The t10 value is related to the specific comminution energy by the Eq. (1):
(1)
t10=A(1-e-bEcs)
The tn versus t10 relationships can then be used to predict the product size distributions at different grind times [16].
It is known that there are many difficulties and problems in drop weight and twin pendulum test methods such as being laborious, requiring long test time and requiring a special apparatus. In this study, breakage behaviours of three different limestones in a laboratory impact crusher were investigated. A new size distribution model equation was developed by t-family value evaluation and Bond work index approach, and this model equation was tested.
2. Materials and method
2.1. Material
Three different limestone samples taken from different region of Turkey were used as the experimental materials. The chemical properties of the limestone samples were presented in Table 1.
Table 1. Chemical composition of limestone samples using in experiments.
Oxides (%) Limestone-I Limestone-II Limestone-III
CaO 31.03 46.85 48.99
SiO2 0.05 8.45 10.60
Al2O3 0.90 1.02 1.07
Fe2O3 0.00 0.35 0.59
MgO 22.42 0.92 1.11
SO3 0.02 0.07 0.09
Na2O 0.07 0.02 0.04
K2O 0.10 0.06 0.08
Loss on ignition 45.24 36.50 38.72
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2.2. The test of standard Bond grindability
The Bond grindability tests were conducted less than 3.35 mm of dry feed materials in a standard ball mill (30.5 × 30.5 cm) following a standard procedural outline described in the literature [17], [18], [19], [20], [21], [22], [23] and [24]. The work indices were determined at a test sieve size of 106 μm. It has no lifters and all the inside corners are rounded. The Bond ball mill (Fig. 3) is operated at 70 rpm and is equipped with a revolution counter. The grinding charge consists of 285 iron balls weighing 20.125 g. The standard Bond grindability test is a closed-cycle dry grinding and screening process, which is carried out until steady state condition is obtained. This test was described as follow [17], [18], [19], [20], [21], [22], [23] and [24].
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the bed coefficient, determined with allowance for the mechanical properties of the rocks composing each bed (it is necessary to determine the technical productivity afresh for each bed).
LITERATURE CITED
1. V. M. Vladimirov et al., Quarry Bucket-Wheel Excavators [in Russian], Tekhnika, Kiev (1968).
2. L. A. Medvedev, "Influence of certain factors on the productivity of bucket-wheel excavators in the Kursk Magnetic Anomaly," in: Improvement of the Technology of Open-Cut Mining of Iron Ore Deposits in the Kursk Magnetic Anomaly [in Russian], Nedra, Moscow (1964).
3.V. S. Men'shov, "Investigation of the elements of a system of open-cut working and the parameters of bucket-wheel excavators, based on the example of the iron ore deposits in the Kursk Magnetic Anomaly," Author's Abstract of Candidate's Dissertation, Moscow (1960).
4.A. M. Pugo and P. N. Kolpakov, "Influence of face height and width on the productivity of the KU-800 and ShRS-2400 bucket-wheel excavators," in: Working Loose Rocks by means of Bucket-Wheel Complexes [in Russian], Gubkin (1973). 反击式破碎机英文文献和中文翻译(2):http://www.751com.cn/fanyi/lunwen_9949.html