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AMN - ZAMBIA: Kabwe treatment plant EIS approved

BMR Group has received confirmation from the Zambia Environmental Management Agency (ZEMA) that its Environmental Social Impact Assessment in respect of its tailings retreatment process and the construction of its planned pilot and main treatment plants in Kabwe has been approved.

The terms of ZEMA's approval include conditions typical in such projects, including the requirement for BMR to conduct air modelling and hydro-geological studies and to install pollution abatement equipment prior to starting operations, and to submit bi-annual results of its monitoring program to ZEMA, as well as to ensure continuous vegetation of new tailings.

The company has continued to refine its plans for the pilot plant with the process and engineering design work for construction already being at an advanced stage. BMR is currently focused on assessing the appropriate levels of both capital expenditure and operating expenditure that are necessary for the construction and subsequent commercialisation of the pilot plant. The costings will now include provision for an SX plant designed to enhance the quality of the products that will therefore augment their end value.

Following intensive and wide ranging metallurgical investigative test work, BMR decided to use a brine/acid leach based process carried out at an ambient pressure and temperature to recover lead and zinc from the tailings. This leaching process has been developed over two years in conjunction with Kupfermelt Metal Processing in South Africa.

Lead and zinc extractions for the wash plant tailings of 90% Pb and 79% zinc have been achieved. Recoveries for the leach plant residue are in the region of 80% lead and 50% zinc.

The test work has produced electro-won lead sponge and zinc cathodes; cemented lead, and zinc sulphate heptahydrate which has the potential to attract a price premium and has a potential market in Zambia.

The brine/acid leaching process is the key to the success of the project yielding the good metal extractions at low potential cost in terms of power and consumables, with sulphuric acid being readily available at competitive cost from the Zambian copper smelters.

The treatment capacity of the pilot plant will be approximately 5 tonnes/hour. The design of the plant has been a collaborative effort between the BMR technical team and Kupfermelt Metal Processing. It will enable BMR to finalise the design parameters of the main plant using different combinations of tailings.

The pilot plant will be operated as a semi-production unit to simulate actual operating conditions.

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