Preliminary Public Dose Evaluation in Support of the Development of the
November 2012
Rare Element Resources Bear Lodge Project
25
Dust Emission from Truck Loading
The total suspended particulate (particles ≤ 30 microns) emission from loading haul trucks at the
BHM was estimated using the equation below adopted from Table 11.9-2 of AP-42 for coal:
= 0.580
1.2
Where:
EF
TL
= dust emission factor for truck loading (kg tonne
-1
)
M
= percent moisture content of material (7.9 percent from Table 11.9-3 of AP-42)
Based on the equation and assumptions above, the dust emission factor for truck loading at the
BHM is 0.049 kg tonne
-1
. The number of tonnes loaded per year was conservatively estimated to
6.6 x 10
6
per year. This mining rate is based predominately on overburden removal and will be
significantly reduced over the life of the mine. Based on the dust emission factor for truck
loading and the mining rate assumption above, the dust emission rate from truck loading
activities is conservatively estimated at 323,400 kg y
-1
.
Dust Emission from Dozer Operations
The total suspended particulate (particles ≤ 30 microns) emission from dozer operations at the
BHM was estimated using the equation below, adopted from Table 11.9-2 of AP-42 for
overburden:
= 2.6
1.2 1.3
Where:
EF
D
= dust emission factor dozer operation (kg tonne
-1
)
s
= silt content of material (6.9 percent from Table 11.9-3 of AP-42)
M
= percent moisture content of material (7.9 percent from Table 11.9-3 of AP-42)
Based on the equation and assumptions above, the dust emission factor for dozing at the BHM is
1.8 kg h
-1
. It is estimated that 3 dozers will operate for 20 h d-, five days per week (wk), 52 wk
y
-1
, or 15,600 h y
-1
(RER, 2012a). Based on this operating schedule and the dust emission factor
for dozers, the estimated dust release rate from dozer operations is 28,080 kg y
-1
.
