Building At Scale

The decision to build the world's largest calcined clay plant did not begin with a sustainability target. It began with a supply chain problem that Ghana's cement industry had absorbed for decades.

Ghana is one of Africa's largest importers of clinker, the energy-intensive intermediate that underpins conventional portland cement. Industry estimates place the country's annual clinker import bill at close to US$500 million. That dependency ties the price of cement directly to global energy costs, shipping rates, and the depreciation pressure on the cedi. When the cedi weakened sharply between 2022 and 2024, retail cement prices in Accra and Kumasi climbed to between GHS110 and GHS135 per 50 kg bag, pushing construction costs beyond the reach of many builders.

CBI Ghana Ltd., founded in 2017 at the Tema Free Zones Enclave, treated this dependency as a problem to be engineered away. Its answer was limestone calcined clay cement, or LC3: a cement technology that replaces a significant share of clinker with calcined clay and limestone, reduces CO2 emissions by up to 40% versus conventional portland cement, and uses raw materials that are abundant across Ghana.

The strategic question was one of scale. CBI Ghana Ltd. chose to pursue LC3 not as a pilot but as a full industrial operation. That commitment, a US$110 million investment, was officially commissioned in March 2026 by H.E. President John Dramani Mahama and is recognised as the largest calcined clay plant of its kind in the world.

The technology, in plain terms

LC3 works on a straightforward idea. Kaolinitic clay, heated to a controlled temperature, becomes a reactive material that can replace part of the clinker in cement. Combined with limestone, this calcined clay produces a cement with strength comparable to conventional grades but with a markedly lower carbon footprint.

The challenge is consistency. Producing reactive calcined clay at industrial volume, from clay of varying quality and in a humid tropical climate, demands precise and reliable processing equipment. CBI Ghana Ltd. awarded the calcination technology contract to Fuller Technologies whose system was selected for its proven efficiency and its ability to hold consistent quality at the throughput the project required.

The calcined clay produced at Tema is blended with clinker and with limestone from a licensed quarry in the Eastern Region.

The blend is calibrated by grade and verified through daily testing at the company's on-site laboratory. Supa Power 42.5R uses 35 – 45% clinker substitution, while Supa Fast 32.5R limits clinker content to no more than 45%, the lowest for any 32.5R grade cement in the world.

The plant's reach is not limited to CBI Ghana Ltd.'s own products. It also supplies calcined clay to other producers in the Ghanaian market, extending the decarbonisation benefit of LC3 technology across a wider share of national cement output than CBI Ghana Ltd.'s own volumes alone would allow.

The challenges behind the milestone

The path from commitment to commissioned plant was not linear. Three challenges stood out.

Raw materials

CBI Ghana Ltd.'s clay is sourced primarily from Torgome in the Volta Region. Establishing a dependable, high-volume supply of a material not previously mined at industrial scale in Ghana required investment in logistics and in quality control since clay chemistry varies between sites and must be managed carefully before it reaches the calciner.

Standards

When CBI Ghana Ltd. began scaling LC3 production, Ghana had no national standard for this class of cement.

Existing portland cement standards did not accommodate the clinker substitution LC3 requires, which risked blocking the product from public and private projects where specification compliance is a procurement condition. Working with the Ghana Standards Authority and research partners, the industry helped bring about GS PAS 5:2024, Ghana's first national standard for LC3 cement. Its adoption was a precondition for commercial scale.

Financing and acceptance

A US$110 million investment in a frontier market required a coalition of partners, and CBI Ghana Ltd. assembled strategic and development finance backing to support it. Certification alone, however, does not win a market accustomed to conventional cement. CBI Ghana Ltd. invested in technical engagement with engineers, contractors, and developers to build the confidence required to specify LC3 across demanding applications.

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Read the article online at: https://www.worldcement.com/special-reports/15072026/building-at-scale/