Sorel cement
Encyclopedia
Sorel cement is a non-hydraulic cement first produced by Frenchman Stanislas Sorel
in 1867.
The cement is a mixture of magnesium
oxide (burnt magnesia) with magnesium chloride
with the approximate chemical formula
Mg4Cl2(OH)6(H2O
)8, corresponding to a weight ratio of 2.5–3.5 parts MgO to one part MgCl2. A variant uses zinc oxide
with zinc chloride
instead of the magnesium compounds.
In use it is usually combined with filler materials such as sand or crushed stone. It is used for grindstone
s, tiles, artificial stone
, and even artificial ivory
(e.g. for billiard balls). It can withstand 10,000 – 12,000 psi
of compressive force whereas standard Portland cement
can only withstand 2,000 psi.
Its chief drawback is its poor water resistance, making it unsuitable for construction applications. In addition, it is relatively expensive compared to standard concrete
and gypsum
.
Stanislas Sorel
Stanislas Sorel was a French engineer, raised the son of a poor clock-maker.Sorel filed a patent on 10 May 1837 for a "galvanic" method of protecting iron from rust by either coating it in a bath of molten zinc or by covering it with galvanic paint...
in 1867.
The cement is a mixture of magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
oxide (burnt magnesia) with magnesium chloride
Magnesium chloride
Magnesium chloride is the name for the chemical compounds with the formulas MgCl2 and its various hydrates MgCl2x. These salts are typical ionic halides, being highly soluble in water. The hydrated magnesium chloride can be extracted from brine or sea water...
with the approximate chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
Mg4Cl2(OH)6(H2O
Water of crystallization
In crystallography, water of crystallization or water of hydration or crystallization water is water that occurs in crystals. Water of crystallization is necessary for the maintenance of crystalline properties, but capable of being removed by sufficient heat...
)8, corresponding to a weight ratio of 2.5–3.5 parts MgO to one part MgCl2. A variant uses zinc oxide
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
with zinc chloride
Zinc chloride
Zinc chloride is the name of chemical compound with the formula ZnCl2 and its hydrates. Zinc chlorides, of which nine crystalline forms are known, are colorless or white, and are highly soluble in water. ZnCl2 itself is hygroscopic and even deliquescent. Samples should therefore be protected from...
instead of the magnesium compounds.
In use it is usually combined with filler materials such as sand or crushed stone. It is used for grindstone
Grindstone (tool)
A grindstone is a round sharpening stone used for grinding or sharpening ferrous tools. They are usually made from sandstone.Grindstone machines usually have pedals in which to speed and slow the stone to sharpen metal to the point of perfection....
s, tiles, artificial stone
Artificial stone
Artificial stone is a name for various kinds of synthetic stone products used from the 18th century onward. They have been used in building construction, civil engineering work, and industrial uses such as grindstones....
, and even artificial ivory
Ivory
Ivory is a term for dentine, which constitutes the bulk of the teeth and tusks of animals, when used as a material for art or manufacturing. Ivory has been important since ancient times for making a range of items, from ivory carvings to false teeth, fans, dominoes, joint tubes, piano keys and...
(e.g. for billiard balls). It can withstand 10,000 – 12,000 psi
Pounds per square inch
The pound per square inch or, more accurately, pound-force per square inch is a unit of pressure or of stress based on avoirdupois units...
of compressive force whereas standard Portland cement
Portland cement
Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout...
can only withstand 2,000 psi.
Its chief drawback is its poor water resistance, making it unsuitable for construction applications. In addition, it is relatively expensive compared to standard concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
and gypsum
Gypsum
Gypsum is a very soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is found in alabaster, a decorative stone used in Ancient Egypt. It is the second softest mineral on the Mohs Hardness Scale...
.