New testing methodology for the quantification of rock crushability: Compressive crushing value (CCV)

Abstract

Crushing is a size reduction process that plays a key role in both mineral processing and crushing–screening plant design. Investigations on rock crushability have become an important issue in mining operations and the manufacture of industrial crusher equipment. The main objective of this research is to quantify the crushability of hard rocks based on their mineralogical and mechanical properties. For this purpose, the mineralogical, physical, and mechanical properties of various hard rocks were determined. A new compressive crushing value (CCV) testing methodology was proposed. The results obtained from CCV tests were compared with those from mineralogical inspections, rock strength as well as mechanical aggregate tests. Strong correlations were found between CCV and several rock and aggregate properties such as uniaxial compressive strength (UCS), the brittleness index (S ₂₀), and aggregate impact value (AIV). Furthermore, the relationship between the mineralogical properties of the rocks and their CCVs were established. It is concluded that the proposed testing methodology is simple and highly repeatable and could be utilized as a pre-design tool in the design stage of the crushing process for rock quarries.

Keywords

crushability / jaw crusher / hard rocks / aggregate / rock strength / crushed stone

References

[1] Gupta A., Yan D. S. Mineral Processing Design and Operations, 2016, Amsterdam, Elsevier 882.

[2] Kelly E. G., Spottiswood D. J. Introduction to Mineral Processing, 1982, Newyork, John Wiley 491.

[3] Thuro K. Drillability prediction: geological influences in hard rock drill and blast tunnelling. Geol. Rundsch., 1997, 86(2): 426.

[4] Bearman R. A., Briggs C. A., Kojovic T. The application of rock mechanics parameters to the prediction of comminution behavior. Miner. Eng., 1997, 10(3): 255.

[5] Öztürk C. A., Nasuf E., Bilgin N. The assessment of rock cutability, and physical and mechanical rock properties from a texture coefficient. J. South Afr. Inst. Min. Metall., 2004, 104(7): 397.

[6] Räisänen M., Torppa A. Quality assessment of a geologically heterogeneous rock quarry in Pirkanmaa county, southern Finland. Bull. Eng. Geol. Environ., 2005, 64(4): 409.

[7] Tsiambaos G., Saroglou H. Excavatability assessment of rock masses using the Geological Strength Index (GSI). Bull. Eng. Geol. Environ., 2010, 69(1): 13.

[8] Mwanga A., Rosenkranz J., Lamberg P. Testing of ore comminution behavior in the geometallurgical context − A review. Minerals., 2015, 5(2): 276.

[9] Afolagboye L. O., Talabi A. O., Oyelami C. A. The use of index tests to determine the mechanical properties of crushed aggregates from Precambrian basement complex rocks, Ado-Ekiti, SW Nigeria. J. Afr. Earth Sci., 2017, 129, 659.

[10] Bruland A., Dahlo T. S., Nilsen B. Tunneling performance estimation based on drillability testing. International Congress on Rock Mechanics, 1995 123.

[11] Macias F. J., Dahl F., Bruland A. New rock abrasivity test method for tool life assessments on hard rock tunnel boring: The rolling indentation abrasion test (RIAT). Rock Mech. Rock Eng., 2016, 49(5): 1679.

[12] Lizotte Y. C., Scoble M. J. Geological control over blast fragmentation. CIM Bull., 1994, 87(983): 57.

[13] Bearman R. A., Barley R. W., Hitchcock A. Prediction of power consumption and product size in cone crushing. Miner. Eng., 1991, 4(12): 1243.

[14] Heikkilä P. Improving the quality of crushed rock aggregate [Dissertation]. Helsinki University of Technology, 1991 191.

[15] Kekec B., Unal M., Sensogut C. Effect of textural properties of rocks on their crushing and grinding features. J. Univ. Sci. Technol. Beijing, 2006, 13(5): 385.

[16] Olaleye B. M. Influence of some rock strength properties on jaw crusher performance in granite quarry. Min. Sci. Technol., 2010, 20(2): 204.

[17] Köken E., Aydin H., Özarslan A. Investigation of S20 brittleness index in terms of the crushability of rocks. 6th International Congress on Mining, Machinery and Technology, Izmir, 2017 105.

[18] Dahl F., Bruland A., Jakobsen P. D., Nilsen B., Grøv E. Classifications of properties influencing the drillability of rocks, based on the NTNU/SINTEF test method. Tunnelling Underground Space Technol., 2012, 28, 150.

[19] Kahraman S., Toraman O. Y. Predicting Los Angeles abrasion loss of rock aggregates from crushability index. Bull. Mater. Sci., 2008, 31(2): 173.

[20] Toraman O. Y., Kahraman S., Cayirli S. Predicting the crushability of rocks from the impact strength index. Miner. Eng., 2010, 23(9): 752.

[21] Teymen A. Estimation of Los Angeles abrasion resistance of igneous rocks from mechanical aggregate properties. Bull. Eng. Geol. Environ., 2017 1.

[22] Kahraman S., Toraman O. Y., Cayirli S. Predicting the strength and brittleness of rocks from a crushability index. Bull. Eng. Geol. Environ., 2017 1.

[23] Çomakli R., Cayirli S. Investigation of the relationship between some shape properties of minerals within rock textures and crushability of rocks. Omer Halisdemir Univ. J. Eng. Sci., 2017, 6(2): 670.

[24] ISRM, Suggested Methods-Rock Characterization Testing and Monitoring, E. T. Brown, ed., Pergamon Press, Oxford, 1981, p. 211.

[25] BS 812–112. Testing Aggregates. Part 112: Method for Determination of Aggregate Impact Value (AIV), 1990 14.

[26] Oparin V. N., Tanaino A. S. A new method to test rock abrasiveness based on physico-mechanical properties and structural properties of rocks. J. Rock Mech. Geotech. Eng., 2015, 7(3): 250.

[27] Federal Highway Administration. Rock and Mineral Identification for Engineers, 1991 57.

[28] Matula M. Rock and soil description and classification for engineering geological mapping report by the IAEG Commission on Engineering Geological Mapping. Bull. Int. Assoc. Eng. Geol., 1981, 24(1): 235.

[29] Smith M. R., Collis L. Aggregates Sand, Gravel and Crushed Rock Aggregate for Construction Purposes, 1993, London, Geological Society of London 360.