If you visit a lot of environmental forums, no doubt you would have come across people claiming that recycling isn't all that effective - that it can take as much energy to recycle materials as it does to extract and produce them in the first place.
I don't claim to have any special knowledge or education, but here's some information I researched on the energy savings involved with various common materials from what I believe to be fairly good sources.
Energy savings - recycling metals
These figures also take into account the sorting and transportation of materials.
Aluminium - 95%
Copper - 85%
Lead - 60%
Steel - 62 - 74%
Zinc - 60%
Data from the British Metal Recycling Association
Aside from the energy savings, the more metals that can be recycled, the less (or slower) destruction of the environment from mining. While the recycling process may produce toxic materials; mining certainly does.
Energy savings - recycling plastics
Post-consumer products may contain as many as 20 different types of plastic material; so one of the biggest challenges is sorting it all. However, according to Dr. Mike Biddle, President of MBA Polymers, recycling plastics uses only roughly 10 percent of the energy that it takes to make a pound of plastic from virgin materials.
Again, the savings aren't just in energy - plastics are still mostly made from petrochemicals; i.e. crude oil. Nearly 10 percent of U.S. oil consumption, which equates to approximately 2 million barrels a day - is used to make plastics. Recycling plastics also means saving oil - through the production process and base materials.
Energy savings - recycling glass
According to Waste Online, for every ton of recycled glass, 1.2 tons of raw materials are not required and after taking into account transport and processing needed to recycle glass, nearly 700 pounds of carbon dioxide is saved per ton of glass melted for the purposes of making bottles and jars.
The Glass Packaging Institute states recycled glass uses only two-thirds the energy needed to manufacture glass from raw materials
Recycled glass isn't just used for making more bottles - it can be turned into fiberglass (which is also used in house insulation), and as a component of bricks; requiring less energy to create the bricks and as the product is lighter, less energy is used in transport. Glass can be recycled indefinitely.
Energy savings - recycling paper
The Department of Energy states that a ton of paper made from recycled fibers conserves 7,000 gallons of water, up to 31 trees, 4,000 KWh of electricity and up to 60 pounds of air pollutants (not including carbon dioxide).
Overall, recycling paper uses about 60% less energy than making paper from new materials.
In case you've heard that there is a glut of old newspapers around and therefore paper is now often shipped to landfill and burned; that used to be the case in some parts of the world, but through new techniques, products and widespread consumer acceptance, demand has caught up with supply.
The recycling trap
Here's a trap that many people fall into - because an item can be recycled, they might feel that extra consumption is no longer a bad thing. Recycling is the last of the 3R's i.e. Reduce, Reuse... lastly, Recycle.
Reduction of consumption means that less needs to be produced in the first place (and you'll save a stack of cash too). Reusing gives old products new life with little or no energy being used for repurposing, whereas recycling still does require substantial energy.