Abstract:It is very important to control carbon and sulfur balance in the high-temperature Bayer leaching production of high-sulfur and high-carbon bauxite, which is related to whether the influence of carbon alkali and sulfur content in the solution system on production is controllable. Lime is the most important and widely used additive in the blending process. Within the conventional blending range, the carbon content in lime accounts for 30%–40% of the total inorganic carbon entering the process. The amount of lime added and its own carbon content have significant impact on the balance of carbon and sulfur in and out of the system. In the production process, when the C/S ratio of red mud is from 0.45 to 1.0, the overall emission of carbon and sulfur entering the red mud increases with the decrease of blending, in which C/S is easy to achieve balance, and organic carbon is easier to achieve balance than inorganic carbon. In the production of bauxite with high sulfur and high carbon in Bayer process, it is necessary to increase the removal of carbon. It is suggested to reduce the amount of lime as far as possible according to the digestion index, remove carbon in lime by improving the quality of lime or dissolving the lime using spent liquor after precipitation, and control the sulfur content of the ore.