The following structures will be required:

Transcription

1 2.3.1 Central Discard Dump Introduction The current discard dump does not have sufficient capacity to accommodate the discard produced from the proposed future operations. A new Discard Dump, called the Central Discard Dump, is proposed on the south eastern side of the current discard dump in Maquasa East. The new discard dump will be utilized for discard generated by the proposed new underground mining, including the Kusipongo operations. The Central Discard Dump will be located within the Maquasa East operation on the remaining (RE) portion of the farm Rooikop 18 HT, with a small area of the dump on the remaining (RE) portion of the farm Maquasa 19 HT (Figure 2.7). The Central Discard Dump will accommodate discard produced from the beneficiation plant located at Maquasa East, which currently washes and processes coal from the surrounding Kangra Coal operations and will receive coal from the future expansion areas. The discard dump was designed by Geotail (Pty) Ltd and the description provided in this section has been extracted from the Design Report (September 2014). The discard dump will be developed as a three-compartment side hill type storage facility with a footprint of approximately 65ha (Table 2.8). The threecompartment layout allows for a modular implementation approach (phases 1, 2 and 3) with the benefit of delaying capital expenditure. The following structures will be required: Lined discard dump (to be constructed in three different compartments/phases); Under-drainage system; Boundary fence; Internal haul roads; Catchment paddocks; Two compartment, High Density Polyethylene (HDPE) lined Pollution Control Dam (PCD) (one compartment to be operated as empty); and Stormwater management infrastructure, such as berms and trenches. The proposed discard dump was three-dimensionally modelled for an accurate determination of the relationship between the height, area and 2-22

2 capacity. The results of this modelling are the capacity and dimensions of the discard dump and these are summarised in Table 2.8. Table 2.8 Dimensions and Capacity of the proposed Discard Dump Description Total/Unit Phase 1 Phase 2 Phase 3 Life of facility 20 years Extent of Discard Dump 65ha Capacity of discard dump 20.2 million tonnes (Mt) Airspace available 11.2 million m³ Final vertical height of Discard Dump m Deposition rate 1 million tonnes per annum of coarse material** Final side slope area ha Final top surface area 38ha

3 Figure 2.7 Central Discard Dump Layout

4 Construction/Disposal Method The coal discard will be transported by truck from the Maquasa East beneficiation plant to the new discard dump, where it will be placed and compacted mechanically. The discard will be placed in horizontal layers (bottom-up) following an approved performance compaction specification. Groundwater Management In order to protect the groundwater resource below and within the vicinity of the discard dump, two mechanisms will be employed to manage seepage from the facility: 1. An under-drainage system; and 2. A liner. Under-Drainage System: The under drainage system is designed to collect seepage on top of the liner and to achieve phreatic surface drawdown at the toe of the discard dump. As such, the under-drainage system is strategically placed along the critical downstream toe line of the discard dump. Discard Dump Liner: The proposed liner system for the discard dump generally complies with the Class C liner type in the waste classification regulations (published in Government Notice R. 634) and comprises four layers (Figure 2.8). Figure 2.8 Proposed Liner for the Discard Dump Source: Geotail, 2014 PCD Liner The liner system for the PCD generally complies with the Class B liner type as described in the waste regulation, GNR643. This liner comprises three layers and as shown in Figure

5 Figure 2.9 Proposed Liner for the PCD Source: Geotail, 2014 Surface Water/Stormwater Management The surface or stormwater management measures are designed to separate clean and dirty water, divert clean water away from the discard dump and collect and contain water found within the discard dump footprint (dirty water). Stormwater Diversion Channels Two channels are deemed necessary to divert clean stormwater away from the discard dump, i.e. the North and South channel. A local watershed runs generally east west through the southern portion the centre compartment of the discard dump. The two channels originate on this watershed. The North Channel runs generally northwards while the South Channel runs southwards before turning west and then northwest around the southern perimeter of the discard dump. The proposed channels have been sized to comply with the GN704 requirements and as such they are designed to convey the 50-year design flood peak (Table 2.9). The catchments for the channels are relatively small. Table 2.9 Stormwater Channel Dimensions Parameter North Channel South Channel Catchment Size 32.9ha 4.9ha Shape Trapezoidal Trapezoidal Base width 1m 1m Side slopes 1:1.5 (V:H) 1:1.5 (V:H) Flow depth 0.83m 0.48m Channel depth* 1.1m 0.8m Max flow velocity** 3.7m/s 2.7m/s- Flow type at max velocity Supercritical Supercritical **Note: Flow velocities are based on the maximum longitudinal gradient. The stormwater channels have been sized assuming unlined channels, and will be excavated into the ground. The material excavated from the channel 2-26

6 will be placed in a berm on the downstream side of the channel to increase the capacity of the channel above its design capacity and provide additional freeboard where required; and to allow cost effective construction as load and haul volumes are minimised. The berm should be compacted and vegetated and the channel kept free of long grass, shrubs and woody vegetation. Discard Dump Design Features The discard dump has been designed to avoid storage of water on the facility, thereby increasing its stability. The side slopes will be terraced and berm penstocks will be utilised to drain the permanent benches. This water will be captured by the catchment paddocks, which will be located at ground level. The runoff will be diverted to the PCD. It is recommended that the discard dump is operated with the minimum of water stored on the top surface at all times. Pollution Control Dams The PCD will serve to collect and contain direct rainfall, runoff from the discard dump surface and the dirty water catchment of the discard dump, as well as seepage captured by the under-drainage system (within the catchment paddocks). The stormwater diversion channels will divert clean water away from the dirty area in order to reduce the amount of polluted water which must be contained, thereby reducing the PCD capacity requirement. The proposed maximum capacity of the PCD is 100,000m³. The water pumped out of the PCD will be sent to the washing plant, before being pumped to Pit D East where it will be evaporated. Access Control A boundary fence will be erected around the perimeter of the discard dump facility to keep out livestock and discourage entry by people. A haul road will be constructed around the discard dump. This haul road will connect to the existing haul road to the east of the proposed discard dump complex. The internal haul road will also lead to the PCD. The haul roads within the discard dump complex will not exceed a width of 8m Maquasa West Extension Underground Works Introduction The authorization for the underground workings applied for was initially approved under the MP 30/5/1/1/2/209MR EMPr for the Maquasa extension by the DMR on the 15 th of May 2008 (Annex B). However, during the consolidation of the EMPr s into 133MR (as approved in July 2014), a section of the 209MR activities were accidentally omitted. This was discovered in

7 during the second EMPr amendment application with the DMR. The DMR responded that the EMPr could not be amended for the Maquasa operation for activities that technically do not exist in the approved consolidated EMPr. As such the omitted section of the MWE underground works will now be applied for as part of this S102 Amendment application. This section describes the proposed underground works activities. The proposed mine plan for the MWE underground works can be seen in Figure These works will be accessed by the proposed new Adit 5 which is discussed in detail in Section The proposed MWE underground works will be located under the properties detailed in Table Table 2.10 Project Infrastructure Summary Description Property Kransbank 15 HT, Portion 1 Kransbank 15 HT, Portion 2 Maquasa 19 HT Remaining Extent Surveyor General Cadastral Code T0HT T0HT T0HT Mining will occur by underground board and pillar methods with chequerboard pillar extraction. Board-and-pillar, or room-and-pillar, is an extensively used underground mining technique. This method uses a grid of tunnels and involves progressively cutting panels into the coal seam whilst leaving behind pillars of coal to support the overburden (NSWMINING, Accessed 4 March 2015). This will be done using a horizontal continuous miner. Mined material is extracted across a horizontal plane, and is extracted in two phases. In the first phase "pillars" of untouched material are left to support the roof overburden, and open areas or "rooms" are extracted underground. This technique is usually used for relatively flat-lying deposits. The key to successful board and pillar mining is in the selection of the optimum pillar size, considering the required safety factors to avoid subsidence on surface. Board and pillar mining is depicted in Figure

8 Figure 2.10 Diagram of Typical Board and Pillar Mining Method Source: Okubo & Yamatomi,.date unknown 2-29

9 Figure 2.11 Maquasa West Extension Underground Works

10 Project Phases Mining projects are developed in set phases, with each phase having a different combination of activities. These phases include the construction, operation and decommissioning/closure phases. These Project phases are discussed in the following sections. Construction Phase: For underground mining operations there is very little construction activities strictly related to the underground portion of the project. Construction activities are almost all related to the construction of the access adit. These activities are discussed in detail in Section Operations Phase: As previously discussed mining will occur using continuous mining equipment and will access the coal reserves using the board and pillar method. Mining will take place from the new Adit 5 and will extend in a southerly and easterly direction as in Figure A mine schedule is shown in Table Table 2.11 Maquasa West Extension Underground Works Mine Schedule Year Tonnes ,647, ,858, ,071, ,577, ,459, ,533, ,126 All coal that is mined from this area will be transported from the Adit 5 via the new overland conveyor to the coal processing facilities at Maquasa West operation, and from there the coal will transported via the existing overland conveyor to the beneficiation plant located at Maquasa East. Discard from this process will initially be disposed of at the existing discard dump and later to the new Central discard dump. Closure Closure is planned for the end of the Project life (approximately 7 years) and will include: Decommissioning and sale of mining equipment and infrastructure; Restoration and rehabilitation of disturbed areas; 2-31

11 Management of mine water decant and water treatment prior to discharge; and Post closure monitoring Adit 5 and Overland Conveyor Introduction In addition to the proposed underground workings in the previous section, Kangra Coal intends to develop and operate a new adit in the Maquasa West Extension area (the Adit 5), an overland conveyor connecting the Adit 5 to Maquasa West coal processing facilities, and an associated servitude road. The coordinates of these facilities are listed in Table Table 2.12 Co-Ordinates of Surface Infrastructure Infrastructure Latitude Longitude Main Adit centre point S E Overland conveyor S E (start pt.) S E (middle pt.) S E (end pt.) This proposed infrastructure will be located on the properties detailed in Table Table 2.13 Details of the properties associated with the Adit 5 and the Overland Conveyor Property Surveyor General Cadastral Code Title Deed Number Adit 5 Kransbank 15HT, Portion 2 T0HT T21311/ Overland Conveyor Kransbank 15HT, Portion 2 T0HT T21311/ Kransbank 15HT, Portion 1 T0HT T139369/2000 Rooikop 18HT, Portion Re T0HT T78816/2004 Infrastructure Development Footprint (Ha) Project Phases The proposed Project will be developed in set phases, with each phase having a different combination of activities. For ease of reference, the proposed Project has been divided into the following phases: Construction Phase; Operational Phase; and Decommissioning and Closure Phase. 2-32

12 Construction Phase Construction of the surface infrastructure is planned to commence in The construction phase will include the following initial activities: Construction of an access road and a powerline to the site of the proposed Adit 5 and along the route of the proposed overland conveyor; Establishment of the mobile offices and support facilities at the Adit 5; Establishment of the Adit 5; Development of the overburden dump and topsoil dump during the adit development; Establishment of the main ventilation fans; Construction of stormwater management features such as diversion berms, stormwater channels and an evaporation dam; Establishment of the overland conveyor; Transmission line development in the overland conveyor servitude; Establishment of a water pipeline along the overland conveyor route; Installation of the water storage tank; and Installation of sewage sump which will be serviced periodically (Sewage effluent be sucked up and transported by tanker to the sewage treatment plant at Adit 4). Operational Phase The operational phase of the project will include the following activities: Conveyance of coal from the underground mining operation at the MWE underground works, via the Maquasa West operation where primary crushing and screening will take place, and then to the existing Maquasa East coal beneficiation plant; Temporary storage of general and hazardous waste in containers at the Adit 5 which will be removed on a regular basis by a licensed waste contractor; Delivery of explosives, fuel, various kinds of machinery typical in mining operations, construction materials from time to time, spare parts for minor reparations of machinery, etc.; 2-33

13 Maintenance of all water management facilities on site such as the evaporation dam and stormwater management system; Management of excess underground water (dewatering and storage ); Management of the on-site sewage storage and disposal; and Ongoing maintenance of the roads, overland conveyor, water treatment plant, process water supply pipeline, sewage treatment plant and transmission line. Decommissioning Phase and Closure Decommissioning and closure occurs at the end of the Project life (approximately 7 years) and will include: Decommissioning and sale of mining equipment and infrastructure; Restoration and rehabilitation of disturbed areas; Management of mine water decant and water treatment prior to discharge; and Post closure monitoring. Proposed Project Infrastructure and Activities The proposed infrastructure forming part of this application is described in this section and can also be referred to in the site layout diagram in Figure Adit 5 The Adit 5 will include main ventilation fans to provide fresh air to the underground mining operations and will be designed in such a way to allow workers, materials and machinery access to underground mining operations (inclined adit). Figure 2.12 and Figure 2.13 are examples of a mine adit. The inclined adit will provide for a conveyor to bring mined coal to the surface. 2-34

14 Figure 2.12 Existing Adit and Coal Handling Facilities at Maquasa West Operations Figure 2.13 Maquasa West Adit: Portal Entrance and Ventilation Fans 2-35

15 Figure 2.14 Proposed Adit 5 Infrastructure Layout

16 The following support infrastructure and facilities are required and will be developed at the main adit: Electrical distribution substation, switch gear and step-down transformers (emergency back-up generators will also be included); An access road along the new overland conveyor to the Adit 5; A stormwater management system; Mobile potable water treatment plant; Septic tank system at the Adit 5 which will be periodically purged and transported to the sewage treatment plant at Adit 4; Firefighting system complete with water storage; A wash bay (including an oil trap) that will be used to wash mining equipment and light duty vehicles; Brake test ramp for mine vehicles; A fuel and oil depot which will be provided by the fuel provider; Small storage building for minor equipment (main stores at Maquasa West to be utilised); Drop-off facility for workers; Above ground parking bays; Temporary waste storage facilities to accommodate general (domestic, recyclables, etc.) and hazardous waste (used oil, solvents, spent batteries, contaminated rags, overalls, descants, etc.); First aid facilities; Lime silo (used for white-wash and dust control); A security fence around the perimeter of the property and substation; and A security (guard) house. This primary and support infrastructure is described in more detail in Table

17 Table 2.14 Infrastructure at the Adit 5 Operational Component / Infrastructure Overburden Dump Description Excavated rock from the mine portal is proposed to be placed immediately adjacent to the portal. This overburden dump will have an area of 2.1 ha and a volume of approximately 379,000m 3. Topsoil Dump Topsoil is required to be stored separately for use during rehabilitation. The topsoil dump will have an area of approximately 2.1 ha. Administration Block There will be containerized offices and a security house at the entrance of the Adit 5. A lamp house and a containerized control room will also be developed in the Adit 5 complex. Pollution Control Dam A silt trap with a footprint of approximately 750m 2 and a volume of approximately 1,000m 3 will be installed at the Adit 5 to manage dirty / oily water from the wash bay and dirty water separation channels. Water from the silt trap will be directed into a PCD of approximately 4,800m 3. The PCD will contain all dirty and excess mine water and have an approximate surface footprint of 0.3 ha. Excess water will be pumped to water storage facilities at Maquasa West and Maquasa East operations. The current water storage facilities are pollution control dams at Maquasa West and East and the void located at Maquasa East Pit (referred to as Pit D East). Kangra Coal utilizes Evaporators to aid in excess water reduction at Pit D East through evaporation process. As this is a fairly new technology the overall efficacy of the evaporators is still to be determined through long term monitoring and analysis Process water pipeline Process water will initially be supplied to the Adit 5 from the existing facilities at the Maquasa West operations through a pipeline along the proposed new overland conveyor route between the Maquasa West adit and Adit 5. Further details are discussed in the section below. The water pumped from the underground workings will be utilised as process water for the remainder of the life of the operation. Incline Conveyor An incline conveyor will be constructed to transport mined coal from the MWE underground works to the surface at the Adit 5. Feed Stockpile A stockpile for feeding the overland conveyor will be developed at the Adit 5 with an approximate volume of 2,000 tonnes. Electrical A 6.6 kv overhead power line will link the Adit 5 to Maquasa West, from which the drive systems for the overland conveyor will be supplied. The transmission line at the Adit 5 will be constructed along the conveyor route. A containerized substation will be constructed at the Adit 5 to provide power to the internal reticulation system at 400/500V. The area will be equipped with emergency power generators for power supply to the main surface fans during power failure. Access Road Only one access road will provide access from Maquasa West operation to the Adit 5 complex. The road will also be used during construction and maintenance of the overland conveyor. 2-38

18 Operational Component / Infrastructure Description The proposed access road is 10.2m wide and 6 Km in length (same as proposed conveyor) and will be compacted with gravel. Stormwater Management System Surface water management at the Adit 5 will ensure that there are clean water systems that divert clean water away from the complex. Earth fill berms, designed to divert clean stormwater runoff associated with a 1:100, 24 hour storm event will be constructed. Storm-water cut-off berms will be constructed during the main earthworks. Impacted dirty stormwater runoff within the Adit 5 footprint will be collected and routed via a silt trap to the PCD. Potable water tank Sewage sump Vehicle Wash Bay The potable water will be sourced from a borehole with adequate yield at Nooitgesien. The water will be treated at Maquasa West Adit 4 offices at the Water Treatment plant prior being reticulated to the tank at the Adit 5 complex. Sewage generated within the Adit 5 complex will be collected into a sump. It will be purged on a periodic basis and transported to the sewage treatment plant at the adit 4 offices. The wash bay structure will consist of a building with sheeted roofing and side cladding. It will accommodate washing of all the mine vehicles. It will be equipped with a high pressure washing systems, vehicle hoist, and ramp systems for effective vehicle washing at all angles. Water emanating from the wash bay will drain into an oil trap equipped with a silt trap. Oil free water released from the oil trap will be directed into the silt trap and then into the PCD. Fuel Storage Stores Drop off Facility Parking Bays Temporary General and Hazardous Waste Storage Areas A fuel and oil depot will accommodate a cumulative volume of less than 30m 3 is proposed. All fuel and oil storage facilities will have all legally required safety measures and will be provided by the fuel supplier. A small storage building for minor equipment will be constructed. The main stores to be used will be the existing one at Maquasa West. The drop off facility will allow mine workers to be dropped off and picked up safely, ensuring the least amount of pedestrian movement across roadways. Provision will be made for a fenced parking area to which access will be controlled. General waste will be collected and temporarily stored in waste skips located near the centre of the Adit 5. Skips will be labelled so that recyclable and reusable items are separated. Skips will be removed from the site by a certified waste service provider. All waste classified as hazardous will be collected in designated hazardous waste skips. A hazardous waste skip will be stored in bunded and roofed facility designated for temporary storage of waste. All hazardous waste such as oil will be recycled or reused. It will be regularly collected by certified waste processors. For 2-39

19 Operational Component / Infrastructure Description disposal, a licensed hazardous waste collecting company will be contracted for transportation and disposal of waste to a licensed landfill site. Skips will also be provided for general waste. The anticipated hazardous waste temporary storage volume of 80 m3, shall not be exceeded Security and Fencing of the Adit 5 The entire Adit 5 will be fenced. It will be provided with access control such as vehicle and pedestrian gates and security access points. Each facility within the Adit 5 will have its own fencing and security where necessary. Overland Conveyor System The footprint of the overland conveyor system is approximately Ha. The infrastructure listed below is proposed and will be developed along the overland conveyor system: An overland conveyor; Road over conveyor crossings; Stream and wetland crossings; and Fencing and security of the overland conveyor system. The overland conveyor system will transport coal from the Adit 5 to the existing facilities at Maquasa West operation, from where it will be transported to the beneficiation plant at Maquasa East through the existing overland conveyor. Included in the conveyor servitude will be overhead transmission lines (OHTL) (approximately 5 m north of the overland conveyor), an access road and a security fence (fenced width of 20m). The conveyor will be ground run supported by light overland modules with angle roof sheeting. Figure 2.15 shows the existing conveyor at Maquasa West. 2-40

20 Figure 2.15 Existing Maquasa West Overland Conveyor Roads over the overland conveyor will be constructed to allow the local farmers and communities safe access to either side of the conveyor when necessary (Figure 2.16). Guardrails will be placed on either side of the ramps over the conveyor route crossing. Figure 2.16 Road over Conveyor Crossing The proposed overland conveyor will cross a number of streams and wetlands. The section of conveyor that traverses a stream, and that is situated within a distance of 12m from the edge of the 1:100 year flood line, will be 2-41

21 fully enclosed and raised on a steel gantry (Figure 2.17). Furthermore, the entire raised section will have a bunded concrete floor to catch any potential coal spillage. Spilled coal will be hand swept into a concrete bunded area, which is positioned at ground level, outside the 1:100 year flood line. Any potentially spilled coal will then be removed from the bunded area and returned to the Adit 5. Figure 2.17 Enclosed Conveyor Over Stream Crossing The gravel service road running parallel to the conveyor will traverse the stream over concrete culverts (Figure 2.18). The gravel road and conveyor terrace will be reduced to one lane to minimise culvert lengths. Figure 2.18 Road Over Stream Crossing 2-42

22 Fencing will be placed on both sides along the entire route of the conveyor with the exception of the conveyor gantries where the fence will be constructed under the gantry and join up with the fence on the adjacent side. This fence denotes the conveyor servitude. The fence will enclose the service road along the conveyor route. 2.4 NEED AND DESIRABILITY Coal provides around 30.1% of global primary energy needs, generates over 40% of the world's electricity and is used in the production of 70% of the world's steel (World Coal Association, 2013). South Africa possesses Africa s only significant coal reserves; over 95% of Africa s coal reserves are found in South Africa (US Energy Information Administration, 2014), with coal reserves of 30,2 billion short tonnes at the end of 2012, which represents 4% of the world s total coal production.. South Africa is the world s seventh largest coal producer, and produced 3.3% of the world s coal in 2013 (256 million tonnes) (World Coal Association, 2013). In 2013, South Africa used coal for 93% of its electricity generation needs, and was the second most dependent coal-to-electricity country in the world, after Mongolia (World Coal Association, 2013). Apart from its domestic needs, South Africa is currently the world s sixth largest coal exporting country, with exports in excess of 70 million tonnes in 2013 (World Coal Association, 2013). Coal plays a crucial role in the South African energy-economy and is fuelling local industry (Eberhard, 2010). The consumption of coal in South African coalfired power stations will continue in the near future (Eberhard, 2010). Increased demand in Eastern countries (driven by rapid economic growth rates) will result in an increased demand for South African coal exports (Eberhard, 2010). Coal exports are expected to increase to 105 million tonnes per annum by the year This will increase the country s export earnings, which in turn will reduce the country s negative trade balance and current account deficit (Eberhard, 2010). Both local and international markets are, at present, highly dependent on South Africa being a main provider of coal, now and in the future. The identification and exploitation of new coal reserves in South Africa is thus a prerequisite in meeting this demand. In addition coal plays a crucial role in the provincial economy of Mpumalanga, where the proposed Project is located and coal mining is a key economic activity in this Province. According to the Mpumalanga Provincial Growth and Development Strategy (PGDS; ), Mpumalanga contributed 7.7% to the national Gross Domestic Product (GDP) in The majority of the contribution to the provincial economy is made up by the manufacturing sector (28.0%) followed by the mining sector (18.0%). To 2-43

23 provide growth and development within the Province, the PGDS has prioritised economic development comprising inter alia, job creation, Small Medium and Micro Enterprises (SMMEs), BEE, mining, manufacturing, tourism and agriculture The economy of the Gert Sibande District Municipality is supported predominantly by mining and manufacturing. Other key sectors that drive the economy of the District include energy supply and agriculture (Gert Sibande District Municipality IDP: ). In terms of employment mining employs 14.3% of the population in the district (Gert Sibande District Municipality IDP: 20012/ /17). In terms of employment in the mining sector in the local municipalities, 7.6% of the population from Mkhondo in 2011 (Mkhondo Local Municipality IDP ) and 2.4% of the population from Dr Pixley Ka Isaka Seme in 2012 (Dr Pixley Ka Isaka Seme Local Municipality IDP 2015/ /17) were employed in the mining industry. Both the Mkhondo Local Municipality IDP (2016/2017) and the Dr. Pixley Kalsaka Seme IDP (2016 /2017), recognise the importance of mining as a key economic sector within these two Municipalities and both recognise the significant challenge they are facing, in balancing the economic and developmental needs of the Region with the needs of environmental protection. The proposed Project components being applied for as part of this application are key factors from a strategic point of view for Kangra Coal. Given that the existing operations are approaching depletion (in 3 years time approximately), new resources are required to maintain the current levels of production and employment. Should the mining operations close, jobs will be lost, both directly at the mine and indirectly in terms of local contractors and businesses providing goods and services to the operation, as well as the people dependent on those working for Kangra Coal (both directly and indirectly). 2-44