NON-CYANIDE NICKEL STRIPPERS
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| Overview: | Non-cyanide based metal stripping removes metal based coatings from production parts by dipping the parts in a bath solution, and rinsing.
Using a non-cyanide based metal stripping process reduces the volume of hazardous waste generated and the associated disposal costs, and
exposure of personnel to hazardous materials and wastes. Until recently, the majority of stripping of metal coatings from production parts has been accomplished using cyanide based processes. Parts that require rework often need to remove previously applied metal coatings. Cyanide based processes are capable of removing many different metal coatings such as nickel (Ni), silver (Ag), copper (Cu), zinc (Zn), gold (Au), and other precious metals without damaging the surface of the part itself. The disadvantages of cyanide-based stripping are that cyanides are hazardous to personnel, frequent bath solution change-outs are required due to a limited bath life, and that the rinse streams generated from this process contain high concentrations of metals and cyanides. The rinse water generated requires pre-treatment to remove the cyanides and metals at the Industrial Wastewater Treatment Plant (IWTP) before the water can be released to the Public Owned Treatment Works (POTW). The treatment process at the IWTP requires the use of toxic chemicals such as sulfuric acid, caustic, chlorine, and other hazardous materials. There are a number of commercially available non-cyanide metal stripping processes that can be implemented to replace cyanide-based metal stripping processes. These alternative metal strippers use amine, aromatic nitro compounds, protein based and/or other oxidizing chemicals. The following process parameters must be examined for any alternative before implementation can occur: stripping rate, corrosion potential of the base metal, reaction with maskants, bath stability, and treatability of rinse waters or spent process bath material.
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| Compliance Benefit: |
Non-cyanide based metal stripping removes metal based
coatings from production parts by dipping the parts in a bath solution,
and rinsing. Using a non-cyanide based metal stripping process, instead
of a more traditional cyanide based bath, reduces the volume of hazardous
waste
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| Materials Compatibility: |
Due to the variability of non-cyanide based bath solutions, it is highly recommended that the activity reference the vendors data for specific incompatibilities between bath solution and other materials/chemicals.
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| Safety and Health: |
Many components of a non-cyanide metal stripper are biodegradable
and present minimal safety risks. However; several components do present
splash, heat and vapor hazards. Bath solution temperatures range from
room temperature to 1800F, appropriate precautions shall be observed.
Nickel compounds can be skin irritants. Proper personnel protective equipment
should be used.
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| Benefits: |
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| Disadvantages: |
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| Economic Analysis: | Non-cyanide nickel strippers can be implemented
using existing tanks, heaters, and ventilation systems. The only cost variable
will be for the initial make up for the process bath, but that will be offset
by the fact that non-cyanide baths have a much higher bath life than cyanide
baths (2 to 3 times). Also, eliminating the cost (chemicals and labor) for
the treatment of cyanide contaminated rinse waters will yield greater savings.
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| Approving Authority: |
Approval is controlled locally and should be implemented only after engineering approval has been granted. Major claimant approval is not required.
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| NSN/MSDS: |
*There are multiple MSDSs for most NSNs. The MSDS (if shown above) is only meant to serve as an example.
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| Points of Contact: | Navy: Mr. Michael Viggiano Naval Facilities Engineering Service Center 1100 23rd Avenue Code 423 Port Hueneme, CA 93043-4370 Phone: (805) 982-4895 DSN: 551-4895 Email: viggianoml@nfesc.navy.mil
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| Vendors: |
Patclin Chemical Co. 4849 S. Rockwell Chicago, IL 60632 Phone: (773) 523-0784 Technic, Inc. 55 Maryland Ave Pawtucket, RI 02860 Phone: (401) 728-7081 This is not meant to be a complete list, as there may be other suppliers of this type of equipment.
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| Sources: | None listed.
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