Abstract: The recovery of antimony in the dressing mill of Hunan Zhazixi antimony mine was achieved by two stage crushing with one closed circuit， manual sorting and discarding with ores over 80 mm， grinding and flotation separating process. However， the manual sorting efficiency is low and the accuracy is poor. Besides， a large number of waste ores in the intermediate product（80~12 mm） between prescreening and rescreening double layer screen couldn't be discarded timely， which goes against sufficient and high-efficient recovery of antimony， quality upgrading and capacity expansion， cost decreasing and benefit increasing of company. In order to solve these problems， the XRT-1200 X-ray intelligent concentrator was used to carry out the pre-separation and discarding tests of ore samples with the same particle size as the intermediate products of double screen， and the scene process was reformed in stages after the success of the test. Laboratory tests showed that: ①XRT-1200 X-ray intelligent concentrator has strong adaptability to sample quality and particle size， and the grade of antimony in waste ores is significantly lower than the controlled grade of setting manual selection. The recovery of lump antimony concentrate by pre-selecting is over 98.50%.②When the controlled grade of manual sorting reduced from 0.20% to 0.12%， the XRT-1200 X-ray intelligent concentrator can throw out the waste ores with yield of 49.41% and antimony grade of 0.08% in the case of the feeding quantity 40 t/h， the feeding grade of antimony 1.50% and the nominal feeding size 70~15 mm. The antimony grade of the waste ores is lower than the antimony grade of the flotation tailings by 0.09 percentage point. ③After the transformation， the dressing mill can achieve the direct benefit of 4.953 5 million yuan per year and significant social benefit. Therefore， XRT series X-ray intelligent concentrator is a kind of new， efficient and intelligent pre-separation equipment for lump ores.

Key words: Antimony ores, X-ray intelligent concentrator, Pre-selection, Particle size