The invention relates to a method for extracting organic solvents and
hydrazine sulfate from
wastewater generated in synthesis of hydrazine
hydrate by a ketazine method. The method comprises the following steps: converting, purifying
hydrazine sulfate, rectifying and preparing isopropanol, wherein the step of conversion comprises the following steps: slowly dropping
sulfuric acid into a hydrazine
hydrate wastewater solution under the condition of 0-15 DEG C so as to precipitate and separate out
hydrazine sulfate from the solution, and performing
centrifugal filtration to obtain a crude hydrazine
sulfate product; the step of purifying hydrazine
sulfate comprises the following steps: filtering the crude hydrazine
sulfate product, washing for 2-3 times by using cold water, and performing
centrifugal filtration and
drying crystallization so as to obtain a pure hydrazine sulfate product; the step of rectifying comprises the following steps: collecting filtrate and a washing liquid, feeding into a rectifying
tower, rectifying when the
tower top temperature is 55-56 DEG C so as to collect a pure
acetone product, and rectifying when the
tower top temperature is 80-82 DEG C so as to collect binary
azeotrope of isopropanol-water; the step of preparing isopropanol comprises the following steps: dehydrating the binary
azeotrope of isopropanol-water by using caustic soda flakes, and subsequently distilling, thereby obtaining a pure isopropanol product.