Kipushi zinc-copper project is a historical underground mine located in the province of Haut-Katanga in the Democratic Republic of the Congo (DRC).
Kipushi Corporation (KICO), a joint venture between Ivanhoe Mines (68%) and state-owned mining company Gécamines (La Générale des Carrières et des Mines, 32%), owns the project.
Prefeasibility study of the project was completed in 2017, while a definitive feasibility study is underway.
Kipushi mine is estimated to process 8.6Mt of ore and produce 2.47 million tonnes (Mt) of zinc concentrate over its life of mine of 11 years. The production is expected to be commenced in 2021. The mine development cost is estimated to be £276m ($337m).
The project is estimated to produce 381,000 dry tonnes per annum of zinc concentrate, graded at 59% zinc, through its life-of-mine of 11 years. It is expected to become one of the largest zinc mines in the world, following the start of production. The average annual zinc production from Kipushi is estimated to be 225,000t.
Kipushi zinc-copper project location and geology
The Kipushi project is situated in the south-western part of the Haut-Katanga Province in the DRC.
The historical project witnessed approximately 60Mt mined between 1924 and 1993 before being placed under care and maintenance. The project also produced more than 12,600t of lead and approximately 278t of germanium between 1956 and 1978.
The mine is situated within the Central African Copperbelt in the Katangan basin. The succession of the basin is divided into three mappable groups, namely the Roan, Nguba, and Kundelungu.
Zinc and copper mineralisation is mostly identified in the Fault Zone, the Copper Nord Riche, the Série Récurrente, the Big Zinc, and the Southern Zone.
Kipushi zinc-copper mine reserves
As of December 2017, the Kipushi zinc-copper mine was estimated to contain 8.8Mt of proven and probable ore reserves grading 32.14% Zn. It is forecasted to contain 2.76Mt of zinc.
Mining at Kipushi zinc-copper mine
Longitudinal sublevel open stoping (SLOS) and pillar retreat methods will be applied at the Big Zinc Zone, the prime focus of the Kipushi project. The mined stopes will be filled with cemented rock fill (CRF), while the sill pillars are proposed to be mined using pillar retreat method.
The mine will be accessed through the existing decline, which is proposed to be developed from the existing level 1,330mRL to the bottom stoping level of 1,590mRL.
The existing underground infrastructure comprises vertical mine shafts with associated headframes and mine excavations.
Ore processing at Kipushi zinc-copper mine
Ore and waste from the Big Zinc Zone will be crushed underground and hoisted to the surface through the modernised Shaft 5, which will act as the main production shaft. The 1.8Mtpa capacity rock-hoisting winder of Shaft 5 was also upgraded as part of the project.
The crushed material will be conveyed to the Old Kipushi Concentrator (OKC). The processing plant at the OKC will consist of two-stage crushing and screening units, dense media separation (DMS), ball mill grinding, and differential flotation circuits to process the ore.
The crushed and screened material will be forwarded to the DMS circuit to separate the dense sphalerite and other minerals from the dolomitic waste. The concentrate produced from the DMS will be sent to the milling section, while the floats will be transferred to the waste handling area.
The DMS concentrate and crusher fines will be grinded in a single-stage ball mill with cyclone classification. Slurry from the mill will be fed to a two-stage selective flotation circuit wherein copper and lead will be separated to produce zinc concentrate.
The zinc flotation concentrate will be thickened, filtered, and bagged for transport. The bagged concentrate will be transported by rail from the new loading terminal to either the port of Durban or Richards Bay in South Africa.
Raw water will be sourced from underground, while potable water will be received from the local municipal supply that will be stored in their respective tanks.
Power will be provided by Société Nationale d’Electricité (SNEL), the state power company of the DRC, from Lubumbashi by using two existing transmission lines. A new 6.6kV overhead line will be laid to provide power to the tailings storage facility (TSF). New diesel generators will provide back-up, for a capacity of 12MW.
A new 34km railway track will be rebuilt to connect the Kipushi Mine to the main Lubumbashi-Sakania railway at Munama.
In October 2017, Ivanhoe signed a memorandum of understanding (MOU) with Société Nationale des Chemins de Fer du Congo (SNCC) to rebuild the rail track connecting the mine.
R&H Rail is responsible for the front-end engineering design study of the new railway track connecting the mine to the main Lubumbashi-Sakania railway at Munama.
KICO engaged OreWin, MSA Group, SRK Consulting, Murray & Roberts, Golder Associates, and MDM Engineering for preparing the 2017 pre-feasibility study (PFS).
The conglomeration of OreWin, the MSA Group, SRK Consulting (South Africa), and MDM (Technical) Africa prepared the updated NI 43-101 technical report for Kipushi zinc-copper mine.