Names | |
---|---|
IUPAC name Strontium carbonate | |
Other names | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.015.131 |
EC Number |
|
PubChem CID | |
RTECS number |
|
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
Properties | |
SrCO3 | |
Molar mass | 147.63 g·mol−1 |
Appearance | White powder |
Odor | Odorless |
Density | 3.5 g/cm3 [1] |
Melting point | 1,494 °C (2,721 °F; 1,767 K) (decomposes) |
0.0011 g/100 mL (18 °C) 0.065 g/100 mL (100 °C) | |
Solubility product (Ksp) | 5.6×10−10 [2] |
Solubility in other solvents | Soluble in ammonium chloride Slightly soluble in ammonia |
−47.0·10−6 cm3/mol | |
Refractive index (nD) | 1.518 |
Structure | |
Rhombic | |
Hazards | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Safety data sheet (SDS) | External MSDS data |
Related compounds | |
Other cations | Beryllium carbonate Magnesium carbonate Calcium carbonate Barium carbonate Radium carbonate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Strontium carbonate (SrCO3) is the carbonate salt of strontium that has the appearance of a white or grey powder. It occurs in nature as the mineral strontianite.
Strontium carbonate is a white, odorless, tasteless powder. Being a carbonate, it is a weak base and therefore is reactive with acids. It is otherwise stable and safe to work with. It is practically insoluble in water (0.0001 g per 100 ml). The solubility is increased significantly if the water is saturated with carbon dioxide, to 0.1 g per 100 ml.
Other than the natural occurrence as a mineral, strontium carbonate is prepared synthetically in one of two processes, both of which start with naturally occurring celestine, a mineral form of strontium sulfate (SrSO4). In the "black ash" process, celesite is roasted with coke at 1100–1300 °C to form strontium sulfide. [3] The sulfate is reduced, leaving the sulfide:
A mixture of strontium sulfide with either carbon dioxide gas or sodium carbonate then leads to formation of a precipitate of strontium carbonate. [4] [3]
In the "direct conversion" or double-decomposition method, a mixture of celesite and sodium carbonate is treated with steam to form strontium carbonate with substantial amounts of undissolved other solids. [3] This material is mixed with hydrochloric acid, which dissolves the strontium carbonate to form a solution of strontium chloride. Carbon dioxide or sodium carbonate is then used to re-precipitate strontium carbonate, as in the black-ash process.
The most common use is as an inexpensive colorant in fireworks. Strontium and its salts emit a brilliant red color in flame. Unlike other strontium salts, the carbonate salt is generally preferred because of its cost and the fact that it is not hygroscopic. Its ability to neutralize acid is also very helpful in pyrotechnics. Another similar application is in road flares.
Strontium carbonate is used for electronic applications. It is used for manufacturing color television receivers to absorb electrons resulting from the cathode. [5]
It is used in the preparation of iridescent glass, luminous paint, strontium oxide, and strontium salts and in refining sugar and certain drugs.
It is widely used in the ceramics industry as an ingredient in glazes. It acts as a flux and also modifies the color of certain metallic oxides. It has some properties similar to barium carbonate.
It is also used in the manufacturing of strontium ferrites for permanent magnets which are used in loudspeakers and door magnets. [6]
Strontium carbonate is also used for making some superconductors such as BSCCO and also for electroluminescent materials where it is first calcined into SrO and then mixed with sulfur to make SrS:x where x is typically europium.[ citation needed ] This is the "blue/green" phosphor which is sensitive to frequency and changes from lime green to blue.[ citation needed ] Other dopants can also be used such as gallium, or yttrium to get a yellow/orange glow instead.
Because of its status as a weak Lewis base, strontium carbonate can be used to produce many different strontium compounds by simple use of the corresponding acid.
The cyanobacteria Calothrix , Synechococcus and Gloeocapsa can precipitate strontian calcite in groundwater. The strontium exists as strontianite in solid solution within the host calcite with the strontium content of up to one percent. [7]
Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element.
A carbonate is a salt of carbonic acid, H2CO3, characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO2−3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C(−O−)2.
Calcium carbonate is a chemical compound with the chemical formula CaCO3. It is a common substance found in rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skeletons and pearls. Materials containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues.
Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the chloralkali process.
Basic copper carbonate is a chemical compound, more properly called copper(II) carbonate hydroxide. It can be classified as a coordination polymer or a salt. It consists of copper(II) bonded to carbonate and hydroxide with formula Cu2(CO3)(OH)2. It is a green solid that occurs in nature as the mineral malachite. It has been used since antiquity as a pigment, and it is still used as such in artist paints, sometimes called verditer, green bice, or mountain green.
Lead(II) sulfate (PbSO4) is a white solid, which appears white in microcrystalline form. It is also known as fast white, milk white, sulfuric acid lead salt or anglesite.
Magnesium carbonate, MgCO3, is an inorganic salt that is a colourless or white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals.
Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds.
Aluminium sulfate is a salt with the formula Al2(SO4)3. It is soluble in water and is mainly used as a coagulating agent (promoting particle collision by neutralizing charge) in the purification of drinking water and wastewater treatment plants, and also in paper manufacturing.
Calcium sulfide is the chemical compound with the formula CaS. This white material crystallizes in cubes like rock salt. CaS has been studied as a component in a process that would recycle gypsum, a product of flue-gas desulfurization. Like many salts containing sulfide ions, CaS typically has an odour of H2S, which results from small amount of this gas formed by hydrolysis of the salt.
Nickel(II) carbonate describes one or a mixture of inorganic compounds containing nickel and carbonate. From the industrial perspective, an important nickel carbonate is basic nickel carbonate with the formula Ni4CO3(OH)6(H2O)4. Simpler carbonates, ones more likely encountered in the laboratory, are NiCO3 and its hexahydrate. All are paramagnetic green solids containing Ni2+ cations. The basic carbonate is an intermediate in the hydrometallurgical purification of nickel from its ores and is used in electroplating of nickel.
In ore deposit geology, supergene processes or enrichment are those that occur relatively near the surface as opposed to deep hypogene processes. Supergene processes include the predominance of meteoric water circulation (i.e. water derived from precipitation) with concomitant oxidation and chemical weathering. The descending meteoric waters oxidize the primary (hypogene) sulfide ore minerals and redistribute the metallic ore elements. Supergene enrichment occurs at the base of the oxidized portion of an ore deposit. Metals that have been leached from the oxidized ore are carried downward by percolating groundwater, and react with hypogene sulfides at the supergene-hypogene boundary. The reaction produces secondary sulfides with metal contents higher than those of the primary ore. This is particularly noted in copper ore deposits where the copper sulfide minerals chalcocite (Cu2S), covellite (CuS), digenite (Cu18S10), and djurleite (Cu31S16) are deposited by the descending surface waters.
Barium chlorate, Ba(ClO3)2, is the barium salt of chloric acid. It is a white crystalline solid, and like all soluble barium compounds, irritant and toxic. It is sometimes used in pyrotechnics to produce a green color. It also finds use in the production of chloric acid.
Cobalt(II) carbonate is the inorganic compound with the formula CoCO3. This pink paramagnetic solid is an intermediate in the hydrometallurgical purification of cobalt from its ores. It is an inorganic pigment, and a precursor to catalysts. Cobalt(II) carbonate also occurs as the rare red/pink mineral spherocobaltite.
Strontium sulfide is the inorganic compound with the formula SrS. It is a white solid. The compound is an intermediate in the conversion of strontium sulfate, the main strontium ore called celestite, to other more useful compounds.
Concrete degradation may have many different causes. Concrete is mostly damaged by the corrosion of reinforcement bars due to the carbonatation of hardened cement paste or chloride attack under wet conditions. Chemical damage is caused by the formation of expansive products produced by chemical reactions, by aggressive chemical species present in groundwater and seawater, or by microorganisms Other damaging processes can also involve calcium leaching by water infiltration, physical phenomena initiating cracks formation and propagation, fire or radiant heat, aggregate expansion, sea water effects, leaching, and erosion by fast-flowing water.
Cobalt extraction refers to the techniques used to extract cobalt from its ores and other compound ores. Several methods exist for the separation of cobalt from copper and nickel. They depend on the concentration of cobalt and the exact composition of the ore used.
Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions.
The strontian process is an obsolete chemical method to recover sugar from molasses. Its use in Europe peaked in the middle of the 19th century. The name strontian comes from the Scottish village Strontian where the source mineral strontianite was first found.