United States Lime & Minerals, Inc., which was incorporated in 1950, conducts
its business through two segments, Lime and Limestone Operations and Natural
Gas Interests. The Company, through its Lime and Limestone Operations, is a
manufacturer of lime and limestone products, supplying primarily the construction
(including highway, road and building contractors), environmental (including
municipal sanitation and water treatment facilities and flue gas treatment processes),
industrial (including paper and glass manufacturers), metals (including steel
producers), roof shingle, oil and gas services and agriculture (including poultry
and cattle feed producers) industries. The Company is headquartered in Dallas,
Texas and operates lime and limestone plants and distribution facilities in
Arkansas, Colorado, Louisiana, Oklahoma and Texas through its wholly owned subsidiaries,
Arkansas Lime Company, Colorado Lime Company, Texas Lime Company, U.S. Lime
Company, U.S. Lime Company—Shreveport, U.S. Lime Company—St. Clair
and U.S. Lime Company—Transportation.
The Company extracts high-quality limestone from its open-pit quarries and
an underground mine and then processes it for sale as pulverized limestone,
quicklime, hydrated lime and lime slurry. Pulverized limestone (also referred
to as ground calcium carbonate) (“PLS”) is produced by applying
heat to dry the limestone, which is then ground to granular and finer sizes.
Quicklime (calcium oxide) is produced by heating limestone to very high temperatures
in kilns in a process called calcination. Hydrated lime (calcium hydroxide)
is produced by reacting quicklime with water in a controlled process. Lime slurry
(milk of lime) is a suspended solution of calcium hydroxide produced by mixing
quicklime with water in a lime slaker.
PLS is used in the production of construction materials such as roof shingles
and asphalt paving, as an additive to agriculture feeds, in the production of
glass, as a soil enhancement, in flue gas treatment for utilities and other
industries requiring scrubbing of emissions for environmental purposes and for
mine safety dust in coal mining operations. Quicklime is used primarily in metal
processing, in flue gas treatment, in soil stabilization for highway, road and
building construction, as well as for oilfield roads and drill sites, in the
manufacturing of paper products and in municipal sanitation and water treatment
facilities. Hydrated lime is used primarily in municipal sanitation and water
treatment facilities, in soil stabilization for highway, road and building construction,
in flue gas treatment, in asphalt as an anti-stripping agent, as a conditioning
agent for oil and gas drilling mud, in the production of chemicals and in the
production of construction materials such as stucco, plaster and mortar. Lime
slurry is used primarily in soil stabilization for highway, road and building
construction.
The Company extracts limestone by the open-pit method at its Texas and Arkansas
quarries. The Monarch Pass Quarry is also an open-pit quarry, but is not being
mined at this time. The open-pit method consists of removing any overburden
comprising soil and other substances, including inferior limestone, and then
extracting the exposed high-quality limestone. The Company removes such overburden
by utilizing both its own employees and equipment and those of outside contractors.
Open-pit mining is generally less expensive than underground mining. The principal
disadvantage of the open-pit method is that operations are subject to inclement
weather and overburden removal. The limestone is extracted by drilling and blasting,
utilizing standard mining equipment. At its St. Clair underground mine, the
Company mines limestone using room and pillar mining. The Company has no knowledge
of any recent changes in the physical quarrying or mining conditions on any
of its properties that have materially affected its quarrying or mining operations,
and no such changes are anticipated.