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利用放射性示踪气体氪－85，通过脉冲响应法试验研究了浮选柱内气相停留时间分布特性。利用专门设计的装置把放射性气体的脉冲导至浮选柱空气分配器内，并且在线测量柱内不同高度的瞬时响应，由此组成本试验。这项技术首先在直径10cm、高8m的试验厂型浮选柱内进行试验。试验中面积的气体流速是0．8～0．9～1．0～1．5cm／s，起泡剂用量是0－10－20ppm。然后，研究了用于辉钼矿精选回路中的直径0．91m、高15m的工业型浮选柱的气相。试验中面积的气体流速是1．3～1．7～2．1cm／s，面积的尾矿流速是0．7cm／s。试验厂型和工业型的浮选柱的瞬时响应曲线显示出大约2～4分的典型的气体滞留时间，气体分散数值分别为0．1和0．4。当面积的气体流速低于1．5cm／s，面积的淋洗水流速0．2～0．4cm／s时，在泡沫层中气相的行为接近于塞流。在工业型浮选柱内可以清楚地视查到有显著的气体短路进入到尾矿流中。
Using radioactive tracer gas Krypton-85, the impulse response method was used to study the gas residence time distribution in flotation column. The test was conducted using a specially designed device to direct the pulses of radioactive gas into the flotation column air distributor and to measure the instantaneous response of the column to different heights within the column. This technique was first tested in a pilot plant flotation column of 10 cm in diameter and 8 m in height. Gas flow rate of the test area is 0.8 ~ 0.9 ~ 1.0 ~ 1.5cm / s, the amount of foaming agent is 0-10-20ppm. Then, the gas phase of an industrial flotation column with a diameter of 0.91 m and a height of 15 m for use in a molybdenum pickling circuit was studied. The area gas flow rate was 1.3-1.7 to 2.1 cm / s and the area tailings flow rate was 0.7 cm / s. The transient response curves of the pilot plant and the industrial flotation column show a typical gas residence time of about 2 to 4 with gas dispersion values of 0.1 and 0.4, respectively. When the gas flow rate is less than 1.5cm / s and the area of rinsing water is 0.2 ~ 0.4cm / s, the behavior of the gas phase in the foam layer is close to that of the plug flow. In the industrial flotation column can be clearly identified as a significant gas short circuit into the tailings flow.