Waste tyres are a core component for the sector, typically used as raw materials in the production of rubber shred or crumb. In some applications, whole tyres are chopped into small chips. In others, chips are ground much more finely and the metal content of the tyres is removed.
Chopping and grinding of tyres produces a low density, porous material through which air can percolate. The combination of permeability to air flow and a high exposed surface area means that that a combustible material such as rubber is potentially susceptible to spontaneous combustion.
Spontaneous ignition of large stockpiles of tyre shred or deep landfill deposits has occurred on numerous occasions. Practical experience suggests auto-ignition normally occurs in large stockpiles (more than three metres deep). Finely shredded tyres are more susceptible because of the increased surface area available for reaction.
The risk of ignition in practical circumstances may be raised by contamination of the tyres (which may allow biological heating in damp conditions) or by the rusting of exposed wires (which also generates heat). The stripping of rubber from wire in the tyre chopping process may be associated with blunting of blades in the shredding machine.
Many of the standard methods of protection against spontaneous combustion are applicable to tyre shred:
- Minimise pile size
- Control of moisture levels
- Management of stock to prevent piles being left for long periods
- Sub-surface temperature monitoring
- Turning of piles at risk of spontaneous heating
- Minimising external heating e.g. shading from direct sunshine
- Control of ventilation by enclosure - if possible
- Heating pipes, light bulbs, space heaters, braziers, shrink-wrapping guns equipment etc should be kept away from piles of tyre shred.
Once established, combustion in large piles of tyre shred and rubber crumb is difficult to suppress. Direct application of water or foam in situ does not generally provide effective extinguishment and may hamper control of oily run-off pollution. The first priority is separation of unburned material from the fire to restrict the extent of spread.
More at www.hse.gov.uk/rubber/spontaneous.htm
Confidential shredding from B&M
B&M Waste Services (B&M) has launched a confidential information destruction division - B&M Secure Shredding – to provide its customers with a recycling one-stop shop.
The scheme will operate throughout the northwest and the division will take the shredder directly to the customer’s door. The division has ISO 9001 and BS 15713 and so is legally compliant with the Data Protection Act (1998). The secure shredding division provides secure lockable containers for customers to store their confidential waste.
“We have a heritage in waste management that spans over a decade,” says B&M Secure Shredding managing director Neil Curtis. “It’s an exciting time for B&M Waste Services as we look to grow the business and diversify into other areas. B&M Secure Shredding will be pivotal to this growth.”
Waste carpet shredding from Blackwater
Blackwater Recycling in Alnwick, Northumberland, has just bought a BMH Ecosaurus 7520 single rotor shredder from Cape Machinery International to process waste carpet.
Installed in early January, the machine is processing carpet waste into a fuel and material for a riding surface for horse arenas. The Ecosaurus comes in six sizes and can tackle tyres, wood, plastics, organic waste, textiles, big bags and more. The baled processed carpet material is low in moisture and high in calorific value.
“It was vitally important to use to have a shredder that is capable of handling the material in an efficient manner, whilst maintaining the throughput as un-shredded carpet is extremely bulky,” says Blackwater md Jim Douglas.
Van Dalen boosted capacity in UK
Metals recycler Van Dalen boosted its UK capacity by investing over £6m including a state-of-the art ferrous shredder at the company’s Sheffield headquarters and creating up to 25 jobs. Van Dalen currently operates 17 shredding and baling sites in the UK and Northern Europe. In the UK, the company supplies the major steel mills, as well as a large number of foundries. It also operates deep sea facilities, which enable export to markets throughout the world. Van Dalen UK managing director Tom Bird said: “Although market conditions have been challenging, we’ve had a really positive 12 months. Going forward, the shredder will transform our Sheffield facility, making it a state-of-the-art metal recycling centre.”
“The focus on non-ferrous operations will complement our existing success in the ferrous arena, helping us to grow volume and market share. In turn, we hope to provide further investment and job creation opportunities in the UK.”