Abstract: Introduced some technology alteration since the commissioning of sijiaying iron mine at 2010-10. Oxide ores system: newly built the plant and added flotation equipments, dilatancy and alteration of filtration equipment, promoted field strength of low magnetic equipment before middle and high intensity magnetic dressing, added high intensity magnetic equipment, gravity separation adding scavenging and gravity separation concentrate controlling screening,the third stage grinding "two to one" alteration, purification of cycle water, alteration of sedimentation pond, optimization of flotation reagent and so on. Primary ore system: return position of magnetic separation column tailings,adding recycle system of tailings and sewage reservoir, altering plumbing system,and realizing zero discarding of industrial waste water.the dressing technique level ,quality and output of concentrate were promoted, and got better social and economic benefits. Meanwhile, put forward the direction of decreasing tailing grade, and improving metal recovery of oxide ore dressing system, improving the feeding ore grade by primary election before grinding of primary ores to get the goal of increasing output and decreasing discarding.

Key words: Sijiaying iron mine, Dressing technology, Evolvement, Alteration