Cement Americas

FAL 2018

Cement Americas provides comprehensive coverage of the North and South American cement markets from raw material extraction to delivery and tranportation to end user.

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44 CEMENT AMERICAS • Fall 2018 • www.cementamericas.com FEATURE The primary electromagnetic field, created by the external power source, interacts with the fields of the ferromagnetic particles, causing several additional effects with beneficial effects on the processed media (cement): •  Direct interaction of the particles and the processed media. •  Magnetostriction (mechanostriction). •  Electrophysical effects etc. The combined power of those effects is so great that can not only pulverize and activate cement, but also intensify these processes. Each ferromagnetic particle functions as both a grinder and an agitator. It only takes the vortex layer unit seconds or minutes to do what other mills do in hours. The efficiency of the activation process in vortex layer units is influenced by several factors: •  Strength and rate of rotation of the electromagnetic field. •  Volume of the active chamber. •  The amounts and ratio of ferromagnetic particles and cement in the active chamber. •  The ratio between ferromagnetic particle length and their diameter, etc. These parameters can be optimized by trial and error depending on the nature of the processed material. Figure 2 shows a part of production line for grinding and activation of cement based on GlobeCore machines, includ- ing two AVS-150 vortex layer units. Figure 2 – Cement grinding and activation processing based on AVS-150 vortex layer units. Results of Experimental Research We set out to research the efficiency of using vortex layer devices for pulverization and activation of cement. For that purpose, we used an AVS-100 (laboratory scale) unit with steel ferromagnetic particles, a 22.5 Rck cement, sand and water. These components were used to prepare samples of concrete, later tested for flexibility and compression. Some samples were made from the original cement, others were made using cement processed for 30, 60 and 120 seconds in the vortex layer device. The results are listed in Table 1. Table 1 – The effects on mean surface area and strength of processing cement in vortex layer devices. Conclusions The data in Table 1 demonstrates that processing of cement in the vortex layer devices for 30 to 60 seconds does not increase mean surface area significantly. However, with retention time of 120 seconds, these parameters are more than doubled. As far as mechanical strength is concerned, its improvement is quite obvious in all instances. Strength was in fact increased from 22.5 to 42.5. These results show how promising the vortex layer devices are in production of microcement and construction mixes. Frank May, GlobeCore service engineer, has more than 30 years of practical experience in operation and servic- ing of various industrial machinery. May is involved in the research of vortex layer device applications (construction material production, wastewater processing), as well as in the equipment for electrical insulation oil regeneration and power transformer servicing. Retention time, seconds Mean surface area, cm 2 /g Flex strength, MPa Compression strength, MPa Days Days 1 7 28 1 7 28 0 2800 1,18 3,34 4,4 4,7 22,16 29,4 30 3300 1,62 5,68 7,58 7,36 27,46 39 60 3700 1,96 5,88 8,2 9,3 28,24 40,2 120 6800 1,5 7,45 8,86 5,88 31,38 44,4

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