By: Chris Steyn
Our approach has always been one of innovation, exploration and improved dust suppression techniques and applications
High pressure fogging vapour dust suppression systems
High pressure fogging vapour dust suppression systems that are capable of providing dust suppression up to 4500 meters employing up to 600 fogging spray nozzles strategically positioned at the different dust generating areas. Water supply standards to the system must be potable standards!
- Power supply 220/380/500V/50Hz
- Models available from 6 to 11kW with water consumption of 15 to 50 litres per minute at 70 bar pressure.
Advantages
- Low water consumption at 80 ml per nozzle @ 70 bar pressure
- Droplet sizes 7 micron and smaller
- Exceptional dust capturing/scrubbing capabilities due to small droplet sizes
- Remove SO and NO gasses from the air
- Reduce risk of fires and explosions at areas of application
Applications
Surface:- transfers, crushers, screens, tipping areas, silos, bunkers, feeders, drill rigs, area scrubbing, cooling etc. Enclosures of transfers recommended.
Underground:- apart from the above – footwall treatment, gulleys, stopes, ore passes, continuous miners, road and haulage dust suppression, scrubbing of inlet/outlet airways etc.
The latest trend is to adapt these high pressure systems to incorporate a high pressure cleaning facilities to enable staff to effectively and quickly clean or discard build-up in chutes etc.
A high pressure fogging application is currently in use at a Coal Mine in Mpumalanga for road dust suppression as well as scrubbing of intake air purposes
Possibilities for incorporating high pressure dust suppression systems with extraction dust suppression systems in order to scrub the escaping air into the atmosphere are on the agenda of some high profile companies. Something to consider as there is no reason why fogging could not be utilized with extraction.
Low pressure spraying Micro/Macro dust suppression systems 20 bar and lower pressures
Units vary from 5 to 110kW with high water consumption from 200 to 2000 litre per minute.
Droplet sizes range from 20 micron to course droplets using this type of dust suppression. The distribution range of droplet sizes vary with different pressure and nozzle configurations employed.
These systems are mostly employed where wetting or flooding of the product produced is tolerated or specifically required to achieve certain outcomes.
Total length of a micro/macro dust suppression is limited due to friction and header material and pressure limitations.
Water quality is not that critical provided that the suspended solids are manageable.
This Type of application is achieving excellent results with chemical pre-treatment of stockpiles in order to prevent/limit dust generation during the reclaiming process for further beneficiation of the product.
Typical applications
Stockpiles, Industries where moisture addition is not a problems.
Area dust suppression spraying systems
Road dust suppression spraying systems
Pre-wetting of Rear dumpers at mines to eliminate/control dust generation during tipping of ore or waste
Possible future applications
Micro/macro systems installed on rear dumpers for dust suppression on haul roads
Draglines, shovels, long term tailings stockpiles treatment
Summary
The use of chemicals for enhanced dust suppression is the cornerstone of our dust suppression program. Envidroclear developed specific products to combat and control specific harmful pollutants which otherwise would continue to pollute the working environment!
The supply water to all our systems is subjected to treatment program which entails flocculation, filtration, chemical treatment and sterilization to enhance and prolong system integrity and ensure that the required dust suppression results are achieved
Combinations of high pressure fogging and low pressure micro/macro systems are used in certain specific applications where excessive water in certain beneficiation processes poses a problem!
Road dust suppressant
Not much has changed in road dust suppression except that a study is currently undertaken to determine the effect of using glycerine in combination with current products on the market
Glycerine is a by-product of the esterification process in bio – fuel production and is relatively cheap compared to existing road dust suppressants.
