What is bismuth oxid?
The pure bismuth trioxide (nanopowder ) is classified into three types: a, b and d. A type is yellow monoclinic crystalline system, melting point of 825, relative density 8,9. It is soluble only in alkali and acid. b type consists of a bright orange to yellow tetragonal crystalline system with relative density 8.55. Melting point 860. Soluble in acid, but insoluble when mixed with water. Hydrogen and hydrocarbons can be used to reduce the material into metallic bismuth. The cubic fluorite structure of dBi2O3 makes it a unique material. The crystal lattice of d-Bi2O3 is void in 1/4, which gives it a high oxygen conductivity. Bismuth Oxide is mainly used for electronic ceramic powder materials. It can also be used as photoelectric materials. As an additive used in electronic ceramic materials, bismuth dioxide is usually required to have purity levels above 99.15%. Main application objects include ceramic capacitors, zinc oxide varistors, and ferrite magnet materials.
The method for synthesis of bismuth dioxide
The aqueous sodium solution without carbon dioxide, which is a solution of aqueous hydroxide in water, was mixed with the bismuth-nitrate solution at 80-90degC. During precipitation the solution remains slightly alkaline. A white, volume-swelling Bismuth Oxide Hydrate Bi(OH3) is precipitated. The solution is heated, stirred and dehydrated to yellow bismuth trioxide. After decantation of water, filtering, and drying the product, bismuth dioxide, is obtained.
A 0.1 mol/L Bismuth Nitrate Solution dissolved in 1 mole/L Nitric Acid (at 80 to90deg C.) was dropped into a 1.5 mol/L NaOH aqueous mixture without CO2. During precipitation, the solution remains alkaline. The white, volume-expanded, bismuth oxide trihydrate Bi(OH3) will precipitate, but it will dehydrate and turn into light yellow after stirring the hot solution. Wash 15 times in water without carbon dioxide or air, then filter and dry.
After melting the metal bismuth in the graphite-crucible, an arc will form between the electrode graphite and the metal’s surface. The arc will heat the metal and cause it to oxidize when oxygen is flowing. For a continuous supply of oxygen to the crucible, it should be kept in a large vessel and placed on agitator. The reaction is carried out at 750-800degC and the b bismuth trioxide is generated quickly with a purity level of 99.8%. A high-temperature phase B-type product is obtained by quenching the product in water or on cold metal plates.
(aka. Technology Co. Ltd., a trusted global chemical materials supplier and manufacturer with more than 12 years experience in providing super-high quality chemicals and Nanomaterials. The bi2o3 powder that we produce is high in purity, has fine particles and low impurity levels. If you need lower, please Contact us.