用木屑制取草酸的工艺研究

The research on the techniques for making oxalic acid from wooden scraps

用浓碱处理木屑的方法，从木屑中制取草酸，试验了碱液浓度、浸泡时间和焙炒温度等对产率的影响，结果表明：用５０％的氢氧化钠浸泡木屑８ｈ（木屑与氢氧化钠溶液的投料质量比为１３），在１９０～２００℃下焙炒，用１５％的氯化钙提取草酸钙，酸度为ｐＨ４～６，得到２２％的产率。产品符合国家ＨＧ３－９８８－７６质量标准。本工艺适用于中小型企业的运作。

The paper put forward an integrated techniques for making oxalic acid from wooden scraps in concentrated alkali, and tested the influence of lye's concentration on immersing time, frying temperature. The result showed that a 22% output rate could be achieved under such technological conditions that wooden scraps are immersed in 50% NaOH for 8 hours, and the input mass of wooden scraps to NaOH solvent is 1:3, and the frying under 190℃～200℃, the concentration of acid to extract CaC 2O 4 with 15% CaCl 2 is pH4～6. The product made with this technique is in conformity with National Quality Standard HG3 988 76. Such technique is highly recommended for small sized and middle sized enterprises.