WET DUST SUPPRESSION - Air/Water or just Water 2

[JackofallMech]

I am investigating Wet Dust Suppression applications for mineral mining (gold,zinc,lead etc). Does anyone have experience with High Pressure Water Fogging? How does it compare to the lower pressure air/water combination approach. Our system is upstream of a floation circuit and thus we need to be carefull not to add chemicals that will affect this circuit. Alos, we are trying to keep water consuption minimal do to the site location. I have talked to proffesionals who have used the compressed air/water combination and have had positive feed back. However, in my readings I have discover that high pressure water fogging is "potentioally" better since it keeps air velocities down, doesn't require air compressor, only needs simple filtration system and is more energy efficient. If anyone has experience with these applications please comment!

 

[Newmanite]

The mine that I work has trialed compressed air/water system and it failed dismally.High pressure water fogging is effective but as long as the driver can vary the flow rate and control the speed of the vehicle to get maximum effect on the road way.Pulse spraying works very well but you need to get the spray height correct or you lose alot to everywhere else but the road way.The watercarts used here are 789b cat haultrucks,the pump unit is run directly off the double pump system to a small hyd motor that drives a warman fire booster pump(unsure what size) and when not in use goes to brake cooling of the truck.Effective low cost and rebuilable pump unit.It has 4 low mounted sprayers and two mid mounted, it can be used individually or all or some and can be set to pulse or full spray,depending on how each signal line is applied to each sprayer

 

[JackofallMech]

Newmanite

Thanks for you info however, I should have made my application more clear. I am hoping to use fogging for conveyor transfer points. Do you have any experience with this?

 

[Newmanite]

Yes this one is really a pain as if you put too much on it causes hang ups in the chute and if you use chute plugs it can cause a few minor problems(nuisance). A spray bar set up above the ore maximum height limit just as the product leaves the belt and another one at the end of the transfer chute.
A fogger of good design will work for your product very well.Set it or them above and below where dust extraction is the greatest for maximum effect

 

[Speedycrete]

Can you use a surfactant to help the water atomise more, therefore reqiring less water consumption. I've also heard of systems that use a chemical to 'foam' the water, giving longer lasting results.

I once used a water-spray system on the dry circuit of our gravel crushing plant (terribly dusty) had a 7 nozzle assembly under the cone crusher and 2 or 3 nozzles at each transfer point. (6 total) At some transfer points we sprayed both sides of the aggregate stream to get effective control. If I recall correctly, the nozzles used about .25 gpm each, The water usage was about 100 gal / hr for about 2 gal / ton. The water pressure was about 120 psi

It was extremely hot and windy on this particular job that we used dust control on....the benefit was not only in the working conditions and overall site cleanliness but in the lowered maintenace costs for the equipment....particularly air filters

Here's a good link:

http://www.aeec.com/Conveyor/Dust_Control/Dust_Suppression_Handbook.aspx

Dust control is also about air control, falling agregate creates it's own wind that's what initially gets the dust airborne....control that and half the dust problem is controlled too.

 

[JackofallMech]

Thank you both for you feed back!