Positive Met Study Results for Zani-Kodo

13 May 2013

Mwana Africa PLC

("Mwana" or the "Company")

Positive Metallurgical Study Results for Zani-Kodo

Mwana is pleased to announce the results from a metallurgical scoping study for its Zani-Kodo project located in the Ituri region of the Democratic Republic of Congo.

The test work was carried out on samples taken from the Kodo Main orebody. The ore was found to be non-refractory and responded well to all recovery processes investigated, with higher than 90% gold extraction being obtained across all the recovery methods tested.

The ore showed high amenability to the following process routes for gold recovery:

• Cyanidation on a milled run of mine ("ROM") ore

• Gravity recovery followed by cyanidation on the gravity concentrate and gravity tails

• Normal flotation on ROM followed by cyanidation

• Flash flotation on ROM followed by cyanidation

• Gravity concentration followed by flotation on the gravity tails and intense leach on the gravity concentrate, and float concentrate with carbon in leach ("CIL") on the final float tails.

The summary results are given in Table 1.

Table 1: Gold recovery achieved with various process routes

The study was managed by SENET, South Africa, with the test work performed by Ammtec in Australia (communition, mineralogy and recovery test work) and by Gravity Concentrators Africa, South Africa (EGRG test work).

Kalaa Mpinga, Chief Executive Officer of Mwana, commented: 


"These metallurgical results are very encouraging, with excellent gold recoveries demonstrated across conventional processing options. The results show that there are a number of low cost and robust routes available to us that can be incorporated into our ongoing feasibility studies at Zani-Kodo."

For further information contact:

Mwana Africa PLC Tel: +44 (0)20 7654 5580

Donald McAlister / Lorenz Werndle

Nominated Adviser and Broker

Liberum Capital Limited Tel: +44 (0)20 3100 2000

Michael Rawlinson / Tom Fyson / Christopher Kololian

Joint Broker

Peel Hunt Tel: +44 (0)20 7418 8900

Matthew Armitt / Andy Crossley

Public & Investor Relations

Tavistock Communications Tel: +44 (0)20 7920 3150

Ed Portman / Simon Hudson / Mike Bartlett

About Mwana Africa PLC

Mwana Africa PLC is a pan-African, multi-commodity mining and development company. Mwana's principal operations and exploration activities cover gold, nickel, copper and diamonds in Zimbabwe, the DRC and South Africa.

The restart of operations at The Trojan Nickel Mine (owned by Mwana's Zimbabwe subsidiary Bindura Nickel Corporation ("BNC")) follows four years during which all of the BNC assets were on care and maintenance. In September 2012, Bindura Nickel Corporation carried out a restructuring and recapitalisation involving US$23m being invested into BNC which has allowed it to restart the Trojan mine. First sale of concentrate to Glencore took place in April 2013.

Mwana's Freda Rebecca gold mine in Zimbabwe, having restarted operations in 2009, produced 65,350 ozs of gold in the 12 months to March 2013.

In February 2013, Mwana announced that the gold mineral resource at its Zani Kodo project in Democratic Republic of Congo had increased to 2.6 million ounces.

In February 2013, Mwana announced it had signed a Joint Venture Agreement with Zhejiang Hailiang Company Limited to jointly explore some of its copper license areas in the Katanga Province of the DRC.

Test Work Summary

The purpose of the metallurgical test work program was to determine process parameters and gold recoverability in order to identify the best potential process flows and economic parameters for use in future feasibility studies.

The test work was performed on a total of 398kg of samples taken from six holes across the Kodo Main orebody. The six holes sampled are considered to provide a representative selection of mineralized locations within the Kodo Main orebody wireframe at the time of sampling. The sampling approach is outlined below:

• The bulk sample was taken from the Kodo Main deposit and consisted of full core (NQ2) samples from three new holes (MET001-003) and quarter core from three previously drilled exploration holes (KDODD063, 066 and 070)

• All samples were taken from Banded Iron Formation host rocks with varying degrees of silicification, quartz veining and brecciation to give a representative selection of mineralized styles

• All samples contain the predominant pyrrhotite-arsenopyrite sulphide suite which is consistent across the deposit

• The locations of the sampled intersections are shown in Figure 1

• The estimated average grade of the Kodo Main deposit at the time of sampling was ~4.0 g/t, so holes were sited adjacent to previously drilled holes with broad intersections of ~4.0 g/t

• Hole MET001 was positioned as close as possible to the historical stopes in order to sample material similar to that previously mined

• Holes MET002 and MET003 were situated to provide strike coverage of approximately 250m across the upper portion of the Kodo Main zone

• Holes KDODD063, 066 and 070 represent intersections in the deeper portions of the deposit. The samples are located approximately 450-500m downdip from holes MET001 and MET002

For the associated map (Figure 1), please click on, or paste the following link in to your web browser, to view the PDF file:

The following tests made up the gold recovery section of the metallurgical test work program: 

• Chemical characterization, size distribution and X-Ray diffraction ("DRX") analysis of the head samples

• Preg-robbing tests

• Gravity separation tests

• Leaching tests under different conditions including grind size, slurry density, cyanide concentration and dissolved oxygen concentration.

The highlights of the gold recovery tests included:

• The ore demonstrated a high gravity gold recoverable ("GRG") component of up to 75.8%. GRG liberation occurred at reasonably coarse grind.

• The leaching conditions for the composites were a grind size of 80% passing 75 μm, slurry density of 50% by weight, cyanide consumption 0,8 -1,0kg/t NaCN, for a residence time of 24hrs with 10 ppm dissolved oxygen concentration at a pH of 10.5.

• Flotation tests were performed on the whole ore (ROM) to determine the response of the ore to flotation recovery. The ore responded well to flotation.

• At a grind of 80%-75μm, a gold recovery of 96.7% to the float concentrate was achieved at a mass pull of 16%. 
Flash flotation at a grind of 80%-212μm achieved a gold recovery of 49.8% to the float concentrate at a mass pull of 1.82%.

A series of nine composites were collected for the grinding test work. These composites were collected such that they represented the main lithology groups found in the ore body.

The following tests made up the grind determination section of the metallurgical test work program:

• SAG Mill Comminution Test (DWi and A x b)

• SAG Power Index Test (SPI)

• Bond Abrasion Index Test (Ai)

• Rod Bond Work Index Test (RMWi)

• Bond Ball Work Index Test (BMWi)

The highlights of the grind determination tests included the following:

• The average results obtained from the grinding determination tests were DWi = 10.2 kWh/m3, A x b = 27.8, SPI = 163.2 minutes, Ai = 0.39, RMWi = 14.48 kWh/st and the BMWi = 14.01 kWh/st.

• These results indicate that the ore is considered to be medium to hard and is amenable to conventional primary crushing, SAG and ball milling.

Further metallurgical test work will be a function of the process circuit selected, which in turn will be based on evaluating the economics of each process.