Barium sulfate
CAS No.: 7727-43-7
EINECS No.: 231-784-4
Barium sulfate is the inorganic compound with the chemical formula BaSO4. It is a white crystalline solid that is odorless and insoluble in water. It occurs as the mineral barite, which is the main commercial source of barium and materials prepared from it. The white opaque appearance and its high density are exploited in its main applications.
Uses
1) Drilling fluids
About 80% of the world's barium sulfate production, mostly purified mineral, is consumed as a component of oil well drilling fluid. It increases the density of the fluid.
2) Pigment
The majority of synthetic barium sulfate is used as a component of white pigment for paints. In oil paint, barium sulfate is almost transparent, and is used as a filler or to modify consistency. One major manufacturer of artists' oil paint sells "permanent white" that contains a mixture of titanium white pigment (TiO2) and barium sulfate. The combination of barium sulfate and zinc sulfide (ZnS) is the inorganic pigment called lithopone. In photography it is used as a coating for certain photographic papers.
3) Radiocontrast agent
Barium sulfate is frequently used clinically as a radiocontrast agent for X-ray imaging and other diagnostic procedures. It is most often used in imaging of the GI tract during what is colloquially known as a 'barium meal'.
4) Niche uses
Barium sulfate is also used during the procedure of the soil pH test. In this test it is used so that it precipitates out any particles (usually clay particles) that would otherwise 'cloud' solution preventing one from seeing the colour of the pH indicator i. e. The result of the test. It is also used in Episal salt, brake linings, anacoustic foams, powder coatings, and root canal filling.
5) Catalyst support
Barium sulfate is a low surface area material used as a support for selectively hydrogenating functional groups sensitive to overreduction. With a low surface area, the contact time of the substrate with the catalyst is shorter.
6) Pyrotechnics
As barium compounds emit a green light when burned, barium salts are often used in green pyrotechnic formulas, but the nitrate and chlorate salts are more common. Barium sulfate is commonly used as a component of "strobe" pyrotechnic compositions.
7) Copper Industry
As barium sulfate has high burning point and is insoluble in water, it is used as a coating material in casting of copper anode plates.
|
Barium sulfate |
|
Identifiers |
|
CAS number |
7727-43-7 |
|
PubChem |
24414 |
|
ChemSpider |
22823 |
|
UNII |
25BB7EKE2E |
|
RTECS number |
CR060000 |
|
ATC code |
V08 BA01 |
|
Properties |
|
Molecular formula |
BaSO4 |
|
Molar mass |
233.43 g/mol |
|
Appearance |
white crystalline |
|
Odor |
odorless |
|
Density |
4.5 g/cm3 |
|
Melting point |
1345 ° C |
|
Boiling point |
1600 ° C (decomp) |
|
Solubility in water |
0.0002448 g/100 mL (20 ° C)
0.000285 g/100 mL (30 ° C) |
|
Solubility product, Ksp |
1.0842 × 10-10 (25 ° C) |
|
Solubility |
insoluble in alcohol, soluble in concentrated sulfuric acid |
|
Refractive index (nD) |
1.64 |
|
Thermochemistry |
Std enthalpy of
formation Δ fHo298 |
− 1465 kJ· mol− 1 |
Standard molar
entropy So298 |
132 J· mol− 1· K− 1 |
|
Pharmacology |
|
Bioavailability |
negligible orally |
|
Hazards |
|
EU classification |
not listed |
We particularly cherish cooperation with customers. We deeply believe that these factors enable us to be a long-standing business enterprise in today''s competitive markets. We spare no effort in meeting each customer''s requirements and winning their satisfaction.
We stick to the principle of "quality first, service first, continuous improvement and innovation to meet the customers" for the management and "zero defect, zero complaints" as the quality objective. To perfect our service, we provide the products with the high quality at the reasonable price.
