Email Feedback|
|Date:||Feb 14, 2011|
|Previous Article:||BPH Energy Limited (ASX:BPH) To Present At The 4th Australian High Content Image Meeting.|
|Next Article:||Meteoric Resources NL (ASX:MEI) Update On Recent Iron Ore Exploration Activities In Coorara District.|