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

TECHNICAL PROGRAM
2:45 PM
Testwork Programs Too Little, Too Late
C. Jeltema, W. Baum, P. Thompson and D. Meadows; FLSmidth,
Midvale, UT
Testwork programs for greenfield projects and expansions are essential for effective
process design, accurate equipment sizing, and timely startups. Adequate
testwork is even more imperative as mined ore bodies are becoming deeper,
harder, more finely grained, and lower grade with higher impurity elements.
Further, these future ores do not always fit within the framework of currently
available testwork databases and installations. The effects of inadequate testwork
are evident in some of the mill sizing errors made in recent years, together with
slow plant ramp ups. It is recognized that achieving adequate testwork is challenging.
The ramifications of inadequate testwork and lack of mineralogical ore
characterization on equipment sizing and process design will be discussed to emphasize
testwork importance. Explanations, examples, interpretation, and cost
estimates of testwork programs will be presented. Finally, recommendations will
be made for the planning, execution, utilization, and follow-through of a minerals
processing testwork program.
3:05 PM
A Sound Strategy: Using Sonic Horns to Prevents Buildups and
Improve the Efficiency of Baghouses and Fans
J. Shelton and S. Griffith; Martin Engineering, Neponset, IL
This presentation will look at how the application of sonic horns can prevent
material buildups and improve the efficiency of bag houses and fans. Sonic
horns use a high-intensity/low-frequency pulse of sound to prevent and/or
break up the accumulations of dry materials. These accumulations can interfere
with the operating efficiency of large industrial fans and impair the efficiency of
fabric dust collectors. In this presentation the authors will discuss the principles
of the application of sound energy to improve industrial operations. He will
then look at specific examples of application of sonic horns on various types of
baghouses and fans.
3:25 PM
Iron Plant Mill Optimization through the Optimization of a
Single Parameter
E. Tuzcu; DAMA Engineering, Ankara, Turkey
Evaluation of the efficiency of the closed grinding mill-classifier circuit is complicated
due to direct and interaction effects of the process variables. Identifying
the effects of design and operating variables in an isolated environment or in a
controlled experiment is easier than to do the same in an industrial plant.
Functional performance efficiency (FPE) coefficient is defined as the function of
classifier and ball mill efficiency and calculated for a particular set of operating
variables to evaluate circuit efficiency. The configuration that gives the best circuit
output and FPE coefficient is announced as the optimal operating conditions. In
order to find out which configuration is better, different mill surveys are carried
out. This is certainly the exact way to verify an engineers solution. However it is
labor and time intensive. In this work, a combined FPE and simulation method is
applied to optimize FPE coefficient. Different mill surveys are carried out in the
simulation environment to find optimum conditions by tracking FPE coefficient
as a function of everything. Finally, based on the best FPE coefficient, the optimum
process variables are proposed.
Mineral & Metallurgical Processing:
Problematic non-sulfide Gangue Minerals
and their detrimental effects
in Flotation Performance
2:00 PM • Tuesday, February 26
chairs: T. Bhambhani, Cytec Industries, Inc., Stamford, CT
M. Vasudevan, Cytec Industries, Inc., Stamford, CT
2:00 PM
Introductions
2:05 PM
Effect of Clay Minerals on Rheology of Flotation Slurries
N. Cruz; The University of Queensland, Brisbane, QLD, Australia
Clay minerals such as kaolinite and smectite, which are often associated with
copper, gold and other valuable minerals, place a widespread problem in mineral
flotation. There have been numerous observations of these clay minerals having
a deleterious effect on mineral flotation grade and recovery, with simultaneous
observations of high flotation pulp viscosity, over-stable froth or the absence of
froth. Rigorous explanations on how clay minerals affect flotation are not available.
There are extensive studies on the formation of network structures of clay
minerals and the development of viscosity, but they do not address the complex
chemical and physical environment of mineral flotation. The aim of this research
is to identify how clay minerals affect the rheological properties of flotation slurries.
Steady and dynamic rheology measurements are conducted for pure clays
(sodium bentonite and kaolinite) and for mixtures of clays with other minerals
and clean ores in the absence and presence of flotation reagents. The size and
structure of mineral aggregates are monitored in conjunction with rheological
measurement and correlated with mineral flotation behaviour.
2:25 PM
Examining the Different Behaviour of Non-ionic Dispersants in
Fresh and Saline Water
D. Liu and Y. Peng; School of Chemical Engineering, The University
of Queensland, Brisbane, QLD, Australia
Clay minerals, which often coat the surface of valuable minerals and bubble surfaces,
have an adverse effect on the coal flotation process, leading to the decrease
of both coal recovery and grade. These problems are exacerbated by saline water
which is used in coal flotation in Australia. The industry has been fully aware of
the difficulties in treating clayey ores in saline water. To improve the coal flotation,
cationic dispersants are normally used to remove the slime coating.
However in the presence of high ionic strength process water, these traditional
dispersants are invalid due to the ionic effect. In this study, two types of non-ionic
dispersants was introduced and developed with the aim to reduce the viscosity in
both pulp and froth phases and remove slime coating from particles and bubbles
in saline water. For a comparison, coal flotation was also conducted in deionized
water using the same dispersants. It is interesting to find that non-ionic dispersants
behaved differently in fresh and saline water as well.
2:45 PM
Atypical Grade-recovery Curves as Diagnostic Tools in Sulfide
Mineral Processing
M. Vasudevan, T. Bhambhani and D. Nagaraj; Mineral Processing
R&D, Cytec Industries, Stamford, CT
In sulfide mineral flotation, grade recovery curves are used to glean the flotation
response/ kinetics of a given mineral to changes in certain flotation parameters.
One usually finds that their day-to-day usage is largely limited to comparing the
flotation response to different reagents, e.g. collectors. Given the large variability
in the complex mineralogy of ores, several ore types routinely processed exhibit
atypical grade recovery characteristics. This paper is an effort to highlight the hidden
and often neglected aspects of these atypical curves which can help gain insights
of the underlying flotation mechanisms and challenges, and thus help in
designing better processes/solutions. Specifically, we present the flotation response
of problematic sulfide ores with very different gangue mineralogy, which
show unusual but similar grade-recovery characteristics. We present hypotheses
and experiments to understand and explain this behavior and the underlying
mechanism. Finally, we propose chemical modifiers as solutions to the problem
and to improve the efficiency of flotation performance.
This is the Technical Program as of September 1, 2012. IT IS SUBJECT TO CHANGE.
87
Please see the Onsite Program for final details.