Which law gives good result for fine grinding?

Rittinger’s law is applicable mainly to that part of the process where new surface is being created and holds most accurately for fine grinding where the increase in surface per unit mass of material is large.

What are the methods of comminution?

There are three forces which typically are used to effect the comminution of particles: impact, shear, and compression.

What is the difference between crushing and grinding?

Crushing breaks the large particles into multiple pieces and the aim is to facilitate easy transportation and storage. Generally +20 mm is acceptable for crushing. Grinding is a more controlled process and the size that can be achieved is in micron level.

What is the last stage of comminution?

The comminution is done in two stages: (1) Crushing and (2) Pulverizing/grinding.

Which law is used for coarse grinding?

Which of the law is used for coarse grinding? Clarification: Kick’s law is used for coarse grinding when the size ratio of original material to end materials is 8:1.

What is Kick’s law and Bond’s law?

• Kick’s law gives reasonably good results for coarse grinding in which there is a relatively small increase in surface area per unit mass. • Rittinger’s law gives better results with fine grinding where there is a much larger increase in surface area • Bond’s law is intermediate between these two.

What is comminution theory?

A general theory of comminution should consist of two parts, one that deals with the energy required to break mineral particles and another that examines how this energy is distributed to the particles generated after breakage.

What is the principle of comminution?

The first principle of comminution states that the specific energy input always equals the energy register of the product minus the energy register of the feed;. Disregard, of this principle and assignment of zero energy register to the feed, results in a distorted, interpretation of comminution results.

What is comminution process?

The process of comminution is the crushing and grinding of a material / ore to reduce it to smaller or finer particles. The comminution process reduces particle sizes by breaking, crushing, or grinding of ore, rock, coal, or other materials.

How is liberation achieved in grinding?

Mineral liberation is achieved by reducing the size of ore particles in various crushing and grinding devices. The fineness to which the ore must be ground, so as to yield sufficient degrees of liberation, increases if the valuable minerals with small grain sizes are disseminated throughout the gangue.

What is rittinger’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 Kick’s Law and Bond’s law?

What is Kick’s law?

Kick’s Law — The amount of energy required to crush a given quantity of material to a specified fraction of its original size is the same, regardless of the original size.

Where is Kick’s law used?

where xf/xp is the size reduction ratio and CK is called Kick’s constant which unit of J/kg . Kick’s law has been found to hold more accurately for coarser crushing, where most of the energy is used in causing fracture along existing cracks.

What are laws of comminution?

Letting n=2, 1 or 3/2 gives the “three comminution laws” due to Von Rittinger, Kick, and Bond. The oldest theory, Von Rittinger (1867), stated that the energy consumed in size reduction is proportional to the area of new surface produced.

What is Kick’s theory?

The Kick’s law states that the energy required to reduce the size of particles is proportional to the ratio of the initial size of a typical dimension (for example the diameter of the particles) to the final size of that dimen- sion. This relation is derived directly form the elasticity theory of ideal brittle solids.

What is comminution and how it is performed?

What is comminution circuit?

A comminution circuit optimisation typically involves a circuit audit and collection of crushing and grinding circuit survey data. This includes an inventory of major equipment sizes and operating conditions.

What is classification in comminution?

Since classification is based on the size, shape, and density of particles, the research in this area is focussed on identifying the best classification system for the material produced by comminution devices based on the three properties as well as downstream requirements.

What is liberation by detachment?

The second type is liberation by detachment or non-random breakage, where the fractures or the cracks propagation are situated along the grain boundaries allowing the preferential liberation of the phases.

What is Rittinger’s law?

Rittinger’s Law: Rittinger’s theory is the law of the cracks. It is well explained in an article by E. A. Hersam in the Mining and Scientific Press, an abstract of which is given in the third volume of Richard’s Ore Dressing, and to which I acknowledge my indebtedness for some of my ideas and,methods.

Is the Rittinger theory correct for crushing?

The results clearly show that the Rittinger theory is so much more nearly correct for crushing operations, that I believe we can accept it and use it for the determination of crushing constants, for machine comparisons, for efficiency tests, etc.

What is k in Rittinger’s law?

Assuming that these values are constant, K is a constant. Equation (6.7) is known as ‘Rittinger’s law’. Due to the inaccuracy of the assumptions on which it is based and the difficulty in determining its parameters, Rittinger’s law is only approximate.

What is the difference between Rittinger’s and bond’s laws?

The Kick and Rittinger laws are special cases of one form, and Bonds law is a special case of the other. Thus it is possible for Rittinger’s and Bond’s laws to apply to the same set of data.