Mill Relining Robot: From Crews Inside to ABB Drives

A grinding mill in a copper or gold concentrator is a rotating steel drum that can be 40 feet across, lined inside with liners that wear and have to be replaced. When they wear out, the mill stops and a crew relines it. A mill relining robot, usually called a mill relining machine, lifts liners out and places new ones so that fewer people have to work inside the drum. This post covers how relines were done by hand, the Australian machines that changed the job, this year's news on semi-automated relining and new liners, and where ABB fits.

Grinding mills in a concentrator, from the cover of ABB's gearless mill drive brochure. Photo: ABB

How crews relined grinding mills by hand

Traditionally, relining meant people inside the mill. Crews climbed into the drum to work on worn liners and sling out the ones that had fallen, in a confined space with uneven footing, suspended loads and mobile equipment around them, as the relining specialist RME describes the old method. The liner maker Tega adds that with conventional liners, peening and oxy cutting can stretch out a changeout and keep more people exposed inside the shell. Mill time is expensive too: ABB estimates that unplanned downtime in large grinding circuits can cost up to 500,000 dollars an hour.

A ball mill at the Utah Copper Company's Magna Concentrator in August 1972. Photo: Jack E. Boucher, HAER / Library of Congress via Wikimedia Commons (public domain)

Mechanised relining started in Australia. Dr John Russell founded Russell Mineral Equipment, RME, in 1985 because he rejected the idea that the safety and productivity risks of relining were unavoidable. His first mechanised mill liner handler, the RUSSELL 6, was commissioned at Mount Isa Mines in Queensland and halved the site's reline times. The RUSSELL 7 followed at the Leinster mine in Western Australia as the world's first large liner placement machine, able to place liners of 2.5 tonnes. Through the 1990s RME's range grew into a full mill relining system.

Mount Isa Mine in Queensland in 1962, the site where RME's first liner handler was later commissioned. Photo: kenhodge13 / Wikimedia Commons (CC BY 2.0)

Adoption sped up during the global mining construction boom, and RME now serves 440 mine sites in 64 countries with machines that exchange liners from under 400 kilograms up to 10 tonnes. In December 2025 it built its 600th RUSSELL mill relining machine, a customised seven-axis RUSSELL 7 with a 1.6 tonne capacity for the 22-foot SAG mill at Northern Star's Pogo gold mine in Alaska. It replaces the mine's 20-year-old machine, which was number 76 off the production line, so one of these machines can serve a mill for two decades.

The shell of a grinding mill, 2008. Photo: Vyacheslav Bukharov / Wikimedia Commons (CC BY-SA 4.0)

Semi-automated relining and lighter liners today

The newest machines work from outside the mill. RME calls its RUSSELL 7-R AutoMotion, built in capacities from 4.5 to 10 tonnes, the world's first semi-automated mill relining machine for relining from outside of the mill. At a high-throughput copper and gold operation in Indonesia, it was fitted with RME's INSIDEOUT tools and with lifters from Bradken designed to be pulled straight out through the mill wall. Worn liners came out with no crew inside the mill, risk exposure fell by 85 percent and removal was 16 percent faster. The site's stated goal is to "eliminate fatal risks and enable automated relining".

Grinding mills under a steel structure, from ABB's gearless mill drive brochure. Photo: ABB

RME also has new owners. In July 2026 the Singapore investment firm Novo Tellus joined Resource Capital Funds and Australia's National Reconstruction Fund Corporation as a shareholder, and RME's chair Andrew Jessett said the capital would help develop "revolutionary automation technology". Liner makers are changing the job from their side. On 6 October 2026 Tega described its DynaPrime liner, which bonds polymers with toughened steel and combines plates and lifters into large single panels, so a reline needs fewer pieces, no oxy cutting and fixings installed from outside the mill.

A retired ball mill of the former Queensland Cement and Lime Company in Rocks Riverside Park, Brisbane, 2022. Photo: Kgbo / Wikimedia Commons (CC BY-SA 4.0)

ABB has no relining machine, and no source links its robots to a reline. What ABB puts on the mill is the drive that turns it. ABB commissioned the first gearless mill drive for a ball mill in 1969 at Ciments Lambert-Lafarge in France, and that 6.4 MW motor still runs; it has now sold more than 160. In a gearless drive the mill itself becomes the motor's rotor, and inching and creeping come from the drive software. ABB's ring-geared RMDplus drive can turn a mill automatically to the angle or liner reference an operator selects, which ABB says cuts the downtime needed for liner changes.

A ball mill with its drive, from the cover of ABB's RMDplus ring-geared mill drive brochure. Photo: ABB

Where automated mill relining goes next

Fully automated relining is the stated next goal at the Indonesian site, and the drive, the liners and the relining machine would all be part of it. ABB has already run one co-development project of this kind in mining. Its Robot Charger, tested with Boliden and LKAB at the Garpenberg zinc mine, automates the charging of blast holes, which ABB calls one of the few manual processes left in mining, as our post on blast-hole charging explains. A similar partnership on relining, linking drive positioning to a relining machine, is a possibility; no such project has been announced.

The ABB Robot Charger on its carrier vehicle underground, with the arm reaching toward the rock face. Photo: ABB

Copper demand drives much of this. ABB cites an estimate that global copper demand will rise 24 percent by 2035, and it is supplying a 24 MW gearless drive for the 40-foot SAG mill at Harmony's Eva Copper project in Queensland, planned to produce about 60,000 tons of copper a year. Steel liners come from foundries such as Bradken's new plant at Chilca, and that is where ABB arms could fit sooner. The IRB 8700 handles up to 1,000 kg with the wrist down and comes with ABB's Foundry Plus 2 protection as standard, and cells like that are usually planned in RobotStudio.

An ABB IRB 7600 holds a wax tree in a falling sand curtain to stucco the shell at TPC Components, Sweden. Photo: ABB

Weight is the first limit. A 10-tonne liner is ten times what even ABB's IRB 8700 can carry, so dedicated relining machines will stay. Every reline still means lost production while the mill stands, and relining machines work around suspended loads in confined spaces. Getting a machine to site is a job in itself: after factory acceptance testing, the Pogo machine is to be taken apart, shipped via Seattle, barged to Anchorage and hauled overland. Skills matter as well. In Indonesia, RME commissioned the new tooling step by step during scheduled shutdowns, with no added downtime, supported by site training and change management.

Engineers with an ABB IRB 5710, a large robot for heavy handling. Photo: ABB

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