Ferroalloy production wastes will clean toxic effluents

The issues of ecological safety of industrial enterprises have been worrying people for a long time. Modern efficient waste recycling technologies are of particular interest. Imagine now that the production wastes can serve to purify other production wastes! Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences, together with scientists from the Institute of Petroleum Chemistry SB RAS and TSU, developed a catalyst to neutralize harmful chemicals. The starting material for this catalyst is the fine fraction formed during crushing of ferroalloys. In fact, it is dust.

- “Production of ferroalloys is multi-tonnage, and as a result, large volumes of industrial wastes are formed, which in turn become a starting material for producing catalysts based on silicon nitrides by self-propagating high-temperature synthesis during the combustion process”, says Konstantin Bolgaru, Senior Researcher (Laboratory of New Metallurgical Processes, TSC SB RAS). “Our catalyst has already been successfully tested at TSU under the supervision of Lidia Skvortsova, Associate Professor (Department of Analytical Chemistry). Studies have shown that under the influence of ultraviolet radiation it purifies aqueous solutions from various soluble organic pollutants, including medications.

This development has great prospects for the disposal of expired medications or for wastewater treatment. At present it surpasses many other technologies in efficiency and cost-effectiveness. In the future, Konstantin explains, the introduction of semiconductor phases into the catalyst will further simplify its application, and it will be able to work in the visible spectrum - in sunlight.

We developed a porous composite material based on silicon nitride, which can be used to obtain filters of different shapes and sizes. It is not easy to do, however, since powders are poorly pressed and disintegrate. The solution to this task was found through cooperation with Vladimir Manzhai and Maria Fufaeva (Institute of Petroleum Chemistry SB RAS), who deal with cryogels. Recall that these are polymeric materials that are initially in a gelatinous state, but after several cycles of freezing and thawing, they become strong and elastic and have high adhesion, that is, the ability to adhere to other substances.

Experiments have shown that if a catalyst is mixed and frozen with polymers, and then this composition is subjected to combustion by the SHS method, it is possible to obtain products of a certain shape, with increased hardness and a unique porous structure. Recently this technology, which makes it possible to produce filters of various modifications, was patented in the Russian Federation. Production of such products will be quite simple, environmentally friendly, energy-intensive and cost-effective.

The next task that the scientists have set themselves is to develop a portable installation based on porous filters. This product can be used for wastewater treatment and industrial waste disposal.