EnvironmEntal Pollution PrevEntion ProjEct Pollution Prevention In Metal Finishing Training Manual Preparedby: HaglerBailly Consulting,Inc 1530 Wilson Boulevard,Suite 900 Arlington, VA 22209-2406 HBIReference No. TR-95-062 EnvironmentalPollutionPrevention ProjectNumber 936-5559 ContractNumber PCE-555-Q-00-3022-00 July 1995 Sponsored by U.S. Agency for International Development (USAID) CONTENTS CHAPTER 1 INTRODUCTION 1-1 1.1 Background and Purpose of Manual 1-1 1.2 Background 1-1 CHAPTER 2 PRETREATMENT AND PREPARATION OF METALS 2-1 2.1 Introduction 2-1 2.2 Removal and Stripping of Coatings 2-2 2.2.1 Process Description 2-2 2.2.2 Pollution Prevention Strategies 2-3 2.2.2.1 Assess the Need to Strip 2-3 2.2.2.2 Use the Most Durable Abrasive Practical 2-3 2.2.2.3 Use Blasting Surface Standards 2-3 2.2.2.4 Use Abrasives in Place cf Chemical Strippers 2-3 2.2.2.5 Use of Cryogenic Methods 2-3 2.2.2.6 Use of High-Temperature Thermal Technologies 2-4 2.2.2.7 Use of Less Hazardous Strippers 2-4 2.2.3 Clean Technologies for Stripping 2-4 2.3 Cleaning and Degreasing of Metal Surfaces 2-4 2.3.1 Process Description 2-4 2.3.2 Pollution Prevention Strategies 2-5 2.3.3 Alternatives to Chlorinated Crganic Solvents 2-7 2.3.3.1 Aqueous Cleaners 2-8 2.3.3.2 Semi-aqueous Cleaners 2-9 2.3.3.3 Abrasive and Non-abrasive Media 2-9 2.3.3.4 Cleaning Elimination 2-9 2.3.3.5 Soil Modification 2-10 2.3.3.6 Solvent Emission Reduction 2-10 2.3.3.7 Emerging Technologies 2-10 2.3.4 Considerations in Cleaner Selection 2-11 2.3.5 Waste Treatment 2-11 CHAPTER 3 METAL TREATMENT AND FINISHING 3-1 ECEP/EP3 Pollution Preventionin Metal Finishing 3.1 Introduction 3-1 3.1.1 Process Description 3-1 3.1.1.1 Metal Treatment 3-2 3.1.1.2 Metal Finishing 3-3 3.1.2 Waste Description 3-4 3.2 Pollution Prevention Strategies 3-7 3.2.1 Introduction 3-7 3.2.2 Source Reduction 3-7 3.2.2.1 Process Baths 3-7 3.2.2.2 Rinse Systems 3-20 3.2.2.3 Improved Housekeeping 3-27 3.2.3 Recycling and Resource Recovery 3-28 3.2.3.1 Reusing Waste Material 3-28 3.2.3.2 Recycling Rinse Water and Process Baths 3-30 3.2.3.3 Recycling Solvents 3-35 3.2.4 Summary 3-37 CHAPTER 4 ORGANIC FINISHING EFFICIENCY 4-1 4.1 Introduction 4-1 4.1.1 Process Description 4-1 4.2 Pollution Prevention Strategies 4-3 4.2.1 Improved Operating and Inventory Practices 4-3 4.2.1.1 Eliminate the Need to Paint 4-3 4.2.1.2 Monitoring Incoming and As Applied Paint Quality (Solids Content) 4-3 4.2.1.3 Standardize Paints and Colors 4-4 4.2.1.4 Implement Strict Material Tracking and Control 4-4 4.2.1.5 Return Expired Materials to Supplier 4-5 4.2.1.6 Set Application Standards 4-5 4.2.2 Efficient Use of Application Equipment 4-6 4.2.2.1 Improving Spray Equipment (Gun) Transfer Efficiency 4-7 4.2.3 Equipment Cleaning and Stripping Alternatives 4-8 4.2.3.1 Equipment Modifications 4-8 4.2.3.2 Solvent Use Reduction Measures 4-9 4.2.3.3 Alternatives to Fast-Evaporating Solvents 4.2.3.4 Use of Enclosed Gun Cleaners 4-10 4.2.4 Segregation (Metal Finish Guide) 4-10 4.2.5 Process Modifications 4-10 4.2.6 Treatment and Recovery Alternatives 4-11 4.2.7 Substitute Coatings/Alternative Technologies 4-11 4.2.8 Pollution Prevention Strategy Summary 4-12 ECEP/EP3 Pollution Prevention in Metal Finishing CONTENTS b ii 3.1.1.2 Metal Finishing 3-3 3.1.2 Waste Description 3-4 3.2 Pollution Prevention Strategies 3-7 3.2.1 Introduction 3-7 3.2.2 Source Reduction 3-7 3.2.2.1 Process Baths 3-7 3.2.2.2 Rinse Systems 3-20 3.2.2.3 Improved Housekeeping 3-27 3.2.3 Recycling and Resource Recovery 3-28 3.2.3.1 Reusing Waste Material 3-28 3.2.3.2 Recycling Rinse Water and Process Baths 3-30 3.2.3.3 Recycling Solvents 3-35 3.2.4 Summary 3-37 CHAIntER 4 ORGANIC FINISHING EffCIENCY 4-1 4.1 Introduction 4-1 4.1.1 Process Description 4-1 4.2 Pollution Prevention Strategies 4-3 4.2.1 Improved Operating and Inventory Practices 4-3 4.2.1.1 Eliminate the Need to Paint 4-3 4.2.1.2 Monitoring Incoming and As Applied Paint Quality (Solids Content) 4-3 4.2.1.3 Standardize Paints and Colors 4-4 4.2.1.4 Implement Strict Material Tracking and Control 4-4 4.2.1.5 Return Expired Materials to Supplier 4-5 4.2.1.6 Set Application Standards 4-5 4.2.2 Efficient Use of Application Equipment 4-6 4.2.2.1 Improving Spray Equipment (Gun) Transfer Efficiency 4-7 4.2.3 Equipment Cleaning and Stripping Alternatives 4-8 4.2.3.1 Equipment Modifications 4-8 4.2.3.2 Solvent Use Reduction Measures 4-9 4.2.3.3 Alternatives to Fast-Evaporating Solvents 4.2.3.4 Use of Enclosed Gun Cleaners 4-10 4.2.4 Segregation (Metal Finish Guide) 4-10 4.2.5 Process Modifications 4-10 4.2.6 Treatment and Recovery Alternatives 4-11 4.2.7 Substitute Coatings/Alternative Technologies 4-11 4.2.8 Pollution Prevention Strategy Summary 4-12 ECEP/EP3 Pollution Prevention in Metal Finishing CONTENTS 0 iii CHAPTER 5 CASE STUDIES IN METAL FINISHING 5-1 5.1 Pollution Prevention Opportunities in Metal Finishing in Egypt 5-1 5.1.1 Introduction 5-1 5.1.2 Key Pollution Prevention Examples 5-2 5.1.2.1 Surface Preparation 5-2 5.1.2.2 Electroplating 5-3 5.1.2.3 Painting 5-3 5.1.2.4 Galvanizing 5-4 5.1.3 Piant Descriptions 5-7 5.1.3.1 Facility MB 5-7 5.1.3.2 Facility MC 5-7 5.1.3.3 Facility MA 5-8 5.1.3.4 Facility MS 5-3 5.1.3.5 Facility MN 5-9 5.2 Case Study 1: EP3 Experience in Metal Furniture Manufacture 5-9 5.2.1 Executive Summary 5-9 5.2.2 Facility Background 5-10 5.2.3 Manufacturing Process 5-10 5.2.4 Environmental Problems 5-11 5.2.5 Pollution Prevention Opportunities 5-11 5.2.5.1 Replace Sulfuric Acid and Benzene with Alkaline Solution for Cleaning 5-12 5.2.5.2 Standardize Sulfuric Acid and Eliminate the Use of Inhibitors 5-12 5.2.5.3 Eliminate the Use of Copper Cyanide 5-12 5.2.5.4 Improve Process Parameters 5-12 5.2.5.5 Reduce Loss of Process Solution During Electroplating (nickel/chrome) 5-12 5.2.5.6 Replace Zinc Cyanide with Zinc Chloride 5-12 5.2.5.7 Improve Water-use Practices 5-12 5.2.5.8 Improve Paint Application Techniques 5-13 5.2.6 Conclusion 5-13 5.3 Case Study 2: EP3 Experience in Electroplating 5-13 5.3.1 Facility Background 5-14 5.3.2 Manufacturing Process 5-14 5.3.3 Existing Pollution Problems 5-15 5.3.4 Pollution Prevention Opportunities 5-15 5.3.4.1 Polishing Debris 5-15 5.3.4.2 Degreasing 5-15 5.3.4.3 Acid Dips 5-15 5.3.4.4 Inefficient Cyanide Electroplating 5-16 5.3.4.5 Unnecessary Nickel and Chrome Waste 5-16 ECEP/EP3 Pollution Prevention in Metal Finishing CONTENTS I iv 5.3.4.6 Excessive Water Use 5-16 5.4 Case Study 3: Metal Recovery - Dragout Reduction 5-16 5.4.1 Introduction 5-17 5.4.2 Basis for Design 5-18 5.4.3 Methods and Materials 5-18 5.4.4 Economics 5-19 5.4.5 Results and Discussions 5-20 5.5 Case Study 4: Metal Recovery - Ion Exchange/Electrolytic Recovery 5-21 5.5.1 Introduction 5-21 5.5.2 Basis for Design 5-22 5.5.3 Methods and Materials 5-23 5.5.4 Economics 5-26 5.5.5 Results and Discussions 5-26 5.6 Case Study 5: Metal Recovery - Dragout Reduction 5-27 5.6.1 Introduction 5-28 5.6.2 Basis for Design 5-28 5.6.3 Methods and Materials 5-30 5.6.4 Economics 5-32 5.6.5 Results and Discussion 5-33 APPENDIX 1: USEPA GUIDE TO CLEANER TECHNOLOGIES - ORGANIC COATING REMOVAL APPENDIX 2: USEPA WASTE MINIMIZATION IN METAL PARTS CLEANING APPENDIX 3: USEPA GUIDE TO CLEANER TECHNOLOGIES - ALTERNATIVES TO CHLORINATED SOLVENTS FOR CLEANING AND DEGREASING APPENDIX 4: USEPA GUIDE TO CLEANER TECHNOLOGIES - ALTERNATIVE METAL FINISHES APPENDIX 5: USEPA GUIDE TO CLEANER TECHNOLOGIES - ORGANIC COATING REPLACEMENTS APPENDIX 6: INFORMATION RESOURCES ON THE METAL FINISHING INDUSTRY ECEP/EP3 Pollution Prevention in Metal Finishing LIST OF EXHIBITS 1-1 Typical Metal Finishing Industry Wastes 1-3 3-1 Typical Metal Finishing Process Step 3-2 3-2 Summary Table of Metal Finishing Industry Waste 3-6 3-3 Metal Treatment/Finisning Replacement Technology Characteristics 3-13 3-4 Sludge Volume Generation 3-21 3-5 Three-Stage Counter Current Rinse System 3-24 3-6 Multiple Reuse of Rinse Water 3-30 3-7 Chemical Rinse Water Recycling System 3-31 3-8 Ion Exchange System for Chronic Acid Recovery 3-34 3-9 Electrodialysis Flow Schematic 3-36 3-10 Pollution Prevention Options 3-38 4-1 Pollution Prevention Summary - Painting Industry 4-13 5-1 Summary of Pollution Prevention Opportunities in 5 Egyptian Plants 5-5 5-2 Pollution Prevention Opportunities in Furniture Manufacturing 5-11 5-3 Original System 5-18 5-4 New System 5-19 5-5 Plating Shop Production Process 5-22 5-6 Original Pretreatment System 5-23 5-7 New Metal Recovery System 5-24 5-8 Original Operation (Rinses) 5-29 5-9 New Operation (Rinses and Treatment) 5-31 ECEP/EP3 Pollution Prevention in Metal Finishing CHAPTER 1 INTRODUCTION 1.1 BACKGROUND AND PURPOSE OF MANUAL This manual provides an introduction to the application of pollution prevention techniques in various metal finishing processes including degreasing and cleaning, metal pretreatment, metal plating (electroless and electrolytic plating), and painting.