The invention relates to a method for recycling iron and aluminum by particle size grading pretreatment of
Bayer process red mud, belonging to the technology for recycling
red mud resources. The method comprises the following steps: firstly,
Bayer process red mud is graded in terms of the particle size by using a physical method into coarse red mud and refined red mud; the coarse red mud is processed using physical mineral dressing processes, such as
magnetic separation,
gravity separation and the like, in order to obtain
iron ore having high iron quality and coarse-grained sand, which are made use of respectively; the refined red mud is mixed with
sodium carbonate, limestone and carbon power and is then subjected to reduction
sintering, and two processes of magnetizing reduction
roasting of iron and
soda lime sintering of aluminum are implemented synchronously by means of the control of
sintering conditions;
sodium aluminate is dissolved out of clinker through dilute alkali solution, dissolved
slag is subjected to
magnetic separation to recover
iron ore concentrate, and after being subjected to dealkalized cleaning, the residual
calcium silicon slag is applied to
building material industry. The method realizes combined
recovery of iron, aluminum and other elements, magnificently achieves the comprehensive utilization of the
Bayer process red mud, is capable of effectively relieving environment
pollution resulting from the accumulation of the Bayer process red mud, and has excellent economic and
social benefits.