Abstract: Sodium carbonate monohydrate was prepared by recrystallization method with tailings from the production of ADC foaming agent as raw material.The influences of crystallization temperature，crystallization time，and use times of the mother liquid on the quality and yield of the sodium carbonate monohydrate were mainly investigated.The optimum process conditions were as follows：evaporation temperature was 85 ℃，crystallization time was 60 min，and use times of the mother liquid was 2. The yield could be up to 89.28% under the optimum coditions.The process has the advantages of high product purity，simple process，and easy operation etc.，which can realize tailings comprehensive utilization，and the green utilization.

Key words: ADC foaming agent, evaporation crystallization, sodium carbonate decahydrate, yield