After the raw material (grape skin residue) is leached and centrifuged by concentrated sulfuric acid, the obtained skin residue is dried and crushed to be added into feed, calcium carbonate is added into the leaching solution to adjust the pH value to 7.0 to obtain calcium tartrate precipitate, the solution contains potassium tartrate component, the supernatant is transferred to another container, calcium oxide is added under full stirring, and all potassium tartrate is converted into calcium tartrate. Then concentrated sulfuric acid is used to hydrolyze calcium tartrate to obtain tartaric acid and calcium sulfate precipitates. Centrifuging, decolorizing with activated carbon, concentrating, crystallizing, and oven drying to obtain pure tartaric acid.
