Fact Sheet: Pollution Prevention: Strategies for the Steel Industry
Center For Hazardous Materials Research (CHMR)
The pollution prevention practices described here have been developed specifically for the steel industry and have been implemented by other steel manufacturers according to environmental law.
What Is pollution prevention?
Pollution prevention is the reduction or elimination of discharges or emissions to the environment. This includes all pollution: hazardous and non-hazardous, regulated and unregulated, across all media, and from all sources. Pollution prevention can be accomplished by reducing the generation of wastes at their source (source reduction) or by using, reusing or reclaiming wastes once they are generated (environmentally sound recycling).
Each of the pollution prevention practices described in this fact sheet is an extension of the simple but powerful idea that it makes far more sense to eliminate the generation of waste than to develop complex and costly treatment schemes once it has been generated.
Why practice pollution prevention?
Pollution prevention is good business. While most pollution control strategies cost money, pollution prevention has saved many firms thousands of dollars in treatment and disposal costs alone.
Many companies have already discovered the tremendous benefits of pollution prevention. The 3M Co.'s "Pollution Prevention Pays" Program has eliminated the annual generation of more than 500,000 tons of pollutants. Cumulative savings since the program began in 1975 are estimated at $426 million.
Smaller companies can also benefit. One firm reduced its hazardous waste disposal costs by 74% and decreased raw material costs by 16%.
By reducing or eliminating wastes a firm can:
Solve the waste disposal problems created by land bans
Reduce waste disposal costs
Reduce costs for energy, water and raw materials
Reduce operating costs
Protect workers, the public and the environment
Reduce risk of spills, accidents and emergencies
Reduce vulnerability to lawsuits and improve its public image
Generate income from wastes that can be sold.
How do we get started?
A systematic approach will produce better results than piecemeal efforts. An essential first step is a comprehensive waste audit. The waste audit identifies all operations that produce waste, and the areas where waste may be reduced.
To conduct a waste audit, follow these steps:
- List all generated waste
- Identify the composition of the waste and the source of each substance
- Identify options to reduce the generation of these substances in the production or manufacturing process
- Focus on wastes that are most hazardous and techniques that are most easily implemented
- Compare the technical and economic feasibility of the options identified
- Evaluate the results and schedule periodic reviews of the program so it can be adapted to reflect changes in regulations, technology, and economic feasibility.
Will pollution prevention work In the steel Industry?
The steel industry handles more raw material per ton of finished product than any other large-scale industry in the world. The wide variety of steelmaking processes produce many kinds of hazardous and non-hazardous waste. Stringent hazardous waste regulations affecting wastes the steel industry produces in large quantities, particularly electric arc furnace dust and pickle liquor, are providing tremendous incentive for the steel industry to implement pollution prevention practices.
Setting up a pollution prevention program does not require exotic or expensive technologies. Some of the most effective techniques are simple and inexpensive. Others require significant capital expenditures, however many provide a return on that investment.
Improved Operating Procedures
Good operating procedures rely not on changes in technology or materials, but on human adaptability. Small changes in personnel practices, housekeeping, inventory control, waste stream segregation, material handling and scheduling improvements, spill and leak prevention and preventive maintenance can mean big waste reductions. Some examples in the steel industry include:
Improve production process control.
Property manage oils used for machinery maintenance.
Recycling approaches and compliance record should be high priority criteria for selection of waste management contractors. The contractor's waste management methods and operations must be carefully monitored by company personnel.
Disposing of hazardous materials has become expensive. It makes sense to substitute less hazardous materials whenever possible. Good material choices can also increase opportunities to recycle. Consider the following substitutions:
Use steel scrap with low lead toxicity and cadmium metal content as a rawmaterial, if possible.
Eliminate the generation of reactive desulfurization slag generated in foundry work by using a less hazardous material in place of calcium carbide.
Process Modifications & Redesign
Metallurgical engineers have done a good job of designing and modifying process equipment and technology to recover product and unconverted raw materials. They pursued this strategy to the point that the cost of further recovery could not be justified.
Now the costs of end-of-pipe treatment and disposal have made source reduction an equally good investment. Greater reductions are possible when metallurgical engineers trained in pollution prevention incorporate waste reduction into process design projects. Designs that reduce the volume of waste generated can also reduce energy consumption, and maintenance costs. For example:
A new technology uses an induction-heated holding furnace following the electric arc furnace to feed the metal in a pseudoplastic state to multiple continuous casting machines. Advantages of this modification include the elimination of the structural defects that may result from using the traditional approach and better conditions for near-net shaping.
Switching to induction melting furnaces for grey iron melting can reduce or eliminate the need for air pollution control equipment.
Replace single-pass wastewater systems with closed-loop systems. This results in minimization of chemical usage in wastewater treatment and reduced water usage.
Finally, in some cases, alternative treatment methods can reduce the toxicity or volume of certain waste streams which cannot be eliminated. For example:
In the ductile iron industry, use of thermal destruction of calcium carbide desulfurization slag by rotary kiln; or a chemical reaction between the slag and strong oxidizing agents such as potassium permanganate and hydrogen peroxide, can reduce toxicity.
Reduce the leaching potential of toxic metals through precipitation, absorption, chemical reduction, or pH control.
Recycling is the use, reuse, or reclamation of a waste after it is generated by a particular process. The steel industry recycles extensively by using scrap steel as raw material. By-products created when coal is converted to coke, such as coke oven gas, coal tar, crude or refined light oils, ammonium sulfate, anhydrous ammonia and naphthalene, are also used as raw materials for other industrial processes. Examples of other recycling opportunities include:
Convert tar-decanter sludge (and other tar-based coke plant wastes) into a fuel that is suitable for open hearth and blast furnaces.
Recycle or reuse oils and greases. Dewater and recycle mill scale, and recharge slag into the melting furnaces.
Recover zinc chromium from electric arc furnace dust.
Recover acids by removing dissolved iron salts from spent acid. For example, employ thermal decomposition for recovery of hydrochloric acid from spent pickle liquor.
Recover ferric sulfate or ferric chloride from pickle liquor through crystallization.
Employ the use of a spray roaster, a fluid bed, or a sliding bed to separate hydrochloric acid from iron oxide in spent pickle liquor.
Use a bipolar membrane/electro dialytic process to separate acid from metal by-products in spent NO 3-HF pickle liquor.
Recover sulfuric acid using low temperature separation of acid and metal crystals.
This fact sheet should only be considered an introduction to pollution prevention, Since new ideas are always being developed, it cannot include every existing pollution prevention practice. Mention of a specific practice should not be considered an unqualified endorsement, and not every practice is suitable for every facility.
Who's going to do it?
Pollution prevention requires a new attitude about pollution control. Traditional thinking places all the responsibility on a few environmental experts in charge of treatment. The new focus makes pollution prevention everyone's responsibility. Preventing pollution may be a new role for production-oriented managers and workers, but their cooperation is crucial. It will be the workers themselves who must make pollution prevention succeed in the workplace.
Management commitment and employee participation are vital to a successful pollution prevention program. Management can demonstrate its commitment to pollution prevention and encourage employee participation by:
Training employees in pollution prevention techniques
Encouraging employee suggestions
Providing incentives for employee participation
Providing resources necessary to get the job done.
Hazardous Waste Minimization Manual for Small Quantity Generators, Second Edition, Center for Hazardous Materials Research, 320 William Pitt Way, Pittsburgh, PA 15238, 1989. (Call 800-334-CHMR)
Hazardous Waste Minimization Industrial Overviews, Edited by Harry M. Freeman, JAPCA Reprint Series RS- 14, Air & Waste Management Association, P.O. Box 2861, Pittsburgh, PA 15230,1989. (Call 412-232-3444)
Electric Arc Furnace Dust Disposal, Recycle & Recovery, Center for Metals Production Report No. 85-2, Mellon Institute, 1988.
Further Pollution Prevention Information
Center For Hazardous
Materials Research (CHMR)
320 William Pitt Way
Pittsburgh, PA 15238
Pollution Prevention Program
U.S. EPA Region III
841 Chestnut Building
Philadelphia, PA 19107 (215)597-9800
Division of Waste Minimization and Planning
PA Department of Environmental Resources
PO Box 2063
Harrisburg, PA 17120
American Iron and Steel Institute
1133 15th Street, N.W., Suite 300
Washington. D.C. 20005
Association of Iron and Steel Engineers
Three Gateway Center
Pittsburgh, PA 15086
Center For Metals Production
4400 Fifth Avenue
Pittsburgh, PA 15213-2683
U.S. Department of the Interior
Bureau of Mines
Materials & Recycling Technology
2401 E Street, N.W.
Washington, D.C. 20241
The Center for Hazardous Materials Research (CHMR) is a non-profit subsidiary of the University of Pittsburgh Trust, and is a non-regulatory organization, Its mission is to assist in developing and implementing practical solutions to the technical, environmental, economic, and health problems associated with hazardous and solid waste, For more information on this and other CHMR publications call (800) 334-CHMR.
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