TSX listed Ivanhoe Mines has announced that an independently prepared estimate has resulted in a significant increase in measured and indicated mineral resources at the company’s high-grade, Kipushi zinc- copper-silver-germanium mine in the DRC.
The Kipushi mine is adjacent to the town of Kipushi, approximately 30 km south-west of Lubumbashi and less than 1 km from the Zambian border. It is oper- ated by Kipushi Corporation (KICO), a joint venture between Ivanhoe Mines (68 %) and Gécamines (32 %), the DRC’s state-owned mining company.
Vertical long section (looking west) showing Kipushi’s Big Zinc, Série Récurrente, Southern Zinc and Fault zones, and the Fault Zone Splay. Traces of the 58 holes drilled by Ivanhoe in 2017 are shown in blue.
The new Mineral Resource Estimate (MRE) is the first update to be issued for Kipushi since Ivanhoe published its ini- tial, independent NI 43-101 estimate in January 2016.
The new MRE, prepared by the MSA Group of Johannesburg, has increased Kipushi’s measured and indicated zinc-rich resources by 16 %, from 10,2 Mt to 11,8 Mt, with an increase in zinc grade from 34,89 % to 35,34 %. In addition, the mine’s mea- sured and indicated copper-rich resources have increased by 40 % from 1,6 Mt to 2,3 Mt, with a slight increase in the copper grade from 4,01 % to 4,03 %.
The zinc grade of Kipushi’s measured and indicated mineral resources is more than twice as high as the world’s next- highest-grade zinc project, independently ranked by Wood Mackenzie, an international industry research and consulting group, based on contained zinc.
The MRE incorporates Ivanhoe’s second phase of underground drilling at Kipushi that was completed late last year, with a total of 9 706 m drilled in 58 holes. Eight holes were drilled for metallurgy, 31 holes in the Southern Zinc and Big Zinc, five holes in the Nord Riche and 14 holes in the Série Récurrente. The updated MRE will be used in the preparation of the Kipushi Deﬁnitive Feasibility Study (DFS), which is expected to be ﬁnalised later this year or early in 2019.
The DFS will update and refine the findings of the Preliminary Feasibility Study (PFS) issued last December. Similar to the PFS, the DFS will focus on the ini- tial mining of Kipushi’s Big Zinc Zone. The planned return to production would establish Kipushi as the world’s highest- grade, major zinc mine.
Robert Friedland, Executive Chairman of Ivanhoe Mines, said that the new resource estimate was very positive for mine plan- ning purposes. “We have always believed that Kipushi held the potential to host sig- nificantly more high-grade zinc, copper, silver and germanium resources than were initially reported in the mineral inventory when we acquired our 68 % interest in the mine in 2011,” he said.
“Kipushi operated for more than 60 years as a high-grade copper mine, with signiﬁcant germanium production, before it was placed on care and maintenance in the 1990s. With continued exploration success, we are confident Kipushi could remain in production for at least several more decades.
“While our initial mine plan focuses on mining Kipushi’s exceptionally high-grade Big Zinc deposit, the adjacent Fault Splay and Southern Zinc zones are compelling, near-term development targets as they have thick, zinc-rich mineralisation zones grading up to 45 % zinc. In addition, the copper-rich zones oﬀer further opportunities to expand and diversify the mine plan once production recommences,” Friedland added.
The planned primary mining method envisaged for the Big Zinc deposit in the PFS is sublevel long-hole, open stoping, with cemented backﬁll. The crown pillars are expected to be mined once adjacent stopes are backﬁlled using a pillar-retreat mining method. The Big Zinc deposit is expected to be accessed via the existing decline and without any significant new development. The main levels are planned to be at 60-m vertical intervals, with sub- levels at 30-m intervals.