The Chilalo graphite undertaking shall be developed as an open-pit mine. It’s positioned inside the Nachingwea property, a 5,400km² tenement space in south-east Tanzania.
The mine was beforehand operated by IMX Assets (Indiana Assets) and bought to Graphex Mining in June 2014.
Graphex Mining was renamed to Marvel Gold in August 2020. The undertaking is now owned and operated by Evolution Power Minerals (Evolution), an entirely owned subsidiary of Marvel Gold.
The pre-feasibility examine (PFS) for the undertaking was accomplished in September 2018. An up to date definitive feasibility examine was accomplished in March 2023.
The estimated lifetime of the mine is 17 years with a preproduction capital estimated at $120m.
Challenge location
The Chilalo undertaking is positioned in south-eastern Tanzania, East Africa, 100km north of the border with Mozambique and roughly 180km west of the coastal port metropolis of Mtwara on the Indian Ocean.
It’s 400km south of Tanzania’s largest metropolis, Dar es Salaam and the property is located within the Ruangwa District of the Lindi Area.
Geology and mineralisation
The mine is positioned inside the famend Mozambique belt, which hosts graphite deposits corresponding to Syrah Assets’ Balama undertaking and Magnis Assets’ Nachu undertaking.
The undertaking entails the event of the Shimba deposit.
Regional geology includes late Proterozoic Mozambique cellular belt lithologies internet hosting mafic to felsic gneisses (aluminous wealthy sediments), that are interlayered with amphibolites (mafic-sourced materials) and meta-sedimentary rocks.
Mineralisation is normally discovered inside 100m of the floor, and primarily hosted in felsic gneiss and amphibolites and inside high-purity marble horizons in uncommon portions.
In early 2023, two new high-grade mineralised zones, Chilalo East and Chilalo E2, have been found.
Chilalo East has high-grade mineralisation of greater than 1.6km out of a possible 3.5km strike size indicated by an electromagnetic conductor.
Chilalo E2, positioned east of Chilalo mining licence and parallel to Chilalo East, has been examined for 1.1km out of a possible 5km strike with mineralisation open to the east and west.
Chilalo graphite undertaking reserves
The undertaking is estimated to include a possible ore reserve of 8 megatonnes (Mt) grading 10.5% whole graphitic carbon with a complete contained graphite of 836,000 tonnes (t), as of March 2023.
Mining methodology
The Shimba deposit shall be developed utilizing open-pit mining strategies integrating typical 50t-60t inflexible and articulated dump vehicles, excavators and shovel operations.
The mining operations shall be undertaken at three open pits – Central, North and West. The event schedule contains two levels for the West and North pits and 4 for the Central pit.
Mining operations shall be carried out in benches with a peak of 10m and 5.25m berms.
The Central pit shall be 950m lengthy, 350m extensive, and 170m deep. The North Pit shall be round with a diameter of 300m and a depth of 122m.
Twin lane ramps of 17m extensive will enable a secure passage for vehicles whereas 12m extensive single lane ramps shall be used for mining final benches and goodbye cuts.
Cutback designs will preserve a minimal mining width of 30m whereas regular benches will preserve a mining width of 20m.
Ore processing at Chilalo graphite undertaking
The Chilalo processing facility is designed to deal with 500,000t a yr.
The run-of-mine ore will endure a two-stage crushing course of, which entails using a main jaw crusher adopted by a secondary cone crusher.
The latter shall be configured in a closed circuit with a double-deck vibrating display.
Ore grinding and classification shall be undertaken in a main grinding mill comprising a rod mill working in a closed circuit with a display.
The undersize from the rod mill display shall be channelled to a flash flotation rougher cell whereas the oversize shall be returned to the first mill for reprocessing.
Graphite of a rough nature shall be harvested inside the flotation circuit, whereas the rougher tailings shall be directed to the ball mill cyclones.
Subsequently, the overflow from the secondary ball mill cyclone shall be conveyed to the rougher scavenger circuit.
The resultant concentrates from each the rougher flash flotation and the rougher scavenger flotation shall be transferred to the first cleaner sharpening mill feed tank.
The fabric will then endure an in depth cleansing course of, consisting of 9 levels of cleaner flotation, 4 levels of sharpening, and three levels of moist screening.
The cleansing course of is designed to yield high-purity graphite concentrates of each coarse and wonderful varieties.
The ultimate product shall be subjected to a filtration course of, adopted by drying and classification into eight distinct bins, every comparable to totally different grades.
The coarse and wonderful graphite concentrates will endure separate filtration and drying processes, utilising a person plate and body filter, and a rotary drum dryer for every respective prepare.
As soon as dry, the graphite focus shall be sorted into varied product sizes utilizing plansifter screens. The ultimate merchandise will then be packaged into luggage, with the choice of both 1t or 25kg capacities, prepared for cargo.
Infrastructure for the Tanzanian graphite undertaking
Energy required for the undertaking shall be generated onsite by a 4MW energy station integrating 4 1MW diesel-powered gensets, certainly one of which is able to function backup.
The method water for the undertaking shall be equipped from an on-site borewell.
Graphite concentrates from the undertaking are to be transported to the Mtwara Port by vehicles utilizing an current 220km highway. Highway sections adjoining to the undertaking web site shall be upgraded.
On the Mtwara Port, the product shall be saved in leased storage services and shipped to industrial prospects, primarily in China.
Different main infrastructure for the undertaking will embrace a tailings storage facility (TSF) and waste dumps.
The undertaking advantages from current infrastructure, together with the Ntaka Hill camp with workplaces, mess corridor, telecommunications, and laboratory services, positioned roughly 20km from the undertaking web site.
Funding
Graphex Mining secured $85m in funding from Castlelake in October 2018 for the undertaking.
Offtake settlement
Evolution signed an offtake settlement with Yichang Xincheng Graphite, a graphite merchandise producer, for the sale of 30,000t each year of coarse flake graphite from the undertaking.
Contractors concerned
The PFS was compiled by BatteryLimits, a mining undertaking improvement consultancy, with inputs from consulting firms ATC Williams for the TSF and Knight Piesold for the water research.
CSA International, a mining consultancy enterprise, decided the mineral useful resource estimates and geological research whereas SGS Australia, a testing, inspection and certification firm, was answerable for metallurgical take a look at work.
Outotec, a know-how supplier to the minerals and metals processing sector, performed the filtration take a look at work.
Dhamana served because the advisor for Evolution providing experience in undertaking administration in addition to environmental and social elements.
CPC Engineering, an engineering firm, was awarded the front-end engineering design contract for the processing plant.
GR Engineering, a course of engineering, design and development firm, was answerable for the method plant, engineering design, general value estimation and report compilation.
AQ2, a water administration consultancy; Mine Waste Administration, an environmental consultancy; and Azure Capital, an advisory firm, have been additionally concerned within the Chilalo graphite undertaking.