A conveyor belt fire is a significant risk. The belting itself can burn; however, it is the length and movement of the belt that poses risks that a belt can spread a fire over a great distance within a facility in a very short time.

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Fires on conveyor belting are most commonly ignited by the heat generated from friction induced by a pulley turning against a stalled (or slipping) belt or by the belt moving over a seized idler. Other conveyor fires have occurred when hot or burning material is inadvertently loaded onto the belt.

With this risk of fire, compounded by the toxic gases, thick smoke, and noxious fumes that can result from a conveyor fire, belting is regulated in those applications where these conditions are most dangerous in underground mining and, particularly, underground coal mining.

It should be noted that all conveyor belts will burn given sufficient heat and airflow. However, standardised laboratory tests have been accepted by governmental regulatory bodies to measure and categorise the burning characteristics of different conveyor belts. In general terms, "self-extinguishing" is considered to be a belt that will not propagate a fire in a laboratory setting once the ignition source has been removed.

In the following section, we will be exploring the SABS Mandate and SANS requirements for conveyor belting.

SABS Mandate

SABS is a statutory body that was established in terms of the Standards Act, (Act No. 24 of ) and continues to operate in terms of the latest edition of the Standards Act, (Act No. 8 of ) as the national standardisation institution in South Africa, mandated to:

• Develop, promote and maintain South African National Standards (SANS)
• Promote quality in connection with commodities, products and services
• Render conformity assessment services and assist in matters connected therewith

This includes the standardisation in the field of manufacturing, conversion and testing in Rubber and Plastics, including aspects of their effects on man and his environment relating to activities in the following fields: plastic pipes and fittings, valves and auxiliary equipment intended for the transport of fluids, retreaded tyres and repairs of tyres that are intended for use on public and private roads, rubber in any form, rubber products (including their dimensional tolerances) and major rubber compounding ingredients, conveyor belting, polymeric membranes, films and barrier products for construction purposes.

SANS Standards for Conveyor Belting

There exist 3 SABS standards for conveyor belting viz. SANS 968 Conveyor Belting - Textile reinforced solid woven carcass construction; SANS Conveyor Belting &#; General purpose textile-reinforced construction; SANS Conveyor belting &#; Steel cord reinforced construction. Each of these standards contains standard classes and standard types.

The classes refer to belt breaking strength while the type refers to the type of cover. Type F is one of the many types. This type is slightly different to the other types in that this type specifies that both the belt carcass and the belt covers must be fire retardant whereas other types refer to the physical properties of the belt covers only.

We will now dive into our Type F 140 Fire Retardant Belting to discuss why and how we provide the best products for any type of application.

Type F 140 - Fire Retardant Belting

For type F conveyor belting there are 4 flame retardancy criteria that must be met:

1. Flame resistance &#; when samples of the belt are held in a flame for 60 seconds in accordance with the SANS 971 test standard all must self-extinguish within a specified time.
2. Electrical conductivity &#; the electrical resistance of each belt surface determined in accordance with SANS 971 shall not exceed 3 x 108 ohm.
3. Drum friction performance &#; a belt sample subjected to the drum friction test method of SANS 971 shall show no signs of flame or glow AND the drum temperature shall not exceed 325°C.
4. Flame propagation &#; When performing the flame propagation test in accordance with SANS 971 the belt shall meet one of the following requirements:

• The length of the test piece remaining undamaged across the entire width shall not exceed 600mm.
• Should the temperature rise not exceed 140°C, the length of the belt consumed shall not exceed mm and the length of the belt undamaged shall be not less than 50mm.

The accepted level of abrasion resistance for type F covers is a loss, when tested in accordance with SANS , of no more than 180mm3.

In comparison, the acceptable maximum abrasion loss for a type N (non-fire retardant) belt cover is 150mm3. This means that in addition to an increase in belt cost, the belt life will be reduced. However, we at Dunlop Industrial Products, have developed rubber compounds that exceed type F requirements and have a maximum abrasion loss of only 140mm3.

Dunlop's FlameTech Conveyor Belting

Dunlop produces three grades of fire-retardant &#;FlameTech&#; conveyor belting: F140, F180, and FR Surface. All three specifications comply with SANS manufacturing standards. The FR Surface (F200) covers are suitable for surface applications where injury or loss of life is unlikely in the event of a conveyor belt fire, with an abrasion loss of 200mm3 when tested to SANS standards. Grade F180 is more suited to underground use, as is F140, which has an abrasion loss of 140mm3, specifically developed to emulate the abrasion resistance of a hard-wearing compound such as grade M or DIN X, thus increasing belt life and lowering operating costs. All three grades are self-extinguishing, meaning that should the flame source be removed, the belt will not continue to burn.

Dunlop has expanded its product range further and is one of the few manufacturers able to supply belting that is both oil- and fire-retardant. These are &#;DIN K ISO 340&#; or &#;DIN K DIN &#; covers that have an abrasion loss of 250mm3 and the same fire-retardant qualities as the &#;F&#; range of covers, with the added benefit of being oil resistant. Additionally, there is an oil-resistant, non-fire-retardant cover compound available if required, known as MOR60, which also has an abrasion loss of 250mm3.

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We hope you enjoyed this technical read and the informational insights into the elongation of conveyor belts. To get a quote today call us on 010 880 or us at

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How to Choose a Mining Conveyor Belt

There are multiple moving parts and components that help power a conveyor system. Idlers, 

winches, bearings, couplings, gearboxes, motors, fluid couplings, and scrapers work in unison to transport materials from Point A to Point B.

One of the more often overlooked parts of a conveyor setup is none other than the belt itself. This pivotal component helps support and transport the product safely to its intended destination.

Read on to learn more about the various types of conveyor belts and the deciding factors you should consider when selecting one for your conveyor system.

WHAT IS A MINING CONVEYOR BELT?

A mining conveyor belt is one of the most essential components of a conveyor system. It transports ore and other materials from the mining site to processing facilities or loading areas. 

Conveyor belts are powered by a motor that runs off electricity or other power sources. 

Depending on the application and several other considerations, the composition of the belt could include a plastic or rubber compound, fabric materials, and steel cables. It&#;s supported by rollers that allow it to safely and efficiently move ore and other materials at a predetermined speed. 

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CONVEYOR BELT COMPOSITION

Conventional conveyor belts are comprised of three layers:

• The top layer, or cover, which is what the product rests on during transportation. 
• The middle layer, also known as the carcass, helps support the belt. The carcass tends to be made of either metal or woven fabric. 
• Finally, there&#;s the bottom cover to complete the belt makeup.

WHAT ARE THE DIFFERENT TYPES OF CONVEYOR BELTS?

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It&#;s critical to choose the right type of conveyor belt to ensure safe and reliable operation. Using the wrong belt can lead to catastrophic consequences and unplanned downtime.

These are the different types of conveyor belts available:

• Multi-ply&#;Consists of various layers of fabric separated by rubber, which helps deaden impact. Tend to be longer-lasting and are used for underground applications. 
• Straight-warp&#;Ideal for tunneling applications, they&#;re most often used in rock quarries and rock crushers. Impact and tear resistance are the two premiere attributes, which feature yarns and polyamide on both sides. A straight-warp belt can achieve higher troughability at narrower belt widths and higher PIW ratings.
• Steel-cord&#;Steel cables running the entire length of the belt anchor this type of conveyor belt, which is used for underground applications.
• Solid woven belts&#;These are more popular in Europe and Asia and not used often in the U.S.
• Heat-resistant&#;Designed to withstand high temperatures.

CONSIDERATIONS FOR CHOOSING A MINING CONVEYOR BELT

If you&#;re shopping for a mining conveyor belt, you should first decide your tensile strength requirement, cover thickness, and cover type depending on the material being transported and loaded. Also of particular importance is the operating environment in which the conveyor transports material.   

Conveyors that move packaging or light materials in temperature-controlled warehouses won&#;t have the same demands as those transporting heavy products underground in mines and quarries.

This is why the application and environment should be the two top considerations when selecting a mining conveyor belt.

ABOVE OR UNDERGROUND?

The key difference between above-ground and underground mining belts is the materials used in the manufacturing process. A standard surface or above-ground mining conveyor belt is composed of highly flammable petrochemicals. If used in an underground mining application, there&#;s a good chance that the belt can combust and present a severe safety hazard. 

UNDERGROUND

Underground mining belts are made of flame-resistant materials. Special agents, impregnation paste, and rubber components are added during manufacturing to help decrease the friction factor and increase fire resistance.

SURFACE/ABOVE-GROUND

The selection of an above-ground conveyor belt is mainly determined by the properties of the raw materials you&#;re transporting. The levels of humidity, granularity, and abrasion characteristics are all essential factors in this decision. 

For example, highly abrasive materials such as iron ore, metallurgic coke, and quartz will require a much sturdier belt than moderately abrasive materials, such as ash or sand.

Here&#;s a chart that delves into a comparison of the Depreux brand of above and underground mining conveyor belts:

ElementDELTA or DELTA CFW Surface/Above-Ground BeltsFirewall&#; &#; Firewall II&#; Underground BeltsFiremaster&#; -PVGUnderground BeltsApplicationTransportation of bulk or other material in various mining and industrial sectors such as quarries, mines, paper and wood, glass, cement, steel, eg.Both Firewall and Firewall II are belts used to transport bulk or other material in various underground mining and quarrying applications or any application in which MSHA Part 14 fire resistance is a requirement.DEPREUX Firemaster-PVG belts offer a longer service life and are ideal for use in severe operating conditions such as moving large material, high-speed systems, long distances, steep slopes, risk of impact damage, edge wear, or longitudinal tearing.Tensile StrengthTensile strength 150 PIW to PIW using 2 to 5 plies.Tensile strength 150 PIW to PIW using 2 to 5 plies.Ranges from a standard of 150 PIW to PIWWidth and LengthStandard 18&#; to 96&#; maximum. Tolerance +/- 1%. Wider belts are available.Standard 36&#; to 84&#; maximum. The width tolerance is +/- 1%. Wider belts are available.Thicknesses and weights vary for different specifications. Contact us for more details.Belt StructureThe DELTA or DELTA CFW belt textile carcase is made up of layers of fabric, from 2 to 5 (or more) plies. Each of these is separated by a rubber layer. This «sandwich» structure enables the belt to absorb shocks.The Fireshield&#; and Firewall II&#; belt carcase is made up of layered fabrics, from 2-5 plies. Each ply is separated by a rubber interlayer which enables the belt to absorb shocks.Made out of a textile <> carcase that&#;s impregnated with a special PVC. The carcase is then further protected via a proprietary DEPREUX cover that provides special characteristics to ensure improved performance and longer life.Belt StretchAt 10% of belt nominal tensile strength: 1.5% max. Permanent stretch: around 0.7% and elastic stretch: around 0.5% for a standard carcase.At 10% of belt nominal tensile strength: 1.5% max. Permanent stretch: around 0.7% and elastic stretch: around 0.5% for standard carcaseAt 10% of nominal belt tensile strength: 1% maximum elastic stretch: 0.5% to 0.7% for a standard carcase. Permanent stretch: 0.4% to 0.7%Main Mechanical PropertiesBelt StretchAdhesionBelt StretchAdhesionBelt StretchFastenersMechanical Resistance

Depreaux Underground Safety Belt Information

Depreaux Surface Conveyor Belt Information

NATURE OF MATERIAL TRANSPORTED 

Under ideal conditions, the average lifespan of a mining conveyor belt is anywhere from three to ten years, depending on length, transfer design, etc. The nature of the bulk materials you&#;re transporting can also significantly affect belt lifespan. 

For example, sharp, jagged, abrasive materials can damage the belt much faster. This is why it&#;s important to choose a belt that&#;s specifically designed for your application and is well-supported in the loading zone.

FIREPROOFING

If your mining conveyor operates in an underground environment, it likely has to comply with MSHA Part 14 fire resistance requirements. Make sure you&#;re fully aware of the rules and regulations that can impact the type of belt you select for your conveyor to ensure you&#;re operating at maximum levels of safety, not to mention staying compliant.

SERVICE LIFE

Some belts are made to last longer than others, and certain factors like longevity and durability are important based on the particular type of environment. 

Conveyors running underground or transporting material from mines and quarries pose greater demands on the conveyor belt than a line in a factory transporting empty boxes.

Understand your needs when it comes to durability and ruggedness. Failure to consider this could result in productivity loss and increased downtime.

PULLEY DIAMETER

Depending on the thickness of the belt fabric from top to bottom, there is a manufacturer-recommended pulley diameter that you&#;ll need to consider.

CORROSION-RESISTANCE 

Belts can corrode&#;especially those that incorporate metals into their makeup. While corrosion may not be as much of a worry in a climate-controlled facility, it can pose challenges on underground conveyors where temperatures, UV light, moisture levels, and humidity tend to fluctuate.

BELT WIDTH & LENGTH 

Since all belts aren&#;t made for the same applications, they aren&#;t constructed in similar widths or sizes. 

For example, the belts you see on the conveyor belt systems in grocery store checkouts are much smaller in width and length than the ones you&#;d find underground transporting products from the mine. 

While many belts can be custom-made to fit a desired length and width, it&#;s always best to know your sizing requirements.

TEMPERATURE

The temperature of the materials you&#;re transporting is another vital consideration. For example, rock and ore that come straight from the ground could be as hot as 220°F. While this is not enough to catch the belt on fire, it could potentially cause irreparable damage. 

A belt designed with specific thermal properties can help mitigate damage caused by high-temperature materials.

Check out our Mining Conveyor Belt Maintenance Guide.

FREQUENTLY ASKED QUESTIONS

Q: What is a conveyor belt for coal?

A: Coal conveyor belts are specifically designed to safely and efficiently move coal from one area to another. West River Conveyors has over 40 years of experience building custom conveyors for the coal mining industry.

Q: Which type of mining uses conveyor belts?

A: Coal, rock, precious metals, iron ore, lead, and lithium are just a few examples of mining operations that use conveyor belts.

Q: What is a quarry conveyor belt?

A: A quarry conveyor belt moves materials, such as sand, gravel, rock, marble, or crushed stone from a quarry site to an endpoint.

Q: What is TPH in a conveyor?

A: The acronym &#;TPH&#; stands for &#;tons per hour&#; and is a critical measurement that determines the ideal conveyor belt to use on a mining conveyor system. It measures how many tons of rock or ore per hour the conveyor belt moves. TPH correlates to belt speed or how fast the belt moves.

SELECTING THE BEST MINING CONVEYOR BELT

Don&#;t overlook the mining conveyor belt when designing the conveyor system for your next project. While there are many different types of conveyor belts to choose from, they are a key piece of the overall puzzle that helps ensure productivity and that your profit goals are not only met&#;but exceeded.

West River carries a full line of products like Cobra/Depreux Fireshield and Deltatherm belts, conveyor belt replacements, and more. Contact us for more information.

Underground Conveyor BeltSurface Conveyor Belt

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