Bushveld P-Q Zone Metallurgical Testwork Results

RNS Number : 4815W

Obtala Resources Limited

28 January 2013

 



28 January 2013

Obtala Resources Limited

("Obtala" or the "Company")

(AIM: OBT)

P-Q Zone Metallurgical Testwork Results - Bushveld Iron Ore Project

The Board of Obtala Resources Limited, the natural resources investment and development company, announces the following RNS made by Bushveld Minerals Limited this morning:

Obtala Resources Francesco Scolaro - Chairman; Simon Rollason - Managing Director www.obtalaresources.com	[phone]
Macquarie Capital (Europe) Limited (Nomad and Broker)
Steve Baldwin; Nicholas Harland	[phone]

Bushveld Minerals Ltd

("Bushveld" or the "Company")

P-Q Zone Metallurgical Testwork Results - Bushveld Iron Ore Project

Bushveld Minerals Limited (AIM: BMN), a mineral development company focused on iron and tin projects in Southern Africa, is pleased to provide a metallurgical testwork update on their iron ore project in Limpopo Province, South Africa. 

Recent results of Davis Tube tests on massive and disseminated iron ore zones of the PQ layer are reported here.

Highlights:

·      As much as 86.5% recoveries for a 54.8% Fe^T product grade of P-Q massive magnetite ore, and as much as 63.1% recoveries for a 55.0% Fe^T product grade of P-Q disseminated magnetite ore confirmed.

·      Size fractions of between 500 µm and 106 µm found to have the best recoveries, eliminating the need for fine grinding of the ore.

·      Significant improvement of the product grades and recoveries over the coarse (-6mm and -12mm) DMS concentrates.

Commenting on these results, Fortune Mojapelo, the CEO of Bushveld Minerals, said "The positive drilling and metallurgical test results continue to reinforce the robustness and consistency of the iron ore mineralisation in both the P-Q zone and the Main Magnetite Layer. In relation to the economics of the project, the high recovery levels at relatively coarse grinds for the massive and disseminated ores imply less intense power requirements to process these ores. We expect that this will provide greater confidence in the fundamentals of the project, which will be reflected in our scoping study report due for release this quarter."

Metallurgy - Davis Tube Test results of size fraction grading

Following preliminary Davis Tube Test ("DTT") testwork undertaken on the -75μm fraction, and preliminary Dense Medium Separation ("DMS") tests on coarse (-12mm and -6mm) fractions of the massive ore (refer to BMN announcement "Preliminary metallurgical test work at the Bushveld Iron Ore Project", 22 October 2012), follow-up DTT investigations have been conducted on a range of size fractions for composited samples of both the massive and disseminated ores.

Massive Ore

Of the recovery/grade tests carried out on the six size fractions of the massive ore from -500µm to -38µm (in addition to the 12mm and 6mm fractions reported on by Bushveld Minerals in December 2012); the 500 µm fraction gives the best product grade/recovery results for all the important constituents of the ore. This suggests that fine grinding of this ore will not be necessary.

The table below summarises the grades and percentage recoveries for the DT product at various size fractions for the massive ore and highlights results obtained for the -500 µm, -212 µm and -106 µm fractions. Total iron (Fe^T) recoveries are positive and compare well with the previous preliminary DTT studies using a -75µm grind.

DTT Results: Massive Ore

	FeT		V2O5	TiO2		SiO2		Al2O3		CaO		MgO
Size Fraction (Mags)	Grade (%)	Recovery (%)	Grade (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)
-500µm	54.8	86.52	0.39	18.5	80.67	1.17	6.52	2.8	33.68	0.11	3.23	0.97	29.9
-212µm	55.1	86.81	0.35	18.7	81.32	1.22	6.62	2.83	33.15	0.11	3.14	0.97	29.12
-106µm	54.8	83.78	0.36	18.4	77.72	1.17	6.5	2.82	33.84	0.12	3.51	0.98	30.14
-75µm	55	77.91	0.35	18.3	71.53	1.13	5.64	2.78	29.98	0.11	2.89	0.92	25.42
-53µm	55.5	43.88	0.42	18.3	40.02	1.24	3.46	2.81	16.95	0.12	1.76	0.93	14.38
-38µm	54.6	35.75	0.36	17.8	32.15	1.67	3.85	2.89	14.4	0.21	2.55	0.98	12.51

Recoveries and product grades of the -500µm concentrate show a significant improvement in the Fe recoveries over the -6mm and -12mm concentrates produced using dense media separation (DMS), as well as a significant reduction in the SiO₂ and MgO grades of the concentrates. This is illustrated in the table below:

Top size	Grade %			Recovery %		Grade in concentrate %
	Fe	TiO2	V2O5	Fe	TiO2	Al2O3	SiO2	MgO	CaO
6mm	50.1	19	0.33	73.4	74.9	2.88	4.66	1.65	0.75
12mm	48.9	18.5	0.32	79.24	79.8	3.29	5.87	1.73	0.96
500µm	54.8	18.5	0.39	86.52	80.67	2.8	1.17	0.97	0.97

Disseminated Ore

Recovery/grade tests on the disseminated ore carried out at various top sizes yielded positive results in all size fractions greater than 106 µm.

The disseminated ore has lower recoveries, which may be expected owing to the fact that more of the iron may be incorporated in pyroxene and olivine in the disseminated ore. Nonetheless, the grades of the disseminated concentrates compare favourably with those of the massive concentrates.

The table below summarises the concentrate grades and recoveries for the various size fractions for the disseminated ore:

DTT Results: Disseminated Ore

	FeT		V2O5	TiO2		SiO2		Al2O3		CaO		MgO
Size Fraction (Mags)	Grade (%)	Recovery (%)	Grade (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)	Grade (%)	Recovery (%)
-500µm	55.1	61.45	0.25	17.8	63.47	1.78	2.46	2.87	10.59	0.19	1.66	0.84	8.22
-212µm	55	63.1	0.24	17.7	64.97	1.97	2.81	2.91	11.05	0.21	1.89	0.9	9.06
-106µm	54.8	61.88	0.36	17.7	63.95	1.8	2.52	2.87	10.73	0.2	1.77	0.86	8.52
-75µm	55.1	51.98	0.23	17.7	53.38	1.94	2.27	2.89	9.02	0.21	1.55	0.86	7.11
-53µm	54.7	16.20	0.22	17.4	16.46	2.25	0.58	2.96	2.31	0.25	0.58	0.89	2.31
-38µm	54.5	3.99	0.27	17.1	3.99	2.95	0.21	3.19	0.61	0.37	0.21	0.95	0.21

Bushveld Minerals is carrying out additional X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Saturation Magnetization Analyser (SATMAGAN) work on the massive and disseminated ore in order to further characterise the total recoverable iron for the various ore types. There is a noticeable drop in recoveries for both the massive and disseminated ores below 106µm, which is likely the result of lower effective magnetic susceptibilities of smaller-size particles. Further XRD, SEM and SATMAGAN work will characterise this, but these results suggest that a fairly coarse grind fraction may be optimal for these ores, reducing the need for expensive milling down to very fine particle sizes.

Enquiries: [e-mail]

Bushveld Minerals Fortune Mojapelo	[phone]
Fox Davies Jonathan Evans	[phone]
Tavistock Communications Jos Simson/ Jessica Fontaine	[phone]
Tielle Communications Stéphanie Leclercq	[phone]

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 Company was admitted to the Alternative Investment Market of the LSE in March 2012.

Competent Person's Statement

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. Jan Rabe has consented to the inclusion of the material in the form and context in which it appears.

 

END

 

 

MSCPGUMWGUPWGUR