Until recently, the majority of silver plating of production parts has been accomplished using cyanide-based processes. The disadvantages of cyanide-based plating are that cyanides are hazardous to personnel, require frequent bath solution change-outs due to limited bath life, and the generation of rinse streams containing 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 before the water can be released to the Public Owned Treatment Works (POTW). The treatment process at the treatment plant requires the use of toxic chemicals such as sulfuric acid, caustic, chlorine, and other hazardous materials.

The compliance benefits listed here should be used as general guidelines and should not be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g., the amount of workload involved.

Consult your local industrial health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing this technology.

• Elimination of cyanides, which results in reductions in worker exposure, and hence, reduced health risk and liability.
• Reduction of costs and materials required for treating cyanide-contaminated rinse waters at wastewater treatment plants.
• The removal of cyanides may enable the reclamation of metals from the bath solution and rinse water.
• The same process equipment (tanks, heaters or coolant coils) that is currently used for cyanide silver processes can be used in the non-cyanide silver process.
• The properties of adhesion, roughness, solderability, hydrogen embrittlement, throwing efficiency, torque tension, and fatigue life attained using the non-cyanide silver process were equal to or better than the cyanide silver deposit when deposited on copper substrates.

• Not an acceptable alternative to the cyanide-base silver plating process for use on all parts due to failure to meet specific requirements. In particular, the process is unsuitable for nickel-plated parts, parts that have a tarnish resistance requirement, and parts that require a high thickness of silver deposit.
• Silver deposit that is produced from the traditional cyanide silver process is of a higher visual quality than the non-cyanide process. In general, the non-cyanide silver deposits had a yellow color and a burnt appearance along the edges of the panels. This visual quality might be improved by experimentation with the racking of parts and the optimization of the process parameters of the solution.
• Use of the non-cyanide bath with brighteners requires a higher degree of control than the non-cyanide bath without brighteners. Once the brighteners were added, the bath became unpredictable and more sensitive to changes in process conditions.