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In 2005, approximately 130 million metric tons
of lime were produced worldwide. Production and consumption increased annually
by 2.0% over the past five years, spurred by a worldwide production increase
in the major consuming industries—steel, soda ash, pulp and paper, refractories,
and the construction industry. Growth in the latter segments came mostly from
demand growth in developing regions, in particular from China. In the United
States and Western Europe, total consumption has been stagnating or showing
moderate growth. Traditionally large consuming areas, construction and steel
are stagnating or decreasing in these regions, and the only substantial growth
is coming from increasing demand in environmental applications. It is expected
that these trends will continue to dominate global lime markets over the next
five years. China and the United States were the largest producers in 2005,
accounting for 19% and 16%, respectively, of total production. Lime is a mature
industry characterized by many regional producers, each serving its regional
markets. There is relatively little world trade, primarily because lime is
readily available in all parts of the world and transportation costs can account
for a significant portion of the product value.
The following graph shows consumption of lime by percentage of total consumption
for each region:
Global production of lime increased at an average annual rate of 1.3% between
1995 and 2005. In 2005, China and the United States were the largest producers
of lime in the world.
Lime operations have been subject to environmental regulations since the mid-1960s.
These regulations have resulted in the closing of a number of installations
and kilns that could not economically comply with the restrictions, especially
regarding the particulate emissions released during processing operations.
In many cases, the cost of building new, more efficient installations has been
prohibitive. Lime generates large volumes of carbon dioxide, which, because
of its relatively low concentration, generally cannot be economically recovered.
The lime industry is increasingly challenged to minimize air, water and noise
pollution.
In accordance with U.S. EPA provisions, U.S. rotary kilns must meet particulate
emission limits of 0.6–1.0 pound per ton of kiln feed and an opacity
limit of 15% when exiting from a dry-emission control device. Plants must also
meet EPA-prescribed state implementation plans that vary with plant production
and ambient area conditions. These regulations generally mean that plants
must have about 99.0–99.8% dust collection efficiency, depending on the
volume of dust loading. In the United States, several lime dust collection
systems are employed, such as cyclones, high-energy wet scrubbers, baghouses,
gravel-bed filters and electrostatic precipitators. Vertical kilns produce
much less dust than rotary kilns.
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