METHOD FOR PREPARING POTASSIUM NITRATE USING A POTASSIUM HYDROXIDE WASTE SOLUTION CONTAINING SILICON COMPOUND AND A WASTE SOLUTION CONTAINING NITRIC ACID

摘要

PURPOSE: A manufacturing method of potassium nitrate by using waste solution including nitrate and NaOH waste solution is provided to reduce environmental contamination and to manufacture potassium nitrate at low cost. CONSTITUTION: A manufacturing method of potassium nitrate by using waste solution including nitrate and NaOH waste solution comprises the following steps: heating waste solution including nitrate, phosphoric acid and acetic acid in order to separate the mixed gas including nitrate and acetic acid from liquid phosphoric acid; obtaining mixed solution including nitrate and acetic acid by cooling the mixed solution; manufacturing a first reaction solution by primarily reacting NaOH waste solution with the mixed solution; removing the acetic acid by heating the first reaction solution; obtaining a second reaction solution by secondary reacting the NaOH waste solution with the primary reaction solution; and obtaining a sodium nitrate solution by removing slurry generated from the secondary reaction. [Reference numerals] (S110) Preparing etching waste solution; (S120) Isolation and removal of phosphoric acid; (S130,S150) Mixing washing waste solution(containing KOH); (S140) Isolation and removal of acetic acid; (S160) Removal of slurry(silicic acid removal)