Download Acid Rock Drainage Activity

Acid Rock Drainage/Splatz Activity
Purpose:
To demonstrate how surface area increases as rocks are broken down and how this leads to
acid rock drainage.
Background:
Acid rock drainage is a natural phenomenon that happens when rocks containing certain
minerals are exposed to water and oxygen. The process of acidification causes water to
become acidic which can have negative consequences on the environment. Although this
process occurs naturally, processes involved in mining can increase the process exponentially,
causing environmental damage. Because acid rock drainage occurs often near mines, it is
commonly referred to as acid mine drainage. You can learn more about acid rock drainage in
this 15-minute video: https://youtu.be/X_qLdplO_ic
Materials
Surface Area
Activity
Since mining breaks rocks up to access the minerals inside. It also increases surface area. In a
mining operation, the surface area can easily be increased several million-fold, greatly
increasing the rate at which acidification can occur. This is even true in placer mining where
rocks are not broken up. In placer mining, stream deposits are dug up and exposed to surface
water in large piles.
- Cellulose (cello) sponges. Found in grocery stores and usually inexpensive, colorful,
and around 5” x 3” x 0.5” in size.
- Scissors
- Ruler
- Calculator
- Thin string like paracord or un-waxed dental floss.
1) Have students measure the surface area of their sponge. Surface area is the sum of the
area of all six surfaces of the sponge.
2) Cut the sponge in half length-wise, repeat step one.
3) Cut the two halves in half lengthwise again (for a total of four long strips) and repeat
step one. There should now be 24 surfaces. Tip: which each cut, the surface area is
increasing by two long-side measurements. Students can simply add this amount
rather than measuring the entire thing again.
4) Compare the surface area before cutting and after to demonstrate how surface area
increases and the object is broken up. Discuss how this provides more surface area for
reactions to take place.
5) Optional: From here I create Splatz, but if you can think of something to do with
sponge cubes, keep cutting and determining surface area. The more you cut, the more
dramatic the results are!
Splatz
activity
This is something to do with the sponge pieces. It provides an eco-friendly alternative to water
balloons and can be great fun.
1) Arrange sponge pieces:
2) Wrap with string or floss and tie TIGHT.
3) Grab a bucket of water (or water fountain, stream, river, etc.) and let the games begin!