Menu:

History of lime in mortar | Graymont


Uploaded by ian aleksander adams on February 8, 2007

Uploaded by ian aleksander adams on February 8, 2007

Lime is a calcium -containing inorganic mineral in which carbonates , oxides , and hydroxides predominate. In the strict sense of the term, lime is calcium oxide or calcium hydroxide . It is also the name of the natural mineral (native lime) CaO which occurs as a product of coal seam fires and in altered limestone xenoliths in volcanic ejecta. [1] The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering . [2]

These materials are still used in large quantities as building and engineering materials (including limestone products, cement , concrete , and mortar ), as chemical feedstocks, and for sugar refining , among other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World . Lime is used extensively for wastewater treatment with ferrous sulfate .

The rocks and minerals from which these materials are derived, typically limestone or chalk , are composed primarily of calcium carbonate . They may be cut, crushed, or pulverized and chemically altered. Burning ( calcination ) converts them into the highly caustic material quicklime ( calcium oxide , CaO) and, through subsequent addition of water, into the less caustic (but still strongly alkaline ) slaked lime or hydrated lime ( calcium hydroxide , Ca(OH) 2 ), the process of which is called slaking of lime . Lime kilns are the kilns used for lime burning and slaking.

When the term is encountered in an agricultural context, it usually refers to agricultural lime , which is crushed limestone, not a product of a lime kiln. Otherwise it most commonly means slaked lime , as the more dangerous form is usually described more specifically as quicklime or burnt lime .

In the lime industry, limestone is a general term for rocks that contain 80% or more of calcium or magnesium carbonates , including marble , chalk , oolite , and marl . Further classification is by composition as high calcium, argillaceous (clayey), silicious , conglomerate , magnesian , dolomite , and other limestones . [3] Uncommon sources of lime include coral, sea shells, calcite , and ankerite .

Limestone is extracted from quarries or mines . Part of the extracted stone, selected according to its chemical composition and optical granulometry , is calcinated at about 1,000 °C (1,830 °F) in different types of lime kilns to produce quicklime according to the reaction:

Uploaded by ian aleksander adams on February 8, 2007

Lime is a calcium -containing inorganic mineral in which carbonates , oxides , and hydroxides predominate. In the strict sense of the term, lime is calcium oxide or calcium hydroxide . It is also the name of the natural mineral (native lime) CaO which occurs as a product of coal seam fires and in altered limestone xenoliths in volcanic ejecta. [1] The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering . [2]

These materials are still used in large quantities as building and engineering materials (including limestone products, cement , concrete , and mortar ), as chemical feedstocks, and for sugar refining , among other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World . Lime is used extensively for wastewater treatment with ferrous sulfate .

The rocks and minerals from which these materials are derived, typically limestone or chalk , are composed primarily of calcium carbonate . They may be cut, crushed, or pulverized and chemically altered. Burning ( calcination ) converts them into the highly caustic material quicklime ( calcium oxide , CaO) and, through subsequent addition of water, into the less caustic (but still strongly alkaline ) slaked lime or hydrated lime ( calcium hydroxide , Ca(OH) 2 ), the process of which is called slaking of lime . Lime kilns are the kilns used for lime burning and slaking.

When the term is encountered in an agricultural context, it usually refers to agricultural lime , which is crushed limestone, not a product of a lime kiln. Otherwise it most commonly means slaked lime , as the more dangerous form is usually described more specifically as quicklime or burnt lime .

In the lime industry, limestone is a general term for rocks that contain 80% or more of calcium or magnesium carbonates , including marble , chalk , oolite , and marl . Further classification is by composition as high calcium, argillaceous (clayey), silicious , conglomerate , magnesian , dolomite , and other limestones . [3] Uncommon sources of lime include coral, sea shells, calcite , and ankerite .

Limestone is extracted from quarries or mines . Part of the extracted stone, selected according to its chemical composition and optical granulometry , is calcinated at about 1,000 °C (1,830 °F) in different types of lime kilns to produce quicklime according to the reaction:

Lime has been an important component of mortars for over 2000 years. The characteristics of hydrated lime provide unique benefits in masonry applications that distinguish cement-lime mortars from other masonry mortar materials. Major benefits include:

Cement and Type S Hydrated Lime mortars have been shown to have high levels of flexural bond strength. High tensile bond strength is enhanced by the following properties of cement-lime mortars:

There are a number of studies that demonstrate the superior bond strength of cement-lime mortars. For copies of these studies, pleasecontact Graymont.

Studies have shown that cement-lime mortars can be used to minimize the potential for water penetration into masonry walls.

Masonry construction is a durable, low maintenance system. The use of lime in mortars contributes to the durability of this system. The durability of lime mortar is evidenced as follows:

After processing, products derived from limestone can eventually revert to their original chemical form by reacting with carbon dioxide in the atmosphere or from industrial processes.


51ADBWC7EDL