061211-Environmental Screening Report-IMAE.pdf - nirb

Ore will be extracted by blasting with explosives and excavating at 5 m intervals. Rock excavationwill be carried out from top to bottom in each pit, and access road and ramp elevation will beadjusted accordingly based on bench advance and progress in rock excavation. The total depths ofthe pits will be approximately 15 m.The ore will be transported from the bulk sample pits to the ore crushing area using 50 t haul trucks(Caterpillar 773’s). The crushing area, shown on Figure 2.3, is where the mined ore sample will becrushed using a portable crusher to produce both a lump ore product (-31.5 mm + 6.3 mm) and afine ore product (6.3 mm minus). Crushing operations are expected to generate 75% lump and 25%fines. The lump ore and fine ore will be handled separately from this point on; separate temporarylump and fine ore stockpiles will be created next to the crusher and at Milne Inlet.Acid rock drainage (ARD) and metal leaching (ML) testing is being conducted on the ore (fresh andweathered hematite and magnetite) and waste rock using drill core and surface samples from theexploration program. The samples have been submitted to SGS Lakefield Research Ltd. for thefollowing tests:• Static Acid Base Accounting (ABA) - modified sobek method• ICP metal scan• XRD (mineral content assessment - % mineralogy)• SPLP 1312 - metal leaching• TCLP 1311 - aggressive metal leaching• Whole rock analysisComplete results from the above tests are not yet available. However, preliminary results that areavailable suggest that ARD may not be produced and ML will be minor.There was no evidence of ARD in the field. Surface water quality downstream of the orebodyexhibits generally neutral pH conditions (between 6.2 and 7.9) and sulphate concentrations in thesurface water downstream are very low from