What are the objectives of size reduction?

OBJECTIVES OF SIZE REDUCTION =In the materials processing industry, size reduction or comminution is usually carried out in order to: ? Increase the surface area because, in most reactions involving solid particles, the rate of reactions is directly proportional to the area of contact with a second phase.

Regarding this, what is size reduction?

Size reduction is a process in which the particle size of a solid is made smaller. The term size reduction is applied to ways in which particles of solids are cut or broken into smaller pieces. Size reduction is necessary if the starting material is too coarse, and the final product needs to be a fine powder.

Additionally, what is the importance of particle size reduction? Size Reduction is an important operation in many pharmaceutical applications. The important reasons for size reduction are easy handling, increase in surface area per unit volume and separation of entrapped components.

Similarly, what are the factors affecting size reduction?

Material structure: ? Some substances are homogeneous in character. ? Mineral substances may have lines of weakness along which ? the materials splits to form flake-like particles. ? Vegetable drugs have a cellular structure often leading to long fibrous particles.

What is size reduction equipment?

Today, there are many different size reduction machines available to make little pieces out of big ones. Particle size-reduction equipment includes primary impact crushers and secondary crushers as well as milling machines - cage mills, hammer mills, pulverizers and grinders.

26 Related Question Answers Found

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.

How do you reduce particle size?

Particle Size Reduction. Many particle size measurements are made to track size reduction operations such as milling, mixing, homogenizing, etc. The size reduction unit operation is performed under set conditions or for a required time frame until a specified size is achieved, as determined by the measurement.

What are the mechanical methods used for size reduction?

13.4 Size Reduction

Technique	Material Cut	Working Environment
Mechanical saws	Metals	Air/water
Orbital cutters	Metals	Air/water
Abrasive cutters (wheels, blades, wires, core drills)	Metals, concrete	Air/water
Milling	Metals	Air/water

Which processes are used to reduce the size of the rock?

Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated.

What is rittinger's law?

Definition of Rittinger's law. The energy required for reduction in particle size of a solid is directly proportional to the increase in surface area. Compare with: Kick's law.

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.

What is size reduction in food industry?

Size reduction is a widespread, multipurpose operation in food processing. Size reduction in solids comprises milling, crushing, chopping, and cutting. Size reduction in liquids includes homogenization. The definition of a representative particle size is problematic.

What is practical application of size reduction pharmacy?

The pharmaceutical size reduction process is also referred to as comminution, diminution or pulverizations. Pharmaceutical size reduction is used primarily for the purposes of control – control of the rates of dissolution and absorption, control of chemical reactions, and control of physical characteristics.

How does a hammer mill work?

A hammer mill is essentially a steel drum containing a vertical or horizontal rotating shaft or drum on which hammers are mounted. The hammers are free to swing on the ends of the cross, or fixed to the central rotor. The rotor is spun at a high speed inside the drum while material is fed into a feed hopper.

What is the working principle of ball mill?

It works on the principle of impact and attrition: size reduction is done by impact as the balls drop from near the top of the shell. A ball mill consists of a hollow cylindrical shell rotating about its axis. The axis of the shell may be either horizontal or at a small angle to the horizontal.

How does a ball mill work?

A Ball Mill grinds material by rotating a cylinder with steel grinding balls, causing the balls to fall back into the cylinder and onto the material to be ground. The rotation is usually between 4 to 20 revolutions per minute, depending upon the diameter of the mill. The larger the diameter, the slower the rotation.

What is fluid energy mill?

Definition of fluid energy mill. A size-reduction unit depending for its action on collisions between the particles being ground, the energy being supplied by a compressed fluid, (e.g., air or steam) that enters the grinding chamber at high speed.

What are the methods of determining particle size?

The most common techniques to determine the particle size distribution are dynamic image analysis (DIA), static laser light scattering (SLS, also called laser diffraction), dynamic light scattering (DLS) and sieve analysis.

What is the size of a particle?

Particle sizes are measured in microns (μ). A micron is 1/1000 mm. or 1/25,400 in. A millimicron (mμ) is 1/1000 of a micron, or 1/1,000,000 mm. Usually particle size is designated as the average diameter in microns, although some literature reports particle radius.

What is the purpose of particle size distribution?

Particle size distribution, also known as gradation, refers to the proportions by dry mass of a soil distributed over specified particle-size ranges. Gradation is used to classify soils for engineering and agricultural purposes, since particle size influences how fast or slow water or other fluid moves through a soil.

What is the importance of particle size analysis?

Importance of Particle Size Analysis in Industry. Particle size analysis gives information on the size distribution of particles. This can be used to calculate different properties of a particle and how they will act under certain conditions. This information is critical in industries to achieve different goals.

What is average particle size?

The average particle size is computed by deriving the specific surface area from the flow velocity of the gas through the powder bed.