The invention discloses a method for continuously producing lactate by utilizing heavy phase
lactic acid. The method comprises the steps as follows: (a)
dilution is carried out; (b) carbon column decolorization is carried out; (c) in the extraction step, an organic extraction phase comprises extracting agents, a
solvent and phase conditioning agents, the extracting agents are
amide compounds or a mixture of the
amide compounds, the
solvent adopts
liquid paraffin, the phase conditioning agents adopt
alcohol compounds or the mixture of the
alcohol compounds, and the
mass ratio of the extracting agents, the
solvent and the phase conditioning agents is (5.5 to 6.5):(2.5 to 3.5):(0.5 to 1); and the
mass ratio of the organic extraction phase and heavy phase
lactic acid to be extracted is (1.1 to 1.5):1, and the
operating temperature for extraction ranges from 20 to 70 DEG C; (d) back extraction is carried out; (e) fine
filtration is performed; and (f) concentration is performed.
Lactic acid is selectively transferred to the organic extraction phase to form a loaded organic phase, and lactate
aqueous solution is obtained after back extraction so as to prepare lactate, so that impurities and
lactic acid in the heavy phase lactic acid can be separated effectively, the process
route is simple, and the manufacturing cost is low.