Positive Preliminary Metallurgical Testwork
|
22 October 2012 |
For Immediate Release |
Bushveld Minerals Ltd
("Bushveld" or the "Company", AIM: BMN)
Operational Update
Preliminary metallurgical testwork at the Bushveld Iron Ore Project
Bushveld Minerals Limited, a mineral development company focused on iron and tin projects in southern Africa, is pleased to provide an update on progress in its metallurgical testwork on the Bushveld Iron Ore Project.
Highlights:
Positive preliminary magnetite recoveries and high grade concentrates achievable on both fine and coarse materials from the Massive Magnetite Ore ("Massive Ore"):
· Fine fractions:The preliminary Davis Tube Test ("DTT") metallurgical testwork undertaken on ˂75μm fraction shows 79% - 84% recovery for Fe₂O₃, V₂O₅and TiO₂, and a magnetic separator concentrate grade in excess of 78% Fe₂O3, 19% TiO₂ and 0.36% V₂O₅.
· Coarse fractions: Preliminary Dense Medium Separation ("DMS") tests on coarse (-12mm and -6mm) fractions shows 73% - 80% recovery for Fe₂O₃, V₂O₅and TiO₂, and a concentrate grade in excess of 70% Fe₂O3, 18.5% TiO₂ and 0.32% V₂O₅.
Fortune Mojapelo, CEO, Bushveld Minerals explained that: "The results of the first metallurgical testwork are in line with our expectations and mark an important milestone for Bushveld while reaffirming our confidence in the project. The positive preliminary recoveries and concentrate grades for Fe2O3, TiO2 and V2O5 that are achievable at coarse sizes of as much as 12mm are very encouraging and should eliminate or minimise the need to mill the product down to fines, thus significantly reducing energy and water requirements. The relative ease of transporting coarse material (compared to finely ground concentrate) will further enhance the project's economics."
Metallurgy
The scope of the testwork has been defined to investigate extractability and pyrometallurgical characteristics of the Company's Iron Ore Project. The Metallurgical and mineralogical characterization and densimetric testwork was conducted by SGS (www.sgs.com) with advisory input from PESCO, ore dressing specialists.
The metallurgical testing comprises two parallel programmes that are focused on the Massive Ore and the Disseminated Magnetite Ore ("Disseminated Ore") that was identified in the Bushveld Minerals geological model in the P-Q Magnetite Zone.
Both ore types are being subjected to extractability and limited pyrometallurgical testwork incorporating pre-reduction tests. The pre-reduction tests will test the potential for a value-added, pre-reduced iron ore product product rather than a plain concentrate.
The focus of Bushveld's metallurgical testwork since June 2012 has been on the Massive Ore. Testwork on the Disseminated Ore has recently also commenced and results from this will be announced in due course.
TESTWORK ON THE MASSIVE ORE
Extractability/concentration and limited pyrometallurgy (pre-reduction) testwork currently underway on the Massive Ore is as follows:
1. Extractability / Concentration Tests:
Various fraction sizes have been investigated, applying DTT to the 75μm fine fractions while DMS techniques were applied to analyse the 6mm to 12mm size fractions.
The objective is to determine the mineralogy of the ore, the potential to concentrate the ore by both magnetic separation and DMS, and to identify the optimal grind size for concentration and the grade of the resulting concentrate.
While observed recoveries on the grind fractions described above are very positive, additional testwork at other fraction sizes, ranging from 38μm to 3mm, is also underway, results of which will be announced before 31 December 2012. The intention is to determine the grind fraction at which optimal recoveries can be expected.
1.1. Initial Davis Tube Tests (˂75μm):
The DTT recoveries and concentrate grade for a 80% < 75 micron grind feed processed at 1 320 Gauss for the massive magnetite are as follows:
|
Mass Recovery to Mags (%) |
Grade (%) |
Recovery (%) |
Grade in concentrate (%) |
|||||||
|
Fe |
TiO₂ |
V₂O₅ |
Fe |
TiO₂ |
V₂O₅ |
Al₂O₃ |
SiO₂ |
MgO |
CaO |
|
|
63.4 |
55.0 |
19.2 |
0.36 |
83.6 |
79.5 |
78.7 |
1.96 |
1.16 |
0.94 |
0.1 |
1.2. Coarse Grind DMS Tests (-6mm & 12mm):
The following tables show recoveries and concentrate grades at a 6mm and 12mm top size for the magnetite recovered at the Massive Zone at a specific gravity (SG) of 3.6:
|
Top size |
Mass Recovery to Sinks (%) |
Grade (%) |
Recovery (%) |
Grade in concentrate (%) |
|||||||
|
Fe |
TiO₂ |
V₂O₅ |
Fe |
TiO₂ |
V₂O₅ |
Al₂O₃ |
SiO₂ |
MgO |
CaO |
||
|
6mm |
61.9 |
50.1 |
19.0 |
0.33 |
73.4 |
74.9 |
78.5 |
2.88 |
4.66 |
1.65 |
0.75 |
|
12mm |
67.3 |
48.9 |
18.5 |
0.32 |
79.2 |
79.8 |
89.7 |
3.29 |
5.87 |
1.73 |
0.96 |
Liberation studies of -6mm and -12mm sample sizes confirmed a close association of magnetite and ilmenite. These were upgraded together, suggesting that the 12mm fraction may be sufficient to obtain economic recoveries with equally attractive product grades. The differences in recoveries between the two size fractions were minimal, indicating that concentration is possible for fairly coarse top sizes.
These positive results indicate that good recoveries can be achieved at fairly coarse top sizes creating scope for a concentrate product, which requires significantly less power than a fine top size concentrate. This is expected to contribute positively to the economics of the project.
2. Pyro Metallurgical Tests: Pre-reduction
Pre-reduction testwork will be undertaken on both the fine and the coarse grind concentrate (from 6mm to 12mm). The process comprises of heating the ore together with a solid reductant to temperatures that are typically around 1000°C (below the melting point of the ore). Under these conditions, the Fe3O4 in the ore is reduced to metallic iron, resulting in significantly less electrical energy being required in the subsequent melting processes than if reduction had to be affected as well.
The objective of the pre-reduction testwork is to evaluate the scope to further upgrade this material to a higher value product that could compete in the scrap metal market. Initial test work will be undertaken on the Massive component of the P-Q Magnetite Layer during this quarter with results expected before end of 31 March 2013.
Furthermore, bench-scale smelting tests will be undertaken on the fine (˂75μm) concentrates. Tests with both fluxed and non-fluxed ore will be carried out in order to determine characteristics of vanadium and titanium partitioning between metal and slag.
Metallurgical testwork on the Disseminated Ore is underway and comprises, as with the Massive Ore, extractability/concentrating and pre-reduction testwork. The results of this testwork are expected before the end of 31 March 2013.
Enquiries: info@bushveldminerals.com
|
Bushveld Minerals Fortune Mojapelo |
+27 (0) 11 268 6555 |
|
Fox Davies Jonathan Evans |
+44 (0) 20 3463 5000 |
|
Tavistock Communications Jos Simson/ Jessica Fontaine |
+44 (0) 20 7920 3150 |
|
Tielle Communications Stéphanie Leclercq |
+27 (0) 83 307 7587 |
This information is provided by RNS
The company news service from the London Stock Exchange
- ENDS -
Notes to the editor
Bushveld Minerals Limited is a mineral development company focused on the Bushveld Iron Ore Project and the Mokopane Tin Project, both located on the northern limb of the Bushveld Complex, South Africa.
The Bushveld Iron Ore Project comprises two licenses covering 7,409 ha where a JORC compliant open-castable resource of 633 million tonnes (comprising 260 million tonnes Indicated and a further 373 million tonnes Inferred) has been established from a 4.5 km strike length. Further drilling along strike is expected to significantly add to the resource on the basis of identified strike extensions several kilometres long to the north and south of the project area with a target resource planned in excess of 1 billion tonnes. A scoping study on the project is underway for completion in Q1 2013.
The Mokopane Tin Project consists of one licence covering 13,422 ha of open-castable disseminated tin resource. The Company has explored one target and plans to drill at a further four targets. The Company has a JORC resource in excess of 5,000 tonnes of tin and is looking to expand the resource base by undertaking a drilling programme on the other three targets in the licence area and one target in a licence area currently under application. In the longer term, the Company intends to expand the resource base by acquiring further projects.
The Company was admitted to the Alternative Investment Market of the LSE in March 2012.
The scientific and technical information contained within this announcement has been reviewed and approved by Jan Rabe, Senior Process Engineer at PESCO, the metallurgical advisor to the Company. Rabe has an honours degree in metallurgy and over 11 years' experience as a practising metallurgical engineer.
This information is provided by RNS
Latest directors dealings
- 1 minute ago Prudential
- 12 minutes ago Vanquis Banking Group 20
- 2 hours ago Frasers Group
- 2 hours ago Cavendish Financial
- 2 hours ago Diaceutics