Interstroyproekt CJSC (Russia):

Arsentyev V. A., Deputy General Director, Doctor of Engineering, interstroyproekt@mail.ru

REC «Mekhanobr-tekhnika» (Russia):

Vaysberg L. A., Scientific Advisor of Company, Corresponding Member of RAS, Doctor of Engineering, Professor, gornyi@mtspb.com

Interstroyproekt CJSC (Russia):

Shuloyakov A. D., General Director, PhD Technical, interstroyproekt@mail.ru

National Mineral Resources University (Russia):

Romashev A. O., Lecturer, art3m@mail.ru

The article describes processing methods, applied for difficultlytreated raw materials, permitting to utilize primaryscreened pitrun fines, otherwise rejected and dumped. Interlinked processes of pitrun fines' staged treatment are presented, allowing for pitrun fines utilization with production of building units and construction materials. Crushed stone production is based on intense screeningout of offsize fine fractions with dewatering of feed material and vibroimpulse action upon crushed material, permitting to modify product shape and grainsize distribution, thus producing crushed stone with low content of flaky grains. By means of drying and dewatering, moisture content in screen ings is reduced to less than 2 %. Grading of screenings permits to divide them into narrow size fractions through more intense vibratory action, providing for material classification at higher vibration frequencies with smaller amplitude. Joint treatment of binding agent and screenings dust fraction is applied in production of vibropressed units, improving rheological properties of concrete mix. Production of granulated aggregate includes granulation of dry mix, which consists of screenings' dust fractions, binding agent and poreforming agent, followed by drying and calcining of produced granules. The developed processes are being implemented at a pilot plant constructed to utilize screenings as filler/aggregate, produced from nonmetallic feed material.