Pierre River Mine Project

MINING AND PROCESSING ERCB SIRS 3 – 38
Section 4.1
NST produced at start-up, before in-pit storage is available, would require aboveground
containment structures. These structures might result in areas of ore
sterilization. Furthermore, the use of overburden to construct NST storage at
start-up would consume construction material required to build in-pit dykes and
delay construction of in-pit storage.
The plan to start NST production in 2029 is based on this balance between fluid
generation, material balances and the availability of in-pit storage space.
Request 34b What steps does Shell plan to take to diminish these constraints?
Response 34b As new information becomes available and engineering constraints change, Shell
will review its mine plans with the intent of advancing NST production and
accelerating reclamation. Currently, the first opportunity to begin NST
production is 2029.
Request 34c Confirm the sand to fines ratio listed for NST.
Response 34c The May 2009 Pierre River Mine, Supplemental Information, Volume 1, Section
4.1, page 4-2, refers to the NST as produced from the tailings processing facility
(SFR44 = 5:1). This ratio, which represents the limit of current pumping
capability, is different from the sand to fines ratio of the orebody (SFR44 = 6.7:1).
This is because coarse sand is bypassed around the NST process and placed
concurrently within the NST deposit.
The May 2009 Pierre River Mine, Supplemental Information, Volume 1, Section
10.1, Table 218-5, lists the sand to fines ratio of the NST deposit as deposited,
and matches the SFR of the orebody.
Request 34d Discuss how Shell will measure the fines captured in the NST deposit and the
strength of the deposit.
Response 34d Shell will collect samples of the NST in the DDA from multiple locations on an
annual basis. The samples will be analyzed to determine solids content and the
percentage of fine minerals solids that are finer than 44 μm. This information
will be used to determine total NST inventory, including density, total mass of
solids and total mass of mineral solids finer than 44 μm. The strength of the NST
deposit will be determined using cone or ball penetrometer results from annual
DDA surveys.
Request 34e What is Shell’s mitigation strategy if fines captured in NST deposit are lower
than targeted?
4-36 Shell Canada Limited April 2010
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