Tag Archives: SME MineXchange Annual Conference & Expo

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.

ABB’s Bonvicini argues the OPEX case for grinding mill installations

ABB’s Leandro Bonvicini is urging mining companies to think outside of the capital expenditure box and conduct numerous tradeoff studies when deciding on their grinding circuit of choice.

Speaking about the Toquepala copper expansion project in Peru (pictured), specifically, in a talk titled, ‘SPCC Toquepala Expansion: Designing a reliable grinding circuit’, at the SME MineXchange Annual Conference & Expo, in Phoenix, Arizona, Bonvicini said the mine owner, Southern Peru Copper, was keen to employ a solution that was not only affordable from a capital cost perspective, but also energy efficient and came with low operating costs.

The $1.2 billion expansion, which saw throughput rise from 60,000 t/d to 120,000 t/d, involved the addition of two new thyssenkrupp-made ball mills, with ABB providing the gearless mill drives (GMD) technology. This came on top of the 33 mills the miner already had up and running as part of the existing 60,000 t/d plant at the operation.

GMDs are the grinding solution of choice in challenging environments, according to ABB. By eliminating bolt-on mechanical components such as ring-gears, pinions, couplings and gearboxes, GMDs offer ore producers unrivalled availability, efficiency and durability, while reducing operating expenditure, the company says.

Unlike more traditional ring-geared mill drives – where a ring-shaped gear encircles the mill and drives it through one or two pinions followed by conventional motors – GMDs work by mounting rotor poles directly to the mill body and surrounding it with the stator ring, meaning the mill itself is incorporated into the motor.

The necessary torque to turn the mill is transmitted between the GMD motor and the mill via the magnetic field in the tiny air gap between the stator and rotor. Because this type of motor system requires no gearing or direct contact transmission, GMDs boost efficiency by reducing frictional losses, while fewer mechanical critical components means less maintenance downtime is required due to wear and tear, according to ABB.

Bonvicini said SPCC weighed up numerous drive options during the due diligence phase but settled on GMDs even though the mill power required was as low as 11 MW. He said this was one of the lower power installations the ABB GMD team had employed, but the operating economics stacked up.

The project team was focused on choosing a solution that, even if it cost slightly more to install, would provide the lowest operating costs over the life of the mine, according to Bonvicini. This convinced the company to employ GMDs for the very first time in its grinding circuits.

In addition to the GMDs on the ball mills, ABB supplied two 2.65 MW motors for the high pressure grinding rolls working at the operation, according to Bonvicini.

GZ Consultants’ O’Brien engineers case for new approach to mine access tunnel work

In his SME MineXchange presentation on Tuesday, Timothy O’Brien of Gall Zeidler Consultants, displayed how using an engineered tunnel approach in the construction and repair of mine access tunnels could result in extended life of mine and an effective risk management process.

During his talk, ‘An Engineered Tunnelling Approach for Mine Access Tunnels’, in Phoenix, Arizona, he revealed details about an ambitious project recently carried out at Rio Tinto’s Bingham Canyon copper mine, in Utah, USA.

With the C-6 tunnel at the mine – used to transport crushed ore from the open pit – suffering from decay, Gall Zeidler Consultants was drafted in to not only inspect the tunnel, but also carry out rehabilitation work on the ground support system to restore access to the tunnel. It chose a system made up of yielding steel sets for this project, knowing that this could cope with the varying condition of the 4.57 km-long tunnel that was built in 1959 originally as a rail tunnel.

The biggest challenge for the consultants was this support system needed to be constructed without interrupting the conveyor system working underneath, which sees 70,000 t of crushed rock conveyed daily.

The engineers came up with a solution that was elevated above the conveyor, allowing crushed material to keep running through the tunnel, according to O’Brien.

The consultants also developed a two-year ground control management plan, including a monitoring and instrumentation program and trigger action response plan to monitor tunnel structural integrity in response to future mining activities.

Newmont turning to software for Peñasquito TSF planning

Newmont is looking to leverage planning software already used in the oil sands industry to create a safe, stable and well-planned tailings storage facility at its Peñasquito gold mine, in Mexico, according to Ross Hunsaker.

Hunsaker, the gold miner’s Tailings and Fresh Water Manager, is due to present ‘Newmont Goldcorp Peñasquito Mine – How Technology has Enhanced Tailings Planning’ at the 2020 SME MineXchange Annual Conference & Expo, in Phoenix, Arizona, on Tuesday, with a presentation abstract revealing more about his talk.

As he said in this abstract, the oil sands industry operates large, complex tailings storage facility (TSF), with these operators taking advantage of tools generated for mining and using them for planning and scheduling TSFs.

“Several different software packages are needed to handle this planning due to beach slope changes, mature fine tailings and water management,” he said. “Mining lags behind the oil sands industry when it comes to tools for tailings planning.”

At the Peñasquito mine, which produced 272,000 oz of gold in 2018, the TSF dam spans 11 km and, at completion, will be 150 m high. It has a centreline raise for three sides and a downstream raise for the fourth side, according to Hunsaker. It is being constructed using a mine fleet of Komatsu 930Es for a buttress, and a fleet of Cat 777 haul trucks for a sliver fill, with 20-ton (18 t) dump trucks for rock fill and cycloned sand, he added.

According to Hunsaker, the Peñasquito team is implementing planning software to integrate all construction activities into one plan, with scenario planning enhanced by software to optimise resources, activity duration and constraint identification.

Back in 2018, Goldcorp (which later merged with Newmont) achieved commercial production at Pyrite Leach project (PLP) at Peñasquito, a project that has seen tailings reprocessed for metal recovery.

The PLP plant processes the existing plant tails, feeding a sequential flotation and leach circuit with precious metals recovered through a Merrill Crowe process, producing doré as the final product. Tails from the new plant report to the existing TSF.

Hunsaker concluded in the abstract: “The overall software implementation is a work in progress with the overall goal of a safe, stable and well planned TSF.”

Kibali automation journey to be discussed at SME Conference

One of the most autonomous underground mines in the world, Barrick Gold’s Kibali operation in the Democratic Republic of the Congo (DRC) recently hit another annual production record.

The mine soared past its 2019 production guidance of 750,000 oz of gold, with 814,027 oz being delivered. This topped the previous 2018 record of 807,251 oz.

At this year’s SME MineXchange Annual Conference & Expo, in Phoenix, Arizona, on February 26, Ismali Traore, Kibali Technical Services Manager, is to reveal more about how the operation has continued to surpass expectations and how safety has become front and centre at the mine, owned 45% by Barrick, 45% by AngloGold Ashanti and 10% by SOKIMO.

In his conference abstract, Traore said, in recent years, the mine has made significant progress by implementing a fully automated production level and material handling system (MHS) at the underground mine.

This sees up to three LHDs operated simultaneously from ore passes to the crusher and multiple LHDs from the stope to the finger raises. The entire automation system is remotely operated from a control room located on surface.

In a recent presentation, the Kibali partners said the system was designed to have autonomous Sandvik LH621 LHDs work in combination with a Sanvdik AutoMine loading system (ALS). The ALS Mission Control System is incorporated with features such as traffic management, auto-loading and tipping with real time tonne-kilometres/h, and a real-time bucket weighing system that is within 3% accuracy level for each bucket trammed to the coarse ore bins (COB) at the operation.

The MHS, meanwhile, uses data obtained from the ALS to interface with SCADA via an OPC interface, according to the partners. COB levels from the SCADA system are then interfaced with ALS to manage the loading of the bins.

All information is interfaced to achieve the nameplate capacity of the hoisting system – which WorleyParsons provided the operating philosophy for and Winder Controls (member of the SIEMAG TECBERG Group) provided the winder design for – while taking into consideration the availability of the ALS to equate the total MHS availability, they said.

In its objective of becoming one of the most efficient Tier One mines globally where safety is a focal point of the operation, a significant amount of time was spent on the traffic management and human interaction with the autonomous mining equipment, Traore said.

This is something Barrick President and Chief Executive, Mark Bristow, picked up on last month, saying the mine is continuing its technological advance with the introduction of truck and drill training simulators and the integration of systems for personnel safety tracking and ventilation demand control.

Traore is to expand on the important safety protocols implemented to mitigate the risk of collision between this equipment and humans within the automated system during his presentation.