A metathesis method
The 13.0g calcium lactic acid powder (pentahydrate matter) and 12.1g zinc sulfate (heptahydrate material) added 100mL water, stirred and heated under reflux. After the reaction was removed by hot filtration and washed with water precipitated calcium sulfate (bluish white powder), and the filtrate was milky white translucent liquid, Lactic acid that is precipitated as white crystals. Final filtration, washed with water and dried to give a white powder (mp 276 ~ 27 7 ℃) 8g, 64% yield.
(C3H503) 2Ca + ZnSO4 → (C3H5O3) 2 Zn + CaSO4 ↓
2, and in France
Lactic acid was added in the final zinc oxide powder stirred and heated 2 ~ 3h, the reaction was cooled crystallized was separated by filtration and washed with water several times, then dried under 60 ~ 65 ℃ finished. This process is simple, the quality is better, but the cost is higher.
2C3H6O3 + ZnO → (C3H5O3) 2Zn + H2O
3, prepared from starch fermentation lactic acid, and then with the zinc reaction.
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