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The development of belt conveyors, capable of transporting virtually any bulk material at thousands of tons per hour in a continuous and uniform stream, has been one of the most important innovations for the modern industry, especially for the construction and mining industry. Today the use of belt conveyors is an important and broadly accepted means of long-distance transport of bulk materials.

Belt conveyors have been in use for decades to transport bulk and unit loads. They have proved their worth everywhere because belt conveyor installations can be adapted to meet nearly all local conditions. They have attained a dominant position in transporting bulk materials because of inherent advantages such as their economy and safety of operation, reliability, versatility, and practically unlimited ranges of capacities. In addition, they are suitable for performing numerous processing functions in addition to their normal purpose of providing a continuous flow of material between two operations. Recently, their conformity to environmental requirements has provided a further incentive for the selection of belt conveyors over other means of transportation.

Low labor and low energy requirements are fundamental with belt conveyors as compared with other means of transportation. The dramatic increase in the operating costs of other means of transport since the oil crisis of the seventies has placed conveyors in an extremely favorable position for applications that were not considered previously.

Technological advances have paralleled and supported this increased application, performance, and economic demands. There has been a quiet revolution in the development of the available widths, normal operating speeds, and tension capabilities of conveyor belts. The mechanical components, too, such as idlers, drive machinery, pulleys, and many accessories, have undergone developments to enhance performance and durability. Most recently, developments have been in the applications of automated, electrical controls employing solid-state components, multiplex wiring, and many other modern techniques of electrical engineering and equipment.

For these reasons, belt conveyors are capable of handling tonnages of bulk materials that would be more costly and often impractical to transport by other means. Belt conveyor systems provide the means of transporting materials via the shortest distance between the required loading and unloading points. They can follow existing terrain on grades of 30 % to 35 %, compared with the 6 % to 8 % being the effective limits for haulage by road.

Characteristics of bulk materials such as density, the effective angle of internal friction, lump size, and shape, are all factors that dictate the maximum incline angle up which material can be conveyed by a standard belt conveyor without having it roll or slip backward on the belt.

Belt conveyors can be arranged to follow an infinite number of profiles or paths of travel. Among these are conveyors that are horizontal, inclined, or declined, or, with the inclusion of concave and convex curves, and any combination of these. Also, numerous arrangements are possible for loading to and discharging from the conveyor.

There can be several loading and discharging arrangements possible with belt conveyors. In addition, belt conveyor stackers can be connected to a mainline conveyor to stockpile material several hundred feet on either or both sides into piles of any practical length, or a combination stacker-reclaimer can be used to stockpile material or to reclaim and return it to the main belt conveyor.

Belt conveyors are the backbone of any mining or quarrying operation. Systems that ensure the movement of bulk material at rates in excess of 1,000 tonnes/hr. are commonplace within the industry. With the carrying length of a conveyor system being virtually unlimited, such systems can convey material from the quarry to the processing plant without the need for heavy transport. Belt conveyors also have the flexibility of design to accommodate inclines and declines, allowing their structures to follow hillsides or to bridge obstacles, and combinations of conveyors, weighers, crushers, magnets, and screens will ensure the end product is sized and free from tramp metal, ready for the next process.

Depending upon the material being quarried, the conveyor can be either open or enclosed. Coarse, wet material is normally transported on open conveyors, whereas dry, dusty material tends to be enclosed to provide protection from the elements. The conveyor covers themselves are available with many options depending upon their use and operating environment. In some cases fully enclosed gantries incorporating walkways and/or maintenance access routes are provided.

Belt conveyors are used to transferring concrete horizontally and limited distance vertically. Conveyors made expressly for handling concrete are relatively inexpensive and may eliminate the need for other more expensive auxiliary equipment such as cranes. They are particularly useful in areas such as tunnels where space is limited and are widely used in building construction, especially large floor slabs and bridge decks. In massive construction, such as mat foundations, dams, and power plants which require large quantities of concrete, conveyors are advantageous because of their placing capacities.

Modern concrete belt conveyors can handle any type of mix but maximum efficiency is achieved with a cohesive mix of approximately two and one-half- to three-inch slump. Low slump concrete is generally best handled by slower-moving belts, high slump concrete by faster-moving belts. The cement content has very little if any effect on the suitability of concrete for conveyors. It should be noted that conveyors are available that will handle concrete with up to six-inch maximum size aggregate and from one- to ten-inch slump without plug-ups or other operational problems.

A growing number of special types of belt conveyors are available for handling aggregates and concrete. Several manufactures produce conveyors that are mounted on trailer-like frames with wheels for easy movement around the job site and between jobs. Belt conveyors mounted in tandem on the extendable boom of hydraulic cranes are also available. These units have a complete 360-degree swing and some models can reach out as much as 135 feet and discharge concrete at a height of 80 feet. Also, telescoping conveyors are available mounted on conventional over the road trucks. As with the crane mounted units, they can swing, reach, and retract while the belt discharges concrete into forms located at grade, above grade, or below grade. Other special types of concrete conveyors are known as side discharge and radial spreader units