METHOD FOR MANUFACTURING HIGH PURITY SULFURIC ACID

摘要

A method for manufacturing high purity sulfuric acid is provided. A mixed solution subsequently undergoes a first preheating step, a second preheating step, a distilling step and an evaporating step to remove peroxide, water, oxygen and insoluble impurities, so as to obtain the first gas containing sulfur trioxide, sulfuric acid and hydrogen oxide. And then, the sulfur trioxide is absorbed by a sulfuric acid solution, thereby forming the high purity sulfuric acid.

主权项

1. A method for manufacturing a high purity sulfuric acid, comprising:
providing a mixed solution, wherein the mixed solution comprises sulfuric acid, a first solution, hydrogen peroxide, water, oxygen gas, and an insoluble impurity, and a boiling point of the first solution is higher than a boiling point of the sulfuric acid; performing sequentially a first preheating step, a second preheating step and a distillation step to the mixed solution by a gravity flow at 1 atm to form a second solution, wherein the hydrogen peroxide, the water, and the oxygen are removed by the first preheating step, the water is removed by the second preheating step and the distillation step, a temperature of the first preheating step is lower than a temperature of the second preheating step, and the temperature of the second preheating step is lower than a temperature of the distillation step; performing an evaporation step to the second solution at a temperature which is higher than a boiling point of the sulfuric acid and lower than a boiling point of the first solution to remove the insoluble impurity and the first solution, thereby obtaining a first gas, wherein the first gas comprises sulfur trioxide (SO3), sulfuric acid, and water; and applying a sulfuric acid to absorb the first gas to form a high purity sulfuric acid, wherein a concentration of the sulfuric acid is larger than 96 weight percent, a concentration of the high purity sulfuric acid is at least 96 weight percent, and a molar concentration of an impurity in the high purity sulfuric acid is less than 0.1 ppb molar concentration.