Steel:
Dolomite and high calcium
quicklime are used in steel converters and
electric arc furnaces as a basic flux in slag
formation to remove impurities such as silica,
phosphorus and sulfur. On a world-wide basis,
steel remains the number one volume market for
lime products.
Constructions:
Infrastructure is essential
for growth with the timely, dependable movement
of goods and services. Lime is a vital chemical
used in building this infrastructure. From the
addition of lime to control expansive clays in
highway and airport construction to special
hydrated dolomitic limes for increased masonry
bond strength in buildings, lime has met this
challenge and will continue to do so.
Environmental:
Environmental uses of lime
are many and ever increasing. For example, Flue
Gas Desulfurization (FGD) at coal-based power
plants are one of several other industries that
use lime for removing sulfur dioxide from their
stack emissions. In industrial wastewater
treatment, lime is used to neutralize a wide
variety of industrial waste streams and as a
reagent for environmental remediation projects.
In biosolids treatment, lime-treated wastewater
residuals produce disposable material that can
be used for land applications.
Metal /
Mining:
Iron, aluminum, copper,
gold, silver, uranium, zinc, etc. are just a few
of today's metals that are quite visible and
some not so visible in our everyday lives. Less
well known is the fact that lime is used in the
mining of many raw metal ores and in the
beneficiation steps for producing these
important metals. In today's efficient gold
extraction processes, micron-sized gold grains
can be extracted from the crushed ore with the
use of hazardous chemicals that are kept safe
and manageable with the addition of lime. This
gold can be found on many of the electrical
contacts in our PC's.
Copper:
In copper
industry lime is used for pH regulation in heap
leaching and the flotation process.
Aluminium:
In
aluminium
production, lime is used in the Bayer bauxite
process to recover the caustic leaching solution
and to enhance the removal of impurities; for
example, silica compounds. Additionally, lime
can be used in gas scrubbing processes for
increased environmental pollution abatement.
Chemicals:
Lime has
numerous applications in the chemical industry
thanks to its natural properties and competitive
price.
It's used in the production of chemicals that
can use the calcium and/or hydroxide molecule.
In addition to being incorporated into other
chemicals, lime's pH control abilities are
readily utilized. Typically, process waters in
the chemical industry require treatment with
lime to correct its pH and adjust mineral
content. Quite often, acidic waste waters are
treated with lime before recycling or release
into the sewage system.
Municipal:
In meeting the growing
water requirements of our population and
industries, we must use more plentiful raw water
sources such as rivers, lakes, high-volume
wells, etc. Generally, these sources must be
treated to meet our end use needs, including
municipal drinking water quality standards. Not
only does lime play an important role in these
purification processes, it is also used in
pumping the water safely to the customers.
Part of the water that we "borrow" every day
becomes contaminated and needs to be
re-processed for discharge into the environment
or reused. Again, lime is there to assist in the
retreatment processes plus one other important
feature, disinfection of the removed
contaminants before disposal. This can be
achieved via pH control or taking advantage of
quicklime's exothermic heat release property
when mixed properly with water.
Paper / Pulp:
Written communication is a
vital part of our daily life and the use of
paper greatly enhances this communication
method. The primary starting material for paper
is a tree. The beginning of paper is the
extraction of "paper" cellulose from trees - the
pulping process, and ends with the alignment,
linking, and filling of this fibrous matte on
the "wires" of a modern, high-speed paper
machine. From beginning to end, lime is involved
in the pulp and papermaking processes.
Pulp:
In the pulping process, lime is used to recover
valuable caustic soda in the pulp-making
process. Additionally, lime can also be used in
applicable water softening processes for the
pulp and/or paper mill.
Paper:
As the paper industry has moved to the alkaline
paper making process, this has opened the door
to the use of different filler and coating
minerals/chemicals - one of which is
Precipitated Calcium Carbonate (PCC). When used
as a filler, it enhances major paper properties
such as whiteness (brightness), opacity, and
texture. In new coatings arena, PCC or blends of
other coating materials allow for better
finishes and the use of modern high speed
printing techniques.
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