4
handler. In the case of boreholes, access may be necessary
for either crane or a drill/workover rig. In these settings, the
surface hopper may be designed for relocation via skid, rail,
wheel, crane, or an articulation arrangement permitting it
to be swung in and out of position.
Belt/Screw Feed
Alternatives to a moveable hopper may be through a feed
conveyor making the final process leg from the hopper
to the slickline. The appropriate equipment can be used
depending on whether dry or wet feed, particle size, etc.
The final conveyor can be moveable or retracting to accom-
modate the slickline access discussed above.
Whether open hoppers or full silos (typical for binder
or dry pre-mixed media, Binder) are used, conveyors provide
standoff distance for transfer line workover. The conveyor
can be detached or rotated clear for service equipment to
position over the collar, without moving the hopper or silo.
Collar Insert
As discussed above in Diameter: Slickline/Dropline, an
impact-resistant collar insert may be used. There are vary-
ing means to incorporate this feature, intended to provide
a relatively easy replacement unit in a relatively high-wear
setting. The insert material is to be matched to the trans-
fer media to achieve efficient serviceability. Collar inserts
would be appropriately considered whether the final
slickline feed is via hopper or conveyor. If the hopper is
moveable and a collar insert is used, the features must be
mutually accommodating.
Caps/Plugs/Gates
Whether wet or dry, coarse or fine, some manner of slick-
line orifice plug ranges from prudent to necessary. In over-
all safe operation, an orifice plug is absolutely necessary to
prevent inadvertent material entry which might impact
personnel below.
Washdown Provisions
The hopper and slickline must be configured for thorough
washdown whether the hopper is on a moveable or fixed
frame. If the hopper is moveable, it is advisable that slick-
line washdown be serviceable with or without the hopper
in place.
VENTILATION
Perhaps not intuitively obvious, there are a number of
ventilation aspects which may arise in particular slickline
settings. High temperature differentials across and/or high
airflow through the transfer system indicate that ventilation
characteristics should be reviewed in design.
Upcast/Downcast Airflow
Airflow quantity and direction can be of concern for dry
transfer and dust management. Airflow direction may
change seasonally, as well as if significant changes occur in
the overall ventilation system – level or mine section break-
throughs, etc.
Whether wet or dry transfer and a shaft-mounted or
borehole slickline, successful operation may be contrary to
the airflow tendency induced by the overall mine ventila-
tion system. A direct solution in those cases can be to use
caps or plugs at the surface orifice(s) of the transfer line.
In preliminary design, it is prudent to model the
expected airflow. A good starting point is to review where
the transfer line begins and ends relative to the mine’s ven-
tilation pressure gradient. Occasionally, slicklines are devel-
oped from existing lines, whether in shaft or boreholes.
Those might provide the opportunity to measure airflow
and psychrometric characteristics prior to or during con-
version to slickline use.
Drying Time
In wet transfer, airflow and psychrometric characteristics of
humidity and temperature can be factors affecting slickline
drying time. Especially for cementitious media, drying time
in turn informs reliable operating and maintenance proce-
dures to sustain target slickline throughput. Conventional
techniques (2, 3) and mine ventilation analyses can be
applied to estimating moisture loads and handling.
Dust Management
Dust control/suppression primarily is an issue with dry
transfer. The location and means are principally dependent
on whether it is an upcast or downcast system. Variations
may exist between shaft-mounted and borehole systems.
Solutions typically include conventional devices -hoods,
scoops, dust collectors, etc. (4).
The dust control design and equipment selection can
follow established procedures for considering volume and
rate as done with ore and waste passes (op. cit.). Essentially,
treat the material within the transfer line as a piston. The
volume of that conduit is calculated and the flow rate is
established by dividing the volume by the freefall time
of the largest aggregate fraction at terminal velocity. This
approach will result in a system that can accept the ini-
tial surge of discharged air, without rupturing the dust
collector(s).
handler. In the case of boreholes, access may be necessary
for either crane or a drill/workover rig. In these settings, the
surface hopper may be designed for relocation via skid, rail,
wheel, crane, or an articulation arrangement permitting it
to be swung in and out of position.
Belt/Screw Feed
Alternatives to a moveable hopper may be through a feed
conveyor making the final process leg from the hopper
to the slickline. The appropriate equipment can be used
depending on whether dry or wet feed, particle size, etc.
The final conveyor can be moveable or retracting to accom-
modate the slickline access discussed above.
Whether open hoppers or full silos (typical for binder
or dry pre-mixed media, Binder) are used, conveyors provide
standoff distance for transfer line workover. The conveyor
can be detached or rotated clear for service equipment to
position over the collar, without moving the hopper or silo.
Collar Insert
As discussed above in Diameter: Slickline/Dropline, an
impact-resistant collar insert may be used. There are vary-
ing means to incorporate this feature, intended to provide
a relatively easy replacement unit in a relatively high-wear
setting. The insert material is to be matched to the trans-
fer media to achieve efficient serviceability. Collar inserts
would be appropriately considered whether the final
slickline feed is via hopper or conveyor. If the hopper is
moveable and a collar insert is used, the features must be
mutually accommodating.
Caps/Plugs/Gates
Whether wet or dry, coarse or fine, some manner of slick-
line orifice plug ranges from prudent to necessary. In over-
all safe operation, an orifice plug is absolutely necessary to
prevent inadvertent material entry which might impact
personnel below.
Washdown Provisions
The hopper and slickline must be configured for thorough
washdown whether the hopper is on a moveable or fixed
frame. If the hopper is moveable, it is advisable that slick-
line washdown be serviceable with or without the hopper
in place.
VENTILATION
Perhaps not intuitively obvious, there are a number of
ventilation aspects which may arise in particular slickline
settings. High temperature differentials across and/or high
airflow through the transfer system indicate that ventilation
characteristics should be reviewed in design.
Upcast/Downcast Airflow
Airflow quantity and direction can be of concern for dry
transfer and dust management. Airflow direction may
change seasonally, as well as if significant changes occur in
the overall ventilation system – level or mine section break-
throughs, etc.
Whether wet or dry transfer and a shaft-mounted or
borehole slickline, successful operation may be contrary to
the airflow tendency induced by the overall mine ventila-
tion system. A direct solution in those cases can be to use
caps or plugs at the surface orifice(s) of the transfer line.
In preliminary design, it is prudent to model the
expected airflow. A good starting point is to review where
the transfer line begins and ends relative to the mine’s ven-
tilation pressure gradient. Occasionally, slicklines are devel-
oped from existing lines, whether in shaft or boreholes.
Those might provide the opportunity to measure airflow
and psychrometric characteristics prior to or during con-
version to slickline use.
Drying Time
In wet transfer, airflow and psychrometric characteristics of
humidity and temperature can be factors affecting slickline
drying time. Especially for cementitious media, drying time
in turn informs reliable operating and maintenance proce-
dures to sustain target slickline throughput. Conventional
techniques (2, 3) and mine ventilation analyses can be
applied to estimating moisture loads and handling.
Dust Management
Dust control/suppression primarily is an issue with dry
transfer. The location and means are principally dependent
on whether it is an upcast or downcast system. Variations
may exist between shaft-mounted and borehole systems.
Solutions typically include conventional devices -hoods,
scoops, dust collectors, etc. (4).
The dust control design and equipment selection can
follow established procedures for considering volume and
rate as done with ore and waste passes (op. cit.). Essentially,
treat the material within the transfer line as a piston. The
volume of that conduit is calculated and the flow rate is
established by dividing the volume by the freefall time
of the largest aggregate fraction at terminal velocity. This
approach will result in a system that can accept the ini-
tial surge of discharged air, without rupturing the dust
collector(s).