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| Beatrix Gold MineTechnical Short Form Report The Beatrix Gold Mine consists of four surface operating shafts that mine various gold bearing reefs from open ground and pillars at depths between 600 and 2,155 m below surface. Ore is processed at two metallurgical plants with mill throughput of approximately 3.0 Mtpa to produce approximately 391 koz of gold. The mine has a workforce of approximately 10,500 employees. The geological and evaluation models for F2010 have been updated to reflect the latest available data. These models are coupled with an integrated and holistic mine design and schedule plan that is based on current performance levels. This Technical Short Form Report reflects the latest Life of Mine plan, together with an updated Mineral Resource and Mineral Reserve statement, as at 30 June 2009. All Mineral Resource and Mineral Reserve figures reported are managed unless otherwise stated and Mineral Resources are inclusive of Mineral Reserves. In summary, the Beatrix Mineral Resource base has increased by 9% year-on-year. The overall Mineral Reserve base has however, decreased slightly by 4% since the June 2008 Mineral Reserve declaration. Significantly increased power, consumable and labour costs have offset increased gold price revenues, with the effect that only nominal reductions in year-on-year paylimits were realised. Salient Features
Key Features
Operating Statistics
Rounding off of figures presented in this report may result in minor computational discrepancies. Where this occurs it is not deemed significant. Geological Setting and Mineralisation The Beatrix Gold Mine forms part of the Free State Goldfields which lies at the southern edge of the Witwatersrand Basin, located near the towns of Virginia and Welkom in South Africa’s Free State Province. The mining area is underlain by Karoo Supergroup sediments followed by the Klipriviersberg Group volcanic rocks, which in turn are underlain by the Central Rand Group that hosts the goldbearing conglomerates (reefs), exploited by Beatrix Gold Mine. Initially, the Beatrix 4 Shaft was developed to exploit the Beisa Reef. The development of this shaft centres on utilising the original Beisa Shaft and a sub-shaft to access the Kalkoenkrans Reef preserved within and beneath the Beisa overturned structure (see 4 Shaft section). The Beatrix Reef (and local facies variations thereof) constitutes 72% of the Mineral Reserves and the Kalkoenkrans Reef the remaining 28%.
Local geology Structurally, the Free State Goldfield lies within a north-south trending syncline forming an apex in the south-western corner of the Witwatersrand Basin. The Central Rand Group in the Free State comprises some 2,000 m of discrete sedimentary sequences deposited over successive unconformity surfaces in an expanding depositional basin. The paucity of major faulting and folding of Central Rand Group age has led to the conclusion that subtle tectonic warping of the basin with granite doming on the margins controlled deposition. The conglomeratic reef units are most commonly deposited at the base of each depositional sequence, although gold may also occur as scours within a given formation. The principal reefs mined in the Free State are the Basal Reef, the Saaiplaas Reef, the Leader Reef, the ‘B’ Reef, the ‘A’ Reef, Elsburg and the Dreyerskuil Reefs. Beatrix is situated in the far south of the Free State Goldfields and is unique compared to other operations in that it exploits the Beatrix Reef (BXR), Aandenk Reef (AAR), VS5 Reef (VS5) and Kalkoenkrans Reef (KKR), as well as composites of all of the above. Mining has been typically on the BXR in the south from 2 Shaft through to 1 Shaft in the north. At Beatrix 3 Shaft, mining is typically done on reef types associated with a transition from BXR to AAR. To the north of 3 Shaft the VS5 erodes the underlying AAR. The BXR is not developed at 4 Shaft where the principle reef is the KKR. Both the BXR and KKR dip at generally shallow angles, with the BXR dipping at 0 – 15° to the north and the KKR dipping regionally to the east at 8 – 10° in the eastern areas of the mine. However, in the west, the dip of the KKR steepens and the reef overturns and to the east there are local variations in dip and strike due to gentle folding. Underground development exposures since 2006 and new surface boreholes confirmed the interpretation of a synclinal structure to the east of 4 Shaft, where the reef is almost flat. The BXR area around the 1 and 2 Shaft areas is largely undeformed, apart from the western periphery (Vlakpan area) and the northern area, north of the 3 Shaft. In these areas, numerous closely spaced, northerly trending normal faults divide the reef into a discontinuous set of narrow north-trending blocks. The gross structure of the 4 Shaft area has been imaged with a three-dimensional seismic survey and a large number of underground holes have been drilled to delineate structure and to sample the reef. Structurally 4 Shaft is fairly complex. The overfold structure is a large north trending synclinal fold associated with the western margin of the Witwatersrand Basin and is complicated by west dipping thrust faulting. A north trending set of normal faults with variable throws is also developed within the flatter portions of the reef towards the east. Historically, over a 5-year review period, geological losses have been estimated at 5% in most areas, increasing up to 10% in the Zone 405 (at West Section) and Vlakpan areas (at 2 Shaft). These losses are accounted for in the major structures interpreted in the structural models. Extensive work has been carried out over the past few years developing local geozone models on all the reef types, and these continue to be reviewed and updated as additional information becomes available. These models are based primarily on reef geological parameters with some refinement based on channel widths and value distributions. The VS5, to the north of 3 Shaft, has not been mined to date. This reef has been exposed, to a limited extent, in underground development as well as in surface and underground exploration drilling. As with all the other reef types, sub-facies have been mapped and are used in the Mineral Resource estimation process. The VS5 is sub-divided into three facies based on maturity and subsequent gold value distribution.
The KKR at 4 Shaft is described as a multiple channel reef consisting of major and minor channels with terrace areas. Gold grades are generally closely associated with channel widths. Geological mapping and exploration drilling over the past few years has led to the development of the current facies model, which defines a primary west to east channel complex. A secondary ancillary channel is developed that trends in a north south direction, immediately to the south of the main channel, in the area called Zone 405. Both channel complexes are interpreted to be of braided fluvial origin which was conducive to conglomerate and gold deposition. Additional sedimentological mapping suggests that the Zone 405 area represents the more distal portion of the main channel. It is now interpreted that the main channel has bifurcated to produce a number of secondary channels in Zone 405.
Exploration and drilling Diamond drilling is generally executed from surface on irregular grids of 500 to 2,000 m dependent on historical exploration strategy, depth of the mineralised horizons and geological uncertainty. Once underground access is available, infill development drilling is undertaken from access haulages and crosscuts to provide a 30 to 100 m grid depending on geological requirements from structural, safety and evaluation perspectives. As part of quality assurance and quality control (QA/QC) procedures, standard reference material, blank samples, repeat assays and inter-laboratory programmes are used to ensure that the laboratories adhere to analytical standards and protocols. Planned task observations and QA/QC procedures are used to ensure sampling protocol is maintained. Final upload of each sample into the Gold Fields’ Integrated Resource and Reserve System (IRRIS) database is only completed following a series of checks and approvals. Conventional underground grid, prospect and infill grade control drilling is planned for F2010 and will take place from main development at all shafts to gain additional information on facies variations, grade distribution and structure models, to optimise mine design for short and long term planning. A number of strategic boreholes have been planned for F2010 in specific areas of the mine. These include the drilling of a number of underground long inclined boreholes (LIB) at North and West Sections (3 and 4 Shafts) and five surface boreholes in the Vlakpan area over the next two years. The time horizon between drilling the boreholes and scheduled development reaching the areas drilled is between 1 to 8 years. These boreholes will be drilled on capital and all of the assaying for gold, uranium and sulphur will be done through independent laboratories. The purpose of this drilling project is to reduce the orebody risk with respect to reef value, structure (for planning purposes) and smectite distribution (specific to the West Section).
Mining Beatrix comprises four operational shafts (1, 2, 3 and 4 Shafts). The final depths below surface of 1 and 2 Shafts are 913 m and 961 m respectively. They were equipped in 1983 and full production was achieved in May 1985. 3 Shaft, which has been sunk to a final depth of 1,447 m, was commissioned in 2001. 4 Shaft operates via a main surface shaft and sub-shaft system with two dedicated ventilation shafts, and has eight working levels spaced 50 m vertically apart down to a depth of 2,200 m below surface. The layouts are typically the same as at 1, 2 and 3 Shafts. Mining methods Stoping operations at 1, 2 and 3 Shafts are at depths of 540 m to 1,200 m below surface. Fifteen levels at 50 m vertical intervals, developed approximately 50 m below the reef, provide access and serve the mining activities. All main haulage development on Beatrix is carried out as twin haulages to reduce the risk associated with methane and to accommodate the scattered mining layout. The flat dip of the orebody requires some crosscuts to reef to be extremely long, resulting in on-reef raise development of between 200 and 500 m between levels. Access to the reef horizon (for stoping the reef) is by means of an inclined travelling way(s) from which the raise is developed to the next level, depending on the structure, evaluation, environmental and rock engineering parameters. Crosscuts and raises are generally 120 m apart on strike. The raise becomes the centre gully during stoping operations. Stoping panels are ~30 m in length. The blasted ore is scraped to the strike gully, which delivers the rock via the centre gully to the ore passes. Locomotive driven hoppers convey the ore from the ore pass box to the shaft ore pass system. Conventional breast mining is the main mining method throughout all the shafts, which allows for scattered or selective mining to be practised throughout. The VS5 Reef north of 3 Shaft will be mined by means of a selective cut, where appropriate. This will involve minor adjustments to the current mining practices and is possible because the value distribution in the mature VS5 reef is predominantly and consistently bottom loaded. At 3 Shaft, hydro-power, as opposed to compressed air, is used for a variety of activities including drilling. The benefits of this include improved cooling underground, improved machine efficiency, lower noise levels and less power wastage. Ventilation The North and South Sections of Beatrix have 4 downcast shafts, of which 2 Shaft has a brattice wall compartment to facilitate both up and downcast flow of ventilation. The 2 Shaft upcast compartment returns the ventilation circulated at Beatrix South and a small portion of Beatrix North, whilst the upcast shaft at 3 Shaft returns the ventilation from Beatrix North. The 2 B Ventilation Shaft is a downcast shaft situated in the west of 2 Shaft, with its primary purpose to ventilate the Beatrix South workings. The total airflow quantity circulating through the North and South complex of Beatrix is 1,215 m3/s. Beatrix West Section has two downcast shafts from surface to 5 level and a single sub-vertical downcast shaft from 5 level to shaft bottom. The up-cast facility consists of a sub-vertical up-cast shaft from 21 level to 5 level and from 5 level through the 1B Ventilation Shaft which extends to surface. In addition to the sub-vertical ventilation shaft, there is a 3.5 m diameter raise bored shaft from 17 level to 5 level, which connects with both the sub-vertical ventilation shaft as well as 1B Ventilation Shaft. The total airflow quantity circulating through Beatrix West Section is 600 m3/s. Methane management The mine has a well executed methane management system to control this risk which comprises the following:
In addition to the normal flammable gas induction training, the mine also has regular awareness training sessions. Mine planning and scheduling Designs and schedules are continuously modified and optimised as new information becomes available. All designs and schedules are done in consultation with production and other technical personnel. Production efficiencies are based on past experience and production models describing activities for the different development layouts and equipment used.
Mineral Reserve development will continue to be a key performance indicator in F2010 and will be accelerated further in appropriate areas. The following tables detail the development advanced for the last 12 months to June 2009. A total of 32.6 kilometres was developed with 6.7 kilometres driven on-reef. Development results
Projects At the North Section, stoping volumes are maintained or increased until approximately 2022 and current development volumes are maintained until approximately 2015, after which time a decline in volumes occurs as the Mineral Reserve will be nearing full development. This production profile is underpinned by two incremental projects that have been added to the North Section. This strategy maximises the LoM of the 3 Shaft complex and extraction from the current infrastructure. The North Section (including the two projects) has a Mineral Reserve of 92.6 tons (3.0 Moz) of gold and contributes 46% of the Mineral Reserve base of Beatrix. The LoM for the North Section is now estimated to 2022. The first project at North Section is a down dip extension (Eastern Decline) from 26 level through to 28 level, adding 11.5 tons (0.4 Moz) of gold to the Mineral Reserve base. The second incremental project at North Section is to access the Vlakpan ground, situated to the far west of 3 Shaft and has a Mineral Reserve of 11.5 tons (0.4 Moz) of gold. The South Section is currently focused on mining available Mineral Reserve blocks. A number of areas have been identified through the secondary on-reef development project that was initiated in 2005 and other secondary mining areas over the remaining LoM. Immediately available Mineral Reserves decline in the short term, but will be replaced by two incremental projects at Vlakpan and the G block in the medium term. The current 2 Shaft infrastructure will have a phased closure over the next two years. Mineral Reserves at South Section (including the two projects) are now 44.6 t of gold (1.4 Moz) or 22% of the Beatrix Mineral Reserve base. The LoM for the South Section is now estimated at 2022. The first project at South Section is a single level decline from 16 to 17 level, adding 7.2 t (0.2 Moz) of gold to the Mineral Reserve base. The second incremental project is to access the Vlakpan area, via three twin access tunnels on 18, 20 and 22 levels has been adopted for the LoM. This has significantly reduced required capital costs and allows for a risk adjusted phased project implementation to sustain production at Beatrix. The total Vlakpan area contributes 32.6 t (1.0 Moz). At West Section (4 Shaft), continued underground drilling and development has continued to support the macro structure and extension of the higher grade Zones 405, 451 and 453 to the south. Local areas of higher grade facies and improved facies/evaluation models have been incorporated in this plan. Delays and impacts associated with smectite (swelling clays) in a number of tunnels, as well as application of the “Theory of Constraints” to eliminate current bottlenecks/optimised layouts, have been taken into account with current mine access tunnel design and scheduling. A number of alternative access ways, either in the hangingwall or in deep footwall, have been designed to ensure long-term tunnel stability and to support the future production profile. A general increase in production volumes at 4 Shaft from the current base of 8,500 m2 (F2010) up to 10,000 m2 a month (F2015) has been planned. The expected LoM for the West Section is 2022 with the overall Mineral Reserve base now at 63.3 t of gold (2.0 Moz) or 32% of the Beatrix Mineral Reserve base.
Mineral Processing Beatrix incorporates 1 Plant, which is part of the old Beatrix Mine and 2 Plant, which is located at 4 Shaft. Beatrix 1 Plant is situated between 1 and 2 Shafts, to the west of the connecting road between the shafts. Ore storage silos have a capacity to store 14,000 t of dry ore and facilities also allow for ore to be stockpiled and reclaimed outside the plant. The Plant uses four Semi-Autogenous Grinding mills with installed power of 3 MW per mill. The downstream process is matched to the milling capacity of 260 ktpm at 96.6% recovery and comprises three 60 m diameter thickeners and twelve mechanically agitated carbon-in- leach tanks with a combined volume of 18,000 m3. The plant has two pressure Zadra elution circuits rated at 20 tons of carbon per day and utilises steam from the mine boilers as heating energy. Regeneration of carbon is carried out in two rotary kilns with a capacity of 250 and 350 kg/hr. In 2003, a gravity gold recovery circuit was retrofitted at 1 Plant and each mill now has a 30-inch Knelson concentrator that recovers gold concentrate from the mill cyclone underflow. An Acacia intensive leach reactor is used to dissolve gold contained in the concentrate, and this gold is then recovered from solution by electro winning. The concentrate is currently being tabled using a Gemini table. Cathode sludge is recovered by high pressure washing and filtration before smelting to produce doré. Bulk reagent storage facilities inside the plant include storage for dry lime, sodium cyanide solution, caustic soda solution, hydrochloric acid and liquid oxygen. Water treatment chemicals are used to control water quality to the Knelson concentrators. The plant was originally designed to treat 170 ktpm. The fourth milling circuit was added in 1996 and current operational capacity is estimated at 260 ktpm. 2 Plant was commissioned in 1992. The Plant has four ore silos with a total capacity of 16,800 tons of dry ore. Ore is fed from the shaft via conveyor belt or via truck onto the plant feed conveyor and receives underground Run-of-Mine (RoM) ore delivered to four mill silos, with each silo serving a single autogenous milling circuit. Four RoM mills are used with installed power of 2 MW per mill and milling capacity is rated as 150 ktpm at a recovery of 96.6%. The downstream process comprises three 50 m diameter thickeners, 8 mechanical agitated leach tanks with a combined volume of 13,000 m3 and a carousel type carbon adsorption circuit comprising eight stages. The elution circuit is also a pressure Zadra circuit and is designed to elute 10 tons of loaded carbon per day utilising fuel-fired burners for heating energy. Regeneration of carbon takes place in one of two rotary kilns. A gravity circuit has recently been installed (October 2006). A stand alone 30 inch Knelson Concentrator is fed by each of the running mills and recovers gold concentrate from the mill discharge sump. This concentrate is further enriched on an automated Gemini table and then smelted to produce gold bullion.
Sustainable Development Gold Fields has embraced Sustainable Development as a business imperative, which is reflected in its Vision, Values and Strategy. Through this, Gold Fields has introduced structures that encourage a networked interface between disciplines like Safety, Health, Environmental Engineering, Natural Environment, Risk, Stakeholder Engagement, Legal and Communication. This approach has allowed Gold Fields to capitalise on synergies and to avoid duplication. In this regard, several Key Performance Indicators (KPIs) are monitored and utilised to make informed business decisions. In terms of community involvement, Beatrix has continued to support the Golden Oils project that results in high quality bulbs being exported and which creates employment for local community members. Beatrix has also initiated a brick making project that is designed to create employment, develop skills and alleviate poverty. Beatrix is also assessing the potential for introducing a day care centre that its employees will be able to utilise. Beatrix’s environmental initiatives are focused on reducing the impact that the mine may have on the receiving environment through concurrent rehabilitation and responsible water management. Water management is a high priority. All potential sources of pollution like the water discharges are monitored and sampled on a regular basis. Beatrix has committed itself to the Mine Health and Safety Council target set by the industry in conjunction with the Department of Mineral Resources. These milestones are based on rate improvements for fatalities, noise induced hearing losses and silicosis, with the objective of aligning to international norms.
Production and hoisting capacities
SV: Sub vertical
Plant capacities
Mineral Reserves per mining section
Mineral Resources and Mineral Reserves The Beatrix Mineral Resource and Mineral Reserve declaration is based on systematic and sustainable mineral reporting practices. Systematic geological mapping and drilling consistently updates geological structurel and facies models, which are used as the basis of each declaration. On-going sampling of all development and stoping on a grid basis is carried out to provide additional data that is incorporated into a detailed evaluation model. Updated mine designs and schedules are then compiled and evaluated based on the most recent technical-economic models to compile a LoM plan for each operational shaft, taking note of infrastructural capacities, limitations and the need for any additional infrastructure requirements. Detailed economic and scenario models are subsequently completed to ensure validity of positive cash flow for Mineral Reserve declaration purposes. Peer review as well as internal and external audits, ensure consistency and compliance to regulatory practices. Beatrix’s Mineral Resource and Mineral Reserve are reported within its mining right and are adjusted to show the split between above (AI) and below (BI) current shaft infrastructure. Mineral Resources Mineral Resources are quoted at an appropriate in-situ economic cut-off grade with tonnages and grades based on the resource block model, which include estimates of any material below the cut-off grade required to be mined to extract the complete pay portion.
Modifying factors
Grade tonnage curve Underground
Mineral Reserves Mineral Reserve estimation at Beatrix is based on the development of an appropriately detailed and engineered LoM plan, which accounts for all necessary access development and stope designs. All design and scheduling work is undertaken with mine planning software. The planning process incorporates appropriate modifying factors and the use of cut-off grade policies and technical-economic investigations.
Mineral Resources and Mineral Reserves Reconciliation year-on-year Mineral Resource Factors that affected Mineral Resource reconciliation:
Change in Mineral Resource F2009 to F2010
Mineral Reserve Factors that affected Mineral Reserve reconciliation:
Change in Mineral Reserve F2009 to F2010
Mineral Reserve sensitivity The following graph indicates the Mineral Reserve sensitivity at –10%, –5%, base, +5%, +10% and +25% to the gold price. The sensitivities are not based on detailed depletion schedules and should be considered on a relative and indicative basis only. Managed Mineral Reserve Sensitivity
Regulatory Codes SAMREC JSE Sarbanes-Oxley Act Environmental Competent Persons SG Becker: Manager Mine Planning and Resource Management C Rose: Chief Geologist CJ Morgan: Chief Evaluator LC Esterhuizen: Chief Surveyor C Opperman: Chief Mine Planner
Key Technical Staff
Beatrix History at a Glance
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