MOSCOW, September 6– . NArFU scientists have proposed a technology for processing diamond mining waste into construction additives that increase the resistance of materials to harsh climatic conditions, as well as mineral fertilizers applicable in the Far North. New products are low cost and highly competitive, the press service of the university reported.
Northern (Arctic) Federal University named after M.V. Lomonosov (NAFU), in collaboration with partners, is creating a high-tech system for the preparation of recycled water from an enrichment plant with processing waste into commercial products.
One of the important stages of the diamond mining process is the enrichment of diamond-bearing rock. This process requires water that can be rationally purified and used again, through the so-called recycled water supply. However, the aqueous suspension obtained during enrichment, which enters a special storage facility, contains a large number of difficult-to-precipitate particles of the natural clay mineral saponite. This complicates the reuse of water.
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“Our observations have shown that the highly dispersed saponite deposits that form are poorly deposited and release water poorly. This fact is confirmed by the low rate of clarification of circulating water (up to 0.1 cm/day). Therefore, special measures are required for the forced sedimentation of suspended substances,” said Maria Frolova, associate professor of the Department of Composite Materials and Building Ecology of the Higher School of Engineering of NArFU.
Scientists have set themselves the task of solving the issue of purifying waste water for reuse. They selected reagents — flocculants and coagulants, which allow removing saponite suspension as quickly as possible.
The result of the work will be the creation of a technological line for water clarification, based on the gravitational sedimentation of the sand fraction and the physico-chemical sedimentation of the clay fraction .
Frolova noted that the precipitated saponite-containing material will also be modified. Work is underway to design a technological line that will process it into a mineral additive for concrete and agricultural fertilizers. Pilot batches of products are planned to be received as early as 2024.
“Mechanically activated saponite-containing material is an active mineral component of hydration-hardening binder compositions. Its use will reduce the consumption of Portland cement for the preparation of concrete, and will also reduce carbon dioxide emissions per unit of production,” she said.
According to scientists , the use of saponite will help replace expensive imported chemical additives with environmentally friendly waste from the mining industry. In addition, the unique properties of saponite will help expand the range of concrete compositions and develop the raw material base of the construction industry.
In agriculture, the use of saponite is just as profitable and promising, according to NArFU researchers. Exhibiting sorption properties, it can be used as an additive to the main substrate when growing crops. This makes it possible to slow down the process of accumulation of nitrates in plants (maximum reduction of nitrates by 60–76%).
«Reducing soil acidity is important to improve their fertility, especially in the northern regions of the country, where highly acidic soils predominate. In addition, the introduction saponite into the soil will help accumulate magnesium in it, an active ionogenic element for agricultural crops,” said Maria Frolova.
Scientists plan to obtain patents for the developed scientific, technical and technological solutions. A pilot plant will also be created for the processing plant of the Lomonosov Mining and Processing Plant in compliance with a closed water balance, which will ensure the production of mineral additives for concrete and agricultural mineral fertilizers.