1. Illinois Mining Institute Annual Meeting
August 25, 2015
Types of Dust Suppressants and
How They Function
Tony Malloy
© 2013 Quaker Chemical Corporation. All rights reserved.

2. A SINGLE DUST SUPPRESSANT CAN NOT CONTROL EVERY DUST PROBLEM
OVERVIEW
A SINGLE DUST SUPPRESSANT CAN NOT CONTROL EVERY DUST PROBLEM
© 2013 Quaker Chemical Corporation. All rights reserved.

3. Dust Suppressant Categories
Controls Dust where it ORIGINATES
Controls Dust where it ACCUMULATES
© 2013 Quaker Chemical Corporation. All rights reserved.

4. Type of Product that Controls Dust where it Originates
Surfactants in Water
This type can be used at:
Crushers
Conveyor Transfer Points
Continuous Miners Shearer
Longwall Shearer

5. How Surfactants in Water Function
Lowers Surface Tension of water which allows water to adsorb onto dust surface and absorb into dust particles.
With the correct nozzles, water will form small droplets to improve opportunity of hitting fine dust.
© 2013 Quaker Chemical Corporation. All rights reserved.

6. Products That Control Dust where it Accumulates
Water
Moisture Absorbing (Hygroscopic) compounds
Petroleum type
Organic Non-Petroleum type
Electrochemical
Synthetic Polymer
Clay Additives

7. Water Controls Some Dust where it Accumulates
Water without additives can be used on some materials to control dust
Water without additives does not control coal dust
Lasts only 2 – 8 hours, or until it evaporates, depending on temperature
Higher cost than expected
Time
Equipment

8. How Water alone Functions
It is absorbed by most particles and makes material bind together.
As material increase in weight, its ability to become airborne decrease.
As water evaporates, material weight decreases, clumped pieces break apart, and eventually the fine size particles become airborne again.
© 2013 Quaker Chemical Corporation. All rights reserved.

9. Moisture Absorbing Compounds Control Dust where it Accumulates
Salts / Brines
Calcium chloride, Magnesium chloride, Sodium chloride
Other Hygroscopic materials
Glycerine
Ethanol
Methanol
Diesel fuel
Sugar

10. How Salts / Brines Function
Absorb air moisture depending on relative humidity.
Calcium chloride begins absorbing at 20% - 29%
Magnesium chloride begins absorbing near 32%
Sodium chloride begins absorbing near 79%
Moisture Binds particles together to increase total weight / prevents them from becoming airborne.
Best time to use during morning hours when relative humidity is typically high and temperatures are low.
© 2013 Quaker Chemical Corporation. All rights reserved.

11. Petroleum Products Control Dust where it Accumulates
Asphalt emulsions
Asphalt – pitch after distillation of petroleum
Cationic or Anionic emulsifiers
Water
Cutback asphalt
Petroleum solvents

12. How Petroleum base product Function
Mix of product and water is applied which migrate into the material containing the dust.
The strong adhesive properties easily binds all particles together forming a continuous layer of surface material and petroleum.
After the water in the emulsion evaporates, the film becomes water resistant.
© 2013 Quaker Chemical Corporation. All rights reserved.

13. Non-Petroleum Organic products control dust where it Accumulates
Lignin
Extracted from softwood tree cells
By the sulfite paper making process
Tall-oil Derivatives
From the sulfate (Kraft) paper making process
Vegetable oils
Soybean soapstock

14. How Non-Petroleum products Function
Mix of product and water is applied which migrates into the material containing the dust.
Surfactants in the application emulsion also help product penetrate into the gravel surface.
Have slightly less adhesive properties than petroleum product, but also binds surface particles together forming a continuous film.
After the water in the emulsion evaporates, the film becomes water resistant.
© 2013 Quaker Chemical Corporation. All rights reserved.

15. Electrochemical Product control Dust where it Accumulates
Enzymes
Act as a catalyst to help fine clay size particles bind with road aggregate
Not effective on all road surfaces
Ionic materials
Cationic type product has positive charged droplets
Anionic type product has negative charged droplets

16. How Electrochemical products function
Enzymes:
Do not become part of the final surface, but act as an aid in the process of particles binding together.
Used with very fine dust that have an electrical charge.
Must be mixed into the roadbed using road grader or rake.
Effective regardless of weather conditions.
Ionic materials:
Cationic products function using electric field attraction by attaching to negative charged surfaces.
Anionic products function using electric field attraction by attaching to positive charged surfaces.
© 2013 Quaker Chemical Corporation. All rights reserved.

17. Synthetic Polymers control Dust where it Accumulates
Synthetic polymers, such as polyvinyl acrylics and acetates, are the primary film forming ingredient
These polymers are manufactured from readily available starting materials

18. How Polymer Suppressant Functions
Mix of product and water is applied which migrates into the material containing dust particles.
Gradual evaporation of water and coalescing agent until the polymers soften and connect.
The polymer continue to coalescence and generate a continuous film.
After all water and coalescing agent has evaporated, the film will be water resistant.
© 2013 Quaker Chemical Corporation. All rights reserved.

19. Evaporation Process

20. Clay Type Suppressants control Dust where it Accumulates
Bentonite is a clay processed from volcanic ash
Very fine material, 2 microns or less
Has strong colloidal properties
Volume increases several times in contact with water

21. How Bentonite Suppressant Functions
Bentonite is mixed with water and applied as a slurry.
The bentonite slurry must be mechanically mixed with road material using road grader or rake.
The mix water increases the volume of the bentonite particles and also make them tacky.
The tacky bentonite binds the fine dust with larger size material and prevents airborne dust.
© 2013 Quaker Chemical Corporation. All rights reserved.

22. Conclusions Two Categories of Dust Suppressants
Where dust originates
Where dust accumulates
Various products to use where dust accumulates
Brines, Petroleum, Non-Petroleum, Electrochemical, Synthetic Polymers, and Clay Additives
Variables affecting Suppressant Performance:
Wind, moisture, local temperature
Geological material creating the dust
Traffic conditions
Industrial activity

23. THANK YOU
FOR YOUR TIME
© 2013 Quaker Chemical Corporation. All rights reserved.