REC «Mekhanobr-Tekhnika» (St. Petersburg, Russia):

Samukov A. D., Head of Department, samykov_ad@npk-mt.spb.ru
Gladkova V. V., Senior Engineer, gladkova_vv@npk-mt.spb.ru

Almost all operating sylvinite ore processing facilities are applying technologies based on «wet» processes — grinding and flotation, leading to an array of environmental problems. A comprehensive solution is to change to dry grinding of potash ores with subsequent dry beneficiation, using magnetic and electrostatic separation, that demand preliminary thermal treatment of ore. The studies on thermal treatment were conducted on the Verkhnekamskoye deposit ore sample. The ore samples structure and texture characteristics were obtained with the help of X-ray microtomography using the apparatus Sky Scan 1173. Heated sylvinite was crushed in laboratory hammer crusher MD-30.65, recording power consumption parameters. It was established, that with sylvinite heating from 120 to 250 °С, specific power consumption per size reduction weighted average degree unit is increased by the factor of 1.03 upon the average; with heating from 250 to 400 °С — by the factor of 1.16 and with heating from 400 до 550 °С — by the factor of 1.48. The studies on the ore samples internal structure prior and following thermal treatment at 500 °С were conducted by the method of X-ray microtomography. The results show that different ore components behave dissimilarly. For the sample that practically does not contain insoluble fractions, it is characteristical that porosity is somewhat increased after thermal treatment and in respect of the samples containing insoluble fractions, porosity is noticeably decreased. The ore mass horizontal deformation (shear) measurement test showed that with increase in ore mass temperature, shearing stress is increased, revealing that ore mass «viscosity» is increased, causing higher power consumption for its disintegration in hammer crusher. As the final result, an innovative method of power consumption estimation in ore disintegration in hammer crusher has been developed. An assumption is put forward that power consumption increase in potash ores disintegration with thermal treatment is mainly attributable to changes in ore mass mechanical-and-physical properties, affecting its behavior in hammer crusher work volume.

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