COHEREX – Dust Control
Dust is more prevalent than any other atmospheric contaminant. When carried into the air, it can damage crops, cause respiratory illness, affect visibility and spread disease. Unchecked it adds to pollution and adversely affects our entire ecology.
Coherex® was developed as a result of years of extensive research and thorough field and laboratory testing. Coherex® stabilizes soil against wind erosion, thereby eliminating airborne dust and movement of sand along the ground.
What is COHEREX?
COHEREX is an effective dust control and wind erosion agent. It is a stable, concentrated, nonvolatile emulsion consisting of approximately 60% semi-liquid natural petroleum resins and 40% wetting solution.
The non-volatile resins are the film forming, dust-binding portion of the preparation.
The wetting solution is water containing a combination of wetting agents and sequestering agents, which serve four purposes:
(1) Disperses the resins into fine particles, which can be kept suspended in the emulsion, making COHEREX a preparation readily miscible in water in all proportions.
(2) Increases the spreading power of the diluted emulsion.
(3) Facilitates penetration of the resinous particles into soils.
(4) Stabilizes the preparation against water; permitting the dilution of the emulsion with almost any water available.
The water contained in the concentrate is an integral part of the preparation. It is the solvent for the wetting and sequestering agents and is proportioned in the concentrate in an amount assuring the greatest storage stability and ease of handling.
Additional water added to the concentrate before use, in amounts recommended at the end of this manual, serves as a diluent to assure greatest economy and increase penetration into the dust layer.
How does COHEREX work?
The prime conditions favoring susceptibility of soil to erosion by wind are:
1) Lack of cohesiveness (loose and dry soil).
2) Lack of protective cover (smooth and bare ground).
3) Lack of shelter from wind (large, unsheltered areas).
In wind-resistant native soils, a correct balance of fine and course particles provides the required cohesiveness to resist the impact of saltation, the start of all erosion.
The development of COHEREX for treatment of soils started with the realization that the three types of movement of soil:
1) Saltation – The effects of direct pressure of the wind on soil particles and by their collision with other particles. Saltating grains can move, by the force of impact, particles over 200 times their own weight
2) Surface Creep – Slow movement of the soil surface that is caused primarily by the direct impact of saltating grains on particles, too heavy to be dislodged by wind, and bounced into the air.
3) Suspension – Is the transporting by wind of small particles. These particles, after having been dislodged from the surface by saltating grains or by mechanical disturbances, like traffic, can be transported long distances.
Can be arrested by imparting cohesiveness to the soil. In other words, COHEREX approach to stabilization of soils against wind erosion is the substitution of a resinous cohesive agent for the fines, which are required for the apparent cohesiveness in naturally wind-stable soils.
When COHEREX contacts the dusty ground, it coats the dust particles and forms cohesive membranes that attach themselves to adjacent particles. The chain-like bonds result in large “agglomerates” too heavy to be dislodged by wind. The resulting overall increase in particle size actually immobilizes the dust and prevents it from becoming airborne. Treatment with COHEREX is a more effective approach to soil stabilization because the required cohesiveness is imparted to the soil without drastically altering its original make-up.
Since treatment with COHEREX leaves a cumulative residue of the resins deposited on the soil particles, areas once conditioned with COHEREX require only occasional re-treatment to bind “new” dust, which has blown or drifted onto the area or which has been stirred up from beneath.
COHEREX is highly stable.
The high stability of COHEREX contributes greatly to the economic value of the product, assuring no loss of material by spoilage. It can be stored for long periods ( 12 months or more) without impairing its quality if kept in clean containers and protected from extreme temperatures (freezing and boiling). Diluted COHEREX should preferably be used within one day, since prolonged storage might result in stratification. If stratification occurs, simple agitation or stirring will prepare the mix for use.
How long does it last?
Under normal atmospheric conditions, and if the recommendations are followed in the COHEREX manual (available upon request), the first application will be effective 3-12 months and each succeeding application up to 12 months. If undisturbed by traffic, the initial treatment could last up to 3 years.
How do you apply COHEREX for best results?
Spreader trucks, hand sprayers, orchard sprayers, or other standard equipment can be used. Apply COHEREX by sprinkling the area with a sufficient amount of the diluted dust-binder to penetrate the layer of dust to the depth. When determining the ratio of COHEREX to water, remember that depth of penetration is controlled by the total amount of fluid (product plus water) applied and the thickness of the deposit of resins on the dust particles is controlled by the amount of COHEREX concentrate in the fluid applied. Soil type influences the amount of fluid required and the time required to reach the depth of penetration desired.