Producing artificial sand from waste iron from a cast iron factory

Instead of landfilling, artificial sand production technology researched by Dr. Nguyen Ngoc Truc can take advantage of cast iron slag to produce sand for construction.

After nearly 3 years of research, Dr. Nguyen Ngoc Truc , Director of the Center for Science, Technology and Training Support, Vietnam National University, Hanoi and his colleagues successfully developed a project to produce artificial sand from blast furnace slag. high iron smelter . The model was initially successful and commercialized the product.

To do this, the team identified three limitations of blast furnace slag: poor adhesion capacity, high pH and angularity. These limitations are overcome by technological innovations, which partially replace the inherent properties of blast furnace slag, limit expansion and reduce angularity. The team also carried out a moisturizing process including reducing the pH in blast furnace slag, using additional additives, minimizing mixing water and increasing adhesion to produce artificial sand.

Blast furnace slag.(Photo: NX).

In particular, the technology is designed not to emit CO ₂ and other toxic substances into the environment, but it can also absorb CO2 in the air, contributing to reducing the greenhouse effect and climate change. "We have studied the type of compressor to absorb CO2 in the air, then put CO ₂ in Carbonic Acid solution (H ₂ CO ₃ ) to neutralize the pH in the furnace slag , " Dr. Truc said. Thanks to the combination of this technology, the artificial sand produced from blast furnace slag has the quality and characteristics that can replace natural sand in construction.

Currently, the research group has started to develop a model in Tuyen Quang, producing artificial sand to market, in early September and put it into operation. Dr. Truc hopes to initially introduce artificial sand products to rural markets at reasonable prices."I am ready to guide and transfer technology to businesses and organizations wishing to apply this model," said Truc.

Dr. Nguyen Ngoc Truc received the award for the model of artificial sand production.(Photo: NX).

Currently, more than 300 enterprises producing iron and steel (accounting for 30% of production) nationwide have no blast furnace slag treatment system. Kiln slag is only buried and stored underground, so it emits no small amount of CO2, adversely affecting the environment and human health.

According to the data of the Department of Building Materials in 2018, the Ministry of Construction needs about 120 million cubic meters of sand per year, while the amount of sand exploited is 28,985 million cubic meters per year (only meeting 24, 2%). This situation has led to an increase in illegal sand mining, which has a significant impact on natural resources, threatening dyke safety and people's livelihood. Therefore, the successful study of artificial sand from blast furnace slag to replace natural sand not only solves the problem of sand scarcity but also contributes to the reuse of industrial waste and can also be commercialized. high economic efficiency.

At the "Demonstration of the 3rd idea: Women and green economy" organized by the Center for Innovation and Climate Change Adaptation (VCIC) held in June, model of Dr. Nguyen Ngoc Truc and his colleagues were selected by the World Bank, Ministry of Science and Technology to award the "Potential - Market Potential Group, aiming to solve the national challenge".