South African mining and industrial group Mantengu Limited has decided to dispose of Sublime Technologies, its silicon carbide production business, after prolonged delays in securing a new electricity tariff agreement with Eskom made continued operations financially unsustainable.

The Johannesburg Stock Exchange-listed company, formerly known as Mantengu Mining, said its Board of Directors has invited interested parties to approach the company regarding the potential acquisition of Sublime.

The decision follows a consultation process with Sublime employees and a trade union in accordance with South Africa’s Labour Relations Act, which began in May 2026 and is expected to conclude by the end of August.

Eskom tariff delay puts Sublime under pressure

Sublime’s financial difficulties stem from the expiry of its negotiated Eskom tariff agreement on March 31, 2025. The agreement had allowed the company to access lower electricity rates through a negotiated pricing arrangement. Sublime applied for a new tariff agreement on June 13, 2024, but Mantengu said it has still not received approval from Eskom.

The delay has placed significant pressure on Sublime because its silicon carbide manufacturing process relies on open-arc furnaces and consumes substantial amounts of electricity.

Mantengu said, similar to other energy-intensive smelting operations in South Africa, Sublime’s operations were no longer viable under prevailing Eskom tariffs and energy costs.

Mantengu targets R4 million monthly cost savings

Sublime has had no income since June 2025, while Mantengu continued carrying the full payroll of its workforce. The consultation process involves approximately 105 employees and is expected to be completed at the end of August 2026.

Once the process is finalized, Mantengu expects group expenditure to decline by R4 million ($250,649) per month from September 2026.

The company said the reduction represents a material cost saving as it seeks to reduce the financial burden associated with maintaining Sublime’s operations.

Company invites buyers for Sublime

Mantengu’s Board has now decided that disposing of Sublime is the appropriate course of action given the prolonged uncertainty surrounding its electricity costs and tariff application.

The company has invited interested parties to approach Mantengu regarding the potential disposal of the silicon carbide business.

The group said it will update shareholders when further material developments occur, including progress on the disposal process.

The decision marks a significant shift for Mantengu as it moves to reduce exposure to an energy-intensive operation that has remained without revenue for more than a year while the company awaits clarity on its Eskom tariff arrangement.