Metso Insights Blog Mining and metals blog State-of-the-art roaster remote refractory demolition concept enables fast and safe shutdown service at Nyrstar Hobart
Mining Metals refining
Feb 22, 2019

State-of-the-art roaster remote refractory demolition concept enables fast and safe shutdown service at Nyrstar Hobart

Outotec was contacted by Nyrstar, number two in global zinc production, in Hobart, Australia in 2017 to perform descaling and demolition of the refractory upper vertical wall and wall accretion removal on the lower conical wall of their 123 m² nozzle grate fluid bed roaster. The roaster with a 123m² nozzle grate area, was the first of that size installed and currently one of the largest zinc roasting plants in operation, made by Outotec.
Roasting Remote Demolition Platform

For safety reasons the refractory and the wall accretion to the large roaster vessel need to be removed without human intervention, which was a concept that did not exist. Outotec developed a completely remotely operated demolition solution. The proprietary product solution makes use of robotic demolition machines suspended on and H-frame within the roaster which is operated remotely via camera.

The remote concept was eagerly accepted by the customer upon on a value-based solution, leading to an order within short period of time. The time restriction was very challenging and needed to be implemented it swiftly and complete for the upcoming plant shutdown, a mere six months away.

Roaster remote demolition robot machine

Roaster remote demolition robot machine

Outotec custom-designed the demolition robot lifting frame, a proprietary equipment. While not an entirely new concept to Outotec, the challenge was the wide diameter of 12.5m and the unique shape of the roaster vessel in which the machine needed to operate. In addition to safety, speed and efficiency were crucial to minimize the overall shutdown time, to enable customer to return to production and profitability as soon as possible.

The frame had to be installed on the roaster nozzle grate/floor, which was 12m in diameter, and then lifted to the upper wall where the roaster vessel widened to a diameter of 16m, all without human entry into this confined space. This was accomplished by incorporating telescoping hydraulic stabilizers to brace the frame against the vertical walls creating the required support for the robot to perform its task. A second machine was mounted on the opposite side of the frame, acting as a counterweight to balance the entire setup.

Despite weather delays during the critical shutdown period, Outotec completed the remote demolition work, the removal of the wall accretion on the sloping wall and low vertical wall and the cleaning of the bed, within the planned 10-day period without safety incidents. Such execution work enabled customer to accelerate the rest of the shutdown schedule and made Outotec the first company to accomplish a remote shutdown work on such a large vessel.

The customer was impressed with the ingenuity and execution meeting their needs in a fast and safe manner.

A great effort with zero incidents, highly skilled operators and an excellent outcome
says Nyrstar’s Hobart turnaround manager Mark Breen.

Expertise at your service

Outotec is a market leader in fluid bed roasting plants and has been performing, planning and executing demolition works for the past 35 years on metallurgical furnaces, with references from over a thousand projects. Outotec’s top demolition experts each have over 25 years of experience in furnace demolition. Learn more about:

Mining Metals refining