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Elko Roundtable 2017;

Site-wide mine closure, planning and management

by Bryan Ulrich and Rick Frechette

In March, Roundtable 2017 “Roundtable                               tends to provide a much less inhibited format
  discussion on site-wide mine closure: Planning,                   for discussion. In the roundtable format, lively
implementation and management” was hosted by                        discussions and applicable tangential departures
                                                                    are encouraged.
Knight Piésold and Co. (Knight Piésold) at the
                                                                        This was the 11th in the series of Elko
Red Lion Hotel and Casino in Elko, NV.                              Roundtable events. Previous roundtables
                                                                    pertained to:
This topic is timely because, as an industry,
                                                                        1.	 Heap leach pad design, construction and
the strategy and approaches available are                                     operation.

constantly evolving and being refined to keep                           2.	 Design, construction and operation of
                                                                              tailings storage facilities.
stride with expectations of interested parties,
                                                                        3.	 Site-wide water considerations.
including the surrounding communities,                                  4.	 Mine closure and cover design.
                                                                        5.	 Strides toward sustainability in mining.
regulatory agencies, land owners, etc.                                  6.	 High-density tailings, paste and filtered

Knight Piésold had local representatives                                      tailings.
                                                                        7.	 Acid rock drainage for engineers and
(Bryan Ulrich and Brittany Hutchings), as
                                                                              environmental scientists.
well as representatives from its Denver office                          8.	 Material co-disposal/Co-placement in

(Rick Frechette, senior vice president) to                                    the mining industry.
                                                                        9.	 Innovations in heap leaching and mine
help facilitate the discussion. Ulrich is Knight
                                                                              waste practices.
Piésold’s senior vice president in charge of the                        10.	 Geotechnical design – Constructability

company’s Nevada operations and Hutchings                                     as a guiding principle.

is a staff engineer. The event hosted more than                         The roundtable format generally follows a
                                                                    pre-set agenda, which is used as guidance, but the
a dozen attendees from several western states.                      actual conversations during the event tend to be
                                                                    rather fluid in nature. The initial subtopics for
One attendee dialed in by telephone to report                       Roundtable 2017 included:

on recent directives on tailings management                             •	 Greetings and introductions/safety share.
                                                                        •	 Design for closure vs. operate for closure.
in Canada. Attendees included personnel                                 •	 The GARD guide and closure covers.
                                                                        •	 Pit closure (backfill, pit lake, pit slope
from numerous mining properties and various
                                                                              design).
corporate offices.                                                      •	 E-cells versus ET-cells, and the evolution

Mine closure, in part or in whole, rightly                                    of E-cells.
                                                                        •	 Passive treatment.
deserves the undivided attention of mining                              •	 Subsurface discharges.
                                                                        •	 Discussion on new and novel approaches.
companies, their consultants and their                                  •	 Social and community involvement.
                                                                        •	 Closure of infrastructure.
contractors to meet sustainability targets and                          •	 Round robin: What does design for

to minimize negative environmental, social                                    closure mean to you?
                                                                        •	 Closing comments.
and economic impacts, as the project, in its
                                                                        There were also three brief presentations
post-closure years, will become the legacy we                       given by Knight Piésold during the roundtable:

leave to our children and grandchildren. The                            •	 Two approaches to closure.
                                                                        •	 Closure trends in Nevada.
actual performance of mine closure, that is,

nature’s determination of the success of the

closure, is a key deciding factor of the public’s

assessment of the future viability of the mining

industry. Without society’s consent, it may be

quite difficult for the mining industry to carry

on mining in many areas of the world. Thus,

establishing good mine closure practices is

paramount to the continued good reputation of

all world-class mine operators (Ulrich, 2006).

The purpose of the roundtable was to

                                     exchange ideas and

Bryan Ulrich and Rick Frechette,     information pertaining
members SME, are                     to broad topics revolving
senior vice president, Nevada        around the subject of closure
Operation and senior vice presi-     planning, implementation
dent, Denver office ofKnight         and management.
Piésold, respectively, email         Compared with traditional
bulrich@knightpiesold.com.           conferences and symposia,
                                     the roundtable type of forum

2 june 2017     Mınıng engıneerıng	                                 www.miningengineeringmagazine.com