The next step in processing our samples is to separate crystals out by density. Once the rock sample has been crushed and milled to a size of less than one millimeter, we use a water table to extract zircon by density separation. The sample is added to the top of the table while water is poured over it as the table vibrates to agitate the particles and help maintain a steady flow. The table is positioned at an angle, so while the water is moving the sample down the feed, the vibration of the table propels the sample into different groves on the table. Once the sample has reached the end of the table, the different groves filter the sample into three different sample collection containers – low density, medium density, and high density. After the entire sample has run through the table, each sample collection container is emptied into a pan and allowed to dry in an oven. The high-density sample is what we’re interested in, and will continue with the mineral separation process for zircon extraction. The rest of the process will be explained in future blog posts!
Click here to see a video of the water table in action!