Tag Archives: Magma

Marks reveals Resolution copper concentrator details at SME

There’s some good news for mineral processing equipment suppliers looking to win business from the Resolution copper mine in Arizona, USA: the Rio Tinto/BHP-owned project already has a preliminary concentrator plan in place.

The sticking point is that, according to Anita Marks, Principal Advisor, Process Engineering, Resolution Copper, the plant ground-breaking is not likely for another eight years!

Speaking at the 2020 SME MineXchange Conference & Expo, in Phoenix, Arizona, on Tuesday, Marks revealed the plans for the concentrator at the mine, which when operational could become the largest copper producer in North America.

The project, situated close to the former-operating Magma mine, is currently in the process of deepening Shaft 9 down to a level of 2,086 m deep. The project partners will have spent over $2 billion (Rio Tinto share $1.1 billion) by the end of this year to develop and permit the project, including $302 million of additional expenditure approved earlier in 2019. Marks’ long timeline to groundbreaking is a reflection of the lengthy permitting process the project will have to go through.

Following the shaft deepening – expected to be completed in 2021 – and if the project receives the required approvals, development work for the block cave mine could start to take place.

At the same time as the company is focused on these aspects of the project, Resolution is leveraging the drill core it has obtained to calculate all-important metallurgical information and come up with a preliminary concentrator design.

The project has delineated indicated and inferred resources totalling 1.97 Bt at 1.53% Cu and 0.036% Mo from drilling, so there are many datapoints to draw from when it comes to generating a process flowsheet. It has used 79,000 ft (24,079 m) of core – including 38 full holes and 10 partial holes – 527 grindability samples, 646 rougher/cleaner kinetic tests and three pilot projects to come up with these plans, according to Marks.

Ahead of the concentrator, ore will be crushed underground – possibly with a gyratory crusher – and conveyed underground before being hoisted to surface.

The concentrator looks like having a SAG and ball mill configuration without a pebble mill (at least in the initial stages), plus a large cell bulk flotation circuit with columns for cleaning. It would have a separate float for tailings separation and produce both a copper and molybdenum concentrate.

This has the potential block cave mine producing 120,000 t/d of ore, with plant availability expected to be 92%.

And water consumption and recycling are high on the priority list for the project, with Marks saying the company is trying to reclaim as much water as possible. A tailings thickener is expected at the concentrator itself, with the aim to capture 80-85% of the water used in the process, she said.