以古龙酸母液为原料,硝酸为氧化剂,在五氧化二钒和铁盐复合催化剂以及硫酸的助催化作用下合成草酸,采用正交试验研究反应时间、反应温度,硝酸用量,硫酸用量以及催化剂配比对草酸收率的影响.得到较优的制备条件:即反应温度55℃,反应时间7 h,古龙酸母液(质量分数15%)用量20 g,硝酸用量16.2 mL,硫酸用量6.0 mL,催化剂V2O5与Fe3+摩尔配比1∶20.草酸的平均收率为84.09%,纯度达99.50%,质量达到国家标准(GB/T1626-88)的工业一级品水平.
Using the liquid waste of gulonic acid as raw material,nitric acid as oxidant,vanadium pentoxide and ferric salt as Composite catalyst,and sulfuric acid as a catalyst,the oxalic acid was synthesized.Effect of reaction temperature,reaction time,the amount of sulfuric acid and nitric acid,catalyst ratio was investigated.By orthogonal test,the best reaction conditions were determined:reaction temperature was 55 ℃;reaction time was 7 h;the amount of nitric acid was 16.2 mL,the amount of sulfuric acid was 6.0 mL and catalyst ratio of vanadium pentaoxide to ferric salt was 1∶20.The average yield of oxalic acid was 84.09 % and the purity was 99.50 %.The quality reached levels of the first grade product specified in the National Standard.