| 20110318260 | MANUFACTURE METHOD OF ULTRA-PURE SULFURIC ACID - The present invention provides a method of manufacturing ultra-pure sulfuric acid. Industrial sulfur trioxide is used as the raw material, gasifying it in a round gasifier, getting it gasified for the second time after condensation, sulfur trioxide gas has been purified. Absorbing the sulfur trioxide gas with the dilute sulfuric acid circularly, collect the target product of ultra-pure sulfuric acid. The main content of the ultra-pure sulfuric acid obtained by the method of the present invention can reach more than 96 wt %, the content of the impurities of metal ions is in conformity with the SEMI C12 standard. Furthermore, secondary gasification is applied in the present invention to improve the purity of sulfur trioxide, the purified sulfur trioxide was absorbed by dilute sulfuric acid with different concentration circularly, and overcome the shortcomings, such as the unstable quality of the product which produced in the traditional production methods, the high content of the impurities of metal ions, high energy consumption, high cost and easy to cause pollution, so this invention is more suitable for large-scale continuous production. | 12-29-2011 |
