In today’s world, we all recognize the need to be concerned with our environment and natural resources.We all realize that these things are limited and not self-restoring. We now have several generations that have always had recycling and environmentalawareness in their lives.
Today there exists a green building awareness that has resulted in the development of Green Building Standards and certifications. In this enlightened age, the use of and concern with recycled content is both commendable and expected.
If you’re a dedicated reader of our Iron Strong Blog you’ve seen some of this information in our recent post “Why Use Ductile Iron Pipe?” This post drills deeper into the question; "What is the recycled content of ductile iron pipe and why is it important?"
What is iron and steel scrap?
Scrap metal is iron and steel that was previously used in products ranging from cars to old appliances like washing machines and refrigerators.It could also be old railroad cars, ships, bridges and steel from building structures. Basically, anything made of iron or steel that has been placed in your recycling bin at home or taken to any recycling center or scrap yard.
Iron and steel is the most recycled material on earth with a rate of over 86 percent being recycled. In North America, over 65 million metric tons of iron and steel are typically recycled every year. Chances are your refrigerator, washer, dryer, car, truck or SUV is made up of a previously recycled product that was itself previously recycled.
The ductile iron pipe you use today was certainly made of scrap from a product that was probably also made of recycled iron and steel. Ductile iron pipe consists of 93 percent to 98 percent recycled iron and steel.
What types of scrap are there and how is scrap categorized?
Scrap suitable for use in our foundry is classified into three main categories for environmental programs: Pre-Consumer, Post-Consumer and Post-Industrial.
- Pre-Consumer scrap metals are any waste that is reclaimed from the manufacturing process.
- Post-Consumer scrap is simply described as anything that was used by individuals then discarded into a waste receptacle or dump.
- Post-Industrial waste is any metals used by businesses that does not go back into the manufacturing process.
Additionally, scrap received from processors will be separated as either shredded scrap or plate and structural metals.
Is one type of scrap better than another - Is there such a thing as bad scrap?
Well, yes, scrap can vary in grade and quality. High quality scrap reduces the need for excess processing and treatment helping to keep manufacturing costs low. Some scrap has high levels of impurities, but this doesn’t make it unusable or products made for it substandard.
Most impurities can be removed in melting and processing although rarely some cannot be removed. In this case, the product made from such scrap is not usable, so foundries go to great lengths in testing to insure only suitable scrap is purchased.
As an additional measure of safety, all scrap metal received at our foundries is screened through radiation detectors prior to offloading. Dealing with reputable scrap dealers is a key component of obtaining quality scrap.
How safe is using iron and steel scrap instead of raw iron ore or pig iron?
Review our process videos on manufacturing and melting for more detail. When the scrap is picked up for insertion into the melting process, an electromagnet is used for handling.This will only pick up iron and steel and leave other metals behind.
Further, when scrap is melted and additives are added, the process results in impurities floating to the surface of the melt. The impurities are then removed as slag. The melted slag is often used as aggregate in concrete so there is little to no waste stream from the use of scrap.
Importance of Recycling or why is using recycled materials good?
Recycling and using recycled products are good for the present and future environments and in the case of iron products, the most economical solution.
The use of recycled ductile iron pipe provides environmental benefits on several levels.
Using recycled products:
- diverts waste from landfills.
- requires less energy consumption than using ore.
- reduces the amount of mining needed to obtain new raw materials.
- encourages communities to recycle more, further benefiting the environment now and in the future.
Why is the recycled content of ductile iron pipe not 100 percent?
All the iron and steel used in making ductile iron pipe is recycled. However, it cannot be referred to as a 100 percent recycled product because there are other materials added, such as magnesium, during the manufacturing process.
Different methods may be used to calculate recycled content and ductile iron pipe, typically being lined with cement or other materials will have a varied recycled content depending on if the determination is done by weight or other methods.
The Green Building movement recognizes the need to increase the utilization of recycled materials and has therefore created within both the US Green Building Council (USGBC) and the Institute for Sustainable Infrastructure (ISI) credits in the Leadership in Environmental Engineering and Design (LEED) and ENVISION.
Further, ductile iron pipe is the only pressure pipe to be certified by the Market for Transformation to Sustainability awarding ductile iron pipe Gold SMaRT Certification. To see how ductile iron pipe and its recycled content can help you meet your project goals contact one of our ENVISIONAccredited Professional Engineers.
Are other piping materials made of recycled materials?
While some alternative pipe materials contain some recycled content, if the product or component is not iron or steel, it is unlikely to be recycled or even recyclable. In fact, some product standards limit the amount of recycled content. Reprocessing or recycling of some materials is more energy intensive than using new raw materials and some materials lose significant physical strength from reprocessing. Iron and steel can be recycled unlimited times without having the new product be of a lower grade than the original.
Today’s ductile iron pipe has greater strength than any of the cast iron products that were previously made and are currently being recycled. Ductile iron pipe from McWane Ductile has the highest level of recycled content of any piping material. Because of that and its other environmental attributes, is the best piping choice you can make for the environment today and for generations to come.
For more information on how McWane Ductile can benefit your community, customers and utility, contact one of our engineers or sales representatives.
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