| Toxic Waste Reduction in Chrome Plating | Mexico | 1997 | Full scale |
MANUFACTURE OF FABRICATED METAL PRODUCTS # 23
Background
Cromadora Delgado S.A. de C.V. is a small, chrome-plating enterprise in Mexico primarily engaged in plating new and used automobile bumpers. They have a total production volume of 2,882 m2 of metal surface plating per year and they employ 18 workers. Chrome-plating comprises polishing, degreasing, copper metal finishing, nickel metal finishing, chrome metal finishing, painting and packaging. Each work piece is rinsed after every plating process step.
This case study shows a successful example of how National Cleaner Production Centers (NCPCs) have assisted companies to rationalize their production process and save money on raw materials, energy, water, and waste treatment costs.
Cleaner Production Principle
Process modification; Recovery, Reuse and Recycle; Housekeeping; New technology
Cleaner Production Application
The CP assessment team investigated all process steps and isolated a number of examples of excessive waste generation. High energy consumption included a significant waste of electricity. Toxic wastes were being released. Raw materials were being lost.
Fourteen CP options were generated and selected for implementation starting in 1997. The major CP options included:
| Reduction of discharge of toxic materials by recovery of rinsing liquors (after the chrome- and nickel-plating process). |
| Elimination of cyanide emission by introducing new polishing substances and amending the degreasing process; |
| Improved monitoring of the three plating process steps to yield better production quality and a reduction in raw materials consumption; |
| The installation of a new, and more efficient electric lighting system. |
Environmental and Economic Benefits
Implementation of CP techniques will reap significant environmental benefits. Cyanide emission (toxic to both workers and the environment) will be eliminated. The electricity consumption will be reduced by 81,000 Kwh per year. Gas consumption will be reduced by 420 million Kcal per year. Significant savings will be made in raw materials.
Five of the fourteen CP options are no-cost options and will result in a US$ 6,000 saving per year. US$ 29,142 is being invested in medium and high cost options and will recoup savings of approximately US$ 59,000 per year. The pay-back periods for these options range from one month to 2.8 years.
Constraints
None reported.
Contacts
Review Status
This National Cleaner Production Center case study was presented in the document "NCPC Case Studies" available from UNEP IE or UNIDO (addresses above). It was formatted and edited for the ICPIC diskette in August 1997.
Subsequently the case study has undergone a technical review by Dr Prasad Modak at Environmental Management Centre, Mumbai, India, in September 1998.