CHANGE OF SPECIFIC SURFACE OF ROCKS UNDER CYCLIC FREEZING-THAWING

The mechanisms of change in external and total specific surfaces under alternating thermal forces are determined for limestone and kimberlite from a few diamond deposits in Yakutia. The test specimens of rocks differed in grain sizes by an order of magnitude: -20+10 mm and -2+1 mm. The external specific surface of the specimens with the grain size of -20+10 mm was determined by the grain size analysis. After 10 cycles of freezing–thawing in aqueous medium, the external surface of carbonate-bearing rocks from Udachnaya and Aikhal Pipes increased by 3–12 times. The external surface of kimberlite from Internatsionalnaya and Mir Pipes enlarged by 8–14 times. The total specific surface of the specimens with the grain size of -2+1 mm was estimated using the BET method on Sorbtometr-M analyzer. The tests show that after 5–10 cycles of freezing–thawing in aqueous medium, the increase in the total specific surface makes 38% for kimberlite from Udachnaya Pipe, 2–12% for carbonate-bearing rocks from Udachnaya Pipe (dolomite, dolomitic limestone, limestone) and 5% for limestone from the Mokhsogollokh surface mine. The intensity of formation both of external and total specific surfaces depends on the saturation and freezing medium, porosity and mineral composition of rocks and on the scale factor. The research findings help understand the mechanism of initiation and growth of structural defects in rocks under alternating thermal forces, which finally result in total disintegration.

Keywords

Freezing–thawing cycles, kimberlite, disintegration, specific surface, BET method, failure.

Issue number: 12
Year: 2018
ISBN:
UDK: 622.23.02
DOI: 10.25018/0236-1493-2018-12-0-31-38
Authors: Zakharov E. V., Kurilko A. S.

About authors: Zakharov E.V., Candidate of Technical Sciences, Senior Researcher, e-mail: zaharoff@igds.ysn.ru, Kurilko A.S., Doctor of Technical Sciences, Head of Laboratory, Deputy Director, e-mail: a.s.kurilko@igds.ysn.ru, Chersky Mining Institute of the North, Siberian Branch, Russian Academy of Sciences, 677018, Yakutsk, Republic of Sakha (Yakutia), Russia.

REFERENCES:

1. Kurilko A. S., Popov V. I., Zakharov E. V. Znakoperemennye temperaturnye vozdeystviya kak faktor energosberezheniya dlya tekhnologiy kompleksnoy podgotovki rudnogo syr'ya v usloviyakh kriolitozony [Alternating thermal effect as a factor of energy saving for the technologies of integrated ore pretreatment under conditions of permafrost], Gornyy informatsionno-analiticheskiy byulleten’. 2015, no 5, pp. 84—92. [In Russ].

2. Zakharov E. V., Kurilko A. S. Lokal'nyy minimum energoemkosti razrusheniya skal'nykh porod v diapazone otritsatel'nykh temperatur [Local minimum of energy consumption of hard rock destruction in negative temperature range], Fiziko-tekhnicheskiye problemy razrabotki poleznykh iskopayemykh. 2014, no 2, pp. 94—98. [In Russ].

3. Zakharov E. V., Kurilko A. S. Effects of low temperatures on strength and power input into rock failure], Science in cold and arid regions, 2014, Vol. 6, issue 5, pp. 455—460.

4. Zakharov E. V. Eksperimental'nye issledovaniya udel'noy energoemkosti razrusheniya karbonatnykh porod pod deystviem tsiklov zamorazhivaniya-ottaivaniya [Experimental research of energy consumption of carbonate-bearing rocks under cyclic freeze and thaw], Nauka i obrazovanie. 2017, no 3, pp. 82—85. [In Russ].

5. Vaysberg L. A., Kameneva E. E. Vzaimosvyaz' strukturnykh osobennostey i fiziko-mekhanicheskikh svoystv gornykh porod [Interaction between structural features and physical–mechanical properties of rocks], Gornyy zhurnal. 2017, no 9, pp. 53—58. [In Russ].

6. Vaysberg L. A., Kameneva E. E. Izmenenie struktury gornykh porod pri tsiklichnom zamorazhivanii i ottaivanii [Structural changes in rocks under cyclic freezing and thawing], Obogashchenie rud. 2015, no 2, pp. 28—31. [In Russ].

7. Zhou Keping, Li Bin, Li Jie-lin, Deng Hong-Wei, Bin Feng. Microscopic damage and dynamic mechanical properties of rock under freeze–thaw environment, Transactions of Nonferrous Metals Society of China. 2015. Vol. 25. Issue 4. рр. 1254—1261.

8. Lubera E. Frost weathering of selected rocks in the Tatra Mountains, Quaestiones Geographicae. 2014. 33(1). Bogucki Wydawnictwo Naukowe, Poznań, pp. 75—88.

9. Freire-Lista D. M., Fort R., Varas-Muriel M. J. Freeze–thaw fracturing in building granites, Cold Regions Science and Technology. 2015. Vol. 113. pp. 40—51.

10. Fener Mustafa, İnce İsmail. Effects of the freeze–thaw (F–T) cycle on the andesitic rocks (Sille-Konya/Turkey) used in construction building], Journal of African Earth Sciences. 2015. Vol. 109. рр. 96—106.

11. Lamp J. L., Marchant D. R., Mackay S. L., Head J. W. Thermal stress weathering and the spalling of Antarctic rocks], Journal of Geophysical Research: Earth Surface. 2016. 121. pp. 1—22.

12. Fedotov P. K. Empiricheskaya zavisimost' predela prochnosti gornykh porod ot razmerov ikh kuskov pri dezintegratsii v porshnevom presse [Empirical curve of strength and size of rock particles under disintegration by piston pressing], Vestnik irkutskogo gosudarstvennogo tekhnicheskogo universiteta. 2014, no 12(95), pp. 92—97. [In Russ].

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