| Title |
Study on the Complex Compound in Bi2O3 - MoO3 System |
| Authors |
이상화(Sang Hwa); 황용길(Lee); (Yong Kil); (Hwang) |
| Abstract |
This study is to find out the mechanism by which reaction products form when the bismuth trioxide and molybdenum trioxide is sufficiently mixed with a mole ratio of 1 to 1 and then heated at various temperatures selected from the differential thermal analyses. The results obtained from the experiment that these reaction products have been alkalileached are summarised as follows ; 1. The reaction products of the mixture of Bi₂O₃and M_0O₃(mole ratio=1 : 1) for 500℃ are Bi₂M_0O_6, Bi₄M_0O_9 and αBi₂O₃, whereas at above 670℃ the product obtained is identified to be Bi₄M_0O_9 by the reaction B₂M_0O_6 +α-Bi₂O₃→Bi₄M_0O_9. 2. At a temperature of 900℃ which is above the melting point of Bi₂O₃there is no change in weight. In the temperature range of 820℃ to 1000℃ below the boiling point of M_0O₃, however, it is shown to be a decrease in weight by 80%. 3. The melting point of Bi₄M_0O_9 is found to be 950℃ the change in weight of Bi₄M_0O_9 formed by mixing M_0O₃and Bi₂ O₃is not shown because of the formation of the compound Bi₄M_0O_9. 4. The chemical reaction analysis has shown that one of the reasons why the leaching rate of roasted ores of M_0S₂containing Bi is lowered can be explained by the fact that Bi₂M_0O_6 and Bi₄M_0O_9 are not soluble in a solution of NaOH under the condition of atmospheric pressure. |