Abstract: Although SSS-II series vertical ring pulsating HGMS（High Gradient Magnetic Separator) with horizontal magnetic field has the advantages of high grade concentrate， jamless magnetic medium and no-corrosion magnetic system， the problems of insufficient magnetic energy utilization rate， low volume magnetic medium ， poor recovery rate and so on restrict its popularization and application. In order to solve these problems， and based on SSS-II series magnetic separators， the SSS-III series vertical ring pulsating HGMS with horizontal magnetic field were developed. The machine adopts a special double layer magnetic medium box sorting ring structure， which significantly improves the utilization rate of magnetic energy， the volume of magnetic medium and the height of separation action， realizes the steps sorting of ferromagnetic and low magnetic particles， plays a short process sorting effect of “one roughing and one scavenging”， and improves equipment processing ability and recovery rate. The double layer washing discharging device ensures the advantage of jamless magnetic medium. The production practice of the roughing workshop of a titanium selection plant in Panzhihua showed that the SSS-III-2750 vertical ring pulsating HGMS with horizontal magnetic field run smoothly and reliably. In the case of the grade of TiO₂ in raw ores 9.89 %， titanium roughing concentrate with TiO₂ grade of 17.54 % and TiO₂ recovery rate of 86.23 % was obtained. Compared with the SSS-II-2750 vertical ring pulsating HGMS with horizontal magnetic field，the recovery rate of TiO₂ increased by 11.91 percentage points in the case of the raw ores with grade lowered by 1.09 percentage points. Compared with a on-site vertical ring pulsating HGMS with vertical magnetic field，the grade and recovery rate of TiO₂ increased significantly by 3.42 percentage points and 15.56 percentage points in the case of raw ores grade only higher by 0.43 percentage points.

Key words: Horizontal magnetic field, Double layer magnetic medium box sorting ring, The short process of “One roughing and one scavenging”, Double layer washing discharging device