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Metal Finishing (433) vs Electroplating (413)

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Finishin g 101 Part 1. Metal Finishing and Electropla ting August 22, 2005
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Page 1: Metal Finishing (433) vs Electroplating (413)

Metal Finishing

101

Part 1. Metal Finishing and Electroplating

August 22, 2005

Page 2: Metal Finishing (433) vs Electroplating (413)

What We Will Cover Today• Introduce the Problem• 40 CFR 413 – Electroplating• 40 CFR 433 – Metal Finishing• 6 Main or “Core” Operations

– Electroplating– Electroless Plating– Anodizing– Coatings– Etching and Chemical Milling– Printed Circuit Board Manufacturing

• How to determine the Difference Between 433 and 413• Other Metal Categories

Page 3: Metal Finishing (433) vs Electroplating (413)

433 or 413, What’s the Problem?• Two Categorical classifications covering

the same processes.• How do we know….

– if it is a categorical discharger (433 or 413);– If so, is it 433 or 413.– Or is it some other category altogether?

Page 4: Metal Finishing (433) vs Electroplating (413)

40 CFR 413 - Electroplating• Original "surface finisher" regulation promulgated

in 1979 and 1981• Covers 6 main or “Core” processes

– Electroplating– Electroless Plating– Anodizing– Coatings– Etching and Chemical Milling– Printed Circuit Board Manufacturing

Page 5: Metal Finishing (433) vs Electroplating (413)

40 CFR 433 – Metal Finishing• Promulgated in 1984• Most 413 CIUs moved to 433• Covers same 6 main “core” processes as 413

– Electroplating– Electroless Plating– Anodizing– Coatings– Etching and Chemical Milling– Printed Circuit Board Manufacturing

• 40 other ancillary metal finishing operations– Cleaning, painting, machining, grinding, polishing, barrel

finishing, burnishing, impact deformation, pressure deformation, shearing, heat treating, thermal cutting, welding, brazing, soldering, flame spraying, sand blasting….

Page 6: Metal Finishing (433) vs Electroplating (413)

Basics of 433 and 413

• Both use various chemical processes to change the surface of a piece of metal, either adding a layer or taking a layer off - often referred to in the business as “surface finishing”

• Some, like plating, very easy to see the surface change.

• Some, like iron phosphating, sometimes difficult to detect with the untrained eye.

Page 7: Metal Finishing (433) vs Electroplating (413)

Basic? Electro-plating

Process

Identify Base Metal

Clean

Acid Descale & Activate

Pre-Plate(If required)

Final Plate

Post Treatments(As Specified)

Rinse

Rinse

Rinse

Rinse

Rinse

Dry & Package

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 2R

Step 3R

Step 4R

Step 5R

Step 6R

Basic Electroplating Procedure

For Example: Steel,Cooper , Brass

For Example:Degrease, Soak, &

Electroclean

For Example:Hydrochloric, Sulfuric,

or Fluoboric Acids.(Some cases Peroxide

Descale or Brite Dip

For Example:Cadmium, Chromium,Copper, Gold, Lead,

Nickel. Silver, Solder, &Tin

For Example:Chromates, Lacquers,

& Seals

For Example: Box orHot Air Spin Dryers

For Example: Copper,Sulfamate Nickel, or

NickelIf more than one is

specified Repeat Steps4 & 4R as needed.

Page 8: Metal Finishing (433) vs Electroplating (413)

The Big 6

Page 9: Metal Finishing (433) vs Electroplating (413)

Core #1 - Electroplating• Electroplating is the deposition of a metallic coating

onto the surface of an object by putting a negative charge onto the object and immersing it into a solution which contains a salt of the metal to be deposited.

Page 10: Metal Finishing (433) vs Electroplating (413)

Core #1 - ElectroplatingBefore - dull

After - shiny

Page 11: Metal Finishing (433) vs Electroplating (413)

Core #2 - Electroless Plating• Electroless plating is “plating without the use of

electrical energy”- a chemical reduction process which depends upon the catalytic reduction process of metal ions in an aqueous solution (containing a chemical reducing agent) and the subsequent deposition of the metal.

• Typical choice for irregularly shaped, highly detailed part shapes because of completely uniform deposit thickness and high precision.

Page 12: Metal Finishing (433) vs Electroplating (413)

Core #3 - Anodizing• Anodizing is the electrochemical process by which

the surface of a metal part is converted into a metal oxide

• Aluminum is the most common metal anodized

1- Aluminum base metal

3- Aluminum oxide layer (Core #3)

5- Coloring matter

Anodizing

Page 13: Metal Finishing (433) vs Electroplating (413)

Core #3 - Anodizing

•A cathode is connected to the negative terminal of a voltage source and placed in the the anodizing solution typically made up of sulfuric acid. A metal part is connected to the positive terminal ofthe voltage source and also placed in the anodizing solution. When the circuit is turned on, the oxygen from the water molecules in the anodizing solution will be liberated and combine with the metal molecules? ions? on the surface of the part, forming a metal oxide coating.

Page 14: Metal Finishing (433) vs Electroplating (413)

Core #4 - Coating

• Any operation that includes:–Chromating, –Phosphating, –Metal coloring, and –Passivating

Page 15: Metal Finishing (433) vs Electroplating (413)

Core #4a – Chromating• Portion of the base metal is converted to a

component of a protective film.

1- Aluminum base metal

2- Chromate coating-core #4

4- Lacquer coating

•Film is composed of:–Base metal–Hexavalent chrome–Active inorganic or organic compounds

Page 16: Metal Finishing (433) vs Electroplating (413)

Core #4a – Chromating

Before Chromating (shiny)

After Chromating (dull)

Page 17: Metal Finishing (433) vs Electroplating (413)

Core #4b - Phosphating• Immersion of steel, iron, or zinc plated steel in

phosphoric acid to add a coating to the surface so that paint or some other substance will stick to the metal

• Zinc phosphating – new layer is easy to see, shiny, but not as shiny as electroplating

• Iron phosphating – new layer is more difficult to see. Iron phosphated surface looks like it has a grayish scaly layer on it – look closely!– Some, especially line workers, will call iron

phosphating “cleaning” – “just cleaning up the part prior to painting!”

Page 18: Metal Finishing (433) vs Electroplating (413)

Core #4b - Phosphating

Iron Phosphating

Page 19: Metal Finishing (433) vs Electroplating (413)

Core #4c - Metal Coloring

• Chemical method of converting the metal surface into an oxide or similar metallic compound to produce a decorative film.

Page 20: Metal Finishing (433) vs Electroplating (413)

Core #4d - Passivating

• Process of forming a protective film on metals by immersion on an acid solution– Nitric acid– Nitric acid with sodium dichromate

Page 21: Metal Finishing (433) vs Electroplating (413)

Core #5 - Etching and Chemical Milling

Page 22: Metal Finishing (433) vs Electroplating (413)

Core #5 - Etching and Chemical Milling

• Etching is the controlled removal of metal by dissolving it with chemical reagents or etchants to produce a specific design configuration.

• Chemical milling is the same process except the rates and depths of metal removal are much greater in chemical milling.

Page 23: Metal Finishing (433) vs Electroplating (413)

Core #6 - Printed Circuit Board Manufacturing

Page 24: Metal Finishing (433) vs Electroplating (413)

Core #6 - Printed Circuit Board Manufacturing

• Formation of circuit pattern of conductive metal (usually copper) on nonconductive board materials such as plastic or glass. Employs “cores” # 1, 2, and 5 in sequence.

• Five basic Steps– Cleaning + surface preparation– Catalyst + electroless plating (#2)– Pattern printing + masking– Electroplating (copper) (#1)– Etching (#5)

Page 25: Metal Finishing (433) vs Electroplating (413)

What about all the

rinsing and cleaning?

Identify Base Metal

Clean

Acid Descale & Activate

Pre-Plate(If required)

Final Plate

Post Treatments(As Specified)

Rinse

Rinse

Rinse

Rinse

Rinse

Dry & Package

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 2R

Step 3R

Step 4R

Step 5R

Step 6R

Basic Electroplating Procedure

For Example: Steel,Cooper , Brass

For Example:Degrease, Soak, &

Electroclean

For Example:Hydrochloric, Sulfuric,

or Fluoboric Acids.(Some cases Peroxide

Descale or Brite Dip

For Example:Cadmium, Chromium,Copper, Gold, Lead,

Nickel. Silver, Solder, &Tin

For Example:Chromates, Lacquers,

& Seals

For Example: Box orHot Air Spin Dryers

For Example: Copper,Sulfamate Nickel, or

NickelIf more than one is

specified Repeat Steps4 & 4R as needed.

Page 26: Metal Finishing (433) vs Electroplating (413)

Cleaning – Ancillary #7• Only action is to remove dirt, oil, etc. from the

top of the surface of the metal. • Does not change the character of the actual

metal surface or the color of the metal itself• Will only look different because dirt layer is

gone• Often confused with phoshating (#4b)

– Usually a 5 stage process: alkaline cleaning, rinse, phosphate, rinse, and sealer or chromating or something

Page 27: Metal Finishing (433) vs Electroplating (413)

Rinsing• Generally rinsing is required after each (core or

ancillary) process step.• Removes chemicals from the previous process step

that are lingering on the surface of the part, thus preventing cross-contamination of process tanks.

• Rinse tanks are generally discharged continuously or in batches to the WWTF.

• Rinse water is considered part of the operation for the purposes of deciding whether an IU discharges from an operation

Page 28: Metal Finishing (433) vs Electroplating (413)

Multi-Stage CountercurrentFlow Rinse

Drain

Work Flow

Water Flow

Page 29: Metal Finishing (433) vs Electroplating (413)

Two Stage Rinse Tank –Hand Dunking

Page 30: Metal Finishing (433) vs Electroplating (413)

Two Stage Rinse –Power Assisted Dunking

Page 31: Metal Finishing (433) vs Electroplating (413)

How do we know which is which?

• Information needed – both in the terms the IU uses, and in regular words you understand– what they make– raw materials and how they are used in the manufacturing

process– other materials used in manufacturing– how they make it - process flow chart (physical and

chemical processes), which steps generate wastewater, and can you see a difference in the surface between any process steps?

More

Page 32: Metal Finishing (433) vs Electroplating (413)

Information needed (continued)

– What operations do they use to change the shape of metal pieces (see Determining Metals CIUs-Part 2)

– Applicable SIC codes– Operation start-up date– Last time production changed (new tanks, base

metals, plating materials)

Page 33: Metal Finishing (433) vs Electroplating (413)

How do we know which is which?• 433 – applies to SIUS who PERFORM one of the 6

“core” processes – AND discharge from any of the 6 “core” OR 40

“ancillary” – All process effluent is 433

• 413 - only applies to SIUs who began operation before September 1982 AND ARE EITHER– A Job Shop – Own <50% metal (annual area basis)

worked on OR – An Independent Circuit Board Manufacturer – make

circuit boards principally for sale to other companies

Page 34: Metal Finishing (433) vs Electroplating (413)

How do we know which is which?Are any of the main “core” 6 performed? Not 433 or 413No

Began operation before 9/1/82 + no significant production changes since

Yes

Yes 433.17 (new source)

YesIndependent Circuit Board ManufacturerNo 413

No 433.16 (existing source)

Yes Discharge from any of the 46? No Not 433 or 413

Own <50 % (area) of materials processed

No

Yes 413

Page 35: Metal Finishing (433) vs Electroplating (413)

How do we know which is which?

• see 40 CFR 433.10(c)(2) and 433.1(c) and (d) and 40 CFR 413.01(a)

• 433/413 Verification Form available from DWQ - SIU fills out to determine which one applies

• Guidance Manual for Electroplating and Metal Finishing Pretreatment Standards, EPA, February 1984. EPA-440/1-84/091g

• Ask your friendly PERCS Staff

Page 36: Metal Finishing (433) vs Electroplating (413)

How do we know which is which?

• Development Document for Effluent Limitations Guidelines and Standards for the ….– Metal Finishing Point Source Category, EPA,

June 1993. EPA-440/1-82/091– Electroplaters Point Source Category, EPA,

August 1979. EPA 440/1-79/003• Ask your friendly PERCS Staff

Page 37: Metal Finishing (433) vs Electroplating (413)

How do we know which is which?

• Comp Guide, Appendix 3-D– categories, subparts, pretreatment regulated

parameters, new source dates• Comp Guide, Appendix 3-F

– EPA contacts for categories• Ask your friendly PERCS Staff

Page 38: Metal Finishing (433) vs Electroplating (413)

Distinguishing Metal CIUs – Part 2

• Not everyone who performs 6 “Core” is 433 or 413. • 40 CFR 465 - Coil Coating

– Coil coaters perform one of 6 “basic” on metal piece that starts and ends with coil, uncoiled to do surface finishing

– 465 also includes can making - do coating• 40 CFR 466 - Porcelain Enameling

– perform one of 6 “basic” on porcelain• What about the SIU who "forms" the basic shape of

the part before they plate it?

Page 39: Metal Finishing (433) vs Electroplating (413)

433/413 Metal Shape Changing

• 413/433s –change shape of metal piece in “relatively minor way” –– drilling and/or threading holes– making bends, holes, dents, etc. by

• impact deformation – Dana says “ka-boom!”• pressure deformation – slow, steady force

– Grinding, machining, or cutting off areas

Page 40: Metal Finishing (433) vs Electroplating (413)

433/413 Metal Shape Changingdrilling threads

Pressure/impact Deformation? welding

Punching holes

Page 41: Metal Finishing (433) vs Electroplating (413)

Other Metals Categories - Major Shape Changing

• Casting = melt metal, pour into cast, allow metal to solidify in new shape

• Rolling = reduce diameter by passing metal between lubricated rollers (metal hot or cold)

• Drawing = pulling metal thru a die to make diameter thinner or change shape

• Extruding = use pressure to force metal to flow thru die

• Forging = use pressure to change shape, with or without dies. Usually on heated metal.

Page 42: Metal Finishing (433) vs Electroplating (413)

Other Metals Categories - Major Shape Changing

• Extrusion and drawing turned plug of aluminum into the fire extinguisher can – 40 CFR 467 – Aluminum Forming.– Note hole from pressure

testing (433/413 ancillary #45)• LP gas regulator – casting

(464)• Tungsten carbide drill bit –

powder forming (471)

Page 43: Metal Finishing (433) vs Electroplating (413)

Other Metals Categories - Major Shape Changing

• Where does 413/433 pressure deformation end and “other metals categories” forging begin?

• Cladding (471) versus brazing (433/413)• for some Other Metals Categories, when perform

casting, drawing, etc., and then do “surface finishing” (6 basic/40 ancillary), the surface finishing wastes are not covered by 413 or 433, but are covered by the casting, drawing, etc., regulation– 40 CFR 433.10(b) and 40 CFR 413.(b)

Page 44: Metal Finishing (433) vs Electroplating (413)

Other Metals Categories• 420-Iron and Steel• 421-Nonferrous metals manufacturing• 424-Ferroalloy Manufacturing• 461-Battery• 464-Metal Molding and Casting• 465-Coil coating• 467-Aluminum Forming• 468-Copper Forming• 471-Nonferrous Metals Forming and

Metal Powders

Page 45: Metal Finishing (433) vs Electroplating (413)

DWQ Pretreatment Contacts• Jeff Poupart, Supervisor – ext. 527• Dana Folley, A - F Towns- ext. 523 • Jon Risgaard, G - M Towns- ext. 580• Deborah Gore, N - X Towns- ext. 593• Daryl Merritt, Y-Z Towns- ext. 554

Phone #: 919-733-5083 email: [email protected]

Page 46: Metal Finishing (433) vs Electroplating (413)

DWQ Pretreatment Website

Homepage:http://h2o.enr.state.nc.us/Pretreat/index.html

Categorical items on Permit Writing Page

Page 47: Metal Finishing (433) vs Electroplating (413)

Thanks to…

• Burrell Brock, City of Raleigh• Chris Hord, Surtronics,Inc• Dana Folley, PERCS Unit

Thank You!

Page 48: Metal Finishing (433) vs Electroplating (413)

Now What?

• Inspecting a Metal Finishing/Plating Facility– by Dawn Padgett


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