Abstract: Acacia mangium tannin extract is a new tannin variety developed in recent years. The process parameters of A.mangium tannin extract are studied in this paper. The results show thas the relation of the baume degree(y,°Bé) and concentration (kg/L) at 20 ℃ is: y=1.2+40x. And the relation of the baume degree(y) and concentration at different temperature(y') is: y=y'+(T-20)/15. Extraction process was that 400 g of A.mangium barks with water absorption rate of 210% were extracted with 1 200 mL water and then 800 mL of water in the following steps. First digestion extract temperature is 100 ℃, and last digestion extract temperature is 128 ℃. The extract time is 12 h, sodium pyrosulfite which is 1.8% of gas dried materials weight is added. The yield of tannin extract is 81.9%, and the sield of tannins is 90.6%. Sulfonation process is that sodium pyrosulfite (Na₂S₂O₅) which is 6% of extract solution oven dried weight is added, and the reaction is carried on at 85 ℃ for 2 h. The tannin content of sulphonated tannin extract is 67.8%, insoluble content is 3.2%, pH value is 4.5, and Lovibond color is 9.6. Other processes are the same as Waxberry tannin extracts production.

Key words: Acacia mangium, tannin, technology