Sand is an indispensable component of practically every building material. As rates of road building and concrete structures production grow, so the need in building sand grows. However, natural sand recovery leads to ecological destruction of regions and river banks, beaches retirement, landslides, ground water discharge. Organizations pay production tax and take environmental measures at quarrying. Moreover, the natural sand recovery is completely forbidden in some countries.
At the same time, a large quantity of screenings produced at rock processing and not fully exploited is stocked in dumps; this leads to environmental pollution as well. But such screenings can be used as marketable products, the price for which is much higher.
Processing of screenings with the use of our classifying complex makes it possible to produce fine crushed stone, building sand, aggregates and other materials. The main element of the line for production of manufactured fractionated sand is multi-product air cascade gravitational classifier, which allows separating screenings to a desired quantity of fractions.
Operation of only one screenings classification line makes it possible to receive about 200 ths. t of marketable products per year.
At present man-made sands are efficiently used at production of building materials. What is more, the quality of materials based on the man-made sand is often higher as compared to the quality of analogous natural sand based materials.
It was observed, that bending strength of fine grain concrete based on centrifugal impact crusher produced sand exceeds comparable values for concrete made of river sand by 36%. At that, the bending strength of the concrete produced with the use of cone inertial crusher is 29% higher. The same ratio is encountered for fine grain cements compression strength values.