Study on optimization of removing nigre in spent bleaching clay by response surface method

The method of removing nigre in soybean oil in the use of spent bleaching clay was studied. The numerous nigre was removed in centrifuge, the spent bleaching clay was added to adsorb nigre, the optimum condition were confirmed by response surface method:spent bleaching clay 0. 5%, adsorbent temperature 100℃, adsorbent time 53min, moisture content 0. 4%, the stirring speed 93r/min, the content of nigre under the above conditions was 25. 3mg/kg.