How exactly is steel made? The SMA video, The Refrigerator Door shows how old, discarded scrap becomes brand new steel, through the energy efficient electric arc furnace process -- providing thousands of jobs and cleaning up the environment!
The Refrigerator Door is available online in Microsoft Windows Media format. You should have Media Player 7.1 or higher, or another equivalent means of playback. The video is available in two different bitrates- 384k and 56k. The 384k version is recommended. If you wish to watch the 384k version as it downloads, you will need a high-speed connection such as DSL, cable modem, or corporate T-1/T-3. The two links below should open the video inside your computer's media player:
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Microsoft Windows Media Player for Windows or Macintosh is available at the Windows Media Download Center. For UNIX-derived systems, consider MPlayer. |
You can also order a copy of The Refrigerator Door on a VHS videocassette (English, NTSC, playing time of 0:11:05). Please e-mail the SMA.
Narrator: This is the end of many of the conveniences that we have come to take for granted.
In this case -- a simple refrigerator door, having served its purpose, its functional life is at an end. However its re-invention as a valuable feedstock for new products is just beginning.
This door and other similar throwaways are at a critical juncture. What becomes of this door typifies the choices we can make.
For, if the door and others like it head for a landfill, steel-containing discards would become a huge part of North America's environmental problem, since they are a large part of the billions of tons of refuse we cast aside every day and try to forget.
But, when the grapple hook of a steel recycler retrieves this refrigerator door, it begins a new life.
Instead of becoming refuse, this door will join millions of tons of steel-containing scrap metal destined to be reborn into the industrial cycle.
Its destination is here at one of North America's modern electric furnace steel mills, among the world's largest recycling operations, mills that provide thousands of high paying, highly skilled manufacturing jobs to workers across the continent. These environmentally safe, internationally competitive plants not only put people to work, they also help to alleviate North America's massive waste problem.
Steel is the most recycled material on earth. Each year, the amount of steel recycled is double that of all other recycled materials combined. That includes all the aluminum and other metals, all the recycled glass, paper and plastics, combined.
Steel is the most widely used metal in the world. It is a key component in most industries including transportation, construction, industrial equipment, machinery, and appliances.
Our refrigerator door is symbolic; steel scrap is available from a wide range of sources, not only from appliances, but also from old automobiles, farm, office and industrial equipment, ships, railroad cars, and obsolete buildings and bridges. Electric furnace steel producers recycle 10-million junked cars every year, and an equal tonnage from other sources of steel scrap.
Steel scrap is sorted and processed into sizes and forms that can be moved about by crane and then put through shredders, shears, and presses to prepare it for melting into new steel products.
Shredders can turn a large car into fist-sized pieces of metal in less than a minute.
The iron and steel metallic components are magnetically separated from other waste components and become the basic raw material, making new steel products.
Many mini-mills use advanced computer technology in the processing of scrap metal. The computer plays a role in selecting scrap that will be melted into the mini-mill's electric arc furnace.
A crane operator ensures that the right amount and composition of raw materials enters the electric furnace.
The newest electric arc melting furnaces are high-powered, with low energy consumption. Electric furnace capacities range in size from 30 to 400 tons. The inside of the furnace is lined with refractory material - ceramic bricks that can withstand the intense heat of melting steel.
After the scrap is loaded into the furnace, "charging" begins. Three graphite electrodes are lowered into the furnace, and an alternating electric current passes from the electrodes to the steel, forming an "arc". The electrodes don't actually touch the steel, but facilitate an electrochemical reaction speeding up the electrons in the scrap. This turns it into a liquid state.
The refrigerator door is a refrigerator door no more.
Melting is controlled through highly sophisticated computer systems. Workers in electric furnace steel plants are highly trained in the use of the computerized equipment.
Steel mills comply with all environmental standards for air emissions and effluent discharges by using state-of-the-art air emission controls and approved water treatment technologies.
When scrap is melted in an electric furnace with 3,000 degree Fahrenheit temperatures, the liquid steel is "tapped" from the furnace. Impurities rise to the top of the molten steel and are poured off into an open pit or a special car under the furnace. This material is known as slag, and when cooled and treated, it becomes a valuable co-product of the steel making process. Resembling natural aggregate, it is used to pave roads, highways, airport runways, and support railroad beds.
Molten steel is sent in transfer cars to ladle furnace stations for additional alloying and refining. Ladle furnaces optimize energy use, and assure continuity of operation of the continuous caster. After achieving the optimum casting temperature and alloy desired, the liquid steel then moves from the ladle station into a tundish, a holding reservoir which feeds a steady flow of the hot metal at the desired temperature to the continuous caster.
Computers control the speed of the 2,860 degree Fahrenheit molten steel, as it enters molds to form either billets or thin cast slabs. Continuous casters operate with intensive water cooling systems, allowing fast casting of billets and slabs for continuous hot rolling into bar and structural products as well as plate and sheet.
Continuous casting and other recent improvements allow mini-mills to add greatly to recycling efficiency and have dramatically reduced the time it takes to make new steel.
More efficient recycling improves the environment. The use of scrap instead of iron ore reduces mining wastes by 97%, air pollution by 86% and water pollution by 76%. For every ton of steel recycled, 2,500 pounds of iron ore, 1000 pounds of coal and 40 pounds of limestone are saved, also improving the environment.
After the new steel is cast, it is rolled. Rolling mill operations are completely computer controlled and include automatic shape and thickness measurement devices.
The billets or slabs are routed to the rolling mill, where they are either reheated in gas-fueled furnaces to more than 2,000 degrees Fahrenheit before rolling, or sent directly through a series of high speed, computer controlled rolling mill stands, to be rolled into final mill products.
These products are shipped across the country--and around the world--as new, useful steel.
Electric furnace mills produce all of the concrete reinforcing bar used in construction, and almost all of the structural steel used in bridges and buildings. The steel in the steel-belted tires of your car was probably made in an electric furnace, from wire rod produced in a minimill. Railroad rails, merchant bars, special shapes, pipes and tubes, and increasingly high tonnages of steel plate and sheet are now being produced in electric furnace mills.
70,000 men and women have high-paying jobs in electric furnace steel mills based on their ability to turn steel scrap discards into brand new steel products.
The North American steel industry and its major supplier industries provide some of the most desirable jobs in the North American economies, while also creating sought-after jobs in other industries. Every 100 jobs created in the primary steelmaking industry produces 437 additional jobs in other industries.
High amounts of energy are saved by recycling steel scrap. On average, making steel from scrap is four to five times more energy efficient than making steel from virgin iron ore. Electric furnace steel production is at least ten times more energy efficient than aluminum production. By recycling scrap, the steel industry saves more then 6 trillion BTUs each year--enough energy to power 18 million households, or the entire city of Los Angeles for eight full years.
Two billion dollars are saved each year in solid waste disposal costs through the recycling of more than 54 million metric tons of ferrous scrap. That's 119 billion pounds of scrap metal.
The sixty North American steel companies that comprise the Steel Manufacturers Association operate over 140 steel plants. Most are electric furnace steel producers. They are good neighbors, concerned employers, and dedicated to the protection of the environment.
They are ready to take discarded refrigerators, old cars and trucks, rail cars and tracks, farm machines, demolished buildings and bridges and turn them into new products that will rebuild North America's aging infrastructure, creating new appliances, roads, buildings, bridges, automobiles, buses, railroads and mass transit systems, as well as an endless number of other new steel products.
A dynamic, rapidly expanding sector of the steel industry, they make high quality, low-cost steel products in efficient plants across North America.