Sizing & Separation of Mixtures

 

Grade Level: grades 4 and up
Subject: Science
Duration: 1 class period
CELs: Communication, Numeracy, Technological Literacy

Objective:

The students will be able to separate mixtures by using a set of sieves.

Background Information:

A number of methods have been developed to separate particles or components
from the ores they are found in. These would include the processes of crushing,
screening and grinding. Some mixtures can be separated by a series of screens.
This activity will demonstrate how screening and crushing might be used
in a milling complex. It might be useful to find or review definitions of
the following terms before starting this activity: mixtures, ore, mineral.

Activity:

Because of the materials that are needed, this activity can be done in groups.
Most of the materials can be purchased from a grocery store.

Materials:

• Jars with lids
• Instant coffee
• some beans
• instant rice
• a large can with a lid
• a supply of fairly large ball bearings (about 1 cm in diameter)
• a set of sieves
• water
• some small rocks (~ 2 cm in diameter)
• some pebbles (~ 1 cm )
• sand and soil.

Method:

1. Mix about ½ cup each of the beans, coffee and rice.
2. Pass this mixture through the set of sieves.
3. Place the rice into the large can along with the ball bearings. Place the can on its side and roll to grind the rice finer.
4. Pass this mixture through the set of sieves.
5. Mix the ground rice and the coffee together.
6. Develop ideas that will help you to separate the coffee from the rice.

Questions & activities:

1. Proceed with the separation of the coffee from the rice.
2. Read some of the brochures on some of the minerals mined in this province. Is this process used in this province?