Foundry and engineering company Thos Begbie recently completed the manufacture and supply of specialised coolers for a platinum producer’s smelting furnace site in Rustenburg, in the North West.

The company’s scope of work included the manufacture and supply of cast copper coolers, drill-and-plug copper coolers, the machining of graphite blocks and the assembly of the graphite composite coolers for the ongoing matte end wall and slag end wall rebuild.

“The replacement and rebuild of the slag end wall and matte end wall were scheduled after three years in operation. The end walls of the furnace take most of the hammering during the smelting process, and as such, will be replaced more frequently than the rest of the furnace. The reason is that extreme heat is exerted on the tapholes as the smelting operation takes place,” explains Thos Begbie sales manager Jurgen Dercksen.

He explains that the slag taphole is situated higher than the matte taphole. Slag consists of impurities that float to the top and can later be recovered, crushed and further processed. The molten slag is tapped off into a granulation plant, where it is pelletised. The molten platinum that remains is tapped off into ladles, where it is then moved to another part of the plant for further processing.

Thos Begbie was awarded the contract in April this year and delivered the specialised coolers to the site in June.

“As the timeline for this project was quite tight, we delivered progressively as and when each component was completed. Our scope of work meant that we had to complete the manufacture of the components for installation within 16 weeks from date of order. This was owing to the rebuild of the end walls, which serves as a routine maintenance shutdown and, therefore, the turnaround time on the manufacturing of the critical components needed to be quick,” Dercksen tells Engineering News.

He notes that the total weight of raw copper used for the project was about 115 000 kg and the total tonnage of graphite used was about 6 500 kg, with the total contract for the manufacture and supply of the components about R50-million.

“Upon completion and delivery to the smelter site, our newly established site-work team, which consists only of a few members, was called on to assist with modifications and repairs on site, should this be required. The site team is on standby, should any modifications or repairs to the graphite be required.”

Dercksen declares that, with Thos Begbie considered the industry experts in terms of the manufacturing of the critical copper components for the type of pyrometallurgical operation, it is the go-to company to advise on repairs.

The rebuild is expected to extend the campaign life of the platinum smelter by another three years before the entire furnace needs to be rebuilt.

Pandemic Impact

Although Thos Begbie completed the project successfully, it had its challenges in terms of performing the work safely while providing a safe work environment amid the Covid-19 pandemic.

The company implemented three-shift systems to reduce the number of workers at the plant simultaneously.

“Regular sanitising of workstations was, and still is, being conducted. Every employee is subject to a Covid-19 screening prior to being granted access to the plant. We have had a couple of employees who tested positive and, as such, contact tracing was conducted and all the exposed employees had to undergo the standard isolation period.”

The company put systems in place to ensure that additional labour contractors were on standby if personnel assistance was required during the isolation periods. This creatied job opportunities for the local community, concludes Dercksen.