High-purity germanium dioxide (GeO 2 ) is obtained by decomposing high-purity germanium tetrachloride (GeCl 4 ) into deionized water. The solid GeO 2 is separated from the hydrolyzate by filtration, and the hydrazine content in the hydrolyzate is generally 2 to 4 g/L. At present, ruthenium is generally recovered by directly adding a chloride salt method to a hydrolyzate or by adding a hydrochloric acid of a different mass, and the ruthenium is recovered in the form of GeCl 4 . Chihong Company uses the second method to recover hydrazine in the hydrolyzate, which consumes 30% of industrial hydrochloric acid at about 110 t/a, and produces a distillation residue with H + concentration of 6.5 mol/L of about 200 m 3 /a. bigger. This study is to find a new environmentally friendly helium recovery process with low cost and low residual liquid production.55%
Hydrazine Hydrate First, the test part
(1) Raw materials
The hydrolyzate 64%Hydrazine hydrate used in the experiment was a hydrolyzed supernatant obtained by hydrolysis of high-purity GeCl 4 to form GeO 2 , which was a pale yellow acidic solution suspended with a small amount of white floating matter. The chemical composition thereof is shown in Table 1. In addition, the reagents used in the experiment were MgCl 2 ·6H 2 O, MgSO 4 ·7H 2 O, and MgO were analytically pure (produced by Daban Fine Chemical Co., Ltd., Shantou City, Guangdong Province); NaOH, NH 3 ·H 2 O was analytically pure (Manufactured by Shanghai Chemical Reagent Co., Ltd.).
Table 1 Main chemical composition of hydrolyzate
Hydrolyzed mother liquor c(H + )/(mol·L -1 ) ρ(Ge)/(g·L -1 )
1 # 4.51 3.40
2 # 4.82 2.75
3 # 5.03 2.12
(two) experimental principle
The chemical reaction formula of high purity GeCl 4 hydrolyzed to high purity GeO 2 is:
GeCl 4 +2H 2 O=GeO 2 +4HCl
Or: GeCl 4 +(x+2)H 2 O=GeO 2 ·xH 2 O+4HCl
The hydrolyzed GeO 2 has a certain solubility (0.004 mol/L) and is a soluble crystalline oxide.
Sodium hydroxide was added to the hydrolyzate and magnesium chloride is first dissolved in water to g
