High-quality building materials have been produced from energy waste.

On average, an energy enterprise generates up to 1,000 tons of waste annually. Chemical reagents based on iron and aluminum, along with lime additives, are used for their disposal at water supply sources, resulting in the formation of sludge.

“The new technology enables the production of building materials from local waste. This makes it economically attractive for countries where construction materials are scarce, and transportation costs significantly increase project expenses. The proposed solution can be adapted for any regions where lime and coagulants are used for water treatment, opening up broad prospects for its global implementation,” noted Valentin Romanovsky, PhD, an expert at the Belarusian State Technological University (BSTU).

Scientists from BSTU, National University of Science and Technology MISIS, and the Southwest University of Science and Technology (China) have presented a technology for converting lime into a high-strength cement analogue—anhydrite (CaSO₄). It is a dehydrated form of calcium sulfate (unlike gypsum, which contains water molecules in its structure). Anhydrite is found in both natural and synthetic forms.

“MISIS University is implementing the ‘Sustainable Development Technologies’ project under the state program ‘Priority-2030’, within which our scientists are creating high-tech solutions that contribute to reducing technogenic load and forming a comfortable environment. The new technology, developed by an international team of researchers led by the young talented scientist, candidate of technical sciences Dmitry Moskovskikh, will significantly reduce the volume of industrial waste,” said Alevtina Chernikova, Rector of MISIS University.

The cement obtained in its pure form does not exhibit plastic properties. To improve compressive strength, the researchers added a mixture of Portland cement, potassium sulfate, and calcium hydroxide. Details of the study are published in the journal Engineering Reports (Q2).

“We have found a way to recycle environmentally harmful waste into a durable building material with a purity of up to 99.8 percent. From the remnants of lime, we created a cement analogue that can be used for constructing houses, roads, or other structures. I should also note that the by-products formed during the centrifugation stage of the synthetic anhydrite suspension can be used as fertilizers. This leachate contains dissolved salts that promote increased root mass and dry plant weight, making it an effective micro-fertilizer. Consequently, the entire process of producing anhydrite is virtually waste-free,” said co-author of the study, candidate of technical sciences Dmitry Moskovskikh, director of the Research Center for Structural Ceramic Nanomaterials at NUST MISIS.

In the future, researchers plan to enhance productivity and reduce the costs of the technological process, as well as adapt the methodology to work with various types of waste, allowing the technology to be applied in enterprises across different countries.