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

TECHNICAL PROGRAM
were obtained from second-stage flotation with conventional sulfide collectors.
Static and bio-kinetic ARD potential tests confirmed that these low-sulfur tailings
were non-acid forming.
3:05 PM
An Investigation on the Surface Chemistry of Some Rare Earth
Minerals During Flotation by TOF-SIMS
S. Chelgani 1 , B. Hart 2 and L. Xia 3 ; 1 Earth Science, Surface Science,
University of Western, London, ON, Canada; 2 Surface Science,
University of Western, London, ON, Canada and 3 Surface Science,
University of Western, London, ON, Canada
The Thor lake deposit is a world class resource of REE in Canada. Development
work to optimize a REE recovery process flow sheet is under way, however, given
the ore mineralogy; the developed reagent scheme is relatively complex. Micro
flotation tests were conducted on a feed sample in order to examine factors affecting
stream partitioning. SEM-EDX was performed to evaluate variability in grain
composition between streams and TOF-SIMS analysis was used to determine statistically
differences in surface species particularly related to potential activation of
the examined mineral phases. SEM-EDX analyses reveal that the concentrate has
a significantly higher proportion of REE bearing grains relative to the tail. Spectral
fingerprinting by TOF-SIMS has allowed for the identification of all reagent
species investigated. Reagent signal intensity discrimination on test stream mineral
surfaces was observed by the TOF-SIMS analysis using reagents at plant concentration
levels. TOF-SIMS analysis confirmed that REE bearing grains reporting
to the concentrate are doing so in response to collector attachment. The
surface analyses of gangues reveal similar reagent discrimination as well.
3:25 PM
Analysis of Collector Adsorption in Kaolinite Flotation Systems
J. Liu, X. Wang and J. Miller; Metallurgical Engineering,
University of Utah, Salt Lake City, UT
Investigation of the surface chemistry of collector adsorption by kaolinite is important
to many flotation processes, including, for example, bauxite flotation,
iron ore flotation, and oil sand processing. The structure of kaolinite consists of
one tetrahedral silica sheet and one octahedral alumina sheet. In our study, two
model surfaces—talc and gibbsite are used to simulate the silica face and alumina
face of kaolinite respectively. The hydrophobicity of the kaolinite surfaces at different
collector concentrations and solution pH values is estimated by measuring
contact angles at the model surfaces. In the case of dodecylamine, the results
show that the hydrophobicity of the gibbsite surface increases with increasing
pH, which implies adsorption of the cationic collector from alkaline solution.
However, the gibbsite surface becomes hydrophilic at higher concentrations of
collector apparently due to the formation of surface micelles. Experimental results
are examined with respect to results from molecular dynamic simulations.
3:45 PM
Design and Development of Mineral Specific Collectors in
Flotation: Selectivity in Apatite-calcite Flotation System
T. Karlkvist 1 , A. Patra 1 , H. Kota 1 , R. Bordea 2 and K. Holmberg 2 ;
1
Minerals and Metals Research Laboratory, Lulea University of
Technology, Lulea, Sweden and 2 Dept. of Chemical and Biological
Engineering, Chalmers Univ. of Technology, Gothenburg, Sweden
The present investigation aims to develop and distinguish mineral specific
reagents with two functional groups to use in flotation for calcium containing
minerals. A reference mono-carboxylate and 3 di-carboxylate surfactants with a
fixed alkyl chain length but having two carboxyl groups with varying geometrical
distances (separated by a spacer of 1, 2 and 3 carbon atoms) between them have
been synthesized. Adsorption behaviors of these reagents on pure apatite and calcite
surfaces were studied using Hallimond flotation, FTIR and ∂ potential measurements.
Relation between adsorption behavior of a given surfactant on a specific
mineral surface and its molecular structure over a range of concentration
and pH values, and region of maximum recovery were established. The results
show that only one of the reagents with a specified geometric distance between
the anchoring groups is more selective for either calcite or apatite surface than
other homologues synthesized. Selective adsorption of a given surfactant to a
particular mineral surface relative to other mineral surfaces as evidenced in flotation
studies is substantiated by ∂ potential and spectroscopy data.
4:05 PM
Water Chemistry Effects on Zeta Potential of Concentrated
Hematite Ore
H. Haselhuhn; Chemical Engineering, Michigan Technological
University, Houghton, MI
The effectiveness of selective flocculation and dispersion processes for the concentration
of hematite ore are strongly dependent on the ionic content of the
process water. It has been noticed that magnesium ions are more detrimental to
iron recoveries during gravity separation and flotation processes than calcium.
This phenomenon was studied by measuring the zeta potential of hematite ore at
various concentrations of sodium, magnesium, calcium, strontium and barium at
a pH of 11. Results showed that zeta potential inverts from negative to positive at
very low concentrations of magnesium ions in the solution. It takes a significantly
higher concentration of calcium, ions to achieve the same effect. This difference
was attributed to the ability of magnesium ions to adsorb to all surface
hydroxyl groups, whereas calcium, due to their larger size, can only adsorb to
every other hydroxyl group. This hypothesis was confirmed by results similar to
those seen with calcium when this test was repeated with strontium and barium
ions. This adsorption theory explains how higher concentrations of calcium ions
are less detrimental to hematite concentration processes than magnesium.
chair:
2:00 PM
Introductions
Mineral & Metallurgical Processing:
Plant design and optimization II
2:00 PM • Tuesday, February 26
H. Haselhuhn, Michigan Technological University,
Houghton, MI
2:05 PM
Haile Gold Mine Metallurgy and Flowsheet Review
J. Wickens and M. Deal; Haile Gold Mine, Kershaw, SC
Haile Gold Mine is located near Kershaw, South Carolina, approximately 50
miles south of Charlotte, North Carolina. Gold was first discovered at the site in
1827, and the property has been through several operating periods since. The relatively
low grade and refractory nature of the deposit has been a challenge for efficient
processing since the start of mining on the property. Early processing techniques
included gravity separation and barrel chlorination. The last operation
employed heap leaching in 1985 through 1991. After being closed and reclaimed
for over 20 years, the property is poised to re-open and produce once again. In
this chapter of the Mines legacy, flotation and ultra-fine grinding will be employed
to achieve economic extraction of gold and silver from the pyrite. This
paper briefly reviews some of the historic processing methods, reviews the current
metallurgical testing and results used to develop the new process flow sheet,
presents the flow sheet and equipment selection, and highlights a few of the specific
project nuances experienced to date.
2:25 PM
Larger Flotation Cells in the Copper Processing Industry Recent
Experiences and Future Considerations for 2012 Onwards
D. Meadows 1 , F. Traczyk 2 and C. Letelier 3 ; 1 FLSmidth Minerals,
Salt Lake City, UT; 2 FLSmidth Minerals, Salt Lake City, UT and
3
FLSmidth Minerals, Salt Lake City, UT
During the last few years the economies of scale have continued to drive copper
projects to larger throughputs to offset the depleting lower grade resources. A
decade ago there were only a small number of projects that stretched beyond
100,000 mtpd throughput rates. Nowadays and moving forward virtually all the
major copper projects are sized beyond this, with throughput rates up to 250,000
mtpd now under evaluation for a number of key projects in Chile and Peru. This
paper explores the development from the 160 m3 flotation cells, through to the
257 m3 cells and nowadays to the 300 m3 cells. A number of specific installations
are reviewed in this growth phase including Kennecott, Minera Los Pelambres,
Mineral Park and Esperanza. Metallurgical results as well as layout, maintenance
and operational aspects are highlighted. Finally some discussion is made on the
new 600 m3 cell and its role and potential in the new flowsheets.
This is the Technical Program as of September 1, 2012. IT IS SUBJECT TO CHANGE.
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Please see the Onsite Program for final details.