Study On Preparation Of Food Grade Magnesium Chloride At Low Temperature

According to statistics from 2000 to 2015,the total production of food additives in Chinahas risen from 2.163 million tons at the beginning to 9.01 million tons an increase of 8.37 tons over the same period last year.The research and development of food additives have been paid more and more attention.This project is commissioned by Dalian Wudao Salt Chemical Group to prepare food additive magnesium chloride by decolorizing desulfurizing,adjusting p H,evaporating,crystallizing,vacuum drying and so on.The following conclusions were drawn from the study:The decolorization of activated carbon,hydrogen peroxide,sodium hypochlorite and calcium hypochlorite in reaction temperature,reaction time,addition amount and p H were compared in a primary decolouring.The reaction conditions were as follows : the reaction temperature was 60 ?,the reaction time was 1 h,the amount of sodium hypochlorite added was 8 wt %,the p H of the solution was 3,the decolorization rate was 83.04 %.H,the amount of resin added is 15 wt.The p H value of the solution is 3,and the decolorization rate is91.38%.In desulphurization operation,calcium chloride is selected as desulfurization agent.The content of calcium chloride,reaction time,reaction temperature and adding method were studied.It is found that the method of step by step addition is more favorable to the reaction of calcium chloride with magnesium sulfate.The theoretical value of calcium chloride is 1.1times,the reaction temperature is 60 ?,the reaction time is 4 h,the residual amount of sulfate radical is at least 0.103 wts.In the test of the properties of the sample and the effect of technological conditions on it,it was found that the theoretical value of calcium chloride was 1.1 times,the evaporation temperature was 140 ?,the p H of the solution was 3.The highest content of magnesium chloride in the sample was 48.85 wts.the calcium content was at least 0.080 wts.the water insoluble content was at least 0.023 wt.The color of the sample dissolved was the best and no white precipitate was formed.