The preparation method of Cupric Gluconate includes the following steps:
(1) Dissolve 1 part of copper nitrate in 500 mL of water, heat it to 60° C. while stirring the mixed solution for 1 hour, filter impurities to obtain a blue and transparent copper nitrate solution.
(2) Dissolve 1 part of potassium carbonate in 250 mL of water, and stir until the dissolution is complete to obtain a potassium carbonate solution.
(3) Slowly adding the potassium carbonate solution to the copper nitrate solution, heating to 60° C., and stirring for 1 hour, a pale green precipitate was produced.
(4) filter the light green precipitate, then disperse the light green precipitate in 600 mL of water, heat to 60° C., stir for 20 minutes, then filter and wash with water to obtain a purified light green precipitate, repeat the above steps, A total of 10 washes were performed.
(5) The purified light green precipitate is placed in an oven for drying and pulverized to obtain a green product, namely basic copper carbonate, and the temperature in the oven is 50°C.
(6) test the nitrate content of the basic copper carbonate, if the nitrate content is less than 0.05%, then enter step (7);
(7) Dissolving 1 part of gluconolactone in 80 mL of water, heating at 60° C. until the dissolution is complete and then stopping the heating to obtain a gluconolactone solution;
(8) add 1.1 parts of basic copper carbonate to the gluconolactone solution, stir for 1 hour and then stand for crystallization, and the crystallization mode adopts the direct crystallization of semi-solid phase reaction;
(9) Drying and pulverizing the crystals obtained in step (8) at 50° C. to obtain Cupric Gluconate.