Specific energy as a criterion for the use of rapid excavation systems in Turkish mines

Copur, Hanifi; Tunçdemir, H.; Bilgin, N.; Dinçer, T.

doi:10.1179/mnt.2001.110.3.149

Cited by 50 publications

(28 citation statements)

References 2 publications

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“…The minimum value of the correlation coefficient is 0.917, indicating strong agreement between the uniaxial compressive strength and specific energy. An exponential relationship exists between the uniaxial compressive strength and specific energy, consistent with the experimental results [52]. The minimum value of the correlation coefficient is 0.943, which indicates that the fitting results are ideal.…”

Section: Depth Of Cut = 3 MMsupporting

confidence: 73%

Numerical Simulation of Fragment Separation during Rock Cutting Using a 3D Dynamic Finite Element Analysis Code

Wan

Zeng

et al. 2017

Advances in Materials Science and Engineering

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To predict fragment separation during rock cutting, previous studies on rock cutting interactions using simulation approaches, experimental tests, and theoretical methods were considered in detail. This study used the numerical code LS-DYNA (3D) to numerically simulate fragment separation. In the simulations, a damage material model and erosion criteria were used for the base rock, and the conical pick was designated a rigid material. The conical pick moved at varying linear speeds to cut the fixed base rock. For a given linear speed of the conical pick, numerical studies were performed for various cutting depths and mechanical properties of rock. The numerical simulation results demonstrated that the cutting forces and sizes of the separated fragments increased significantly with increasing cutting depth, compressive strength, and elastic modulus of the base rock. A strong linear relationship was observed between the mean peak cutting forces obtained from the numerical, theoretical, and experimental studies with correlation coefficients of 0.698, 0.8111, 0.868, and 0.768. The simulation results also showed an exponential relationship between the specific energy and cutting depth and a linear relationship between the specific energy and compressive strength. Overall, LS-DYNA (3D) is effective and reliable for predicting the cutting performance of a conical pick.

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Section: Depth Of Cut = 3 MMsupporting

confidence: 73%

Numerical Simulation of Fragment Separation during Rock Cutting Using a 3D Dynamic Finite Element Analysis Code

Wan

Zeng

et al. 2017

Advances in Materials Science and Engineering

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“…They stated that the cone indenter test consistently proved to be the best predictor for SE. Copur et al (2001) correlated the SE with the UCS and BTS for some rock and ore types. They found good correlation between SE and both UCS and BTS.…”

mentioning

confidence: 99%

Estimating specific energy from the brittleness indexes in cutting metallic ores

Çomaklı

Kahraman

Balcı

et al. 2016

J. South. Afr. Inst. Min. Metall.

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Specific energy (SE) is an important parameter in mechanical rock excavation. It can be simply used for predicting the performance of roadheaders (Rostami, Ozdemir, and Neil, 1994). However, obtaining the SE from smallscale or full-scale cutting tests is very difficult and expensive. For this reason, some researchers have investigated the relationships between SE and rock properties and suggested empirical equations for the estimation of SE. McFeat-Smith and Fowell (1979) carried out experimental studies for correlating the SE obtained by small-scale cutting tests with some rock properties such as cone indenter index, cementation coefficient, Schmidt hammer rebound value, and compressive strength. They stated that the cone indenter test consistently proved to be the best predictor for SE. Copur et al. (2001) correlated the SE with the UCS and BTS for some rock and ore types. They found good correlation between SE and both UCS and BTS. They also showed that the relation between SE and the product of UCS and BTS has a better correlation coefficient than that of the relations between SE and both UCS and BTS. Balci et al. (2004) tested 23 different rock and ore types and investigated the predictability of SE from physical and mechanical properties. They found good or very good correlations between the SE and rock properties such as UCS, Brazilian tensile strength, static and dynamic elastic moduli, and the Schmidt hammer value. Tiryaki and Dikmen (2006) carried out mineralogical and petrographic analyses, rock mechanics, and linear rock cutting tests on sandstones. They investigated the relations between SE and rock properties using regression analysis. They showed that the texture coefficient and feldspar content of sandstones affected rock cuttability, evidenced by significant correlations between these parameters and SE. However, the felsic and mafic mineral contents of sandstones exhibited no significant correlation with SE. On the other hand, cementation coefficient, effective porosity, and pore volume indicated good correlations with SE. Poisson's ratio, Brazilian tensile strength, Shore scleroscope hardness, Schmidt hammer hardness, dry density, and point load strength index showed very strong linear correlations with SE. Tumac et al. (2007) investigated the predictability of rock cuttability from Shore hardness and compressive strength. They showed that there was a relation between Shore hardness values, optimum specific energy, and compressive strength.Estimating specific energy from the brittleness indexes in cutting metallic ores by R. Comakli*, S, Kahraman † , C. Balci ‡ , and D. Tumac ‡ Specific energy (SE) is a very useful parameter for assessing rock excavation by machine. Predicting the SE from the brittleness will be practical, especially for preliminary studies, due to the fact that determining the SE from cutting tests is difficult and expensive. In this study, the predictability of the SE from different brittleness concepts was investigated for metallic ores such as chromite, haematite, galena, a...

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“…Copur et al [3,85] specific energy decrease rapidly as the attack angle increases from 40° to 50°. After that any increase in the attack angle resulted in increases in both parameters [57,86].…”

Section: Specific Energymentioning

confidence: 99%

“…Another advantage of SMART*CUT picks in terms of lower potential for frictional ignition is that diamond materials have much higher thermal conductivities than tungsten carbide. As the major ingredient of TSDC is synthetic diamond, it is expected that the thermal conductivity of a TSDC tip 85 should be much higher than that of a WC tip. So the heat produced during the cutting process was transferred to the steel body more quickly, thus leading to the reduction of the thermal energy at any hotspot that is known to be a major ignition source.…”

Section: Forcementioning

confidence: 99%

“…Estimation of tool forces from full-scale laboratory rock cutting test is the most widely accepted, reliable and precise method [7,[40][41][42]. Although the full-scale cutting test is usually a very complicated, costly and a time consuming process, and there are only a few of such laboratories 11 around the world, the cutting forces measured from the laboratory can be directly input into cutterhead design software to determine the capability and efficiency of the selected cutterhead and excavation machines [2,7,28,[41][42][43].…”

Section: Research On Cutting Forcesmentioning

confidence: 99%

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A study of rock cutting with point attack picks

Shao¹

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Hard rock mining is currently carried out by drill-and-blast. With the increasing demand for automated, selective and remote mining, the industry hopes to replace conventional drill-and-blast with mechanical excavation. Modern mining machines have sufficient power for cutting hard rocks.The 'bottleneck' which limits the use of mechanical excavation for hard rock mining is the cutting tool wear. Rock cutting tools usually use tungsten carbide (WC) tipped picks. The WC tipped picks are effective and adequate for cutting relatively soft rocks, but unsuitable for hard rocks. To address this issue, CSIRO has developed Super Material Abrasive Resistant Tool (SMART*CUT), aiming at providing an effective cutting tool for hard rock mining. The key feature of the SMART*CUT technology is replacing the conventional WC with thermally stable diamond composite (TSDC) as the cutting tip of the pick. The main advantages of the TSDC tipped picks include (a) good thermal stability, (b) high wear resistance and (c) the ability to mine relatively hard deposits in comparison with the WC tipped picks. The disadvantage of the TSDC tipped picks is their low fracture toughness. To optimise the application of the TSDC tipped picks, this work aimed to improve the understanding of the rock cutting process and mechanisms, in particular to gain a better insight into the interaction between tools and rocks through systematic experimental and numerical studies. The rock cutting processes with the TSDC and WC tipped point attack picks were comprehensively investigated in terms of cutting force, specific energy, tool tip temperature and cutting chips.A study of rock cutting was systematically carried out using the Taguchi method to determine the effects of the cutting parameters on the performance of the TSDC tipped picks. The signal-to-noise (S/N) ratios and the analysis of variance (ANOVA) were applied to investigate the effects of the depth of cut, attack angle, spacing and cutting speed on the mean cutting, normal and bending forces involved in the rock cutting process. The statistical significance of process factors was determined and the optimum parametric combinations were successfully identified. Furthermore, the multiple linear regression (MLR) and artificial neural network (ANN) techniques were adopted to develop the empirical models for predicting the mean cutting and normal forces with the TSDC tipped picks. The established empirical force models showed good predictive capabilities with acceptable accuracy. The ANN models offered better accuracy and less deviation than the MLR models.The pick cutting temperature involved in rock cutting was measured using thermal infrared imaging and embedded thermocouple techniques. The temperature distribution in the cutting area was acquired by using a thermal infrared camera with high speed imaging rates. The results showed that II the TSDC tipped picks generated much lower thermal energy and much fewer sparks than the WC tipped picks. The temperature at the pick tip in the contact area wi...

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Specific energy as a criterion for the use of rapid excavation systems in Turkish mines

Cited by 50 publications

References 2 publications

Numerical Simulation of Fragment Separation during Rock Cutting Using a 3D Dynamic Finite Element Analysis Code

Numerical Simulation of Fragment Separation during Rock Cutting Using a 3D Dynamic Finite Element Analysis Code

Estimating specific energy from the brittleness indexes in cutting metallic ores

A study of rock cutting with point attack picks

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