Presumably you mean slaked lime? If so it is calcium hydroxide - Ca(OH)2
Read more: http://wiki.answers.com/Q/What_is_slate_lime%27s_chemical_name#ixzz1LDSKLzlM
Showing posts with label slaked lime. Show all posts
Showing posts with label slaked lime. Show all posts
Monday, May 2, 2011
Wednesday, April 20, 2011
What is Lime?
Lime chemical terminology explained - click here
Building lime terminology explained - click here
Other chemical & misc. terminology explained - click here
Lime is made from calcium carbonate. This can be found in a variety of forms for example chalk, limestone or sea shells. In the British Isles sources are almost invariably chalk or limestone. In the case of Singleton Birch, it is mainly chalk quarried in Lincolnshire.
To convert the raw material into lime, heating to temperatures between 800 C - 1000 C is required. At these temperatures the chalk breaks down by giving off carbon dioxide leaving calcium oxide which is known as quicklime.
Quicklime is unstable and reacts, often very rapidly, with water to form calcium hydroxide. This process produces heat and is known as hydration. When exposed to the atmosphere this calcium hydroxide can react again by absorbing carbon dioxide from the atmosphere to once again become calcium carbonate.
This is known as the lime cycle and is shown in the diagram below.
It is calcium hydroxide which, when mixed with sand to make a mortar, builders have used over the millennia. The setting process is the re-absorption of carbon dioxide from the atmosphere called carbonation.
Calcium hydroxide can be used by Builders in two forms, firstly, if it is hydrated with an excess of water, lime putty is produced or if the water quantity is reduced a powder is formed which can be bagged.
All sources of pure calcium carbonate produce a similar result, however the Romans discovered that the calcium hydroxide would also react with volcanic ash, essentially a mixture of silica and alumina. The resulting mixes set very much harder and for the first time enabled structures of high strength to be built. By varying the quantity of silica and alumina, mortars (and lime concretes) of different strengths could be produced. These reactions are referred to as pozzolanic, from the town of Pozzuoli in Italy from where the original material came.
The processes described so far use chalk or limestone that is relatively pure containing over 95% calcium carbonate. However some limestones are less pure and can contain quantities of silica and alumina which when heated produce very similar results to the Roman mixes of pure lime with volcanic ash. These impure limestones if they contain quantities of silica and alumina are referred to as Natural Hydraulic Limes (NHL).
Hydraulic in this context refers to the ability of the material to set under water as opposed to pure air limes which can only set when exposed to atmospheric carbon dioxide. As with addition of pozzolanic silica and alumina, the strength of NHL's depends upon the quality of these materials in the limestone. As the quantities increase so does the strength but also the free lime (calcium hydroxide) in the mortar reduces so that the set depends more on chemical reaction and the process of carbonation reduces.
Singleton Birch have worked to develop a range of NHL products by sourcing the appropriate chalk or limestone for burning, based on its' geology and mineralogy.
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Lime terminology
calcium carbonate
also known as: chalk, limestone, agricultural lime
chemical formula: CaCO3
calcium oxide
also known as: quicklime, burnt lime
chemical formula: CaO
calcium hydroxide
also known as: hydrated lime, slaked lime
chemical formula: Ca(OH)2
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Building Lime terminology
Air lime
Air lime, or high calcium lime does not have any hydraulic component. It can be quicklime for slaking or hydrated lime. It gains strength slowly, by combining with atmospheric carbon dioxide to form calcium carbonate (as per the lime cycle). Several grades of air lime are identified in EN459 the European standard for Building Lime.
Hydraulic lime
Lime with hydraulic or cementitious properties which will set when exposed to moisture. Several grades of hydraulic lime are identified in EN459 the European standard for Building Lime.
Natural hydraulic lime
Hydraulic lime which does not contain any performance enhancing additives. Its properties are as a result of the mineralogy of the calcium carbonate stone which is quarried for burning.
Hydrated lime
Hydrated lime is NOT hydraulic lime and will not set in contact with water.
CL90 & CL90 S
Grades of air lime for building as described in EN459 the European standard for Building Lime. CL90 is the purest grade of building quicklime and CL90 S is the purest grade of hydrated lime for building. Several grades of air lime are identified in EN459 the European standard for Building Lime.
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Other chemical & misc. terminology
carbon dioxide
chemical formula: CO2
water
chemical formula: H20
silica
chemical formula: Si02
alumina
chemical formula: Al203
back to top
Building lime terminology explained - click here
Other chemical & misc. terminology explained - click here
Lime is made from calcium carbonate. This can be found in a variety of forms for example chalk, limestone or sea shells. In the British Isles sources are almost invariably chalk or limestone. In the case of Singleton Birch, it is mainly chalk quarried in Lincolnshire.
To convert the raw material into lime, heating to temperatures between 800 C - 1000 C is required. At these temperatures the chalk breaks down by giving off carbon dioxide leaving calcium oxide which is known as quicklime.
Quicklime is unstable and reacts, often very rapidly, with water to form calcium hydroxide. This process produces heat and is known as hydration. When exposed to the atmosphere this calcium hydroxide can react again by absorbing carbon dioxide from the atmosphere to once again become calcium carbonate.
This is known as the lime cycle and is shown in the diagram below.
It is calcium hydroxide which, when mixed with sand to make a mortar, builders have used over the millennia. The setting process is the re-absorption of carbon dioxide from the atmosphere called carbonation.
Calcium hydroxide can be used by Builders in two forms, firstly, if it is hydrated with an excess of water, lime putty is produced or if the water quantity is reduced a powder is formed which can be bagged.
All sources of pure calcium carbonate produce a similar result, however the Romans discovered that the calcium hydroxide would also react with volcanic ash, essentially a mixture of silica and alumina. The resulting mixes set very much harder and for the first time enabled structures of high strength to be built. By varying the quantity of silica and alumina, mortars (and lime concretes) of different strengths could be produced. These reactions are referred to as pozzolanic, from the town of Pozzuoli in Italy from where the original material came.
The processes described so far use chalk or limestone that is relatively pure containing over 95% calcium carbonate. However some limestones are less pure and can contain quantities of silica and alumina which when heated produce very similar results to the Roman mixes of pure lime with volcanic ash. These impure limestones if they contain quantities of silica and alumina are referred to as Natural Hydraulic Limes (NHL).
Hydraulic in this context refers to the ability of the material to set under water as opposed to pure air limes which can only set when exposed to atmospheric carbon dioxide. As with addition of pozzolanic silica and alumina, the strength of NHL's depends upon the quality of these materials in the limestone. As the quantities increase so does the strength but also the free lime (calcium hydroxide) in the mortar reduces so that the set depends more on chemical reaction and the process of carbonation reduces.
Singleton Birch have worked to develop a range of NHL products by sourcing the appropriate chalk or limestone for burning, based on its' geology and mineralogy.
back to top
Lime terminology
calcium carbonate
also known as: chalk, limestone, agricultural lime
chemical formula: CaCO3
calcium oxide
also known as: quicklime, burnt lime
chemical formula: CaO
calcium hydroxide
also known as: hydrated lime, slaked lime
chemical formula: Ca(OH)2
back to top
Building Lime terminology
Air lime
Air lime, or high calcium lime does not have any hydraulic component. It can be quicklime for slaking or hydrated lime. It gains strength slowly, by combining with atmospheric carbon dioxide to form calcium carbonate (as per the lime cycle). Several grades of air lime are identified in EN459 the European standard for Building Lime.
Hydraulic lime
Lime with hydraulic or cementitious properties which will set when exposed to moisture. Several grades of hydraulic lime are identified in EN459 the European standard for Building Lime.
Natural hydraulic lime
Hydraulic lime which does not contain any performance enhancing additives. Its properties are as a result of the mineralogy of the calcium carbonate stone which is quarried for burning.
Hydrated lime
Hydrated lime is NOT hydraulic lime and will not set in contact with water.
CL90 & CL90 S
Grades of air lime for building as described in EN459 the European standard for Building Lime. CL90 is the purest grade of building quicklime and CL90 S is the purest grade of hydrated lime for building. Several grades of air lime are identified in EN459 the European standard for Building Lime.
back to top
Other chemical & misc. terminology
carbon dioxide
chemical formula: CO2
water
chemical formula: H20
silica
chemical formula: Si02
alumina
chemical formula: Al203
back to top
Lime Mineral Data
Help on Chemical Formula: Chemical Formula: CaO
Help on Composition: Composition: Molecular Weight = 56.08 gm
Calcium 71.47 % Ca 100.00 % CaO
Oxygen 28.53 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaO
Help on Environment: Environment: Thermally metamorphosed calcareous ejecta.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1935
Help on Locality: Locality: Vesuvius, Campania, Italy Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named from the Old English, quicklime.
Help on Name Pronunciation: Name Pronunciation: Lime Say LIME
Help on Synonym: Synonym: Calcium Oxide
Chaux
ICSD 75785
PDF 37-1497
Help on Composition: Composition: Molecular Weight = 56.08 gm
Calcium 71.47 % Ca 100.00 % CaO
Oxygen 28.53 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaO
Help on Environment: Environment: Thermally metamorphosed calcareous ejecta.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1935
Help on Locality: Locality: Vesuvius, Campania, Italy Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named from the Old English, quicklime.
Help on Name Pronunciation: Name Pronunciation: Lime Say LIME
Help on Synonym: Synonym: Calcium Oxide
Chaux
ICSD 75785
PDF 37-1497
Thursday, April 14, 2011
Hydrated Lime/Slaked Lime/Calcium Hydroxide
Hydrated Lime (or calcium hydroxide, or slaked lime) is usually a dry powder resulting from the controlled slaking of quicklime with water. The exothermic or released heat of reaction is captured and used to evaporate the excess slaking water.
Hydrated Lime is a chemical, with chemical formula Ca(OH)2 {Calcium Hydroxide}. Hydrated Lime is also known as Slaked Lime. It is white and in powder form with Ca(OH)2 contents varying from 96% to 70%.
IDENTIFICATION
Chemical name: Calcium hydroxide
Product name(s): Hydrated Lime, Industrial Hydrate
Formula: Ca(OH)2
Molecular Weight 74.08
Material Uses . Water Treatment Plant
. Effluent Treatment Plant
. pH Control
. Paint Industries
. Petroleum refining Industries
. Food Industries
. Leather Industry
. Paper Industry
. Pesticides
. Fertilizers
. Metallurgical Industries (Copper, Aluminum, Steel, Iron, etc)
. Marble/Granite Cutting
. Glass Industry
. Pharmaceutical Industry
. Cement paints
. Bleaching Powder
. Di Calcium Phosphate manufacturing
. Rubber Industry
. Road making and construction
. Sugar Industries
Specification of Hydrated Lime - Hydrated Lime/Slaked Lime/Calcium Hydroxide
Calcium Hydroxide
Ca(OH)2
96%
92%
90%
85%
80%
75%
70%
Calcium Oxide
CaO
72.5%
69.5%
68%
64%
60.5%
56.7%
52.9%
Calcium Carbonate
CaCO3
0.5%
1%
2%
4%
6%
8%
12%
Magnesium Oxide
MgO
0.4%
0.4%
0.4%
0.4%
1%
1%
1%
Acid Insoluble
SiO2
0.1 %
0.2%
0.4%
1.2%
2.5%
4%
6%
Alumina
Al2O3
0.03%
0.03%
0.05%
0.10%
0.15%
0.20%
0.25%
Iron
Fe2O3
0.03%
0.03%
0.05%
0.10%
0.15%
0.20%
0.25%
Moisture
0.2%
0.3%
0.5%
0.5%
0.5%
0.5%
0.5%
Mesh
(BSS)
400
375
250
200
175
150
150
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