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

wednesday, february 27
morning
Coal & Energy: Coal Preparation
Bulk Material Handling by Conveyor Belt 7:
Solving Real Problems Using Numerical
Analysis and Simulation
9:00 AM • Wednesday, February 27
Chair: T. Hollingsworth, Conveyor Engineering, Meridian, ID
9:05 AM
Simulation for Equipment Sizing – Longwall to Stockpile
E. O’Donovan; E.J. O’Donovan & Associates, Spring Hill, QLD, Australia
When longwall equipment is being specified, a nominal capacity is generally
given on which to base the design of the various face and out-bye systems and
components. This capacity generally comes from a nominal annual capacity
requirement based on realistic utilization rates. From illustrative examples of
simple system simulation, this paper sets out to show that a single nominal
capacity is not sufficient to size the different systems. The manner in which
the Longwall is operated and the overall system configuration can have a significant
impact on overall productivity. The importance of component availability
on overall output is also addressed.
9:35 AM
Simulation as a Tool to Determine Stockyard Handling Capacity
E. Monrad and H. King; Simulation Modelling Group, Sandwell
Engineering, Vancouver, BC, Canada
Discrete event simulation modeling provides a tool to quantify the throughput
capacity of stockyards. Interactions between the main equipment types
(trains, dumpers, conveyors, stackers, reclaimers, shiploaders) can be captured,
including route blockages, breakdowns, and planned maintenance.
This tool has been successfully used at world-class stockyard facilities to determine
current capacity and to identify gains resulting from improvement
projects. Recent projects have focused on iron-ore, coal, and soya facilities,
but the technology is suitable to be used on any bulk material type.
10:05 AM
Interfacing Belt Feeders and Hoppers to Achieve Reliable Operation
J. Carson 1 , F. Cabrejos 3 and M. Rulff 2 ; 1 Jenike & Johanson, Inc., Tyngsboro,
MA; 2 Jenike & Johanson, Ltd, Toronto, ON, Canada and 3 Jenike & Johanson
Chile S.A., Vina del Mar, Chile
Belt feeders are commonly used to meter the flow of bulk solids from bins
and hoppers. If the interface between the hopper outlet and belt feeder is not
designed correctly, flow from the bin may be severely compromised, resulting
in problems of no-flow, segregation, flooding, etc. By knowing the flow
characteristics of the bulk solid being handled and applying proven design
techniques, such problems can be avoided. Relevant bulk solids flow characteristics
will be identified, along with measurement techniques. Design procedures
for correcting problems with existing feeders as well as proper design
of new feeders will be presented, along with case histories of successful
application of these procedures.
10:35 AM
Predicting Material Behavior on Conveyors using DEM
B. Ren and G. Mustoe; Colorado School of Mines, Golden, CO
Energy losses are important factors in a conveyor’s performance and design.
A significant energy loss due to belt sag within a conveyor system occurs
when shearing motion between the bulk material particles occurs as the material
moves along the belt. This sag energy loss has been studied previously
using analytical mechanical methods that employ several simplifying approximations
such as: a) dry bulk material, b) assumed pressure distributions between
the bulk material and belt, and c) inertial effects within the bulk material
and belt, etc. The current work employs a discrete element modeling
(DEM) approach eliminating the need for the simplifying assumptions required
in previous analyses. The DEM method models: a) the bulk material as
a discrete system of particles with a specified size distribution, and interaction
laws for dry and wet materials, and b) the belt geometry shape with a detailed
3D CAD description. In this paper the effects of: a) idler spacing, b)
belt speed, b) belt sag, and c) different bulk materials are studied.
9:00 AM • Wednesday, February 27
Chairs: R. Honaker, University of Kentucky, Lexington, KY
M. Mohanty, Southern Illinois University Carbondale,
Carbondale, IL
9:05 AM
Capital and Operating Cost Models for Coal Preparation Plants
Z. Huang 1 , M. Mohanty 2 , H. Sevim 3 , B. Arnold 4 and S. Bhagwat 5 ; 1 Mintec
Inc., Tucson, AZ; 2 Department of Mining and Mineral Resources
Engineering, Southern Illinois University Carbondale, Carbondale, IL;
3
School of Engineering, Southern Illinois University Edwardsville,
Edwardsville, IL; 4 PrepTech, Inc., Apollo, PA and 5 Illinois State Geological
Survey, Champaign, IL
Circuit-wise capital and operating cost models are developed for those cleaning
and dewatering circuits that are widely used in current coal preparation
plants. For each circuit, capital and operating costs are calculated for at least
five feed capacities. For each feed capacity, the sizes of the major and ancillary
equipment in the circuit are determined. The purchasing cost and operating
cost of each piece of equipment are calculated based on the cost data collected
from a variety of sources. The circuit capital cost is calculated as the
sum of the capital cost of each piece of equipment in the circuit. Similarly,
circuit operating cost is the sum of the operating cost of individual equipment
in the circuit. Capital and operating cost estimating equations are then obtained
by best-fitting the cost data as a function of feed capacities. The capital
cost also includes the installation cost. Capital and operating cost tables,
equations and figures are given for each cleaning and dewatering circuit. The
utilization of these equations is also introduced by applying them in a new
developed coal preparation plant simulator for conducting cost and
economic analysis.
9:25 AM
The Design, Construction, Commissioning and Operation of the Arch
Castle Valley Plant in Wellington, Utah
P. Bethell 1 and M. Kelley 2 ; 1 Arch Coal Inc., Charleston, WV and 2 Castle
Valley Plant, AWBG, Wellington, UT
This paper will describe the design philosophy behind the 400 t.p.h. “Coarse
Only Washing” preparation plant. The study of the potential feed coals lead to
the design incorporating the latest technology of fine dry coal screening
(Roxon Roller Screen). The plant also incorporates a Peters Dense Media
Vessel treating the plus 1 ⁄4” material. Once the circuit was designed, the plant
was bid and CEnty of Salt Lake City, Utah was awarded the contract to build
the facility. The new Roxon/Dense Media Vessel plant was retrofitted into an
old McNally jig plant, which posed obvious demolition/construction issues.
The plant was successfully commissioned in October 2006 and has subsequently
run highly efficiently at in excess of 20% above design capacity.
Plant efficiency data will be reviewed, as will availability and quality data.
9:45 AM
Development of a Transponder-Based Tracer System for Evaluating
Dense Medium Separator Performance
C. Barbee 1 , C. Wood 2 and G. Luttrell 3 ; 1 Arch Coal, Inc., Charleston, WV;
2
Partition Enterprises Pty Ltd., Indooroopilly, QLD, Australia and 3 Mining
& Minerals Engineering, Virginia Tech, Blacksburg, VA
Density tracers are a useful diagnostic tool for evaluating the separation efficiency
of dense medium circuits. Unfortunately, the full capabilities of density
tracers are often not realized in practice due to problems that occur during
the retrieval step. To overcome this problem, an electronic monitoring
system has been developed to automatically identify and count the tracers as
they pass through a coal cleaning circuit. This technique, which relies on recent
technological breakthroughs in transponder technology, improves the reliability
of tracer data by eliminating statistical errors associated with lost
tracers. Field tests showed that very accurate counts (>98%) of the transponder-based
tracers could be achieved in full-scale trials. In addition, this simple
system makes it possible for efficiency tests to be performed very rapidly
by a single person in an extremely cost-efficient manner.
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