Arrow Driefontein Gold Mine
Arrow Kloof Gold Mine
Arrow Beatrix Gold Mine
Arrow South Deep Gold Mine
Arrow Tarkwa Gold Mine
Arrow Damang Gold Mine
Arrow St Ives Gold Mine
Arrow Agnew Gold Mine
Arrow Cerro Corona Mine
Arrow Gold Fields Exploration
Click to HIDE this navigation
Click to SHOW this navigation

Kloof Gold Mines

Technical Short Form Report

Kloof is a large, well-established intermediate to ultra deep level gold mine that is accessed from surface through a number of shafts to 45 Level (the lowest working level) some 3,347 m below surface. Kloof consists of five shaft systems and two gold plants.

In F2009 Kloof Gold Mine produced 0.643 Moz of gold from a combination of underground mining and processing of surface waste rock dump material at a Notional Cash Expenditure (NCE) of US$ 698/oz. Kloof total employees costed for F2009 was 16,476 including contractors. The area mined averaged some 35,674 m2 per month, underground ore processed at 200 kt per month and surface material treated 77 kt per month. Total gold production averaged some 1,667 kg per month at an average yield grade of 6.0 g/t. Significant increases in power, consumable and labour costs have limited the benefit of an increased gold price with the effect that paylimits show only nominal reductions year-on-year.

This Technical Short Form Report reflects the latest Life of Mine plan, coupled 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.

Salient Features

  • Focus on safe, steady state production driving volume, value and quality.
  • Robust orebody with world class Mineral Resources of 79.0 Moz.
  • Mineral Reserves of 10.5 Moz.
  • Main Shaft pillar extraction to commence in F2010.
  • Major shaft infrastructure refurbishment complete.
  • Underground uranium Mineral Resource models have been generated.
  • Kloof has installed an emergency generation plant of 14.4 MW to ensure that mine personnel can be evacuated in case of power outages.
  • Life of Mine extends to 2030.

Kloof Gold Mine (Kloof) is located in the Far West Rand Goldfield and is situated in the geologically unique and world renowned Witwatersrand Basin, one of the world’s premier gold regions. The Witwatersrand Basin has made significant contributions to South Africa’s economy and remains the most important gold depository in the history of mining. Since the establishment of the first shaft in 1934, Kloof has produced more than 70 Moz of gold.

Kloof includes the former Venterspost, Libanon, Kloof and Leeudoorn gold mines. The original Kloof was granted a lease to mine at depths of between 2,500 and 3,700 m, downdip of the Libanon mine in 1963 and its current form dates from April 2000 when the four mines amalgamated.

Activity within the mining authorization area (20,087 ha), which extends for more than 27.5 km on strike and 7.5 km on dip, has gradually moved south, and several shafts in the northern extent of the mining authorization are presently managed on a care and maintenance basis.

View enlarged graphic [file size - 562kb]

View enlarged graphic [file size - 562kb]

Key Features

  Independent Audit   Figures reported in this declaration were as reviewed and approved by independent, external consultants as at 30 June 2009
  Prepared by   Gold Fields Limited
  Effective date   30 June 2009
  Source of Information   This Technical Statement is a summary of the internally sourced document entitled F2010 Kloof Competent Persons Report
  Personal Inspection   Personal inspection is conducted by the Competent Persons as listed, who are full time employees of Gold Fields Limited
  General Location   Kloof Gold Mine is situated some 60 km west of Johannesburg at latitude 26° 24’ S and longitude 27 °36’ E, near Westonaria in the Gauteng Province. The mine is accessed via the N12 highway between Johannesburg and Potchefstroom. A well developed network of tarred roads surrounds the area
  Licence Status and Holdings   The arial extent of the Kloof Mining Right is 20,087 ha. All required operating permits have been obtained, and are in good standing. Mining rights were converted in terms of Item 7 of Schedule II of the Mineral and Petroleum Resources Development Act, 2002 (Act no. 28 of 2002) on 30 January 2007 (File no. GP30/5/1/2/2(66) MR, Application no. H2003/12/09/003)
  Operational Infrastructure   Kloof Gold Mine operates two gold plants and the underground workings are accessed from surface through five shaft systems to a depth of 3,347 m below surface
  Climate   No extreme climatic conditions are experienced that may affect mining operations
  Deposit Type   Intermediate to ultra deep level gold mine (>2,000 m below surface) exploiting auriferous paleoplacers (reefs), i.e. the Ventersdorp Contact Reef (VCR) of the Venterspost Conglomerate Formation, the Kloof Reef of the Kimberley Conglomerate Formation and the Middelvlei Reef of the Main Conglomerate Formation
  Life of Mine (LoM)   It is estimated that the current Mineral Reserves will be depleted in 2030
  Environmental   Kloof’s systems, procedures, training etc. are at international best practice levels. ISO 14001:2004 certification has been obtained for this operation and OHSAS 18001 was maintained after external audit in F2009. The mine also obtained full compliance for International Cyanide Management code in September 2009
  Regulatory Codes   Gold Fields reports its Mineral Resources and Mineral Reserves in accordance with the South African Code for The Reporting of Exploration Results, Mineral Resources and Mineral Reserves (2007 SAMREC Code), and other relevant international codes such as SEC Industry Guide 7, JORC Code and NI 43-101. The Mineral Resources and Mineral Reserves are underpinned by a sufficient Mineral Resource Management process and protocol to ensure adequate corporate governance in respect of the intent of the Sarbanes-Oxley Act

Gold Fields has stated that: “If we cannot mine safely, we will not mine”. This principle is embedded at Kloof.

Operating Statistics

  Year ended June     F2009   F2008   F2007   F2006   F2005  
  Main development km   22.8   33.6   35.0   30.4   33.9  
  Main on-reef development km   3.7   5.0   6.1   7.3   6.7  
  Main on-reef development value cm.g/t   1,777   1,717   1,410   1,788   1,857  
  Area mined ’000m²   428   519   620   607   616  
  Tons milled ’000 tons   3,319   3,953   3,829   3,666   4,655  
  Source of ore                        
  – Underground ’000 tons   2,398   2,941   3,447   3,206   3,471  
  – Yield g/t   8.1   8.4   8.2   8.7   9.1  
  – Surface ’000 tons   921   1,012   382   460   1,184  
  – Yield g/t   0.7   0.9   1.2   1.1   0.7  
  – Average yield g/t   6.0   6.5   7.5   7.8   6.9  
  – Gold produced kg   19,998   25,533   28,705   28,429   32,258  
  – Gold produced ’000 oz   643   821   923   914   1,037  
  Operating cost                        
  – Underground R/ton   1254   893   727   703   710  
  – Surface R/ton   84   62   82   61   68  
  Total R/ton   929   680   662   622   546  
  Gold sold kg   19,998   25,533   28,705   28,429   32,258  
  Cash cost US$/oz   507   430   366   374   373  
  Cash cost R/kg   14,926   100,419   84,672   76,918   75,696  
  – Capital expenditure Rm   959   898   776   208   230  
  – NCE R/kg   202,140   140,512   115,377   97,200    
  Number of employees     16,476   16,986   17,143   15,020   15,338  
  Expected Life-of-Mine years   21   15   20   14   17  
  Mineral Reserves million tons   53.2   51.0   52.8   54.2   56.3  
  Grade of Mineral Reserves g/t   6.2   6.8   8.0   8.2   8.3  

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

All of Gold Fields’ South African operations are located in the Witwatersrand Basin and are intermediate to deep level underground mines exploiting gold bearing, shallowly dipping tabular ore bodies. The gold mineralisation in the Witwatersrand Basin occurs within quartz pebble conglomerates termed “reefs”.

Kloof is located in the West Wits Line Goldfield of the Witwatersrand Basin. This goldfield is geographically divided into the Far West Rand and the West Rand areas. The bulk of the Kloof mining right is situated in the Far West Rand, but the more northerly portions of Kloof straddle the boundary and can be viewed as being marginal to the West Rand area.

The mining area is underlain by outliers of Karoo Supergroup shales and sandstones, followed by Pretoria Group sediments and the Chuniespoort Group dolomites. The Dolomites overlie the Klipriviersberg Group volcanic rocks, which in turn cap the Ventersdorp Contact Reef and sediments of the Central Rand Group that hosts the other gold-bearing reefs exploited by Kloof.

Local geology

Kloof lies between two major normal faults being the north-south trending West Rand Fault to the east, separating Kloof from South Deep Gold Mine, and the Bank Fault to the west, separating Kloof from Driefontein Gold Mine.

In the Far West Rand area, three primary reefs are exploited, the Ventersdorp Contact Reef (VCR) located at the top of the Central Rand Group, the Carbon Leader Reef (CL) near the base and the Middelvlei Reef (MR), which stratigraphically occurs some 50 to 75 m above the CL. The Kloof Reef (KR) and Libanon Reef (LR), which are found approximately midway between the VCR and MR, represent secondary reefs in the area and are mined on a small-scale due to localised payability. Kloof exploits the VCR, MR, KR and LR.

The structure of the West Rand area is dominated by the West Rand and Panvlakte Horst blocks, which are superimposed over broad folding associated with the south-east plunging West Rand Syncline. The northern limb of the syncline dips in a south-south-westerly direction and the southern limb in an east-south-easterly direction. Pilanesberg, Bushveld and Ventersdorp age dykes are also present.

Within Kloof’s boundary, the VCR and the underlying Central Rand Group strata of the Witwatersrand Supergroup have a general north-east strike and dip to the south-east at between 250o and 450o. Major geological structures within the property comprise normal faults sub-parallel to the West Rand Fault. Sympathetic to it are north-north-east trending dykes with little or no apparent offset of the stratigraphic units and younger, easterly trending sinistral faults, some of which host dyke material.

Typical section through the Kloof orebody
Typical section through the Kloof orebody

Local bedding plane faulting along the VCR has resulted in the elimination and local duplication of the VCR horizon.

In 2003, a 3D seismic survey was undertaken over a portion of the south-eastern part of the mining area, which covers much of the area below infrastructure, including the Eastern Boundary Area (EBA) and the Kloof Extension Area (KEA) projects.

The 3D seismic survey resulted in a change in the interpretation of the West Rand Fault position and also indicated that the downthrow on the West Rand Fault decreases from 1,5 km in the north to 500 metres in the southern part of the mining area. It also refined the position of a number of major faults (Danie’s Fault, Danie’s Twin Fault and the Shaft Fault). The full interpretation of the 3D seismic dataset was completed and incorporated in the 4 and 7 Shaft models, as well as the KEA and EBA areas.

The majority of the mining takes place on the VCR, which constitutes 84% of the Mineral Reserve, the MR 14%, and the Kloof and Libanon Reefs together constitute the remaining 2%. Limited quantities of surface rock dump material are also processed.

Ventersdorp Contact Reef (VCR)

A palaeomorphological slope and terrace facies model was introduced for the VCR in October 2003, aimed at improving support for short term planning and the targeting of pillars. This model identifies six types of terrace facies and a low-grade slope facies. An external audit, in 2005, endorsed the model and highlighted areas for further refinement.

VCR Milky Cobble Terrace Facies
VCR Milky Cobble Terrace Facies

The 2005 model had facies trends honouring the old geozones in the below infrastructure areas, that is on a west to east palaeocurrent direction. The audit showed that the younger Sandy 1 and 2 facies were introduced from a northern source, with sediment transported along a north to south palaeocurrent direction, thus resulting in a fundamental change in the geological interpretation for the VCR orebody, particularly impacting the below infrastructure areas.

VCR Sandy 1 Facies
VCR Sandy 1 Facies

This observation confirmed earlier suggestions that this younger sediment was introduced into the Kloof area along a structurally controlled channel running parallel to the scarp created by the West Rand Fault. Geostatistical evidence supports this change in depositional direction. The current model is now fully aligned with the geozones for the Sandy 1 and 2 facies that honour the north-south palaeocurrent direction.

For the 30 June 2009 Mineral Resource and Mineral Reserve estimate, changes were made to the VCR facies model based on the latest geological information.

Secondary reefs

In the Middelvlei Reef (MR), the majority of the gold is contained in the lower 40 – 85 cm of the reef package, which is generally highly channelised.

The MR is exploited at No. 3, 8 and 1SV Shafts. In 2003 external consultants produced a model based on sedimentology and value/channel width trends to highlight prospective areas and constrain the estimation process.

For the 30 June 2009 Mineral Resource estimate, changes were made to the facies model at 1 Sub-vertical and 8 Shafts based on the latest geological information.

The Kloof Reef is a relatively minor component of the Kloof Mineral Resource. It is also channelised and a scope of work has been proposed to carry out a similar exercise to that done on the MR.

Schematic diagram of the VCR Palaeomorphological Slope and Terrace Model
Schematic diagram of the VCR Palaeomorphological Slope and Terrace Model


Exploration and drilling

The exploration strategy includes the following:

  • Reduced uncertainty inherent to the deposit;
  • Underground fan drilling;
  • Timeous prospect development;
  • Proactive geology; and
  • Reconnaissance visits to previously mined areas to confirm structure and facies.

For F2009, the following was achieved:

  • Working cost exploration drilling: 9,937 m at a cost of R6.1 million.

The working cost strategy involved the drilling of a fan of holes from each crosscut and limited pillar infill drilling. The current working cost drilling strategy involves the drilling of a fan of up to 3 inclined holes per crosscut and a cover hole. Pillar infill drilling is conducted in areas where structure and grade require refinement.

  • Capital exploration drilling: 4,828 m at a cost of R4.1 million.

The down-dip extension of a high grade trend was targeted on the Middelvlei Reef at 1SV Shaft. Infill drilling was conducted on the VCR in the Main Shaft pillar area. The down-dip extension of a high grade facies (Sandy 1) was targeted on the VCR at 7 Shaft.

The current capital programme will target Middelvlei Reef down-dip trends at 1SV Shaft toward the east and west and confirmation of facies trends on the VCR at 3 Shaft and at 7 Shaft.

Underground Rocor drilling machine capable of drilling boreholes in excess of 1,000 metres in length
Underground Rocor drilling machine capable of drilling boreholes in excess of 1,000 metres in length



The Kloof operation is engaged in underground and rock dump mining. A significant challenge facing the Kloof operation is seismicity and to a lesser extent flammable gas. To reduce the impact of seismicity, Kloof practices the closely spaced dip pillar mining method and has also adopted a revised stope support standard in all areas with friable hangwall and in areas that have the Westonaria Formation Lava hangwall.

Early detection methods and increased ventilation of the shafts are being used to minimize the risk of incidents caused by flammable gas. Extensive cooling infrastructure is required to maintain comfortable conditions for workers due to the depth of its operations.

An application for additional power was made to the supplier of power in fiscal 2009. This has been granted and Kloof is now permitted to utilize power at an increased baseline of 234.4 MW, rather than 214.4 MW.

In addition, in the unlikely event of a total power outage for a prolonged period, Kloof has installed and commissioned an emergency generation plant of 14.4 MW to allow mine personnel to be evacuated speedily.

Mining methods

The predominant mining layout at Kloof is breast stoping with dip pillars, with a minor contribution from scattered mining. Breast stoping with dip pillars has been selected for the below infrastructure projects. Mining spans and pillar widths depend on the location, the reef being mined and the depth of working.

Mine planning and scheduling

All mine design and scheduling is undertaken using Cadsmine© computer software in conjunction with the Integrated Resource and Reserve Information System (IRRIS) proprietary to Gold Fields. This includes the delineation of mining or stoping areas for each mining level and section, usually leading from an extension to the existing mining sequence, and the definition of the necessary development layouts. The latest update of the geological structure model is referenced and incorporated into the mine design.

The mine design includes rock engineering pillars comprising bracket pillars along major geological structures, as well as stability pillars related to the appropriate mining method. An allowance for minor faulting, structure and reef loss, based on historical results, is applied.

The mine design is scheduled on a monthly basis for the first 2 years of the operational plan, which is extended on an annual basis for the remaining period of the LoM Plan. The production parameters necessary for the development of the strategic LoM plan are captured from the computer models on a shaft basis for each period. The inclusion of the surface Mineral Resources at Kloof is reviewed annually as part of the strategic planning process.

The F2010 operational plan, with respect to remnant pillar mining, was aligned to the updated Gold Fields Pillar Mining Code of Practice, which takes cognisance of a stringent safe remnant extraction practice. The rock engineering risk factors (risk matrix) associated with remnant extraction were identified as: Energy Release Rate; Average Pillar Stress; Shape; Width-to-Height Ratio; and the presence of seismically active geological structures. Additional pillars and remnants have therefore been excluded from Kloof’s F2010 Mineral Reserves.

Mineral Reserve development will continue to be a key performance indicator and will be accelerated further in appropriate areas. The following table indicates the development advanced for the last 12 months to June 2009. A total of 22.8 kilometres was developed with 3.7 kilometres driven on-reef.

Development results

  Category Main   Kloof   VCR  
  Main advanced (m) 3,514   399   19,925  
  Advanced on-reef (m) 838   212   2,678  
  Sampled (m) 876   207   2,296  
  Channel width (cm) 117   180   127  
  Average grade (g/t) 6.6   4.7   17.7  
  Average value (cm.g/t) 780   854   2,241  



The Main Shaft Pillar Extraction Project

The final design for the mining of the Main Shaft pillar with the necessary bracket and regional stability pillars is currently being modelled and the final mining sequence and seismic risk analysis will then be completed.

The 69 Decline Project

The 69 Decline (a depth extension project from No. 7 Shaft) has been incorporated into 7 Shaft’s LoM profile and is progressing as scheduled.

The 55 Decline Project

This Modified KEA Project Design of the decline and ancillary excavations, together with the access developments and stoping layouts from 45 level down to 48 level and the scheduling of the decline development, has been completed.

An external company has been contracted to complete detailed costing of the decline, service ways, airways and cooling and hydropower reticulation, to ultimately produce a detailed capital estimate and schedule.

The 55 decline project targets the VCR south of Danie’s Fault down dip from the current workings between 45 and 48 levels. Access will be from the hangingwall via a 14° conveyor decline with a chairlift and a separate raise bored service way, similar to the design for the 69 Decline Project. The project is treated as a depth extension to the No. 4 Shaft complex and the Mineral Reserves are determined according to a computer aided mine design and schedule and utilise comparable modifying factors to the Mineral Reserves above 45 level.


Mineral Processing

Kloof has two operational metallurgical facilities using proven metallurgical processes, with a central elution and smelting facility located at 2 Plant. The third metallurgical facility that processed surface material was closed in April 2005. The facility was demolished and all gold recovered. 1 Plant was commissioned in 1968 to treat underground ore. This plant comprises three stage crushing, utilising open circuit rod mills for primary milling and closed circuit pebble mills for secondary milling. After milling, the pulp is thickened and then processed through air agitated leaching, drum filtration, zinc precipitation and smelting to doré. In June 2001 an AAC Pump Cell CIP circuit was installed to replace the less efficient drum filtration and Zinc precipitation. Smelting was also discontinued, with loaded carbon being transported to 2 Plant for elution and thermal regeneration. The current operational capacity of 1 Plant is 180 ktpm.

2 Plant was commissioned in November 1990. This Plant receives underground Run-of-Mine ore (RoM), which is crushed and delivered to a stacker reclaimer system, where the ore is stored and blended prior to reclamation and delivery to the mills. Surface material is also delivered to the stacker pad to utilise plant capacity. There are two Semi-Autogenous Grinding (SAG) mills, which are equipped with variable-speed ring motor drives, and can be operated as fully autogenous units or as semi-autogenous units by adding steel grinding balls. Milled ore is thickened ahead of cyanide leaching in air-agitated tanks and adsorption onto activated carbon in a conventional CIP circuit. Loaded carbon is eluted in an AARL elution circuit, which was upgraded in June 2001 and further in October 2003. It now serves as the central elution facility for Kloof. The upgrade included the installation of Continuous Electrowinning Sludge Reactors, which are working very efficiently. Cathode sludge is filtered and smelted to produce doré. The current operational capacity of 2 Plant is 150 ktpm.

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 capitalize 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, Kloof has initiated a programme to improve the understanding of Mathematics and Science among school pupils, whereby Kloof employees volunteer their time to assist local schools. Some pupils are also sponsored to become involved in advanced programmes of this nature. Kloof has also initiated a process, through cooperation with the local municipality, that will result in a community clinic being built. Other community projects include waste recycling, alien vegetation eradication and making sporting facilities available to local schools.

Kloof’s environmental initiatives are focused on reducing the impact that the mine may have on the receiving environment. All potential sources of pollution like the water discharges are sampled, analysed and monitored on a regular basis. Concurrent rehabilitation projects, like alien vegetation eradication are the current focus.

Gold Fields is designing a safety management system called the Safe Production Management System, to address outstanding issues identified and to assist Kloof to improve health and safety to best practice levels.

Gold Fields 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 with international norms.

Passing of the Mine Health and Safety Act in 1996 heralded a transition to a new paradigm shift in mining health and safety in South Africa. Since that time, the Mine Health and Safety Council has set a benchmark for reduction of accidents to international standards in the South African mining industry by 2013.

  Safety Statistics Units   F2005   F2006   F2007   F2008   F2009  
  Fatalities (No)   12   16   11   15   10  
  Fatality Rate (per mmhrs)   0.28   0.37   0.23   0.33   0.25  
  LDIFR (per mmhrs)   17.35   19.1   15.4   11.1   6.1  


Production and hoisting capacities

  Shaft Zone   Planned
  Main       1   265,000  
  1   52,312   1SV   187,000  
  2   26,515   2SV   101,000  
  3   43,273   3SV   131,000  
  4       4   112,000  
      80,020   4SV   166,000  
  7       7   176,000  
      53,533   7SV   195,000  
  8   28,170   8   84,000  

* 5 year average

2 Processing Plant, Kloof Gold Mine
2 Processing Plant, Kloof Gold Mine


Plant capacity

  Plant Capacity (tpm)  
  1 180,000  
  2 150,000  

Mineral Reserves per mining area

  Mining Area     Proved           Probable      
Tons (Mt)   Grade (g/t)   Gold (koz)   Tons (Mt)   Grade (g/t)   Gold (koz)  
  1 Shaft 6.8   4.2   909   1.0   4.4   141  
  2 Shaft 4.6   11.8   1,760        
  3 Shaft 2.0   9.8   641   1.2   10.6   395  
  4 Shaft 1.3   11.5   466   9.6   8.8   2,696  
  7 Shaft includes 69 decline area 1.9   7.0   428   6.3   6.6   1,332  
  8 Shaft 2.6   5.9   499   0.4   3.7   45  
  55 Decline Area (4 Shaft below 45L)*             3.4   8.0   868  
  Surface stockpile       12.2   0.9   341  
  Total 19.2   7.6   4,704   34.0   5.4   5,817  

* Below Infrastructure

Mineral Resources and Mineral Reserves

Kloof’s Mineral Resources and Mineral Reserves are reported within its mining right and are adjusted to show the split between above (AI) and below (BI) current shaft infrastructure as defined by 45 level.

A group developed geostatistics evaluation system is used in the modelling and estimation process at Kloof. Based on the structural and geological models, the Mineral Resource is divided into various domains, which are used as the basis for the homogenous geostatistical zones or geozones. The main interpolation methodologies used are ordinary and simple kriging. Macro kriging, Sichel ‘t’ and declustered averaging techniques are used for larger areas where the Mineral Resource estimates are predominantly based on relatively few surface and underground boreholes. Detailed variography studies are carried out on point and regularised data.

Mineral Resources

The F2010 Mineral Resource includes dip pillars from the areas where breast mining configured with dip pillars is the mining method employed. A limited number of these pillars at 7 Shaft and Main Shaft are, however, excluded from the Mineral Resource.

Mineral Resources are quoted at an appropriate in-situ economic cut-off grade with tonnages and grades based on the resource block model. They also include estimates of any material below the cut-off grade required to be mined to extract the complete pay portion of the Mineral Resource.

  Mineral Resource Classification Tons (Mt)   Grade (g/t)   Gold (‘000 oz)  
June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006  
  Measured 71.1   55.6   51.7   11.6   12.8   13.8   26,549   22,962   22,966  
  Indicated (AI) 73.9   92.4   76.9   8.0   9.0   9.5   19,071   26,839   23,570  
  Total (AI) 145.0   148.0   128.6   9.8   10.5   11.3   45,620   49,801   46,536  
  Indicated (BI) 79.5   54.6   49.0   12.8   12.2   14.0   32,729   21,355   22,121  
  Total underground 224.6   202.7   177.6   10.9   10.9   12.0   78,350   71,156   68,657  
  Surface stockpiles                                    
  Indicated surface 30.7   31.4   32.0   0.6   0.6   0.6   604   618   632  
  Total surface stockpiles 30.7   31.4   32.0   0.6   0.6   0.6   604   618   632  
  Grand Total 255.2   234.0   209.6   9.6   9.5   10.3   78,954   71,774   69,289  

The Mineral Resource estimate for underground uranium plus the uranium and gold in the Tailings Storage Facilities (TSF), are included for the first time and the figures are as follows:

  Mineral Resource Classification (Uranium) Tons (Mt)   Grade (kg/t)   Uranium (Mlb)  
June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006  
  Inferred (scheduled) 35.5       0.045       3.554      
  Total underground 3.5       0.045       3.554      
  Surface tailings                                    
  Measured tailings 234.9       0.039       20.450      
  Total surface tailings 234.9       0.039       20.450      
  Grand Total 270.4       0.040       24.004      

  Mineral Resource Classification (Gold) Tons (Mt)   Grade (kg/t)   Gold ('000 oz)  
June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006  
  Surface tailings                                    
  Measured tailings 234.9       0.3       2.145      
  Total TSFs 234.9       0.3       2.145      

Modifying factors

  • The Measured and Indicated Mineral Resources are inclusive of those Mineral Resources corrected to produce Mineral Reserves;
  • Unless otherwise stated, all Mineral Resources and Mineral Reserves are quoted as 100% managed and are not attributable with respect to ownership;
  • All Mineral Reserves are quoted in terms of RoM grades and tonnages as delivered to the metallurgical processing facilities and are fully diluted;
  • Mineral Reserve statements include only Measured and Indicated Mineral Resources, modified to produce Mineral Reserves and contained in the LoM plan; and
  • Mineral Resources and Mineral Reserves undergo both internal and external audits either during the year, yearly or biannually, and any issues identified are rectified usually during the current reporting cycle.
  Modifying Factors      
  Mineral Resource Gold Price US$/ oz 1,000  
  Exchange Rate ZAR:US$ 8.95:1  
  Mineral Reserve Gold Price US$/ oz 800  
  Mineral Resource Paylimit cm.g/t 1,030  
  Mineral Reserve Block Width cmt 146  
  Mineral Reserve Paylimit cm.g/t 1,310  
  Mine Call Factor % 85  
  Block Factor % 100  
  Shortfall % 11  
  Stoping Width cm 146  
  Mill Width cm 200  
  Plant Recovery % 97.6  

Grade tonnage curve

This grade tonnage curve represents undiluted grade (at block width) and tons within the total Mineral Resource. Underground Mineral Resources make provision for minor faulting and minor geological losses.

Grade tonnage curve

Main Shaft, Kloof Gold Mine
Main Shaft, Kloof Gold Mine


Mineral Reserves

Mineral Reserve estimation at Kloof is based on development of an appropriately detailed and engineered LoM plan, which accounts for all necessary access development and stope designs. The planning process incorporates appropriate modifying and technical-economic factors.

Significant increases in power, consumables and labour costs have limited the benefit of an increased gold price, with the result that paylimits show only nominal reductions year-on-year for Mineral Resources and Mineral Reserves respectively.

  Mineral Reserve Classification Tons (Mt)   Grade (g/t)   Gold (‘000 oz)
June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006   June 2009   June 2008   Dec 2006  
  Proved 19.2   18.7   12.0   7.6   8.9   10.7   4,704   5.334   4,150  
  Probable (AI) 18.4   17.2   24.2   7.8   8.7   9.5   4,609   4.790   7,415  
  Total (AI) 37.6   35.9   36.2   7.7   8.8   9.9   9,313   10,124   11,565  
  Probable (BI) 3.4   2.3   4.3   8.0   7.9   12.1   868   584   1,692  
  Total underground 41.0   38.2   40.5   7.7   8.7   10.2   10,180   10,708   13,257  
  Surface stockpiles                                    
  Probable surface 12.2   12.8   12.3   0.9   0.8   0.7   341   362   296  
  Total surface stockpiles 12.2   12.8   12.3   0.9   0.8   0.7   341   362   296  
  Grand Total 53.2   51.0   52.8   6.2   6.8   8.0   10,521   11,070   13,553  

Mineral Resources and Mineral Reserves Reconciliation year-on-year

Mineral Resources

Factors that affected Mineral Resource reconciliation:

  • The higher gold price resulted in an increase of 11.2 Moz; and
  • Remodelling removed 6.7 Moz, with other inclusions totalling 3.5 Moz as indicated in the accompanying graph.

Change in Mineral Resource F2009 to F2010

Change in Mineral Resource F2009 to F2010

Mineral Reserves

Factors that affected the Mineral Reserve reconciliation:

  • 636 koz production depleted; and
  • Other minor changes are as indicated in the accompanying graph.

Change in Mineral Reserve F2009 to F2010

Change in Mineral Reserve F2009 to F2010


Mineral Reserve sensitivity

The following graph indicates the Managed Mineral Reserve sensitivity at –10%, -5%, base, +5%, +10% and +25% to the gold price.

Managed Mineral Reserve Sensitivity

Managed Mineral Reserve Sensitivity


Regulatory Codes

This Technical Statement has been prepared in Compliance with the South Africa Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (2007 SAMREC Code).

This Technical Statement has been prepared in compliance with the listing requirements of the JSE Securities Exchange, South Africa (JSE), specifically Section 12 – Issue 11.

Sarbanes-Oxley Act
The Mineral Resource and Mineral Reserve is underpinned by an adequate Mineral Resource Management process and protocol to ensure adequate corporate governance in respect of the intent of the Sarbanes-Oxley Act.

Kloof has an environmental management team who are supported by specialist assistance from the South Africa regional office in Johannesburg. The systems, procedures, training etc. are at international best practice levels. Gold Fields has produced a Sustainability Report in 2009 and intends reporting annually in accordance with the Global Reporting Initiative.

Competent Persons

S. Reddi: Manager Mine Planning and Resource Management
GDE (Mining Engineering), B.Tech (Mineral Resource Management), Mine Surveyors Certificate of Competency, Registered with PLATO as Professional Mine Surveyor Reg. no. PMS 0193, Fellow of the Institute of Mine Surveyors of S.A. Mr Reddi has 24 years experience in the Mining Industry (6 years at Kloof) and is responsible for the overall correctness, standard and compliance of this declaration.

N Reddy: Chief Geologist
B.Sc (Hons.) Geology, SAIMM (No. 704065), Member GSSA. Mr Reddy has 19 years experience in the mining industry (4 years at Kloof) and is responsible for geology and exploration for Kloof.

M Tandree: Chief Evaluator
National Diploma in Mine Surveying, Mine Surveyors Certificate of Competency, SAIMM registration pending. Mr Tandree has 12 years experience in the mining industry (6 years at Kloof) and is responsible for the sampling and evaluation functions at Kloof.

JH Engelbrecht: Chief Surveyor
Chief Surveyor, NHD (Mineral Resource Management), National Diploma in Mine Surveying, Mine Surveyors Certificate of Competency, PLATO Reg. no. MS 0105. Mr Engelbrecht has 25 years experience in the mining industry (23 years at Kloof) and is responsible for the mine survey, reporting and historical modifying factors for Kloof.

DT Foley: Chief Mine Planner
GDE (Mining Engineering), CoM Survey certification, Member SAIMM No. 703904. Mr Foley has 31 years experience in the mining industry (6 years at Kloof) and is responsible for the mine planning and scheduling for Kloof.

SW van Coller: Chief Mine Planner - Projects
B.Sc (Mining Geology), M.Sc (Geology), Pr. Sci. Nat. (Reg. no. 400328/04). Mr van Coller has 27 years experience in the mining industry (15 years at Kloof) and is responsible for LoM projects.

Key Technical Staff

  Post Incumbent Qualifications Years Key Responsibilities  
  Vice President and Head of Operations Philip Schoeman NHD Metalliferous Mining, BCom   Overall strategic direction,
leadership & management
  Mining: Senior Manager Operations Jock Pywell Mine Managers Certificate of Competency 26 Full operational management,  
  Mining: Senior Manager Operations Garth Oliver NHD (Metalliferous Mining) Mine Managers Certificate of Competency 27 Full operational management,  
  Mineral Resources Manager: Mine Planning and Resource Management Presley Reddi B.TECH (MRM), GDE (Mining Engineering) NHD (Mineral Resource Management) Mine Surveyors Certificate of Competency 22 Mine Planning, Mineral
Resources & Mineral Reserves
and compilation of CPR
  Manager Engineering Ben Potgieter NHD (Electrical & Mechanical Engineering) Pr. Cert. Engineer 31 Engineering, logistics,
infrastructure and capital
  Financial Manager Johan Britz FCIS (SA) Charted Secretary & Administrator, AGA (SA) No. 3270292, Reg Institute of Charted Accountant CPA (SA) 35 Financial reporting, compliance  
  Human Resources Manager M Ngema HR M (Hons), Advance Program in Organisational Development 14 Human resource management  
  Metallurgical Manager R Vorster NHD Extr. Metallurgy 11 Metallurgical management  

Kloof History at a Glance

View enlarged graphic [file size - 177kb]

Driefontein History at a Glance

View enlarged graphic [file size - 177kb]