them when the temperature falls below 4f
C (40f F). All trona producers have
established a rehabilitation program to
recover and release contaminated birds
and to minimize the mortality and
morbidity rate.
Land surrounding trona operations in
Wyoming is relatively undeveloped, and
the influx of large numbers of workers
has caused great strain on the local
facilities for housing, schools, shopping,
and entertainment. Soda ash companies
have provided financial assistance to aid
local government in handling any
overloads caused by the migration of
their employees and families into the
community. The companies have given
financial aid to employees purchasing
homes in the surrounding communities
and other fringe benefits such as low-cost
transportation to and from work.
Toxicity.-Although soda ash is not
considered a highly toxic substance,
contact with the eyes may be injurious
and prolonged contact with the skin may
cause irritation, especially to those who
have allergic reactions to alkaline
materials. It also has been found to be
corrosive to the stomach lining if
ingested. It has an acute oral lethal dose
(LD5O) of 2.8 grams per kilogram (when
tested on a rat) and a primary skin
irritation index (PSII) of 2.54 (when
tested on a rabbit).   Simultaneous
exposure to soda ash and lime dusts
should be minimized because in the
presence  of  moisture,  as  from
perspiration, the two materials combine
to form caustic soda, which is very
harmful. Soda ash is not flammable, and
the dust is not explosive.
Employment.-According to a survey
conducted by the U.S. Bureau of Mines,
the Wyoming soda ash industry employed
1,191 people in the 5 trona mines and
1,540 people in the soda ash refineries in
1993. The total quantity of trona mined
by these workers was 14,491,288 tons in
1993. Of the five Wyoming companies,
only FMC and General Chemical are
unionized. The workers are represented
by United Steelworkers Union Local
15320.


Energy Requirements.-Natural soda
ash plants consume considerably less
energy per unit of product produced than
do synthetic soda ash facilities. As the
cost of energy has increased since the
1973 energy crisis, the differential in
production costs between natural and
synthetic soda ash has become greater.
Excluding energy costs to transport the
material to market, this is one of the
major reasons why U.S. natural soda ash
has maintained its competitiveness in the
world market and why several synthetic
soda ash producers have expressed
interest in obtaining a partnership or
ownership in the U.S. soda ash industry.
An early U.S. Bureau of Mines energy
study using 1973 data indicated that 15.8
million British thermal units (Btu's) was
required to produce 1 ton of synthetic
soda ash, whereas the energy requirement
to produce the same quantity from trona
was 7.2 million Btu. The domestic soda
ash industry has reduced its energy
requirements significantly since 1973 by
replacing gas-fired dryers with steam-tube
units and installing mechanical vapor
recompression units to replace triple-
effect evaporators. The industry has also
converted to coal exclusively or combined
with other fuel sources. Plants operated
by Tg and Solvay Minerals and the Argus
plant operated by North American
Chemical Co. use coal only. As a result
of these energy-saving measures, the
Wyoming soda ash industry lowered its
energy requirement to a range of 4.5 to 6
million Btu, depending on the individual
producer. An estimated one-half of the
energy consumed in natural soda ash
refining using triple-effect evaporators is
for  evaporating,  one-third  is  for
calcining, and the remainder, for drying.
These energy requirements exclude the
amount of energy needed to ship soda ash
to foreign markets. Although it has been
estimated that it would take about 2.9
million Btu of additional energy to
transport soda ash by rail and by ship to
Western Europe, nevertheless natural
soda ash production requires less energy
than the Solvay process or any other
synthetic technique.
Transportation.-The western
geographic locations of the domestic


natural soda ash industry often pose
problems because of the great shipping
distance to most foreign customers. Even
within the United States, the majority of
domestic consumption is in the Midwest
and east of the Mississippi River.
Overland and ocean transportation rates
become important factors in the delivered
price of soda ash and must be considered
seriously in negotiations with foreign
consumers who often have alternate
supply sources. Bulk freight rates usually
can be reduced by shipping in larger
volumes, such as in 7,500-ton unit trains.
The railroad is the dominant mode of
transportation for the shipment of soda
ash. In Wyoming, the Union Pacific
Railroad provides the main service to the
industry. All bulk soda ash that is railed
is carried in covered hopper cars, each
handling about 98 tons. Although the
railroad companies make their cars
available, most soda ash companies have
their own sizable fleet.
Beginning in 1985, soda ash was
shipped in large quantities by truck.
Bonneville Transloaders, Inc. trucked
soda ash from Green River to the
Burlington Northern Railroad's line at
Shoshoni, WY.    Of the almost 8.4
million tons (9.2 million short tons) of
soda ash produced in Wyoming,
Bonneville trucks about 770,000 tons
(850,000 short tons) out of Green River.
Other trucking companies have started
similar operations with the Southern
Pacific (shipping more than 227,000 tons
or 250,000 short tons per year) and
Denver Rio Grande Railroads to compete
with Union Pacific.
The railroad companies have been
involved in establishing soda ash bulk
loading terminals at ports to handle large
volumes of material for export. Kansas
City Southern Railroad's terminal at Port
Arthur, TX, has a railcar unloading
capacity of about 1,000 tons per hour.
Material is conveyed to a ship loader
spout for transfer to bulk cargo ocean
vessels. Port Arthur was the third largest
port of the 24 ports that shipped soda ash
in 1993, most of which was shipped to
South America. The Columbia-Snake
customs district in the Pacific Northwest
has a bulk loading terminal that
transported the most soda ash in 1993,


SODA ASH-1993








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