INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY # 97

1.   Headline:  Internal recycling in the mobile phone industry

2.   Background:  See below.

3.   Cleaner Production Principle:  Internal recycling

4.   Description of Cleaner Production Application:  This
     facility uses two-stage distillation to recover solvents.
     Printed circuit boards are produced using the subtractive
     technique and solvent-based photoresists.  Methylene
     chloride resist stripper and TCE developer are
     continuously recycled in closed-loop stills.  The TCE
     developer wastes are recovered in a Dupont Riston SRS-120
     solvent recovery still which operates at atmospheric
     pressure and 165 F with product returned to the developer
     line.  The facility uses a Recyclene RX-35 solvent
     recovery system to further recover the TCE from the
     SRS-120 unit still bottoms.  The RX-35 is a batch
     distillation system with a 30 gallon capacity with a cycle
     time of approximately 90 minutes.  Purity of recovered
     solvent was 99.99%.  The still bottoms contained 7.5
     weight percent TCE.

     Material/Energy Balance and Substitutions

                              FEEDSTOCKS:
                              1,1,1-trichloroethane (TCE)
                              resist developer still bottoms

                              WASTES:              Resist
                              developer still bottoms

                              MEDIUM:
                              1,1,1-trichloroethylene

5.   Economics

                              CAPITAL COST:         $ 26,150

                         MONTHS TO RECOVER: 7.3

                              DIRECT COST:          $43,105

6.   Advantages:

                              FEEDSTOCK REDUCTION:    99.8%
                              solvent recovery

                              WASTE PRODUCTION:      97.5%
                              volume reduction

                              IMPACT:              Reduces
                              disposal volume of solvents and
                              reduces virgin solvent
                              requirements.

7.   Constraints:  No information provided.

8.                            Contact and Citation:

     "Case Studies of Existing Treatment Applied to Hazardous
     Waste Banned from Landfill Phase II, Summary of Waste
     Minimization Case Study Results"  U.S. EPA, Hazardous
     Waste Engineering Research Laboratory, Cincinnati, Ohio,
     October, 1986, Page 96.

     Name and Location of Company:

     U.S. Environmental Protection Agency
     Hazardous Waste Engineering Research Laboratory
     Cincinnati, Ohio 45268
                    United States
     c/o Harry Freeman

9.   Keywords:  United States, USA, telephone equipment, mobile
     phone, recycling, solvent, printed circuit board,
     trichloroethane, trichloroethylene, TCE,
     telecommunication, ISIC 3661.

10.  Reviewer's Comments:  This case study was originally
     abstracted for the United States Environmental Protection
     Agency's 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 by UNEP IE in July 1995.

(DOCNO: UNEP01.52  101-010-A-009)