JSE- and Nasdaq-listed advanced materials company ASP Isotopes (ASPI) has successfully restarted the first 18 stages, comprising segments one and two, of its Silicon-28 (Si-28) enrichment facility, in Pretoria, South Africa.

It expects to make initial commercial shipments of enriched Si-28 in the third quarter of this year.

ASPI has signed three commercial contracts for enriched Si-28 with US-based customers that require it for quantum computing and next-generation semiconductors.

It shipped its first samples of enriched Si-28 to a US customer in August 2025 and independent analysis confirmed that enrichment levels were in line with theoretical calculations.

Following customer site visits in the second half of 2025, ASPI began implementing several engineering modifications to noncore elements of the Si-28 enrichment facility, such as valves, compressors and piping.

Having implemented these planned enhancements and operated the first 18 stages of the Si-28 enrichment facility for more than three weeks, ASPI's engineering team believes it has found an optimised engineering solution.

Further, these same engineering enhancements are expected to be implemented for the remaining stages of the Si-28 enrichment facility to enable commercial production of enriched Si-28 safely and efficiently, the company says.

“While the core enrichment technology has been operating in line with our expectations, many of the noncore components did not operate in line with the specifications provided by the original-equipment manufacturer suppliers,” says ASPI head of engineering Heino van Wyk.

“Over the past nine months, the engineering team has worked to correct these peripheral issues to construct a plant that is designed to be safe and efficient,” he says.

Further, enriched Si-28 is emerging as a critical material. In quantum computing, the purity of enriched Si-28 allows qubits – the fundamental building blocks of quantum computers – to hold their entangled state for significantly longer before collapsing, which is a persistent challenge that has historically stood between quantum computing and real-world commercial use.

Providing access to enriched silane, or SiH₄, for this purpose may allow them to make meaningful strides in advancing the technology, says ASPI.

Further, the company has also been demonstrating that enriched Si-28 has a superior ability to conduct and dissipate heat. This property may allow it to meaningfully improve the performance and reliability of conventional semiconductors.

“As we scale our production capabilities over the coming quarters, both of these applications will be central to our strategy. We have seen considerable interest in many isotopes to enable next-generation technologies,” says ASPI Electronics and Space division president Stefano Marani.