ZIRCON SEPARATION USING THE JCR CONCENTRATING TABLE: AN EVALUATION OF YIELD, CONCENTRATION, AND TIME EFFICIENCY

Mineral separation techniques are designed to concentrate the heavy minerals of a sample so that age determination work can be performed. The JCR concentrating table utilizes vibration and water flow to concentrate dense minerals. To test the table’s efficiency, I simulated typical samples by mixing 1 kg silica sand (grain size: 200-500 um) with 100-300 mg of magnetite sand (grain size: 100-200 um). The silica sand acts as the bulk of a crushed sample, while the magnetite is meant to represent the zircons, having high density, low abundance and small relative size. 7 separate trials were performed using this simulated sample, varying a single operational parameter for each. A control test yielded a recovery of 68%. The following trials included testing variables such as table tilt angle, increased flow rates, reconcentration, and volume reduction, yielding recovery rates ranging from 83% to 98%. These test samples each took ~ 3 hours to process. We were able to completely eliminate the need for heavy liquid separation for 12 natural samples processed using these run conditions. We were also able to recover zircons from a sample containing only 7 ppm zirconium. A shortwave UV light is effective for monitoring zircon concentration effectiveness while samples are processed on the concentrating table. The next phase of tests will be performed on a suite samples from the Mt. Stuart Batholith, WA. I will use whole-rock geochemistry to determine the theoretical zircon yield in terms of weight %, and XRD analysis on the concentrates from all trials to determine actual yield (resulting in concentration and yield efficiency measurements).