What is Lime ?

The word "Lime" refers to products derived from burnt (calcined) limestone, such as quicklime and hydrated lime. Limestone is a naturally occurring and abundent sedimentary rock consisting of high levels of calcium and/or magnesium carbonate, and/or dolomite (calcium and magnesium carbonate), along with small amounts of other minerals. It is extracted from quarries and underground mines all over the world. Lime and limestone products are among the oldest materials used by humans for a very diverse range of applications. Today these products serve as an essential building block in every industrial process.

Lime Cycle
After processing, products derived from limestone have the unique ability to return to their original chemical form. The lime cycle consists of first burning of limestone to form quicklime. Hydrated lime can then be produced by adding water to the quicklime. In the diagram below, carbon dioxide in the atmosphere or from industrial combustion processes react with hydrated lime to convert it back to limestone. This cycle of sustainability is called the lime cycle.

Hydrated Lime Products:
Quicklime can be converted into a fine, dry powder called hydrated lime by adding water (hydration) under controlled conditions. Hydrated lime is used in many applications including water and waste treatment, soil stabilization, agricultural applications, asphalt modification and flue gas desulfurization. These products are used in many of the same applications as quicklime but hydrated lime products are more chemically dilute than quicklime. They are used in industrial applications where controlled sizing is needed or where slakers are not utilized. Hydrated lime normally does not give off heat when it is combined with water. Hydrated lime is used as a component in building products such as mortars, plasters, whitewash and stuccos.

High Calcium Quicklime
High calcium quicklime is lime made from excellent deposits of high calcium limestone containing less than 5% magnesium carbonate. Calcium oxide (CaO), commonly known as lime or quicklime, is a widely used chemical compound. It is a white, alkaline, and crystalline solid. Quicklime is created by heating limestone as shown in the following equation : CaCO₃ + Heat = CaO + CO₂

High calcium quicklime provides superior chemical base performance. It will provide exceptional performance for your acid neutralization, SO₂ absorption, sludge stabilization or other industrial alkali applications.

Pulverized Lime
It is a specially milled quicklime product for various metallurgical, industrial, chemical and agricultural applications. Final product size is milled to less than 100-mesh. Pulverized lime is also available with an additive for enhanced handling and flow ability.

Uses Of Lime :

Because of its strong basic properties, calcium hydroxide has many and varied uses:

A flocculant, in water and sewage treatment and improvement of acid soils

An ingredient in whitewash, mortar, and plaster

An alkali used as a lye substitute in no-lye hair relaxers

A chemical depilatory agent found in Nair

An ingredient in baby formula milk

A chemical reagent

In the reef aquarium hobby for adding bio-available calcium in solution for calcium-using animals such as algae, snails, hard tube worms, and Corals (often referred to as Kalkwasser mix), and also to increase the alkalinity of the water.

In the tanning industry for neutralization of acid, the liming of hides and skins and the flocculation of wastewater.

In the petroleum refining industry for the manufacture of additives to oils (salicatic, sulphatic, fenatic)

In the chemical industry for manufacture of calcium stearate

In the food industry for processing water (for alcoholic and soft drinks)

For clearing a brine of carbonates of calcium and magnesium in the manufacture of salt for food and pharmacopoeia

In Native American and Latin American cooking, calcium hydroxide is called "cal". Corn cooked with cal becomes nixtamal which significantly increases its nutrition value, and is also considered tastier and easier to digest.

In chewing Betel nut or coca leaves, calcium hydroxide is usually chewed alongside to keep the alkaloid stimulants chemically available for absorption by the body

Similarly, Native Americans traditionally chewed tobacco leaves with calcium hydroxide derived from burnt shells to enhance the effects

A filler

In the petrochemical industry for manufacturing solid oil of various marks

In the manufacture of brake pads

In the manufacture of ebonite

For preparation of dry mixes for painting and decorating

In manufacturing mixes for pesticides

In manufacturing the trademarked compound "Polikar", an antifungal and antimicrobial preservative for vegetables in storage

In Dentistry, it is used as dressing in paste form used for anti-microbial effect during a dental root canal procedure. Calcium hydroxide is known to have a strong anti-microbial effect and is a bone-regeneration stimulant.[2]

It has been proposed to add it to sea water in great quantities to reduce atmospheric CO₂ and fight the greenhouse effect[1]

Used as an acid supressor in the production of metals. Lime is injected into the waste gas stream to neutralise acids such as fluorides and chlorides prior to being released to atmosphere.