Static Separation
Overview
When ore is pulverized into a fine dust, it can be transported by a variety of means such as conveyers and augers or by blowing or dropping the dust with gravity. Some materials in ores are attracted to electrical charges. Unlike electrolysis that occurs in a liquid, static separation can remove dry minerals.
Materials
• Variety of plastic spoons, knives, combs, plastic bags or other plastic materials
• Variety of fabrics and fur
• Fine sand or crushed rock
• Tiny pieces of paper
• Magnifier or loop
Exploration
1. Experiment with combinations of plastic and cloth to determine the best way to generate static. Test the combinations by trying to pick up tiny pieces of paper. Which combinations attracts the most paper bits? Find a reliable combination such as a plastic spoon and piece of fur to create static.
2. Energize the plastic spoon and bring it near a pile of fine sand or crushed ruck. See if anything is attracted to the spoon.
3. Examine the particles with a magnifier. What do most of the grains look like?
4. Try another rock sample. Crush it to a fine consistency. What minerals do you see being separated?
Static Separation
Some minerals can be more easily separated using static separation. See http://mine-engineer.com/mining/minproc/elstat1.htm
•In the STEM Notebook, record the trials for determining the best combinations for creating static. Then record through drawing and writing the results of removing particles with static. Draw a conclusion about what has occurred.
