Production method for food-grade potassium metabisulfite

Abstract

The invention discloses a production method for food-grade potassium metabisulfite. The production method comprises the following steps: (1) conducting batching on tap water, purified water or potassium metabisulfite mother liquid and potassium hydroxide or potassium carbonate to form a solution, wherein the solution contains K<+> by 100-400 g / L; then adding an edulcoration agent A and an additive B; (2) carrying out filtration by a micropore filtering device of which the pore diameter is 0.1-10 <Mu>m to obtain a clarified solution; (3) pumping in gas or introducing SO2 liquid until the PH value is 2.5-5.0; reacting to generate a potassium bisulfite solution; (4) cooling and stirring the solution, and enabling the content of the potassium bisulfite in the solution to reach to supersaturated density; separating potassium metabisulfite crystal; conducting seriflux on the separated potassium metabisulfite crystal; obtaining a potassium metabisulfite crystal wet material and the mother liquid after solid-liquid separation, wherein the mother liquid can be used for batching with the potassium hydroxide or the potassium carbonate in the step (1) over again to form the solution; (5) conducting microwave drying on the potassium metabisulfite crystal wet material in the step (4) to obtain the food-grade potassium metabisulfite product.

Description

Technical field: [0001] The invention relates to the field of chemical industry, in particular to a new process production method of food-grade potassium metabisulfite. Background technique [0002] The finished product of food grade potassium metabisulfite is colorless crystal or white crystalline powder, with sulfur dioxide odor, easily soluble in water, and the aqueous solution is acidic, mainly used for food bleaching agent, preservative, antioxidant, wine, fruit juice preservation Fresh-keeping agent, beer clarifying agent, dechlorinating agent for drinking water, fresh-keeping agent for fresh fruits and vegetables, meat and grapes, is one of the widely used food additives. [0003] The old wet production process of potassium pyrosulfite: Potassium bisulfate is prepared into a 45°Bé aqueous solution, and sulfur dioxide is passed through at 80°C to make the solution concentration gradually reach 41-42°Bé. At this time, K 2 S 2 o 5 The content is about 60-62%, and then...

AI Technical Summary

Problems solved by technology

Using the old wet production process, the content of the products produced is 92-95%, heavy metals 0.01-0.005%, arsenic, lead, and selenium are far greater than the requirements of the national food safety standard GB25570, and because the concentration of materials in the production process is too high, it cannot be filtered , the clarity of the product is very poor, which cannot meet the requirements of use, and the finished product is in a powder state, which is easy to agglomerate and makes it difficult to use

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