How To Store Liquid Calcium Chloride

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To successfully handle and store liquid and dry calcium chloride, it is important to understand that five product attributes strongly influence most of the recommended practices.

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1. Calcium chloride is hygroscopic. It is capable of absorbing moisture from the air. This can cause clumping and caking in dry calcium chloride products, such as pellets, flakes and briquettes.
2. Calcium chloride is deliquescent. Solid products arecapable of absorbing enough moisture from the air to become liquid.
3. Calcium chloride has an exothermic heat of solution. Solid products release a large amount of heat when dissolved in water.
4. Chlorides in the presence of water and oxygen are associated with the accelerated corrosion of common metals, such as steel, copper and brass.
5. Calcium chloride brines are electrically conductive. There is a risk of electric shock if energized electrical
equipment is handled with hands or fabric gloves that are wet with brine.
Personnel must be familiar with the contents of the MSDS and abide by the guidelines contained therein.
End users are responsible for maintaining full compliance with federal, state, provincial and local requirements
applicable to handling and storing calcium chloride.
Packaged Products
Package types. Solid calcium chloride products come in a variety of package types, including bags, boxes, pails, drums and Flexible Intermediate Bulk Containers (FIBCs).
1. Bags are made of plastic or multilayered paper containing a moisture barrier. The bag closure is either a valve type* or heat-seal.
2. Boxes are constructed of cardboard with a plastic liner that is sealed with a twist tie.
3. Pails are heavy-duty plastic with snap-on lids.
4. Drums are standard 50-gallon steel with a removable
top held in place with a clamping ring.
5. FIBCs have a woven polymer exterior, a plastic liner and a bottom spout for unloading.Packaged products are delivered on wooden pallets, and most are either covered with a plastic shroud or stretch-wrapped. Available package type, size and pallet configuration will vary by product.
Packaged product handling. Packaged products are shipped via flatbed truck, enclosed van, intermodal
container or boxcar. Pallets loaded onto a flatbed truck should be fully covered by tarps to maintain the cleanliness and integrity of the packaging and to keep the load secure while in transit.
A full pallet of product requires a forklift or pallet
jack to lift and move. Pallets are typically four-way,
meaning that they may be lifted from all four sides.
The exceptions to this are those carrying FIBCs or
drums, which are two-way only.
Product inventory should be managed on a first-in,
first-out basis to minimize the chance of quality
issues arising from moisture absorption that occurs
over time. If a bag becomes damaged, it should be
mended and used ahead of others. Packaged product storage. Palletized product covered by an intact plastic shroud may be stored outdoors on a well-drained, asphalt or concrete surface. If the shroud is torn, pierced or removed, the
palletized product should be stored indoors or under a waterproof tarp. Products packaged in boxes, drums
or FIBCs are typically not shrouded. Therefore, these packages should be stored indoors or under a waterproof tarp. Palletized pails are stretch-wrapped, but not shrouded. Because pails are watertight, they may be stored outdoors without a waterproof covering.
Full pallets of bags can typically be stacked three high in a 2-2-1 configuration, with the top row straddling the
center line of the first two rows. Pallets of pails, boxes or drums may be stacked three high and two wide (2-2-2).
Pallets of FIBCs are typically stacked two high and

Individual packages should be stored indoors in a dry
area. Unused bags with a valve-type closure should lie
flat so that product presses the valve against the top
panel of the bag to maintain a seal. Any package that has
been opened, but only partially used, must be tightly
resealed to prevent exposure to humid air that may lead
to caking and liquid brine formation.
Bulk Solid Shipment Modes
Bulk shipments are made in hopper cars of
approximately 90 tons and in hopper trucks of
various capacities.
Bulk solid handling. Bulk solid calcium chloride may
be unloaded and transported by a number of different
methods, including drag chains, screw conveyors,
pneumatic conveyors, bucket elevators and belt conveyors. The most effective handling equipment is
mechanically reliable while minimizing potential
detrimental impacts from attrition, exposure to humid
air and dust emissions.
Hot-dipped, galvanized and stainless steels are
materials that have been shown to work well for
solids-handling equipment operating at ambient temperatures. After formation of a rust-colored
surface layer, these materials are resistant to generalized corrosion. Stainless steels may not be suitable
for handling hot, bulk solids (>100°F [>38°C]), since
they are susceptible to chloride stress cracking at elevated temperatures.
Bulk solid storage. To prevent caking and clumping
problems in storage, the hopper design should minimize product exposure to humid air. If uniform particle-size distribution is important, the design should
take into consideration the effects of hopper configuration on particle-size segregation, because sifting
occurs when filling a bin. The fine particles sift
through the coarse particles, allowing the fines to
concentrate in the center, while the coarse particles
roll or slide to the outside. In a poorly designed hopper,
solids will empty from the center of the pile while
solids on the sides remain stagnant. In a well-designed
“mass flow” hopper, all solids move downward
together as the hopper is emptied, helping to maintain
a more uniform particle-size distribution.
The preferred material of construction for large
hoppers is carbon steel with an internal epoxy-based
lining and an exterior epoxy-based paint. Stainless
steels that are resistant to stress cracking are effective
for smaller, surge hoppers, such as those that provide
surge capacity for packaging systems. A rust-colored
surface layer forms on the stainless steel; however,
generalized corrosion under ambient conditions
is low. Nonmetallic materials, such as fiberglass
and common plastics, will not corrode in calcium
chloride service; however, their structural integrity
could be in jeopardy from the heat release associated
with dissolving solids if it becomes necessary to wash
a large quantity of solids from the vessel.
Bulk liquid shipment modes. Bulk liquid calcium
chloride is available in concentrations from 28 percent to
42 percent by weight. Product is delivered by tank truck
or tank car.
The configurations of transportation equipment and
unloading stations vary on a case-by-case basis. An
overview of important considerations is provided
below; however, it is the responsibility of the end user
to develop detailed procedures that are safe, effective in
their particular situation and in full compliance with
applicable regulations.
Bulk liquid handling. As calcium chloride concentration increases, so does the crystallization
temperature (freeze point) of the solution. When
the ambient temperature is lower than the freeze
point, handling equipment must be designed to
keep the product warm (insulation, heat tracing)
and/or to drain completely empty when out of service (sloped lines, drains at low points). Freezing points
for a few typical concentrations are provided below.
For more information, refer to “Calcium Chloride:
A Guide to Physical Properties”, available at
www.oxycalciumchloride.com.
CaCl2 concentration 32% 35% 38% 42%
Freezing pt. °F -17 +20 +48 +69
Freezing pt. °C -27 -7 +9 +21

Safe Handling and Storage
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Tank trucks and tank cars that carry calcium chloride
solutions are normally unloaded through a bottom
outlet using a fixed pump to transfer the solution to
a storage tank (Figures 1 and 2). A thick-walled,
flexible hose is typically used to connect the unloading
pump to the outlet valve. The design of the unloading
system will depend on the desired unloading time,
distance to storage, elevation change, available utilities
and other situation-specific factors.
Failure to properly vent the sending and/or receiving
tanks during liquid transfer can result in rupture or
collapse of the tank. For a tank truck or tank car, it
is recommended that the vent valve be open AND
the manway be propped open. CAUTION: Do not
attempt to open the manway cover unless it is certain
that the tank truck or tank car is NOT under pressure.
Tank trucks and tank cars usually have both an internal
and external valve on the outlet. If either valve is
difficult to turn, it may be frozen in place with crystallized calcium chloride. Attempting to force open
a frozen valve may result in equipment damage. If
crystallization is suspected, blowing steam or warm
air on the exterior of the piping is recommended to
melt the frozen product and free up the valve.
Air pressure may be used instead of a pump to unload
from the bottom or top outlets; the latter of which
depends on the presence of an internal dip pipe
(Figure 3). The air supply must be regulated at a maximum of 50 psig or below the pressure rating
of the tank and its relief device, whichever is lower.
When unloading is complete, air pressure in the tank
will drop and the sound of air rushing through the
unloading line is heard. All pressure must be vented
from the tank truck or tank car before releasing it for
return transit.
Some tank trucks and tank cars are insulated and
fitted with steam coils to allow heating the product
prior to off-loading. To prevent equipment damage,
the following precautions should be taken when
applying steam:
(a) Increase coil pressure gradually, keeping maximum
steam pressure below 150 psig.
(b) Keep calcium chloride solution temperature well
below 170°F (77°C).
(c) Shut off steam to the coils after 1/4 of the solution
has been unloaded.
(d) Blow steam coils empty after use to prevent
freezing of residual water while in winter transit.
(e) Do not attempt to increase product temperature by
blowing steam directly into the liquid.
Figure 2: Unloading of Tank Car by Pump: Bottom
Note: Car’s equipment to this point includes external outlet valve.

 

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