Selenium powder, chemical formula Se, black-gray non-metallic, soluble in concentrated sulfuric acid and chloroform, slightly soluble in carbon disulfide, toxic, insoluble in water and ethanol.
Selenium powder is usually in powder or granular form, with pure appearance, consistent color, purity up to 99.99%, no impurities such as soil, stable composition, and uniform moisture.
Improve the combustion accuracy of silicon-based deferrable drugs: Studies have shown that selenium powder improves the combustion accuracy of silicon-based deferred drugs. In the mixed medicine, selenium powder first begins to endothermic and melts at the melting point temperature, and then oxidizes, which has a deoxidizing effect. The result of its combined effects of heat absorption, deoxygenation, covering, penetration, filling, etc. will change the operating conditions in the original pharmaceutical system.
For example, solid-phase reactions require close contact, and the melt penetration, covering, and filling effects of selenium powder block the contact between components. The added selenium powder first inhibited the progress of the solid-phase reaction between red lead and antimony sulfide in the original system.
Secondly, the infiltration, covering and filling of the selenium powder melt to a certain extent isolate the free oxygen generated by the reactants from contact with antimony sulfide, limit the reaction of oxygen and antimony sulfide, and reduce the production of SO2. Reduce the influence of gas on the accuracy of medicament combustion.
Thirdly, after adding selenium powder, the reaction between antimony sulfide and red lead is prevented, the ratio of base drug red lead and silicon is kept unchanged, the heat balance and oxygen balance of the original agent are ensured, and the combustion and heat transfer are uniform and orderly According to its inherent laws, the selenium powder improves the combustion accuracy of the silicon-based delay medicine, which is the result of the combined effects of the above three aspects.