Modern Mining April 2018

MINING News

two 40-tonne rock-hoisting skips. The headgear for the permanent hoisting facility was designed by South Africa-based Murray & Roberts Cementation. The early-works for Shaft 2 include the excavation of a surface boxcut to a depth of approximately 29 m below surface and the construction of the con- crete hitch (foundation) for the 103‑m-high concrete headgear (headframe) that will house the shaft’s permanent hoist- ing facilities and support the shaft collar. Excavation of the boxcut commenced in January 2018 and is expected to be com- pleted by the end of 2018. Shaft 2 has been engineered with a crushing and hoisting capacity of 6 Mt/a – the single largest hoisting capacity at any mine in Africa. This will allow a relatively quick and capital-efficient first expan- sion of the Platreef project to 6 Mt/a by increasing underground development and commissioning a third 2 Mt/a processing module and associated surface infrastruc- ture as required. A further expansion to more than 8 Mt/a would entail converting Shaft 1 from a ventilation shaft into a hoisting shaft. This would require additional ven- tilation exhaust raises, as well as a further increase of underground development, commissioning of a fourth 2 Mt/a pro- cessing module and associated surface infrastructure, described in the Platreef preliminary economic assessment as Phase 2 of the project. The mining zones in the current Platreef mine plan occur at depths ranging from approximately 700 m to 1 200 m below surface. Primary access to the mining zones will be by way of Shaft 2; second- ary access will be via Shaft 1. During mine production, both shafts also will serve as ventilation intakes. Three additional ventilation exhaust raises are planned to achieve steady-state production. The planned mining operation will use highly productive, mechanised methods, including long-hole stoping and drift- and-fill. Each method will utilise cemented backfill for maximum ore extraction. The ore will be hauled from the stopes to a series of internal ore passes and fed to the bottom of Shaft 2, where it will be crushed and hoisted to surface. It is currently envisaged that the first phase of the Platreef mine will be commis- sioned by 2022. 

Caula could be in production by mid-2019 ASX-listed Mustang Resources says that a strategic review led by its new MD, Dr Bernard Olivier, has concluded that the com- pany’s Caula graphite project in Mozambique could achieve first production by the middle of next year. Dr Evan Kirby, who recently joined the Mustang board as a Non-Executive Director and consultant (and who has sig- nificant graphite and vanadium experience), assisted Dr Olivier in the review.

proven capability to obtain exploration and mining permits and the ability to develop trial mining and processing operations. The team will be able to utilise the existing infrastructure and operations camp of the ruby project to assist with graphite project development. Furthermore, the 200 t/h capacity of the processing plant for the ruby project is ten times larger than the capacity required for the trial mining phase of the graphite and vanadium project. Mustang considers that trial mining and processing operations at Caula could produce both graphite and vanadium con- centrates. The vanadium concentrate would either be sold or stockpiled for further pro- cessing to high purity vanadium products as part of full-scale development. The trial mining development strategy is based on a robust, low-cost mining operation and construction of a processing plant capa- ble of handling approximately 100 000 t/a of ore. This scale of operations was decided after discussions with an equipment sup- plier, followed by preliminary considerations of costs and potential revenues. The plant will be designed to produce high-grade graphite concentrates as well as vanadium concentrate. In practice, con- centrate production rates and qualities will depend on the ore grades fed to the plant, the processing characteristics of the ore, and on plant performance levels achieved. It is anticipated that sales of graphite and vana- dium products produced from trial mining will help to secure binding off-take agree- ments and associated finance required for full-scale project development. The complex nature of graphite and vana- dium extraction means that it is likely that virtually all of the equipment purchased for trial mining will be incorporated into full- scale operations. Development of a full-scale mining and processing operation will be considered by the Scoping Study. Conditional on a positive outcome of the Scoping Study, a Definitive Feasibility Study (DFS) will be undertaken to serve as a basis for project development and financing. Wherever possible, operational experience from trial mining and processing operations will be incorporated into the DFS. The Caula project has delivered a maiden JORC inferred resource of 5,4Mt at an average grade of 13 %TGC (6 % cut-off) for more than 700 000 tonnes of contained graphite. The exploration results included exceptionally high-grade intercepts of up to 26 %TGC. 

The strategic review does not form part of the formal Scoping Study, which is set for completion in the June 2018 quarter. The Scoping Study will consider the merits of a full commercial-scale graphite and vanadium project with production levels appropriate to an updated Mineral Resource Estimate, and full consideration of the modifying factors covered in the JORC Code, 2012 Edition. The key outcome of the review was the recommendation to establish trial mining and processing operations for completion during Q2 2019. Mustang’s board has accepted the recommendation. This recommendation is based on the following considerations:  Exploration activities have encountered wide intersections of mineralisation with potentially economic graphite and vana- dium values.  Furthermore, the scale and configuration (general topography, width, dip, strike length and surface outcrop) of the deposit are favourable to trial mining activities ahead of full economic scale exploitation.  Trial mining and processing will gener- ate detailed technical information for use in formal feasibility studies of full-scale project development. It will also provide product samples for evaluation by offtake partners, the evaluation of marketing arrangements and the generation of rev- enue from the sale of the graphite and vanadium products. Cost considerations indicate that Mustang could finance the establishment of trial mining and processing from its currently available finance facility and planned fund- ing through the current rights issue. Work completed to date has shown that Caula could deliver an exceptional com- bination of both high-grade (13 % TGC) mineralisation and large flakes sizes (approxi- mately 55 % large, jumbo and super jumbo) and acceptable purity levels (>95 %TGC aver- age in all graphite product flake sizes). The vanadium content of the ore could contribute very significant additional value. At the adjacent Montepuez ruby pro­ ject, Mustang has an experienced team with

April 2018  MODERN MINING  5