Technology News
OSH

May 1997

Development of a Research Facility To Improve Mine
Hoisting and Ore Pass Safety

Objective

Construct a research facility to Lest sensor technology and en-
gineering controls and to increase awareness of the proper func-
Honing of mine hoists. Improve safety and prevent injuries and
fatalities related to vertical movement of personnel and materi:
in mine shafts and ore passes.

Background

Mine hoisting and control of material flow in org and wasic
passes are the most important and potentially the most hazardous
operations in underground mining. In addition to providing access
to the network of openings used to recover an underground mineral
resource, ore and waste passes serve as cscapeways in emergencies
and allow yerlical movement of miners and materials. Hoist and
elevator systems and ore pass chutes Jor underground metal/
nonmetal mines must meet the requirements specified in the Code
of Federal Regulations (CFR), Parts 57 and 75. The Mine Safety
and Health Administration (MSHA) has requested new safeguards
and design criteria for hoists and ore passes. However, equipment
suppliers and mining companies cannot justify the costs nor in-
terrupt production to develop and test safer technology for vertical
haulageways.

Approach

A hoist and ore pass facility was designed and constructed lo
permit testing of safety features and sensor and design technology
ina controlled setting. Studies of equipment salety features and
MSHA accident statistics suggested that research should be
focused on—

(1) Shaft conveyance monitoring to provide better operational
data and warnings of potentially dangerous situations to operators.
inspectors, and maintenance personnel and

(2) Ore pass design criteria that might lead to structural im-
provements for chutes and gates and better detection of and re-
mediation measures for ore pass blockages.

Results

Progress 10 date has resulted in completion of a state-of-the-art
hoisting and ore pass research facility in which safety features and
opcrational characteristics rclated to mine hoists and ore passes can
be evaluated. Figure 1 shows the configuration of the simulated
mine shafl and ore p: The hoist tower simulates a headframe,
and an 18-ft-deep concrete section simulates a “shaft.” The ore
is simulated by wood or steel liners of varying cross-sections,
Ore is initially loaded through a ground-level grizzly into a below-
ground chute and loading cartridge, and then into the skip. The
joading cartridge is equipped with balancing load cells to monitor
the net weight of material in the cartridge prior to its discharge into
the skip. Output from these cells, as well as loading gate position
sensors, control skip Ivading functions. The skip hoists the ore to
the top of the headframe, where it is dumped into a hopper con-
nected to the ore pass.

The hoist room components include a winding drum and
motor-gearbox interface with a capacity of 500 ft of 3/8-in diam
wire rope with 500-to 1000-Ib hoisting capacity. Operation of the
hoisting motor and ore pass system is controlled by a program-
mable controller and HMI software. Loading chutes and gate po-
sition, ore levels and loads, conveyance net weight and position,
and speed and wire rope tension can all be viewed from process
Braphics screens on an operator consol (figure 2). A conventional
Lilly controller provides backup in the event ot conveyance over-

speed und overtravel.

Conveyance-mounted sensors and real-time data acquisition
and transmitting devices that monitor hoist position and speed,
conveyance load, rope tension, and shaft guide misalignment are
currently being tested. A position sensor mounted on the convey-
ance eliminates the need to correct the position of the conveyance
because of rope stretch. A flex-cable load sensor mounted just

wen

U.S. Department of Health and Human Services
Public Health Service
Centers for Disease Control and Prevention
Nationat Institute for Occupational Safety and Health

CENTERS FOR DISEASE CONTROt
‘AND PREVENTION


above the conveyance protects against slack and tight rope. A
third sensor monitors misalignment of the shaft guides. These
measurements are taken in real time and transmitted via wireless
equipment from the conveyance to the hoist room.

Current work in ore pass design includes measurements of
static and dynamic forces on chutes and gates from simulated
loads. Results to date indicate that the dynamic forces caused by
impact loads on chute gates, (i.c., release of hang-ups) may be
much higher than previously thought.

Patent Status

The U.S. Dept. of Energy and NIOSH flave applied (min-
9603) for a patent entilled “Cable Load Sensing Device.”

For More Information

Report of Investigations 9637, “Development of a Mine Shaft
and Ore Pass Research Facility” by M.J. Beus and T.M. Ruff, is
available from the authors. Call (509) 354-8064 or (509) 354-8053.

NIOSH is secking cooperators lo assist in further tests of minc
hoist and ore pass technology to improve mining safely. Addi-
tional information can be obtained by contacting Elaine Cullen,
Technology ‘Transfer officer, NIOSH, Spokane Research Labor-
atory, Spokane, WA 99207 al (509) 354-8057.

To receive additional information about mining issues or
other occupational safety and health problems, call t-800-
35-NIOSH (1-800-356-4674), or visit the NIOSH
Home Page on the World Wide Web at http:avww.cde.gow!
niosh/homepage html.

As of October 1996 the safety and health rescarch functions
of the former U.S. Bureau of Mines are now located in the
National Institute for Occupational Safety and Ilealth
(NIOSTD.

Skip
156m
Headtrame
Ore pass
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Loading pocket
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Figure 2.Process

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