Investigation of Laboratory Procedure for Evaluating Chemical Dust Palliative Performance

An experimental testing protocol was developed to compare the relative effectiveness of chemical dust palliatives. The methods and application simulate field construction using commercial spray components. The test devices were constructed to simulate wind speeds and conditions for rotary wing aircraft. Fifteen chemical dust suppressants were evaluated using this methodology. These commercial products were applied topically to prepared soil specimens and allowed to cure for one and 48 h. Effectiveness was determined from the relative mass loss of the soil samples from erosion when samples were subjected to an air impingement device. An optical dust sensor was installed in the test device to measure airborne dust concentrations as an additional method for quantifying performance. A method to disturb the treated soil surface was also introduced to simulate the effect of traffic. Select application rates of the palliatives were used in sample preparation to identify minimal quantities necessary for the desired performance. The testing equipment and processes provided a rapid screening methodology for selecting potential dust palliatives. Results indicated good correlation between erosion and airborne dust concentrations with higher application rates and complete curing of materials demonstrating reduced dust levels. The traffic simulation test identified products with a propensity to form surface crusts that may be disturbed by traffic.