The invention discloses a method for purifying acid-containing low-abundance
heavy water. The method comprises the following steps: (1)
neutralization: adding
carbonate without protons into the acid-containing low-abundance
heavy water for
neutralization reaction; (2)
crystallization and separation: cooling and crystallizing the neutralized neutral
salt solution, and filtering and separating; (3) reduced pressure
distillation: performing reduced pressure
distillation on the filtrate, and concentrating and evaporating to
dryness to obtain pure low-abundance
heavy water; and (4) rectification: carrying out
isotope rectification on the low-abundance heavy water to improve the abundance of the heavy water, and carrying out multiple times of rectification and abundance improvement to obtain a pure high-abundance heavy
water product. The
carbonate is used as the neutralizer, does not contain protons, can effectively remove acid, and does not introduce
hydrogen atoms into a heavy water
system, so that the deuteration degree reduction caused by the
neutralization process is avoided; through the combination of cooling
crystallization and reduced pressure
distillation, inorganic salt generated by neutralization can be effectively removed, and pure high-abundance heavy water with extremely
low salt content is obtained; the method is simple to operate, low in
equipment requirement and suitable for industrial-scale
recovery treatment of acid-containing heavy water.