Wakefield-based thermal and metallurgical engineering firm Inprotec has completed a seven-figure project to support the creation of the world’s first ‘clean plant’ antimony and gold processing facility in Sohar, Oman.

The facility, known as an ‘antimony roaster’, is the largest of its kind outside of China and the world’s first clean plant, designed and built to European Union environmental standards.

Created by Strategic and Precious Metals Processing LLC (SPMP), it has the capacity to produce more than 50,000 ounces of gold per annum and 20,000 tonnes of the rare and critical metal, antimony, which is used to fire-proof printed circuit boards and other electronics, and often alloyed with other metals such as lead for use in lead-acid batteries.

Family-owned Inprotec was approached by SPMP and lead engineering contractor Worley Parsons in recognition of the company’s industry leading expertise in designing, supplying and commissioning bespoke furnaces used to melt, smelt and refine non-ferrous and precious metals.

Over the course of the two-year project, Inprotec designed, manufactured, and commissioned two drum-style furnaces, known as refining converters, which are used to remove any impurities in the final stage of refining antimony.

Inprotec also provided all of the ancillary plant required to support the two refining converters, including a trough-like molten metal launder system to carry molten alloys from one location to another using gravity, and an air lancing system used in the refining process.

After extensive testing, the facility recently produced its first refined antimony and, once fully operational, the plant is expected to account for between 12-15% of the world’s antimony production, establishing Oman as a major global producer of this rare and critical metal.

Critical raw material
Inprotec managing director Chris Oldroyd said: “Most people haven’t heard of antimony as it is not the headline grabbing commodity that gold is, but it has been categorised as a critical raw material in recent years due to the fact that it is used widely in electronics.

“Over the last two years we have worked closely with SPMP to design, supply and commission world-leading plant that enables them to cost-effectively, efficiently and safely refine antimony.”

David Fourie, smelting manager at SPMP, said: “Not only is this the first antimony roaster to be built outside of China in the last 30 years, but it’s also the world’s first ‘clean plant’, designed and built to the highest environmental standards.

“It is an incredible feat of engineering and Inprotec’s skilled team have played a key part in helping us to realise this hugely impressive plant and its world-leading capabilities.”

Established over 40 years ago, Inprotec designs, supplies and commissions thermal processing equipment for a growing portfolio of clients across multiple industries, from secondary and primary metal processing through to hazardous waste treatment.

It operates globally to provide cost-effective and timely thermal and metallurgical solutions to some of the biggest companies in the world, such as Glencore, Teck and Johnson Matthey.

In June this year, Mr Oldroyd was appointed to the board of the Institute of Materials, Minerals and Mining Sustainable Development Group (SDG), which serves as a global centre of expertise on sustainability and the environment.

The role sees him act as the representative for the Mineral Processing and Extractive Metallurgy division.