Bushveld Iron Ore Project Update - Pyro-metallurgy
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11 June 2014 |
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Bushveld Minerals Ltd
("Bushveld" or the "Company")
Bushveld Iron Ore Project Operational Update - Pyro-metallurgy
Pyro-metallurgical Testwork on the Bushveld MML Vanadium and P-Q Zone Deposits
Bushveld Minerals Limited (AIM: BMN) a diversified mineral development company with projects in Africa, is pleased to provide an update on pyro-metallurgical testwork at its Bushveld Vanadium and P-Q Deposits in Limpopo Province, South Africa.
The Company is conducting a pyro-metallurgical testwork programme for the beneficiation of the Main Magnetite MML layer (or "MML"), as part of the Scoping Study for the Bushveld Vanadium Project. The test work will evaluate two alternative proven processing routes: a) the salt roast process to produce vanadium pentoxide flakes and/or ferrovanadium and b) the smelting process to produce pig iron or steel and high-grade vanadium slag.
The Company has recently completed modelling of the smelting beneficiation route. This flowsheet entails pre-reduction in rotary kilns, smelting in electric arc furnaces and vanadium extraction from the hot metal through a shaking ladle circuit. Testwork continues on the salt roast beneficiation route.
Primary Findings
The modelling exercise, conducted on Bushveld Vanadium Project's MML resource by Hatch Goba and Exxaro Research and Development, has yielded positive results:
· The favourable vanadium grade of MML concentrate supports production of a premium-grade vanadium slag (approximately 25% V2O5) following pig iron production and vanadium extraction;
· Approximately 370kg of pig iron and 35kg of high-grade vanadium slag (25% V2O5) can be obtained from every tonne of MML concentrate processed (excluding handling losses); and
· Pre-reduction of MML ore to proven levels of metallization (60%) and hot-charging the pre-reduced ore to the furnaces can reduce electricity consumption by approximately 70%, which offers significant cost-saving implications for the Project.
Previous modelling work on non-fluxed smelting of concentrate from the P-Q Zone Deposit showed it is possible to obtain a slag containing approximately 60% TiO2, levels amenable to further upgrading.
Fortune Mojapelo, CEO of Bushveld Minerals, said: "We are fortunate to have two proven processing route options for the MML Deposit, both of which are currently being used on the Bushveld Complex.
The Scoping Study currently underway will assist us in determining which route is optimal. We are pleased that modelling on the smelting route has yielded the positive results reported today, and we look forward to providing results on the salt roast processing route and completing the Scoping Study on this world class deposit."
BENEFICIATION OF THE MML
Bushveld is considering two flowsheet options for the beneficiation of MML ore:
· Smelting of pre-reduced ore, followed by the recovery of high-grade vanadium slag from pig iron in a converter operation (the pig iron/vanadium slag flowsheet). This flowsheet is similar to the process used by Evraz Highveld Steel and Vanadium Limited (EHSV) for the production of steel and high-grade vanadium slag, from Bushveld Complex MML ore, at their Steelworks in eMalahleni, Mpumalanga, South Africa and by New Zealand Steel at their Steelworks in Glenbrook, New Zealand;
· Salt roasting, followed by leaching to produce vanadium pentoxide (the V2O5 flowsheet). This is the standard flowsheet used for the production of vanadium pentoxide, used by Glencore plc at their Bushveld Complex-based Rhovan Vanadium Mine near Rustenburg, North-West Province, South Africa;
· Both flowsheet options are proven concepts, utilised by major steel and high grade vanadium producers globally.
A preliminary modelling study on the pig iron / vanadium slag flowsheet showed the following significant outcomes:
· Excluding handling losses, approximately 370kg of pig iron and 35kg of high-grade vanadium slag can be obtained from every tonne of MML concentrate processed;
· Pre-reduction of the ore can significantly reduce the electrical energy required for smelting. Based on a proven level of pre-reduction of the MML-type titano-magnetite ore, where 60% of the iron is metallised before smelting, and with a transfer temperature of 800°C for the pre-reduced ore, the electrical energy requirement can be reduced by approximately 70%; from ±3.3 megawatt hours (MWh) per tonne to ±1.1 MWh per tonne of hot metal produced during electric furnace smelting, with significant cost saving implications;
· Additional cost saving implications can be realised by hot-charging pre-reduced ore to the smelting furnaces;
· Hot metal from the electric furnace smelting is expected to have vanadium content of at least 1.4% due to the favourable vanadium grade of MML concentrate (approximately 1.6% V2O5). The high vanadium grade of the MML ore results in the formation of premium-grade vanadium slag during converting, with a slag vanadium content of 25% V2O5;
· The titanium dioxide content of electric furnace slag will be in the range of 35% TiO2, approaching the titanium grade of ilmenite, which is a standard feedstock for titanium dioxide pigment production in the sulphate process.
The Bushveld Vanadium Project Scoping Study currently underway will assess both the salt roast and the smelting processing routes and will recommend the ideal flowsheet for further investigation in a Pre-Feasibility Study.
PREVIOUS MODELLING WORK ON THE P-Q ZONE
The P-Q Zone Scoping Study, released in April 2013, included similar modelling results on the P-Q Zone concentrate, in addition to bench-scale fluxed smelting tests, both conducted at Mintek.
Successful fluxed smelting tests in laboratory-scale crucibles, at temperatures of 1500°C, showed iron recovery of 99% and approximately 70% vanadium recovery with between 50% and 54% of metallic product in the concentrate mass. The sulphur and phosphorous concentrations in this metallic product were 0.2% and 0.02% respectively. The resulting slag contained approximately 30% TiO2.
The modelling study on the P-Q concentrate (simulating unfluxed smelting) indicated that an iron recovery of 96% resulted in a slag containing 8% FeO, a level sufficient to allow stable furnace operation at 1700°C. Not requiring flux addition, it was possible to obtain a slag containing approximately 60% TiO2, alevel which may offer opportunities for upgrading. Calculated alloys for this smelting operation range between 48% and 51% of the concentrate mass. Modelling of the fluxless process indicated that energy requirement of 2.17 MWh per ton of metal (excluding heat losses) could be reduced to 0.91 MWh per ton of metal with a combination of pre-reduction and pre-heating. These results will be included in an updated Scoping Study for the P-Q Deposit, which will consider the production of pig iron and high-grade titanium slag.
Enquiries: info@bushveldminerals.com
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Bushveld Minerals Fortune Mojapelo |
+27 (0) 11 268 6555 |
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Strand Hanson Andrew Emmott |
+44 (0) 20 7409 3494 |
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Fox Davies Jonathan Evans |
+44 (0) 20 3463 5000 |
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RFC Ambrian Jonathan Williams |
+44 (0) 20 3440 6800 |
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Tavistock Communications Jos Simson/ Nuala Gallagher |
+44 (0) 20 7920 3150 |
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Tielle Communications Stéphanie Leclercq |
+27 (0) 83 307 7587 |
- ENDS -
Notes to the editor
Bushveld Minerals Limited is a mineral development company with a portfolio of vanadium-and titanium bearing iron ore and tin assets in Southern Africa. The Company owns the Bushveld Iron Ore Project and Mokopane Tin Project, both located on the northern limb of the Bushveld Complex, South Africa. In addition, Bushveld has a controlling 52.22% interest in Lemur Resources (ASX: LMR), that owns the Imaloto coal project in Madagascar.
Bushveld was admitted to the AIM Market of the London Stock Exchange in March 2012.
This information is provided by RNS
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