Abstract: The settling performance of digested red mud pulp during sweetening process was investigated with Weipa ore from Australia and Al(OH)3 as additions. Blanked experiments without flocculant and with starch and A-1000 as flocculants were conducted comparatively to clarify the effect of flocculant on the settling performance of red mud pulp, as well as the settling performance of sweetened red mud pulp in comparison with that unsweetened. The results showed that applying the sweetening process to treating ore can obviously improve the settling performance of digested pulp, and the digested pulp with Weipa ore as the addition during the sweetening process has better settling performance than without addition or using other flocculants.