Dust Control Handbook for Industrial Minerals Mining and Processing

e a significant factor when optimizing the fragmentation and cost of the crushing and grindingcircuit [Hustrulid 1999]. While blasting seemingly generates large amounts of dust, theoperation occurs infrequently enough that it is not considered to be a significant contributor toparticulate matter less than 10 micrometers (µm), or PM 10 [EPA 1991; Richards and Brozell2001]. Testing has been conducted to create an estimator for the amount of dust generated fromblasting. The estimator is shown as the following equation:e 0.00050A 1.5where e = total suspended particulate emission factor (lb/blast); and2A = area blasted (m ) as long as hole depth does not exceed 70 feet.To estimate the PM 10 emissions from blasting, the following equation is used:PM 10e x 0.5where PM 10 = pounds per blast of particulate matter less than 10µm; ande = total suspended particulate emission factor (lb/blast).It must be noted here that the U.S. EPA determined that this estimator should only be used forguidance. More reliable emission factors for particulate emissions should be based upon sitespecificfield testing in order to determine the amount of particulate matter generated fromblasting [EPA 1998].Blasting Dust Control MeasuresAs a result of blasting being considered an insignificant dust source, there is very littledocumentation for dust control of blasting operations. There are five methods of dustsuppression that can be used for the control of dust during blasting, many of which are effectivefor underground mining only [Cummins and Given 1973]:wetting down the entire blasting area prior to initiating the blast;the use of water cartridges alongside explosives;the use of an air-water fogger spray prior to, during, and after initiating the blast;the use of a filtration system to remove pollutants from the air after the blast; anddispersal and removal of the dust and gases using a well-designed ventilation system.Wetting Down Blasting AreaA common method of dust control for blasting operations is to wet down the entire blasting areaprior to initiating the blast. This procedure minimizes dust being entrained into the air from theblasting activity by allowing it to adhere to the wet surfaces [Cummins and Given 1973]. Thismethod has been shown to be effective for dust control during blasting in underground mines. Itcould also be effective for surface mining depending upon the time interval between wateringand blast initiation, with the possibility of exposure to the surface atmospheric conditionscausing the moisture to quickly evaporate and rendering the watering ineffective. However,Drilling and Blasting 101