关键词: 无水亚硫酸钠, 食品级, 二氧化硫

Abstract: Firstly，the sulfur dioxide flue gas from the sulfuric acid unit was pretreated.Then the sodium sulfite solution was used for sulfur dioxide absorption in packing column and then neutralized with sodium hydroxide to prepare high purity anhydrous sodium sulfite product.The new process improved the comprehensive utilization efficiency of resources and solved the problems，such as unstable running and difficult to guarantee the purity of products as the high concentration sodium hydroxide being applied to absorb sulfur dioxide directly in the previous process.The trial result showed the variable production cost of the new process is lower than that of sodium carbonate method，and the product quality could meet the standard requirements of food grade sodium sulfite.

Key words: anhydrous sodium sulfite, food grade, sulfur dioxide