PROCESS FOR PRODUCING SODIUM HYDROGEN CARBONATE CRYSTAL GRAIN OF LOW CAKING TENDENCY

摘要

A process for producing sodium hydrogencarbonate crystals, which comprises subjecting sodium hydrogencarbonate crystal powder having an average particle size of from 50 to 500 µm based on the mass to heat treatment at a temperature of from 70 to 95°C by a heating gas having a carbon dioxide gas concentration of at most the concentration calculated by the following formula (1) : Carbon dioxide gas concentration = 0.071 × e 0.1 × T × R - 0.0005 × T - 0.9574 (wherein T is the temperature (%) of sodium hydrogencarbonate crystals, and R is the relative humidity (%), provided that the upper limit of the carbon dioxide gas concentration is 100 vol%) with reference to the graph of Fig. 1 wherein the horizontal axis (X-axis) represents the relative humidity and the vertical axis (Y-axis) represents the carbon dioxide gas concentration, to form anhydrous sodium carbonate on the surface of the sodium hydrogencarbonate crystal particles with a content of anhydrous sodium carbonate of from 0.03 to 0.40 mass% in the sodium hydrogencarbonate crystals. A process for producing sodium hydrogencarbonate crystal particles having a low caking property, which are useful in the field of food products, pharmaceuticals, bath additives, etc., which require no necessity to contain an anticaking agent, can be provided.