Louis Aucamp

Waterval East Chrome Mine, Rustenburg Infrastructure Review Background Phele Mining Consulting and Projects (Pty) Ltd prepared a proposal for Gencore for an operational review for Waterval East Chrome Mine dated 24 August. Site visits were conducted at the mine site on various days during the start of September by the Consultants of Phele Mining. Louis Aucamp visited the mine site on 9 September 2016 to review the average condition of the Mine Infrastructure utilised for operations and the maintenance regime that was in place for ensuring continued operations. Information Requirements The site visit information gathering consisted of visual observations, including an underground visit and discussions with the Mine Manager, the Operations Manager, the Engineering Manager, Health and Safety Manager and various employees. In order to review the infrastructure role in the operations the following information was requested in electronic or paper copy format: 1. NB - Water balance i. Water management plan and Water use licence and requirements ii. Storm water details and management iii. Storage tanks, reservoirs and pump stations details iv. Fire water reticulation if separate from the other water lines. v. Potable and raw water, material, diameters, pressure ratings, flow rates (measured and design rates) lengths of lines. vi. Waste water and sewerage details, sizes, materials, lengths and treatment plant 2. Plans, layouts and details of all services 3. Traffic management plan 4. Waste management plan 5. Energy balance and management plan 6. Environmental management plan 7. No of shifts and no of people per shift, divided into mining personnel and admin personnel To date none of the requested information has been submitted so that the following report will be based on visual observations and the discussions. Infrastructure Observations General The general impression regarding the mine infrastructure, buildings and facilities is that of a wellmanaged and orderly operation with good housekeeping in place. Safety and operational signage is clear, informative and concise and movement control seems to be well managed. Personal protective equipment is issued to all personnel and visitors and is generally in use for the purpose for which each item has been issued. Buildings Buildings and structures are of different materials and ages as would be expected on a working mine. General impressions were good with surfaces being maintained on a regular basis and cleaned, painted, as needed. Very few rust or peeling paint patches or rundown facilities were observed and where they exist they are most likely not in use anymore and planned for demolishing/removal. Traffic management and roads Roads are paved with asphalt/tar, gravel, sand or cement (in the works). The condition of the roads appear to be reasonably good. At the secondary parking area outside the entrance some dust suppression would be an advantage. Roads and foot paths are clearly marked with traffic and safety signs and separation of underground, above ground and pedestrian traffic incorporated in the traffic management. With crossing lights (robots) pedestrian traffic seem to take precedence. Sewerage and Waste management Sewerage are not considered to pose problems as the mine is connected to the municipal sewer system. Underground sewer is contained in chemical toilets and cleaned out by a dedicated contractor who also disposes of the waste material. The mine does not generate any hazardous waste. All other waste are sorted into separate bins according to material and conveyed to Kroondal where it is processed by the Company’s central facility. Water management The water requirements and water management is one of the crucial operations factors that must be closely managed. The water used by Waterval East consist of potable water, raw water, grey water from the mine operations such as drilling and wash down, recycled water from the settlement dams, ground water, storm water and other divers sources that could not be directly identified. Potable water is sourced from the municipality. The fire reticulation system is a separate and extend underground on the conveyors. Automatic fire systems has been installed and is in the process of extension as the underground fibre optic system is extended. Without having seen layouts and the water balance it is postulated that the operations water system more or less confirms with the following generic layout. Typical Closed Mine Water Reticulation (Source: Reticulation of Mine service water, P F Loveday, A S Atkins and N I Aziz, 1984 Water enters the underground operation via gravity feed or is pumped from surface reservoirs and is piped alongside the conveyor system and delivered to underground point for utilisation. Water that has been used in the operations and underground seepage is collected into a reservoir and settlement pond. Some of this water is re-used directly as drilling water but the balance is pumped to the surface via 1 or 2 extra reservoirs depending on the head requirement. Water is pumped to Kroondal where the settlement ponds and filters is situated. After processing the water is kept in a storage water reservoir to be used as required by operations. Excess water is purified to DWA standards and decanted into the Hex River. Pipe materials consist of cast iron, steel, galvanised steel and HDPE pipes of various diameters and conditions. The network seems well maintained with no obvious leaks or problems. Pump stations could not be observed so no comments are made on the condition and efficiency of the pumping operations. Fire hydrants etc. are clearly marked. No comments can made about the conformance to regulatory requirements, water use license conditions and the efficiency of the water management plan/water balance as this information has not been available. The platform underneath the stockpile is constructed of concrete and impervious material so does not seem to pose any environmental hazard. Communications management Communications is carried via telephone networks and radio networks. Infrastructure seems to be in a good state and fibre optics is being utilised and extended. Automation of operations is part of the operations management but I cannot comment on the extent and level of automation without the required information being submitted. Security and fencing Different areas are clearly separated by security fences and barriers. All the security equipment is deemed to be in good condition with regular inspections. Dust suppression No dust suppression is required. Geo-technical management Waterval’s Geotech conditions for road beds, foundations etc. appear to be sound. The mine do not have the black clay problems that are prevalent in other areas in the vicinity. Geotech reports has been requested and is being awaited. Energy management Energy for operations seem to be supplied by electricity, diesel fuel and compressed air. I cannot comment on the efficiency and effectiveness of the energy management without requested information. Recommendations and Proposals Water regulatory requirements Review the water use license and water management plan for compliance with the Water Act and supporting regulations. Specifically conduct an audit on the water balance against the following water regulatory/advisory documents:  Department of Water Affairs and Forestry, 2000. Operational Guideline No. M6.1. Guideline document for the implementation of regulations on use of water for mining and related activities aimed at the protection of water resources. Second Edition. The DWA has developed a series of Best Practice Guidelines (BPGs) for mines in line with International Principles and Approaches towards sustainability. The series of BPGs have been grouped as outlined below: BPGs dealing with aspects of DWA’s water management hierarchies prefaced with the letter H. The topics that are covered in these guidelines include: H1. Integrated Mine Water Management H2. Pollution Prevention and Minimisation of Impacts H3. Water Reuse and Reclamation H4. Water Treatment BPGs dealing with general water management strategies, techniques and tools, which could be applied cross-sectoral and always prefaced by the letter G. The topics that are covered in these guidelines include: G1. Storm Water Management G2. Water and Salt Balances G3. Water Monitoring Systems G4. Impact Prediction BPGs dealing with specific mining activities or aspects and always prefaced by the letter A. These guidelines address the prevention and management of impacts from: A1 Small-scale Mining A2 Water Management for Mine Residue Deposits A3. Water Management in Hydrometallurgical Plants A4 Pollution Control Dams A5 Water Management for Surface Mines A6 Water Management for Underground Mines Water balance Conduct a water balance simulation as a modelling exercise. Two initial models will be required: 1. A theoretical model based on the system parameters such as heights, pressures, theoretical flows, sizes etc. 2. A calibrated model based on actual measurements which will pinpoint areas where efficiency and effectiveness can be improved. The models will also provide pointers to pumping efficiencies and where improvements and savings can be realised but must be measured against cost outlay. Models that can be utilised include Epanet, P-Smart, P-Sim, WaterCad, Iwisa and any other competent hydraulic modelling package. Alternative de-watering methods If Waterval East already employ one or more of these systems please delete and ignore this section. Due to the high cost of electricity, alternative methods to dewater the shafts are being utilised. The potential energy of the service water entering the shaft is harvested through a hydropower turbine or a Three Chamber Pump Feeder System (3-CPFS) Both these systems has a high initial cost and must be carefully investigated. 3-CPFS A 3-CPFS harvests the potential energy of the service water entering the shaft to pump the clear hot water [27]. The surface water has a high pressure due to the head of the water in the columns. Installing a 3-CPFS can result in an electricity reduction of up to 80% The basic principle of a U-tube is applied on a 3-CPFS via a series of valves. One or multiple booster pumps are installed to overcome the friction head in the columns. A PLC controls the valves and pumps in sequence to ensure the potential energy if fully harvested. Refer to the single stage above to interpret table 1 below. (Source: Best practices for automation and control of mine dewatering systems, PJ Oberholzer, 2015) Hydropower turbines Multiple shafts have installed turbines to harvest the potential energy of the service water. The turbines are usually installed near a pumping chamber. Some shafts have multiple turbines installed. The output shaft can either be coupled to a generator or a multistage pump. The output power of a turbine can vary from 1 to 5 MW. Pelton wheel turbines are the most efficient type of turbine. The typical efficiency of a turbine installed in a mine ranges from 55 to 60%. A Pelton wheel turbine consists of a shaft, wheel, multiple buckets and water jet nozzles. The buckets are installed on the periphery of the wheel. The buckets are shaped in the form of spoons held together. The water jet nozzles increase the velocity of the water. The water is directed at a tangent angle to the wheel onto the centre of the buckets where the two spoons join. This causes a moment on the wheel which results in rotation of the shaft. The diagram below indicate a generic layout that utilises both 3-CPFS and turbine power included. Typical Improved Mine Water Reticulation with 3-CPFS and turbine power implemented (Source: Best practices for automation and control of mine dewatering systems, PJ Oberholzer, 2015) Indicators for water management in mining Implement the guidelines of Report Number:- - 12779 – 3, Targets for Water Conservation / Water Demand Management in the Mining Sector. Key Indicators, Methodologies to Set Targets and Commodity-based Targets submitted to the DWA in July 2014. KEY WATER USE EFFICIENCY PERFORMANCE INDICATORS Key Indicators for Defining Water Use Efficiency Focus on two categories of water usage as defined below: 1. Total water use: Total intake of all water entering the operation. This includes rainfall and runoff that is not separated from and diverted around the operation, groundwater make and/or abstraction, water obtained from water supply boards, water abstracted from any surface water resource, wastewater (or any other water) obtained from an external third party. This total water intake is also, by definition, equivalent to the total water output. 2. Consumptive water use: This is water used by the mine which effectively removes the water from the water cycle - thus it is not available for use by other users. Examples are seepage, evaporation and discharge of dirty water. This specifically excludes water supplied to third parties for their use as well as water discharged to the environment that demonstrably meets DWS discharge standards. This category of water use will be lower than the Total Water Use. The key indicators shown below is relevant in terms of water conservation/water demand management and should be used Volumetric indicators:   Total water use (volume flow as defined above) Consumptive water use (volume flow as defined above) Water use efficiency performance indicators:     Total water use efficiency per production measure (m3 per tonne of ore mined {ROM}) Consumptive water use efficiency per production measure (m3 per tonne of ore mined{ROM}) Percentage of the total volume of wastewater generated that is not reused (%) Water recycling ratio (%) The six key indicators listed above can be applied to the total mine (all operations associated with the mine), as well as to individual mining operations (e.g. mining, beneficiation and residue disposal). Note that the production measure used for the individual mining operations will differ, e.g. beneficiation might be expressed per mass of material processed. An indication of benchmarks for measurement is given below as taken from the report mentioned at the start of this section. Energy management/balance The general energy usage on mines is high as shown in the average use diagram shown below: (Source: Best practices for automation and control of mine dewatering systems, PJ Oberholzer, 2015) It is recommended that an energy audit/balance be conducted on the total energy consumed by Waterval to determine areas where more in depth analysis and modelling may be beneficial. A typical model that was developed to measure dewatering efficiencies is presented below for information. Similar models and methodologies exist for other areas of the process. (Source: A new minimum cost model for water reticulation systems on deep mines, Jan C Vosloo, 2008)