An independently prepared estimate has resulted in a significant increase in measured and indicated mineral resources at Ivanhoe Mines’ high-grade Kipushi zinc-copper-silver-germanium mine.
DRC - The new mineral resource estimate is the first update to be issued for Kipushi since Ivanhoe Mines published its initial, independent NI 43-101 estimate in January 2016.
The new mineral resource estimate 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 measured 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 new mineral resource estimate 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 mineral resource 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 initial mining of Kipushi’s Big Zinc Zone. The planned return to production would establish Kipushi as the world’s highest-grade, major zinc mine.
Infill drilling establishes Southern Zinc as high-value, poly-metallic zone
Infill and confirmation drilling in the Southern Zinc Zone has confirmed the high tenor of this mineralised zone (tenor is the percentage of minerals that is actual metal to be extracted), which is characterised by high zinc, copper, lead and silver grades.
The poly-metallic style of mineralisation in the Southern Zinc is very similar to historical Kipushi production, with a clear zonation of copper-rich to zinc-rich zones.
Using a zinc cut-off of 7%, the Southern Zinc Zone contains 0.88 Mt of indicated mineral resources at a grade of 24.5% zinc, 2.97% copper, 1.95% lead and 75 g/t silver.
Additional inferred mineral resources in this zone are 0.16 Mt at a grade of 24.37% zinc, 1.64% copper, 1.2% lead and 38 g/t silver.
Robert Friedland, executive chairman of Ivanhoe Mines said that the new resource estimate is very positive for mine planning purposes, adding another 1.6 Mt of measured and indicated zinc-rich resources and, at the same time, improving the overall zinc grade of the resources.
“We have always believed that Kipushi held the potential to host significantly 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,” Friedland 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.
Given the significant, very-high-grade zinc resource at Kipushi – which is rich in potential by-product credits including copper, silver and germanium – and the ongoing exploration campaign at Kipushi, Ivanhoe and the Gécamines technical team are continuing to investigate additional downstream processing options.
Germanium is a strategic metal that is a key component of fibre-optic systems, infrared optics, high-efficiency solar cell applications and light-emitting diodes. The current spot price of germanium is approximately US$1 900/kg (US$54/oz).