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Alekseevich K.V.,Interstroyproekt CISC | Danilovich S.A.,Interstroyproekt CISC | Alekseevna S.V.,Russian Academy of Sciences
Obogashchenie Rud | Year: 2013

Fine size products of magmatic rock crushing-and-screening operations can be used as feed for the production of high-grade aggregate for lightweight concrete as an effective alternative to claydite. Laboratory experiments have shown that solid mineral fines can be converted to foam glass fillers for lightweight concrete with a bulk density of 400-770 kg/m3 and a crushing strength of 1.1-4.5 MPa. It has been found that to produce filler aggregates for lightweight concretes only specific varieties of magmatic rocks can be used as feed, i. e. those that meet certain requirements: the rock should melt at low temperatures to ensure minimized power draw by the aggregate production process, whereas the molten mass should be able to foam under the effect of a gas generator and to retain foamy structure for a time required for foam to stabilize. Equations were composed to calculate the time for outflow of liquid from the foam of melts to the point when the liquid films and the Plateau-Gibbs borders reach sufficient critical thickness to initiate coalescence of bubbles about to destroy the foam. An initial thickness of films and sections of the Plateau-Gibbs borders between the bubbles at a reference initial point in time for a given proportion of bubbles in the foam has been determined, and a foam melt stability diagram has been drawn. It has been found that on balance of evidence based on the criteria of viscosity and lowest melting temperature, fines and oversize of the granites, syenites, rhyolites, dacites, diorites and andesites are the preferred mineral feed for the production of porous aggregates. Source

Anatolyevich S.P.,Interstroyproekt CISC | Vasilyevna Z.O.,Interstroyproekt CISC
Obogashchenie Rud | Year: 2013

The article describes a flowsheet for processing difficult-to-treat non-recyclable quarry fines, which uses special methods of screening substandard fines and vibration pulse impacts on the material being crushed, to produce high-grade 5-10 mm ballast. These methods are implemented in the proposed mechanical flowchart of the process by including high-frequency vibrating screens ensuring efficient screening with dewatering of the oversize feed coming in for crushing. To produce high-grade ballast a special low reduction ratio vibrating crusher has been developed with a crushing chamber configuration to modify the shape and size distribution of the crushed material which represents predominantly ballast of cubic stone chips with a low content of flaky grains. The article also provides a description of the proposed flowsheet, as well as qualitative and quantitative performance indicators of the ballast production process. Furthermore, it shows the ballast production testing results for the above flowsheet, and these results corroborate the quantitative and qualitative indicators, equipment specification requirements and grade of the crushed product as provided in the operational regulations. Source

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