INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

Case Study # 128

1.   Headline:  Rotalyt-Alutop process for aluminum plating
     reduces emission of cadmium into the environment while
     also reducing costs.

2.   Background:  See below.

3.   Cleaner Production Application:  New technology

4.   Description of Cleaner Production Application:   The
     Rotalyt-Alutop process for aluminum plating is based on
     the chemo-mechanical plating of pieces in a medium
     containing an impact body, and metal particles and
     catalysts, using relative movement.  The pieces are loaded
     into a perforated drum, and lowered into a plating bath
     where glass balls are added as the impact body and the
     aluminum flakes are added.  The drum passes through a
     separation tank where the glass balls are separated for
     reuse, to a centrifuge unit, and to an unloading station
     for drying.  The cathodic corrosion protection properties
     are considerably improved by the use of zinc containing
     aluminum alloys, or preplating to add a zinc/tin layer.

     Material/Energy and Balances and Substitution

     FEEDSTOCKS:  Electric energy - 140 kWh/t, Al metal - 14
     kg/t, rinse water -200 l/t, catalyst - 5 kg/t, pre- and
     post- treatment - 20 kg/t

     WASTES: Wastewaters, chemical baths

     MEDIUM: Aqueous

5.   Economics

     CAPITAL COST: 500,000 DM (1983)

     OPERATION/MAINTENANCE: 294 DM/t treated goods

     DISPOSAL & FEEDSTOCK:  100,000 DM reduction in capital
     cost, 94 DM/t of treated goods reduction on process costs

6.   Advantages:

     FEEDSTOCK REDUCTION:  Electrical requirements reduced by
     780 kWh/t, rinsewater by 800 l/t, 14 kg/t Al required
     compared to 15 kg/t Cadmium, treatment chemicals by 100
     kg/t

     WASTE PRODUCTION: Wastewaters produced from conventional
     process contains cadmium, cyanide, and chromium compounds.
     The waters are neutralized, precipitated, and dumped.  The
     low waste technology reduces the toxicity of the waste.

     IMPACT:  Reduction of environmental pollution from the
     proven toxicity of cadmium while reducing costs.

7.   Constraints:  No information provided.

8.   CITATION/PAGE: Compendium on Low and Non-waste Technology,
     United Nations Economic and Social Counsel,   Monograph
     "Rotalyt-Alutop" ENV/WP.2/5/Add.124

9.   Keywords:  Germany, metal, aluminum, plating, new
     technology, cadmium, chemical bath, electroplating, ISIC
     3844.

10.  Reviewers Comments:  This case study was originally
     abstracted for the US EPA Pollution Prevention Information
     Clearinghouse.  It underwent a UNEP IE funded technical
     review in 1994 for quality and completeness. It was edited
     for the ICPIC diskette in July 1995.

 (DOCNO: 400-124-A-331)