How does gravity separation concentrate titanium minerals from sand?

Gravity separation is a fundamental technique used to concentrate titanium minerals from sand by exploiting the differences in density between valuable minerals and waste material (gangue). Because titanium-bearing minerals like ilmenite and rutile are denser than the surrounding sand, they can be effectively separated using several methods:12

• Spirals: This is a highly efficient method for concentrating heavy mineral sands. As a pulp of sand and water flows down a vertical spiral channel, the heavier titanium minerals concentrate toward the inner side of the stream, where they are collected through specialized openings.1
• Jigging: In this process, a water stream is pulsed upward and downward through a bed of material. This oscillating motion causes the bed to stratify by density, with the heaviest titanium minerals settling into the lowest layer.1
• Shaking Tables: These devices use a combination of water flow and mechanical vibration. As the material moves down an inclined, vibrating surface, it is stratified into heavy and light layers, allowing the denser titanium particles to be separated from the lighter sand.1

These gravity-based systems are favored for their simplicity and low energy costs.1