Once the plant is in operation, there is seldom time
available to stop operations to remodel; therefore, the
layout and erection of the crusher unit should be given
adequate time to ensure an efficient facility is built.
Special attention should be given to creating a
logical flow of material from the point where trucks
enter the plant with raw material to the point where
trucks depart from the crusher with crushed aggregate
products. You should evaluate the physical
environmental requirements of each piece of
equipment, such as foundation requirements, water
requirements, and power requirements, to ensure they
are included during the construction stage.
Adequate drainage charnels should be constructed
during the initial earthworking stage of construction and
constantly improved as the plant is built. This is
significant because most of the rock crushing plants
have electrical components inherent to their operation.
Equipment should be oriented in such a manner that
prevailing winds carry the rock dust generated by the
crusher away from the facility. Support equipment, such
as generators and water pumps, and permanent
facilities, such as latrines, offices, and maintenance
shops, should be located out of the path of winds
carrying the rock dust.
DO NOT FORGET THE DEPARTMENT OF
ENVIRONMENTAL QUALITY (DEQ) REQUIRE-
MENTS FOR DUST CONTROL. The DEQ works for
the Environmental Projection Agency (EPA). The EPA
has established standards for controlling the amount of
rock dust that can be admitted into the air.
The COMSECOND/COMTHIRDNCB Equipment
Offices work closely with the DEQ to ensure the plants
in the NCF abide by the rules of the DEQ. Sprinkler
systems have been installed on rock crushers in the NCF
to control the rock dust produced from crushing
operations to meet the requirements of one rule. As the
crusher supervisor, you are responsible to make sure
these systems remain operational.
Organization of Space
The crusher design should include adequate space
around the equipment. This space is required to provide
access areas for maintenance personnel to perform
repairs, space to move cranes in and out to lift out and
replace or rotate worn jaw plates and roll shells, space
for the fuel truck to refuel the equipment, and space to
remove and replace components of the crusher unit.
Material Handling and Storage
T h e p l a nt
material-handling devices to expedite the flow of
material through the plant and eliminate double
handling of the material.
A headwall ramp should be constructed to allow
haul units or loaders to back up to or approach the apron
feeder of the primary unit and discharge their loads. If
a problem with oversized rock is anticipated, you should
have a prescreening grizzly built in the quarry or over
the apron feeder to remove the oversized rock.
When possible, store quality product size aggregate
in bins, rather than in open stockpiles. This is most
important when the aggregate is crushed to
specifications sizes or has been washed. Open
stockpiling of aggregate can be contaminated by
windblown sand, fines, and trash.
When bins are not available for aggregate storage,
headwalls should be constructed for stockpiles to ensure
separation of different sizes of aggregate being
processed. The area separating headwalls should be
large enough to stockpile a large supply of aggregate and
have adequate space on the front side for loading
vehicles without causing congested traffic areas.
Aggregate stockpiles are loaded by loaders or
clamshells. These machines are most efficient for
loading vehicles with clean aggregate off the top of
stockpiles. The aggregates at the bottom of stockpiles
become embedded in the ground and tend to become
contaminated. This layer is lost for use.
Stockpiling is most efficiently accomplished on
hard, flat, clear areas. The location of the stockpiles
should be convenient to the quarry, the crusher, and the
hauling unit. When available space is large compared
with the bulk of material to be stored, trucks may dump
piles as closely as possible to each other.