The belt conveyor is an endless belt moving over two end pulleys at fixed positions and used for transporting material horizontally or at an incline up or down. The main components of a belt conveyor are:

1. The belt that forms the moving and supporting surface on which the conveyed material rides. It is the attractive element. The belt should be selected considering the material to be transported.
2. The idlers, which form the supports for the carrying and return stands of the belt.
3. The pulleys support and move the belt and control its tension.
4. The drive that imparts power to one or more pulleys to move the belt and its loads.
5. The structure that supports and maintains the alignments of the idlers and pulleys and supports the driving machinery.

Other components include:

1. A loading chute or feeder chute that organises the flow of material and directs it on the belt conveyor.
2. Take-up device, which is used to maintain the proper tension of the belt for effective power transmission.
3. A belt cleaner that keeps the belt free from materials sticking to the belt.
4. A tramp removal device, which is optionally used when the conveyed material has a chance of containing tramp iron and requires its removal during subsequent handling of the material.
5. Continuous weighing device for constantly measuring the load being carried by the conveyor belt.
6. Discharge chutes to guide the discharged projectile to subsequent conveyor or other receiving point.
7. Surge hopper and feeder, which is essential for supplying material to the conveyor at uniform rate when the supply of material is intermittent.
8. Trip arrangement to discharge material at a different point or to another device.

Application

Conveyor belts are widely used in the mineral industry. Underground mine transport, opencast mine transport, and processing plants deploy conveyor belts of different kinds to adapt to the specific job requirements. The main advantages of the conveyor belt system are:

1. A wider range of material can be handled, which poses problems for other transportation means. Belt conveyor can be used for abrasive, wet, dry, sticky, or dirty material. The lump size of the transported material is limited by the width of the belt. Belts up to 2500 mm wide are used in the mining industry.
2. Higher capacity can be handled than any other form of conveyor at a considerably lower cost per tonne kilometre. Conveyor belts with a capacity of 11000t/h and even higher can be deployed to match with higher capacity mining machinery.
3. Longer distances can be covered more economically than any other transportation system. A single belt conveyor or a series of belt conveyors can do this. Belt conveyors can be adopted for cross-country laying.
4. By the use of many forms of ancillary equipment, such as mobile trippers or spreaders, bulk material can be distributed and deposited whenever required.
5. Many other functions can be performed with the basic conveying, like weighing, sorting, picking, sampling, blending, spraying, cooling, drying, etc.
6. Structurally, it is one of the lightest forms of conveying machines. It is comparatively cheaper, and supporting structures can be used for many otherwise impossible structures, such as crossing rivers, streets, and valleys.
7. The belt conveyor can be adopted for special purposes (fire resistant, wear resistant, corrosion resistant, high-angle negotiation, etc.) and can be integrated with other equipment.
8. It can be horizontal, inclined, declining, or a combination of all.
9. Minimum labour is required for the operation and maintenance of the belt conveyor system.
10. In underground mine transport, belt conveyor can be used in thin seams as it eliminates the rock works that might otherwise be required to gain haulage height. Moreover, a belt conveyor can provide continuous haulage service from pit bottom to the surface.

The limitations of the conveyor belt are:

1. The loading and transfer points need to be properly designed.
2. A number of protective devices have to be incorporated to save the belt from getting damaged by operational problems.
3. The belt needs higher initial tension (40-200% of useful pull).
4. The use of the elt is restricted by the lump size.
5. Conveying sticky material is associated with problems of cleaning and discharge, causing poor productivity.
6. Higher elongation of the belt (4% elongation may take place at the working load).

Belt Conveyor Types

Permanent: This type of conveyor is installed for the life of the mine. They are used in main line, slope, long overland installation, preparation plants, and stockpiles.

Portable: These are characterised by relative ease of assembling and disassembling to facilitate advances and recovery in development and retreat operations in underground mining. Portable conveyors mounted on crawlers or wheels are also used in mechanised quarries and surface mines.

Shiftable: Used in continuous surface mining, this type of conveyor is mounted on a skid or supporting structures aligned together, and the whole can be shifted transversely to follow the advancing working face.

High Angle Conveyor: This is a special type of conveyor belt arrangement used for negotiating steeper angles of inclination. Such belts can work on slopes up to 70-80⁰. A sandwich belt conveyor is a type of belt conveyor.

Cable Belt Conveyor: Where the belt is carried on moving wire ropes and the tractive force is applied through the rope to the belt is known as a cable belt conveyor.