Metso Outotec designs innovative automated system that further optimizes an operation at Dundee Precious Metals’ Tsumeb in Namibia

A bit under a year and a half since we first made contact – and almost 11 months from when we were first on site for a workshop – the DPMT (Dundee Precious Metals Tsumeb, the smelting subsidiary of DPM) Offgas Optimizer has been successfully commissioned in Dundee Precious Metals located in Tsumeb, Namibia. The project journey as a whole is an example of the outcomes that can be achieved when we place the Metso Outotec values of "Care for the Customer" and "Perform Together" at the forefront of our value creation efforts.

Dundee Precious Metals Tsumeb (Pty) Limited), is located in Tsumeb, Namibia, which is approximately 430 km north of the capital city of Windhoek. The smelter was constructed in the early 1960’s to process concentrate from the Tsumeb copper mine and other mines in the country. The facility consists of a primary smelting furnace, the Ausmelt furnace, as well as two Peirce Smith Converters, a slag concentrator plant, two oxygen plants, and a sulphuric acid plant. The smelter employs approximately 800 people and is one of only a few in the world that can treat complex copper concentrates containing various impurity elements. Blister copper and sulphuric acid are smelter products.

CHALLENGE

• To create an automated system that could manage the dynamic conditions and constraints within the Pierce Smith Converter offgas train during the roll in and roll outs, whilst also maximising the offgas pull from the operator areas to create a better working environment and reduce rouge offgas emissions during steady operation

The challenge was to create an automated system that could manage the dynamic conditions and constraints within the Pierce Smith Converter (PSC) offgas train during the roll in and roll outs, whilst also maximizing the offgas pull from the operator areas at the Ausmelt furnace and PSCs. This was in hopes to create a better working environment and reduce rouge offgas emissions during steady operation. The key to the customer acceptance was a solution that incorporated a step wise approach on a modular system that could be expanded later. This is exactly something that the ACT system was developed to be able to deliver.

From the initial stages of the Idea Miner (A co-creation methodology used by Outotec based on the Google Design Sprint) to the actual development and commissioning on site, the Outotec engineers were able to bring their key specialist knowledge and capabilities in the Metals and Mining industry to produce immediate value to the customer. Working directly with the operators in the control room, the development of product was moulded by their experience and captured the best practices for standardisation.

SOLUTION

• An Offgas Draught Optimizer built on the Metso Outotec ACT advanced control platform
• Ongoing IT and digitalization support services to facilitate continual upgrade and expansion of the product
• Key specialist knowledge and capabilities in the Metals and Mining industry to produce immediate value to the customer
• Working directly with the operators in the control room, the development of the product was moulded by their experience and captured the best practices for standardisation

The Idea Miner methodology was used to test the idea right at the conception stage, which allowed for an immediate user acceptance. Although there was a plan in place to commission in stages from manual to semi-automatic to fully automatic operation, the testing had to go immediately to fully automatic operation. Properly prepared by a hazard and operability study (HAZOP) with Outotec involvement, this switch from manual to immediate fully automatic operation went without incident and the operators have continued to use it since. When asked about their acceptance of the system and their willingness to keep it operating, the consensus was: “If you try to take it away from us now, there’s going to be a fight.”

BENEFITS

• Better working environment
• Reduced rouge offgas emissions during steady operation
• Robust operation of the offgas train for draught control
• The customer now has a system that can handle the difficult conditions in a standard and automated manner capturing the current best practices of their operators
• This allows them to further consistently optimise their operations and adapt to future changes without major rework and redesign

Combined with another product also developed via the Idea Miner method – titled the DPMT Tapping Advisor (aka the Ausmelt level ‘soft sensor’ or digital twin) – these products form the start of a smelter advanced control and intelligence system at DPMT built on the foundations of the Outotec HSC and ACT platforms. When management was asked about their opinion on the outcomes of the project, they responded in what I would consider the most ideal way: “So what’s the next project?”

On the back of this success, DPMT are now looking to work with Metso Outotec to implement an AI/ML system that will help improve operations in the Ausmelt section of the plant, with a view to expanding it across the site to manage the three critical plants (Ausmelt, Converters and Acid Plant) and then onto a central AI controller. The investment in the AI and ML by the Ausmelt Product Group/Smelting Business Line are now bearing fruit and will be instrumental to being able to deliver DPMT and Metso Outotec’s vision for a Fully Automated and Intelligent Smelter.

This article is part of our Smelting Newsletter Issue 1/2020. Visit the issue front page for all articles and greetings from Jyrki Makkonen, Vice President of Smelting business line.