Environment
Kenmare is committed to management of its operations in accordance with the World Bank “Environment, Health and Safety Guidelines for Mining and Milling – Open Pit” and the African Development Bank’s “Environmental Guidelines for Mining Projects”, in addition to the environmental laws and standards in force in Mozambique.
Kenmare’s Environmental Management Plan (EMP) identifies the monitoring activities, management and training programmes, reporting activities, auditing and mitigation measures that are needed in order to identify and reduce any negative impacts of its operations and to comply with applicable environmental laws and guidelines. It incorporates into a single document all mitigation measures and recommendations identified during the development and construction phases of the mine so that they can be considered during the remaining phases of the project (operations and decommissioning). The EMP is a clear record of the standards and intentions of Kenmare’s environmental programme.
Environmental Objectives
Kenmare will:
• conduct regular performance reviews and legal compliance audits and act upon the results to ensure compliance with national laws and Company policy;
• provide adequate resources, staff and training so that employees at all levels recognise and are able to fulfil their responsibilities;
• develop, maintain and test emergency procedures in conjunction with the relevant authorities; and
• make annual statements of environmental performance and communicate it to all interested and affected parties.
Rehabilitation
As the mining face advances, the rear of the mining pond fills with tailings from the floating concentrator to a level of, or slightly above, the pre-existing land surface. Thereafter, the tailings will be contoured, covered with a layer of slimes material (clay-rich <45 micron material), and the top layer will be mixed with previously stored topsoil to produce a better water-retaining, more fertile substrate for vegetation than existed previously. The rehabilitation will be completed by fertilising and seeding with a variety of native species. Trials are required to determine the combination of plants most suitable for rehabilitation of the mining area, which will include both native flora and food crops. Kenmare is working with the WWF to identify the optimum re-vegetation strategy. To this end a nursery area is being established to investigate the optimum conditions and plants for rehabilitation of the area. The slimes dam and the initial tailings stockpile area are part of the trial area.
The total area to be affected by the mine, processing plant and associated infrastructure is approximately 2,829 hectares, as shown in Table 1, of which the mine path is 2,500 hectares. Given that clearing, mining, tailings disposal and land rehabilitation can be completed in a 5 to 6 year cycle, approximately one-third of the mining area or 800 hectares will not be available for agricultural purposes at any one time. Infrastructure areas can be rehabilitated only after closure of the operation.
Table 1: Disturbed areas over the life of the mine
Area
Item Hectares
Mine - Dredge 2,500
Slimes Dam 120
Sand Tailings 165
Infrastructure and other areas 44
Total 2,829
Tailings Disposal
The great majority of the waste material comprises sand, silt and clay particles removed from the ore in the Wet Concentrator Plant (WCP). These can be sub-divided into sand tailings (>0.045 mm) and slimes (<0.045 mm), which are collected in a series of hoppers at the back of the WCP. Disposal of sand-sized particles is straightforward, these being pumped to the rear of the pond and deposited by means of cyclones which are located on top of a mobile stacker.
Disposal of slimes material is more complex, given the propensity for this size fraction to remain in suspension for a longer period. A minor proportion of slimes can be incorporated between sand grains within the sand tailings, although this quantity seldom exceeds 1.5%. During initial operations, the slimes have been pumped into a temporary slimes dam. As these slimes do not remain in suspension no flocculants or coagulants need to be added to assist in the settling process. After settling and some measure of consolidation has occurred, the slimes will be re-combined with sand tailings and used in the final rehabilitation of mined areas.
Water Supply
Water for the mine is supplied from an aquifer via 12 individual boreholes, and from a surface lake. The total water abstraction capacity exceeds 40,000 m3/day. Water is mainly used in the dredge pond and processing plants as well as for domestic use. The aquifer recharges each year with rainfall. A water monitoring programme, which has been approved by the Mozambique authorities under a separate document from the EMP, has been undertaken during the past 3 years. A total of 11 surface waters, 8 community water wells and 6 ground water sites are regularly monitored for a wide range of constituents.
Sewage and Waste Water Handling Facilities
Sewage treatment plants have been provided for the process plant, wet concentrator plant and accommodation village. The treatment plants each comprise a collector tank and pumping station, aerobic treatment unit, agitated aeration tank and sludge disposal to a sludge digestion pond. Liquid wastes such as laboratory effluent and surface run-off from the plant and workshop areas, which may contain potential pollutants, are collected in sumps and treated in the appropriate fashion to avoid release to the general environment.
Non-Hazardous Solid Wastes
Solid wastes include materials from the workshop, laboratory and domestic sources. A solid waste disposal facility has been provided, including a lined area for non-inert material.
Energy Consumption
Electrical power is used for the dredges, concentrator, waste disposal pumps and MSP, as well as offices and the accommodation village. This is sourced from the national grid by means of a 110 kV overhead transmission line from the sub-station at Nampula. The power is generated by the hydro-electric dam at Cahora Bassa. A small on-site diesel power station has been constructed to supply back-up power for critical equipment in the event of power outages. This power station is rated at 6 MW and is capable of supplying the MSP and other key equipment (but not the mining operation) during an extended grid outage. The overhead transmission line was electrified on 15 January 2007. Kenmare is working with the power utility company, EdM, to extend distribution of power to the host communities.
Emissions
A monitoring unit has been installed within the ilmenite roaster plant which records ambient meteorological conditions, as well as the primary anticipated pollutants (inhalable particulates, total particulate matter, CO, SOx, and NOx). Kenmare intends to report against the applicable standards during 2008, once the roaster is commissioned. Data will be presented in the form of wind roses, pollution roses and average concentrations per measured parameter. Emissions modeling which was conducted at the roaster stack design stage confirmed that the off-gas would be adequately dispersed.
Workplace Noise
Monitoring equipment was installed during 2007 to ensure that operations do not exceed applicable noise standards. The mine will comply with the following occupational noise exposure: a maximum of 8 hours exposure to 85 dB (A), 2 hours exposure to 91 dB (A), and 1 hour exposure to 94 dB (A) is allowed. A maximum limit of 115 dB (A) is allowed.
Radiation
Radioactivity occurs naturally within heavy minerals, resulting in a natural level of radioactivity in the region. The extraction and processing of the heavy minerals merely concentrates naturally occurring radioactive minerals; no radioactive substances are created by mining or processing. The standards used for radiation protection for the Moma Titanium Minerals Mine are the international standards recommended in the Basic Safety Standards of the International Atomic Energy Association.
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