Rod Mill Batch Process . The mill dimensions, (D × L), are 0.204 × 0.3 m and it is loaded with 8.55 kg steel rods 14 to 20 mm diameter. The mill rotates on rolls and its frequency is set to 70 RPM corresponding to 85% of the critical frequency. The mill power is = 22.5 Watts, calculated by (6). Fi- P
Modelling Rod mill work index is used in the SAGMILLING.COM Bond/Barratt specific energy consumption model. The work index is used to calculate the energy requirement to grind rocks in the medium size range, from 10 mm - 20 mm down to about 2 mm.
Basic EquationsSize Distribution and Exposure RatioEquations For Work Index VariationsWork Index and Crack EnergyThe rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing 12.7 mm (½ inch, the original test being developed in imperial units) to a product size of approximately 1 mm (in the original and still the standard, 14 mesh; see Chapter 4 for definition of mesh), thus determining the rod mill work index (WiR or RWi).
3.4.7 Bond rod mill standard test Standard conditions for determining the work index of rod mills under laboratory conditions are: mill size = 305 mm (internal diameter) × 610 mm (internal length…
Bond Rod Mill Grindability Test. The test determines the Bond Rod Mill Work Index which is used with Bond’s Third Theory of Comminution to calculate net power requirements when sizing ball mills*. Various correction factors may have to be applied. The test is a closed-circuit dry grindability test performed in a standard rod mill.
1.145×P80] (3) The EF4 formula requires both the rod mill and ball mill work index (rod mill Wi is used to calculate the optimal feed size) and because this is a “single-stage ball mill” calculation, the F80is actually the rod mill feed size (10,000
Rod Mill Batch Process . The mill dimensions, (D × L), are 0.204 × 0.3 m and it is loaded with 8.55 kg steel rods 14 to 20 mm diameter. The mill rotates on rolls and its frequency is set to 70 RPM corresponding to 85% of the critical frequency. The mill power is = 22.5 Watts, calculated by (6). Fi- P
Rod mill work index is used in the SAGMILLING.COM Bond/Barratt specific energy consumption model. The work index is used to calculate the energy requirement to grind rocks in the medium size range, from 10 mm - 20 mm down to about 2 mm.
Standard conditions for determining the work index of rod mills under laboratory conditions are: mill size = 305 mm (internal diameter) × 610 mm (internal length) with wave type lining. material dry mineral. size − reduced to 100% < 13,200 μm.
EF5BM=[ P80+10.3 1.145×P80] ( 3 ) The EF4 formula requires both the rod mill and ball mill work index (rod mill Wi is used to calculate the optimal feed size) and because this is a “single-stage ball mill” calculation, the F80 is actually the rod mill feed size (10,000 µm) from Table 1 and the P80 is the ball mill circuit product. The EF5 factor only applies below 75 µm to ball
Rod mill power is dependent on mill capacity and work index. Mill power increases with: Increasing rod charge; Increasing mill speed; Increasing mill length. Rowland and Kjos (1980) provided an expression to quantify power draw at the pinion shaft per unit mass of rods: P↓M / …
· The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond Work Index, bulk density, specific .
Bond Rod Mill Grindability Test. Grinding Solutions can carry out Bond Rod Mill Work Index tests to determine the energy requirements for milling ore in a rod mill. The test requires a minimum of 20kg of -12.5mm material. Closing screen sizes typically range from 4.75mm to 212µm. Abrasion Index Test
The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial .
· Measuring ore grindability in rod mills. The Bond Rod Mill Work Index is a measure of the resistance of the material to grinding in a rod mill. It can be used to determine the grinding power required for a given throughput of material under rod mill grinding conditions. It is a 'locked cycle' test conducted in closed circuit with a laboratory .
correlation between the abrasion value(X2) and work index (Wi) is found to be Wi = -1.8 Ln (X2) + 11.5 with correlation coefficient of 0.80. KEYWORDS: Bond work index ± Mechanical properties of rocks ± Grinding energy- Crushing resistance 1- INTRODUCTION Comminution in a mineral processing plant, or mill, involves a sequence of crushi ng
Rod Mill Ball Mill Closed circuit crushing to 16 mm Open circuit 8’ dia. rod mill to 1 mm Closed circuit 8’ dia. ball mill to P80 um The ore Test Work Index = Circuit Operating Work Index 9 The Standard Bond Circuit Coarse Ore Bins Fine Ore Bins Screen Crushing Screen Classification Rod Mill Ball Mill THIS IS THE REFERENCE BASIS FOR ALL .
You can also review the step-by-step Bond Work Index Test Procedure I posted here. See thisuseful summaryTable of Bond Work Index by Minerals. For any circuit, whether a crushing circuit, a rod mill, or a closed ball mill circuit, the Work Index always means the equivalent amount of energy to reduce one ton of the ore from a very large size to .
Indices. (It is also the Bond ‘design’ Work Index for this circuit.) To avoid the introduction of any designinefficiency factors in the Bond reference standard circuit, assume 8 foot (2.44 m) diameter, overflow mills, and use a rod mill feed size (F80) of 16,000 m and a rod mill µ product size of 1,000 m .
and the spindle rotates through 1 complete Revolution or by 360 degrees, one complete turn off the crank will cause the spindle and the work to rotate through 360/40=9 degrees. Therefore in order to turn work through a required angle, the number of turns required for index …
Rod Mill Batch Process . The mill dimensions, (D × L), are 0.204 × 0.3 m and it is loaded with 8.55 kg steel rods 14 to 20 mm diameter. The mill rotates on rolls and its frequency is set to 70 RPM corresponding to 85% of the critical frequency. The mill power is = 22.5 Watts, calculated by (6). Fi- P
