A method for further extracting calcium gluconate from Ca Gluconate crystalline waste liquid, comprising the following operation steps;
Step 1: Filter the impurities in the mixed solution
Collect the waste liquid in a centralized manner, transfer and store the waste liquid in a collection box, install a water pump to pump the waste liquid out, and arrange a filter box so that a 0.45μm filter membrane is installed at the inlet of the filter box, and a water pump is used to pump the waste liquid to the filter membrane. To the waste liquid, the fine impurities in the waste liquid are filtered, and the Ca Gluconate dissolved in the waste liquid is passed through and mixed in the filtered solution.
The second step: heating and concentration of the filtered solution
The filtered solution is collected in the heating box, and magnesium chloride powder is added to the heating box, and the magnesium chloride is gradually heated by mixing and stirring to increase the heating temperature, and the heating solution is uniformly stirred while heating, so that the content of the solution in the heating box is reduced to Three-fifths of the original solution, stop stirring and close the lid to seal, so that the solution is allowed to stand and cool down after heating.
The third step: crystallization
The concentrated solution is easily placed in a crystallization barrel, and ethanol is added to the concentrated solution, and after adding ethanol, the crystallization barrel is placed in a cold water jacket, and the four sides of the crystallization barrel are kept wet by cold water, the temperature of the mixed solution is lowered, and the ethanol is mixed. The speed is reduced, and crystallization occurs in the clean cylinder over time.
Step 4: Obtaining Ca Gluconate
Put a 0.45μm filter membrane on top of the liquid outlet, pour the supernatant, so that the supernatant after the precipitation flows out through the 0.45μm filter membrane, so that the Ca Gluconate crystals remain after filtration, and the filtered crystals are cleaned by spraying the magnesium chloride solution. Adopt 70 ° temperature drying to purify, obtain calcium gluconate.
The method for extracting calcium gluconate from mother liquor after Ca Gluconate crystallization comprises impurity removal, concentrated mother liquor, crystallization, separation and purification process steps, and concrete steps are as follows:
A. impurity removal
Add 10g activated carbon to the mother liquor after 1000ml Ca Gluconate crystallization, stir for 8h, filter and reclaim activated carbon, and remove impurities for subsequent use in the mother liquor;
B. to concentrate
Take 1000ml of mother liquor after removing impurities, concentrate at 100°C to about containing calcium gluconate greater than 90g/L, then cool to 23-27°C, and concentrate to 590ml;
C. to crystallize
Add edible ethanol to the above-mentioned mother liquor after every 1000ml of concentrated cooling, make the final concentration be 12%, add Ca Gluconate seed crystal 0.1g after mixing, and leave standstill for 24h to allow the crystallization to separate out naturally;
D. Separation and purification
The supernatant was poured off, filtered with suction, the crystals were washed with 50 ml of absolute ethanol, and then dried under reduced pressure at 80° C. to obtain a white granular Ca Gluconate product; the purity of the calcium gluconate obtained by separation and purification was greater than 95%.