COAL MINING COMPLEX OPERATIONS SA

TECHNICAL REPORT

1. INTRODUCTION

The Tweefontein Complex mined a number of small opencast pits from 2008- 2011 in the Witbank

Coalfields area. Ongoing concurrent operational rehabilitation was done but the final voids were left.

In 2011 Xstrata Coal undertook an exercise to evaluate the establishment of a legacy rehabilitation

section that would undertake final rehabilitation of legacy areas and also provide opencast training for the

new Tweefontein Opencut operation.

Based on the results of the study it was estimated that the Legacy rehabilitation team could conduct the

rehabilitation using mostly old equipment from the existing operations and do so around 20% cheaper.

The rehabilitation areas were prioritised and final designs were done.

The Legacy rehabilitation team was established in November 2011 and started work on the Tweefontein

South Pit triangle voids and South 2 Pit voids.

This report describes how the team performed in the first three and a half years to complete 165,4

hectares of very difficult rehabilitation while also training underground operators from the closed

Tavistock Colliery to become proficient in the opencast operation.

Figure 1: Map showing location of the area under discussion and its vicinity

Background

Technical report- SACMA General meeting Gerhard Stenzel Group Consulting Engineer Opencast technology Group Services Glencore Coal SA Gerhard.Stenzel@glencore.co.za +27 13 653 5311 (Tel) +27 83 768 0391 (Mobile)

Date: 17 May 2016 Ref. No.

Group Rehab

Title: Tweefontein Legacy Rehabilitation

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2. PROJECT SCOPE

The following sites were identified as the initial, most important locations for owner rehabilitation: • South Pit Triangle • Southstock 5 Seam O/C • Tweefontein South East Pit • Tweefontein Hamster • Tweefontein South 2 Pit • iMpunzi Butterfly • Old Moolmans Pit • Old Witcons discard dump The various sites were prioritised in terms of the importance and urgency of rehabilitation. However, not all the designs for site rehabilitation had been completed as per prioritisation. This resulted in the scheduling of site rehabilitation to be slightly different from the original priority list. A list of new equipment was compiled to conduct the rehabilitation. The list of equipment was carefully selected to ensure an optimum installed capacity within a constrained budget for the remaining 2011 financial year. In order to accelerate the start of rehabilitation, a list of older equipment was received from the iMpunzi Operation. Only some of the old equipment was available in November 2011 to start with early rehabilitation, some dozing capacity was available to commence with initial levelling. A SWOT analysis was conducted and resulted in the following:

The original team with the first New ADT that arrived in April 2012

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The site offices purchased in order to be functional yet mobile. In order to establish the requirement for infrastructure the basic temporary site layout design of Diesel Power was used.

Figure 6. Rehabilitation office site layout Source: Diesel Power

3. DESIRED OUTCOMES

The focus of the project was to rehabilitate and restore the mined out areas and to train underground

mining personnel to operate successfully in an opencast environment.

To establish a “walk away” situation in which natural processes function as close to normal as

possible.

To create a safe environment for the local community.

To rehabilitate according to the mine’s approved EMPR

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4. SELECTED SITES

From the original list of legacy sites two areas were selected and work started in November 2011.

The team of 10 experienced operators was selected from local communities and the supervisors

were all redeployed (previous underground employees made redundant by the closure of the

underground operations). A survey plan showing the available dumps (indicated in brown) was

compiled and also shown are the voids that needed to be filled (indicated in blue) on the plan below

Plan 1 Showing the available dumps and voids for the South pit triangle and South 2 pit areas

Starting dumps m3 Ha

Starting voids m3 Ha

1 76458 2.6

m3 Ha

2 10448 0.5 A 84015 2.07

84015 0

3 2150409 13.68 B 1659964 18.54

748819 8.47

4 107694 3.05 C 232600 11.63

0 11.63

5 79603 6.22 D 784184 11.78

0 11.78

6 160312 3.93 E 194471 2.29

0 2.29

7 631927 5.82 F 692056 18.33

83544 11.24

8 48722 2.64 G 81052 2.24

0 2.24

9 196785 11.05

916378

Total 3 462 358 49.49 Total 3 728 342 66.88 1130319.86

4.1.South Pit Triangle

The design of the South Pit Triangle was complete. An aerial photograph as well as a graphical illustration of the site rehabilitation is provided in Figure 1.

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Figure 1. Photo and the graphical design before rehabilitation. Dumps1,2,3,4 Voids A, B Initial quantitative rehabilitation information available on the site was:

Area : 17.6 ha

Dozing : 6 590 m3

Load & Haul: 1 885 620 m3

Top Soil: 76 000 m3

4.2 Tweefontein South 2 Pit

The design for the South 2 Pit was completed prior to work starting

Figure 2. Tweefontein South 2 Pit before work started Dumps 5,6,7 and Voids D,E and

just prior to grassing

Initial quantitative rehabilitation information available for the site was:

Area : 103 ha

Dozing : 41 729 m3

Load & Haul: 3 379 887 m3

Top Soil: 751 086 m3

5. ACTIVITIES CONDUCTED

5.1 South Pit triangle rehabilitation

Photo 1 South pit triangle at start of project November 2011 showing the final void and dumps.Picture on

right taken in June 2015 just prior to grassing , taken from other side.

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Photo 2 Shaft void area A in June 2012 Photo 3 Area A levelled by November 2012

Photo 4 area A grassed February 2013

.

Photo 5 South pit Triangle – Void Area B in February 2012

Pit dewatering and dumping of hard materials onto floor for maximum compaction

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Photo 5a Dump reduction loading operations using Cat 992 FEL with Cat 777 dump trucks and smaller

Cat 390 Excavator matched with Cat 740 ADT trucks

Photo 6 Void area B June 2012 Photo 7 Void Area B June 2013

Photo 8 Void B final topsoil placement August 2014 Photo 9 Void area B Hydro Seeding September 2014

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Photo 10 South East Pit triangle (area B) Hydro seeding using Hydro mulch with mine seed mix

Photo 11 Area B teff growing January 2015 photo 12 Area B teff was baled May 2015

Photo 13 SE Pit void (Area B) Permanent grasses established and bird life returning February 2016

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5.2 Rehabilitation of Burning coal waste dump (Dump 9 into Void E,F)

After completing the South East pit triangle voids the team tackled a burning coal waste dump again

with great success

Photo 14 Burning coal waste dump 9

Photo 15 Hot ash and burning coal exposed when loading started

Photo 16/17 Water sprayed onto dump to cool it for loading with FEL and truck

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Photo 18/19 Showing dump area May 2015 and with first season grass (Teff) in February 2016

5.3 South 2 pit rehabilitation Voids D,E,F

Photo 20 Showing the South 2 pit final void D as at 2012

Photo 21 Void D closure by September 2014, void completed by February 2015

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Photo 22 South 2 pit final levelling June 2015 and fully grassed February 2016

Photo 23/24/25Voids E and F levelled June 2014 and seeded December 2014 and now February 2016

6. ACHIEVEMENT VS DESIRED OUTCOMES

The following overall outcomes have been achieved to date at the Tweefontein sites:

In 4,5 years this team has not had any medical treatment injuries.

TRIFR=0 LTIFR =0 since the start of the project in November 2011.

Closure of two final voids(South Pit triangle and South 2 pits), Closure of one underground shaft

portal and removal of a waste coal dump: Total of 165,5 Ha was fully rehabilitated

Creation of 57 permanent jobs due to the financial success of this project the team has moved on

to the next area. Most of the current operators and supervisors worked underground at several

sites that closed down. 14 operators trained and promoted further to Tweefontein Openpit

operation (TOC)

Approval and satisfaction (continuous involvement) from Authorities on the proposed

rehabilitation measures; Site was visited by authorities and the Tweefontein revised EMPR and

Water use licences were approved. Site has not had any Section 54 or 55 orders.

Sustainable (i.e. walk-away) areas have been created, i.e. sustainable grassland; 165 ha at

Tweefontein was completely rehabilitated.

Costs: the cost per ha was 23% below the 2011 plan. A total of 5 661 639 m3 was moved by the

team at Tweefontein and monthly costs/ Bcm moved was carefully controlled and was well below

the cost of local contract mining.

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The rehabilitation team (shown in Green) that completed the Tweefontein Rehabilitation from 2011-2015

and is now working on the Butterfly Pits rehabilitation at Impunzi Complex.

7. CURRENT STATUS/SUSTAINABILITY

Second season grasses have all established and no further fertilization will added, small areas

will be reseeded under warranty where germination was not to standard.

Post closure sustainable monitoring will continue.

The current team that was successful at Tweefontein has been redeployed and is working

on the next legacy rehabilitation site as determined by the risk ranking.

Bee boxes have been erected and birdlife is returning

Bee boxes have been put up to resore nature and bird life is returning naturally