Foam Dust Suppression helps resolve Dust Issues at Bardon Hill

• 
• 15th July 2008
• Quarrying
 

Situated in Coalville, Leicestershire is Bardon Hill Quarry one of the flagship operations of Aggregate Industries.  It is a long established quarry producing over 3 million tonnes of aggregate per annum. 

The production plant comprises a primary crusher, secondary crushers and tertiary and quaternary crushers, additionally; there are screens at various intermediary stages as well as final screen houses.

Controlling dust emissions in quarries is vitally important and this is no different at Bardon Hill.  The management are acutely aware of their responsibilities not only to their employees in providing a safe environment to work in but also to their neighbours and the wider community.

In common with most quarries Bardon Hill experiences airborne dust emissions at various stages of the process plant including:

• crushing shed
• transfer points
• intermediary screen
• final screens
• vehicle load out points

A number of mitigation measures had been introduced over the years. These measures have varying degrees of effectiveness at their specific points of application. There is a limit as to how much moisture that can be added through spray systems as excess moisture can cause screening problems. Additionally, the extraction plant also has number of operational disadvantages including high energy, maintenance and consumables costs.

The management were determined to explore other methods of dust control at Bardon Hill. In November 2005 Best-Chem were approached to carry out a site survey to see if its unique Foam Dust Suppression System could make the difference that they were seeking.

Best-Chem as a pioneers of Foam Dust Suppression Systems here in the UK have not only developed unique application equipment but also manufacture at their site in Stourport, Worcestershire a number of proprietary foaming agents used in the system. Best-Chem has also built a mobile demonstration system which can be easily set up and give potential customers a realistic appraisal of what can be achieved.

Given the complexity of the process plant at Bardon Hill a demonstration was set up whereby two quaternary crushers were to be treated with the Best-Chem Foam System.  The output from these two crushers goes to a separate dedicated screening process for small sized aggregates.

The demonstration unit was set up outside normal operating times to avoid any disruption to production. Trials were carried out under normal production operations. Within half an hour of operating the system there was a negligible amount of airborne dust.

Following this successful trial - Best-Chem was invited to install a comprehensive Foam Dust Suppression System throughout the process plant.

In March 2007 a foam system was installed at the primary crushing plant, and earlier this year a comprehensive installation was carried out at the tertiary / quaternary crushing shed. 

Each of these systems is housed in a new fully fitted container and comprises:

• Foam Generating Unit - this is Best-Chem's own design and allows foam to be applied at remote locations up at 150 metres away.
• Bunded chemical storage tank for Dustrol 70
• Air operated chemical transfer pumps
• Heating & lighting

An air compressor was not supplied as there was sufficient spare capacity at the process plant.  The installations were carried out by Best-Chem engineers with little disruption to production.

Utilising this System - foam is generated at dilution rates of over 200 parts water to 1 part foaming agent through a series of nozzles directly in to the crushers.  This has the effect of wetting the aggregate and capturing the dust before it becomes airborne. Thus in essence the Best-Chem approach is to "prevent the dust from getting airborne."

The typical application rate into a crusher processing 150 tph is in the region of 3 litres of solution per minute (at 200:1).  This is approximately 0.1% moisture addition by weight and does not lead to screens blinding over - yet prevents most of the dust from getting airborne.

The system is fully automated and individual nozzles are turned on or off by signals from associated equipment. In this way foam is only applied when it is needed thus minimising wastage.

Further Information:
Best-Chem Ltd
Barracks Rd
Sandy Lane Industrial Estate
Stourport-On-Severn
Worcestershire
DY13 9QB
Tel: 01299 827232
Fax: 01299 827608

Email: info@best-chem.co.uk
Web:   http://www.best-chem.co.uk/

 

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• Hub-4 Profile of Best-Chem Ltd
• Best-Chem Ltd Company Website