A tailings dump of approximately 100 000 tons from earlier treatment exists at Radium Hill. A report of laboratory flotation tests on this material was issued in June, 1960, (AMDL 40). The laboratory work showed that recovery at the grade of 10.0 lb U308 per ton suggested by Radium Hill, was approximately 30 percent and that this recovery dropped sharply on cleaning. For example, when a mixture of upper and lower layer tailings (approximately 0.8 lb U308/ton) was treated a concentrate grade of 12.5 lb U308/ton was achieved with three stages of cleaning, but only 13.0 percent of the uranium was recovered. It was pointed out that in plant practice this would mean an abnormally high circulating load of middlings, with reconditioning of these middlings with reagent possibly being unnecessary. The pilot plant test to check the laboratory tests was approved with the exception that only higher grade lower layer material was to be used.