Coke is a fuel with few impurities and a high carbon content, usually made from coal. It is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur bituminous coal.
Cokes made from coal are grey, hard, and porous. While coke can be formed naturally, the commonly used form is man-made. The form known as petroleum coke, or pet coke, is derived from oil refinery coker units or other cracking processes.
Coke is used in preparation of producer gas which is a mixture of carbon monoxide and nitrogen. Producer gas is produced by passing air over red-hot coke. Coke is also used to manufacture water gas.
Coke is used as a fuel and as a reducing agent in smelting iron ore in a blast furnace. The carbon monoxide produced by its combustion reduces iron oxide (hematite) in the production of the iron product.
Since smoke-producing constituents are driven off during the coking of coal, coke forms a desirable fuel for stoves and furnaces in which conditions are not suitable for the complete burning of bituminous coal itself. Coke may be combusted producing little or no smoke, while bituminous coal would produce much smoke. Coke is commonly used as fuel for blacksmithing.
Significant quantities of fugitive dust from pet coke storage and handling operations present a health risk. Particles that are 10 micrometers in diameter or smaller (referred to as PM10) are the particles that generally pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects.
Coke Dust is Combustible and is an Explosion Hazard:
When most people think of controlling dust in the workplace, they think of taking steps to avoid inhaling dusts to prevent health problems. However, the accumulation of combustible dusts in the workplace can lead to far greater consequences. As seen in recent years, neglect of housekeeping and improper handling of combustible dusts can lead to property damage, injuries and loss of life.
A potentially catastrophic hazard which must be controlled in coke handling operations is the possibility of a combustible dust explosion or deflagration. Coke Dust is readily able to form dust clouds of finely divided, combustible material. OSHA’s National Emphasis Program for Combustible Dust emphasizes the need for administrative and engineering controls including immediate housekeeping, prevention of ignition sources, ventilation with spark detection and explosion/deflagration suppression systems, when a combustible dust layer exceeds 1/32 of an inch (about the thickness of a typical paper clip) on more than 5% of the floor area of a facility or any given room.
The National Fire Protection Association (NFPA) defines a combustible dust as “a combustible particulate solid that presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations, regardless of particle size or shape.” In general, combustible particulates having an effective diameter of 420 μm or smaller, as determined by passing through a U.S. No. 40 Standard Sieve, are generally considered to be combustible dusts. However, agglomerates of combustible materials that have lengths that are large compared to their diameter (and will not usually pass through a 420 μm sieve) can still pose a deflagration hazard. Therefore, any particle that has a surface area to volume ratio greater than that of a 420 μm diameter sphere should also be considered a combustible dust. The vast majority of natural and synthetic organic materials, as well as some metals, can form combustible dust. The NFPA’s Industrial Fire Hazards Handbook states, “any industrial process that reduces a combustible material and some normally non-combustible materials to a finely divided state presents a potential for a serious fire or explosion.”
Suggested Industrial Vacuums for Recovery of Toxic & Combustible Dust
PrestiVac HEPAPlus* Vacuums are specifically designed to safely vacuum toxic dusts. Equipped with a Certified Absolute HEPAPlus*filter with an efficiency of 99.995% on 0.2 micron so there is no risk of exposure or contamination for the operator or the environment. These vacuums are tested for absolute filtration. Testing Method: IEST RP-CC034.3. H14. MIL-STD 282 / A.S.T.M. - D2986-91. MPPS method EN 1822.
PrestiVac Explosion Proof/Dust Ignition Protected Vacuums are designed to safely vacuum explosive, flammable, combustible conductive* dusts. Our Explosion Proof/Dust Ignition Protected Vacuums are completely grounded and static dissipating because they are built entirely with non-sparking metals and do not have any painted components so there is no risk of fire or explosion from a spark or static build up. All the electrical components, including the motor and starter are totally enclosed so there is no source of ignition. Our explosion proof vacuum cleaners comply with NFPA 484 guidelines and are an effective tool for good housekeeping practise as per OSHA.
Which Industries are at Risk with Coke Dust?