What is the bond work index?
Abstract: 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 comminution plants designing.
How do you calculate work index?
The work index of a particular material is determined in the laboratory by conducting the standard Bond grindability test. Bond developed separate tests for the rod mill and the ball mill. The simplified test method described in this paper is an alternative procedure to the ball mill grindability test.
What is the meaning of work index?
‘Work Index’ is the amount of energy required to do this work. It is a measurement of how hard the rock is and an expression of the resistance that a material has to crusher. Shown in the table below is typical Work Index, reflecting the different rock characteristics.
What is work index in size reduction?
‘Work Index’ is to measuring energy in size reduction what the ‘meter’ is to measuring distance. It is a standard measure that brings all size reduction circuits onto a common basis for comparison. It starts with Bond’s Work Index equation: W is the work (energy) input per ton.
What is Bond’s law?
Bond, In law, a formal written agreement by which a person undertakes to perform a certain act (e.g., appearing in court or fulfilling the obligations of a contract). Failure to perform the act obligates the person to pay a sum of money or to forfeit money on deposit.
Which law of crushing is more accurate for coarse crushing?
Kick’s law, more closely relates to the energy required to effect elastic deformation before fracture occurs, and is more accurate than Rittinger’s law for coarse crushing where the amount of surface produced is considerably less.
What are the size reduction laws?
It may not be well known, but there are three physical laws that describe the energy required for size reduction. They are the Bond’s Law, Rittinger’s Law, and Kick’s Law. Rittinger’s Law — The energy required for reduction in particle size of a solid is directly proportional to the increase in surface area.
What is rittinger’s law formula?
Rittinger’s Law — The energy required for reduction in particle size of a solid is directly proportional to the increase in surface area. E = KRfc(1/L2– 1/L1)
What is meant by crushing efficiency?
Crushing efficiency : It is defined as the ratio of surface energy created by crushing during crushing to the energy absorbed by the solid . This crushing efficiency is constant and for a given machine and material , is independent of the sizes of the feed and product .
What are the advantages of size reduction?
Key Benefits of Particle Size Reduction: Part 1
- Increased Dissolution Rate.
- Improved Drug Delivery.
- Cleaning Product Health & Safety.
- Controlling Rate of Reaction.
- Greater Density.
- Greater Sedimentation Stability.
- BEE’s Particle Size Reduction Technology.
What is rittinger number?
Rittinger’s number designates the new surface created per unit mechanical energy absorbed by the material being crushed.
What is crushing process?
Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do.
How is the Bond Work Index wi100 calculated?
The standard work index Wi100 values calculated from Eq. (9) for each ore at each mesh size are included in Table I. Comparison for each ore shows a reasonable agreement among the tests made at various mesh sizes, and indicates that Eq. (9) and Eq. (10) can be used with confidence.
How is Bond work index related to Rittinger’s law?
The Bond work index (Bond, 1960) is based on Bond’s law, which states that the energy consumed is proportional to the 1.5 power of particle size rather than the square of Rittinger’s law. Accordingly, the energy consumed in reducing the particle size from x F to x p (both measured as 80% undersize) is given by
Can you simulate the Bond Work Index test?
The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index.
How is Bond work index related to screen size?
Magdalinovic [38] measured the Bond work index of three ore types using different test screen sizes. He produced a correlation between the mass of test screen undersize per revolution, G, and the square root of the test screen size, D: The constant K1 is dependent on the ore type.