Annual Meeting Preliminary Program - Full Brochure (PDF) - SME

ent on the bleeder entry conditions and many other contributing factors. This
study is an investigation of the locations of hot-spots in the gob using CFD
(Computational Fluid Dynamics) package. It also includes permeability
measurements on selected coal samples, and studies on the effectiveness of
existing and proposed ventilation systems.
3:45 PM
Skyline Mine - A case study in two-entry coal mining
G. Kenzy; Skyline Mine, Helper, UT
This paper describes and illustrates the Skyline Mine primary ventilation system
and the ventilation of two-entry longwall gateroads during development
and retreat longwall mining. The mine-wide utilization of an atmospheric
monitoring system and the specific mine atmospheric monitoring requirements
in two-entry development and retreat mining is presented and analyzed.
The efficiency and performance of the mine, gateroad and bleeder ventilation
systems are described, analyzed and illustrated using computer-based
ventilation network modeling. Spontaneous combustion prevention in both
ventilated and sealed longwall gobs is detailed, including a description and
examples of the instrumentation and procedures used.
Chair:
Environmental: Acid Rock Drainage
2:00 PM • Tuesday, February 26
R. Williams, Bureau of Land Management, Butte, MT
2:05 PM
Culturing and Characterization of Rock Pile Microbes
J. Kennedy, B. Richins and D. Adams; University of Utah,
Salt Lake City, UT
Expansive rock piles are often generated during large-scale mining operations.
Microorganisms can directly contribute weathering actions and accelerate
reactions that contribute to stability or instability within rock piles.
Pared rock pile samples were collected for microbial and geochemical analysis
to examine microbial variation across geological zones and geochemistry.
Microbial populations were examined using selected microbial media, classical
culture techniques, and nucleic acid profiling. The information gathered
was used to examine the microbial populations relative to the site, across geological
zones found within the rock pile, and geochemical parameters.
Microbial populations found included aerobic and facultative anaerobic sp.,
sulfate and iron reducing and oxidizing sp., Archea sp., Thiobacillus and
Leptosprillum sp, denitrifying sp., and acidophilic species. Denaturing gradient
gel electrophoresis (DGGE) was used to generate microbial population
nucleic acid profiles for selected cultures obtained from different rock pile
samples. Selected sequences from the profiles generated were further
analyzed to identify the specific microbes present.
2:25 PM
Arsenic Binding Proteins for Removal of Arsenic From Solution
J. Kennedy 1 , B. Richins 2 and D. Adams 3 ; 1 Metallurgical Engineering,
University of Utah, Salt Lake City, UT; 2 Metallurgical Engineering,
University of Utah, Salt Lake City, UT and 3 Metallurgical Engineering,
University of Utah, Salt Lake City, UT
Removal of soluble forms of arsenic from water is an expensive process.
Alginate biopolymer bead immobilization was selected as a method to evaluate
the ability of arsenic binding proteins to remove arsenic from water.
Protein extracts were obtained from several microbial consortiums selected
for their ability to reduce soluble metalloids. Immobilized protein extracts at
a concentration 0.50 mg/ml yielded near maximal arsenic removal. Arsenic
removal was somewhat dependent on temperature and pH, with maximum
removal occurring at about 35° C and pH of 5.8. Kinetics studies show that
selected protein mixtures remove ~98% of soluble arsenic in 24 hours. When
compared with the live microbes from which they were extracted, the immobilized
proteins bind more than four times the arsenic. Immobilization of
arsenic-binding proteins permits arsenic recovery and potential reuse of the
immobilization biopolymer-protein complex. Additional data will be
presented on the arsenic-binding proteins, functional lifespan of various
immobilization biopolymer-protein complexes, and arsenic removal in a
bench scale bioreactor.
2:45 PM
Optimisation of single-layer cover made of desulphurized tailings :
application to the Doyon mine tailings impoundment
I. Demers 1 , B. Bussiere 1 , M. Mbonimpa 1 and A. Blier 2 ; 1 UQAT, Rouyn-
Noranda, QC, Canada and 2 UQAT, Rouyn-Noranda, QC, Canada
Doyon mine, Quebec, Canada evaluates the possibility of desulphurizing
their tailings to produce material to be used in as cover over their acid generating
tailings impoundment. Laboratory tests were conducted and showed
that a single-layer desulphurized tailings cover placed over reactive tailings
can prevent the generation of acid mine drainage. Modelling with the software
Vadose was undertaken to optimize the design parameters, namely
cover thickness, water table position, and residual sulphide content of desulphurized
tailings following laboratory work. The optimal scenario for the
Doyon mine tailings impoundment was selected according to a maximal
acceptable oxygen flux reaching the reactive tailings predicted by the model.
3:05 PM
Arsenic retention by soil mineral components is inhibited by natural
organic matter
A. Redman 1 , D. Macalady 2 , D. Ahmann 2 and K. Ritter 2 ; 1 HydroQual,
Millville, UT and 2 Colorado School of Mines, Golden, CO
Inorganic arsenic species (e.g. arsenate and arsenite) are commonly found in
acid rock drainage. The migration and retention of these inorganic arsenic
species by soils or sediment are generally controlled by the adsorption of
these compounds to iron and aluminum oxides. This reaction can be strongly
affected by certain water quality characteristics. Dissolved, naturally occurring
organic matter (NOM) from stream water was shown to dramatically reduce
the rate and extent of arsenate and arsenite retention by a pure ironoxide
mineral and by natural soils or sands. The apparent decline in arsenic
removal by the presence of NOM is due to three major process: 1) competitive
adsorption of NOM to the mineral phases, 2) formation of stable aqueous,
or colloidal complexes that reduces that availability of arsenic to bind to
soil minerals and 3) NOM promotes the reduction of arsenate to a more
mobile form of arsenite. Stable aqueous complexes are thought to occur
through the formation of dissolved ternary NOM-metal-arsenic complexes
that are most likely mediated by iron or aluminum ions.
3:25 PM
Update on the INAP GARD Guide
T. Chatwin 1 and K. Ferguson 2 ; 1 Technical Manager, INAP, Salt Lake City,
UT and 2 Principal, Sustainability Engineering, Vancouver, BC, Canada
The objective of the INAP GARD Guide (Global Acid Rock Drainage Guide)
is to produce the broadest and most up-to-date reference for the mining industry,
regulators, NGO’s and the public on the subject of acid-rock drainage
(ARD). The Guide will address the production of contaminants from sulfide
mineral oxidation that can result in ARD, neutral mine drainage (NMD) and
saline mine drainage (SD). The GARD Guide is bringing together best technical
and management practices with the objective of creating a body of work
with high industry and external stakeholder credibility. The Guide will cover
all phases of a mining operation from initial discovery through to final closure
(“cradle-to-cradle”). Thus, it will assist industry in providing high levels
of environmental protection, assist governments in the assessment and regulation
of facilities under their jurisdiction and enable the public to have a
higher degree of confidence in and understanding of acid prevention
proposals and practices.
3:45 PM
Automated Mineralogy in the prediction of Acid Rock Drainage:
Accessible mineralogy using QEMSCAN®
W. Goodall; Intellection Pty Ltd, Brisbane, QLD, Australia
Mineralogy is a key driver in Acid Rock Drainage (ARD) and yet access to
routine and scalable mineral identification techniques has been limited on the
scale required for accurate ARD prediction. Quantitative X-Ray Diffraction
(XRD) has been utilised but is limited in its achievable detection limits for
minerals of interest. An alternative, with cost comparisons, is proposed using
QEMSCAN® for quantitative bulk mineralogical analysis. The use of QEM-
SCAN® makes routine mineralogical analysis a cost effective and useful addition
to ARD characterisation programs opening up new possibilities for the
application of mineralogical information in better ARD management.
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