Improving Continuously
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| COMPLY OR DIE This plating shop plans to comply with the U.S. EPA's new, more stringent regulations on nickel effluent |
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| DIVERSE SHAPES tend to drag nickel solutions out of the process |
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A plater gears up to improve its ability to recycle and recover nickel
Nickel magazine, Dec. 01 -- The public remains skeptical about the degree to which many "old economy" industries are committed to environmental protection. However, certain companies are showing leadership that may change that perception. Consider nickel plating, wherein various substrates are covered with nickel to enhance and protect goods. Many companies have taken extraordinary steps to address the impact that the wastes generated by their processes have on the environment.
One such company is Kuntz Electroplating Inc. of Kitchener-Waterloo, Ontario, Canada, which electroplates wheel rims, bumpers and other components for the automotive industry.
Robin Leach, Kuntz's waste management supervisor, says the company "strives to exceed, rather than just comply with, regulations, and we have the full commitment of upper management to make sure it gets done." This commitment was a primary reason why the company became, in 1998, one the first electroplaters in North America to receive ISO 14001 certification.
The electroplating industry uses about 83,000 tonnes of nickel a year. In solution, nickel primarily exists in the form of sulphates and chlorides. These solutions may be lost from the process through an effect called "drag-out," which occurs when nickel-bearing solutions on plated parts are carried over into successive rinse tanks. In order to reduce the cost of replacing that "lost" nickel and the associated environmental impact of increased nickel in the plant effluent, a technique called counter-flow rinsing is used.
Since Kuntz handles a wide variety of bumpers and rims in all shapes and sizes during the course of one day, more efficient rinsing technologies are being designed to minimize the overall drag-out of nickel. "Our biggest plus is that we are a multi-job shop," says Leach. "We often run six types of components a day through one process line. The downside is the increased drag-out, [though] we are making advances on spray and rinsing technologies that will minimize this effect."
In order to improve the existing recovery and recycling of nickel from counter-flow rinsing, Kuntz recently committed $5 million toward expanding and upgrading its water treatment facility. Drag-out rinses, which contain relatively high concentrations of nickel, are transferred to vacuum evaporators for further concentration. This technique reclaims about 85% of the nickel. As technology progresses, further treatment of these concentrated nickel solutions for organic contamination will be possible. But for now, simply diverting this waste away from the continuous waste treatment system has been extremely successful in reducing overall loading to the system. The remaining nickel rinse waters are processed through the conventional waste treatment system, where salts are precipitated and concentrated in thickening tanks.
The nickel wastes from the continuous system and evaporators are combined, processed and pumped through a filter press, which produces a de-watered filter cake with a moisture content of about 70%. The moisture content is further reduced to 40% using a low relative humidity dryer. The resulting material, which has a nickel content of 14% to 18% by weight, is then transported to Inco Ltd.'s refinery in Thompson, Manitoba, to be recycled. In all, Kuntz expects to ship about 800 dry tonnes of nickel hydroxide material to Inco this year.
The company is implementing other process modifications to comply with pending stringent regulations outlined in the Metals Products and Machinery Rule draft proposal of the U.S. Environmental Protection Agency. Canada's leading platers operate in strict compliance with EPA guidelines.
The nickel plating industry is clearly meeting the challenge of complying with increasing stringent
environmental regulations and, in doing so, demonstrating that it is flexible and committed to
improvement.
Photo: Tim Pelling/NiDI
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Kuntz Electroplating
Also, please see NiDI Technical Paper No 10088: "Nickel plating and electroforming: Essential industries for today and the future," by Ron Parkinson. |
