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Session Chairman: Allen Jones, CEF,
Atotech USA, Inc.,
Somerset, NJ
1 p.m.-Corrosion of Hard Chromium Electrodeposits
Dr. Allen R. Jones, CEF,
Atotech USA, Inc.,
Somerset, NJ
Hard chromium electrodeposits are used in a multitude of
corrosive environments. Hard chromium is a barrier-type coating. The
corrosion resistance of a given thickness of hard chromium can vary
widely, depending upon the preplate and postplate finish of the part.
The preplate, plating and postplating steps are all critical and
interdependent with respect to corrosion resistance.The optimization
of each of these steps and the system will be dis-cussed. Data on the
corrosion resistance of hard chromium in various environ-ments will
be reviewed.
1:30 p.m.-Practical & Theoretical As-pects of Chromium
Activation & Reverse Etching
N.V. Mandich, HBM Electrochemical Engineering Corporation,
Lansing, IL
In chromium plating, reverse etching ("re-versing") is a critical
step in the process, used either prior to the plating over the base
metal or when replating (chromium over chromium). There is very
little literature on this important step or on the electrochemical
mechanisms involved. Practical aspects will be considered, to-gether
with related chemistry and electrochemistry. The number of reversing
methods will be presented, as well as the activation methods for
bright chromium plating over nickel.
2 p.m.-Break
2:30 p.m.-AESF Research Project: Porous Ceramic Diaphragm-Separation
of Metallic Impurities from Chromium Plating Baths
Professor Bob Selman, C.C. Li, S. Rao Guddati, T. Olsen,
Illinois Institute of Technology, Chicago, IL
Experiments were carried out using a laboratory-scale ceramic
diaphragm cell (also known as "porous pot") at different current
densities with simulated spent hard chromium plating solutions having
different concentrations of metallic impurities. The results show
that the optimum conditions for the efficient opera-tion of the cell
depend on current density, initial pH, and the nature of the cathodic
surface used. The rate of transport of impurities from the bulk
plating solution into the pot was found to be controlled mainly by
migration as a result of the electric field. The potential gradient
across the diaphragm and the ratio of ceramic dia-phragm area to the
volume of spent solu-tion determine the impurity removal rate from
the plating solution. Low current densities favor the operation of
the po-rous pot on a continuous basis, for on-line purification of
plating solutions. A porous lead cathode gives a better on-line
performance than a flat lead cathode, be-cause fewer interruptions
for cleaning are required and the impurities precipitate as a compact
sludge. When a flat lead electrode is used as cathode and the initial
pot electrolyte is acidic, the impurities are likely to be coated
onto the cathode as an adherent layer.
3 p.m.-New Chromium Plating Bath for Ultra-high-speed Plating
Dr. Kenneth R. Newby,
Atotech USA, Inc. Somerset, NJ
Since its inception in the 1920s, chromium plating has been
limited to operat-ing temperatures at or below 140 °F (60
°C) and current densities usually below 5 ASI. These limitations
were the result of a combination of tank lining materials and, more
importantly, of catalyst stabil-ity at higher temperatures in
relatively con-centrated chromic acid solutions. The tank lining
stability has been overcome by very long-lasting materials, such as
PVDF. The catalyst stability problem was overcome with the
introduction in the U.S. in 1994 of a new non-fluoride chemistry that
is stable at temperatures exceed-ing 180 °F. This catalyst
permits electro-platers to utilize current densities of 10 ASI and
higher, depending only upon the current distribution capability of
the part being plated. Deposit properties and ap-pearance are that of
deposits plated from "conventional" non-fluoride, high-speed
chemistry. Early applications have in-cluded shock absorbers, struts,
engine valve stems, aluminum engine cylinder walls, and piston
rings.
3:30 p.m.-Sampling Techniques on Hard Chromium Tanks · The
306 Method
Kevin Walls, MARCOR Environmen-tal, Inc., Hunt Valley , MD
Kevin Walls, an environmental con-sultant experienced in 306 air
sampling, will provide a review of the 306 Isokinetic Stack Sampling
Methodology and its application to the new Chromium MACT Standard. He
will discuss the repeatability and accuracy of the test and the more
general use of the technique for other compliance demonstrations.
· Comparison of Logical Applications for 306 and 306A
Whitby Ellsworth,
National Chromium
Company, Inc., Putnam, CT
Whitby Ellsworth, a chromium plater who has performed more than
30 306A tests, will discuss areas where each of the two methods may
have some advantages over the other, and will provide some overview
and organizational materials for anyone wishing to perform his own
306A sampling.
· 306A Method-Full Demonstra-tion of Sampling Train &
Methods
Frank Clay, U.S. EPA, Durham, NC
Frank Clay, the developer of the 306A chromium sampling method,
will provide a detailed review of this new method, as well as the
procedures that need to be followed in performing it.
Session Chairman: Whitby Ellsworth,
National Chromium
Company, Inc., Putnam, CT
8:30 a.m.-Hard Chrome Plating Tank Ventilation
Technologies
Thomas E. Miles, Conserve Engineering, Laguna Beach, CA
In today's regulatory climate, one of the most important
decisions facing the hard chromium plater is the selection of tank
ventilation technology. This decision has far-reaching effects, such
as: Compliance with EPA, OSHA and fire codes; health risk exposure
for all employees; size, cost and efficiency of emission control
equipment; and operating costs relating to energy, water consumption
and chemical additives. Most chromium plating ventilation sys-tems
operating today do not comply with current OSHA design standards.
OSHA standards will be described and compared to ACGIH and other
industrial ventilation standards. Design and operating parameters for
various ventilation technologies will be discussed and compared,
includ-ing lateral exhaust, push-pull, covers and enclosures, and
chemical mist suppressants.
9 a.m.-Regulatory Update
William Sonntag, AESF/NAMF/MFSA Government Relations,
Washington, DC
9:30 a.m.-OSHA's Reduction of Per-missible Exposure Level (PEL)-The
Outlook for Action in 1996 William Sonntag, AESF/NAMF/MFSA
Government Relations, Washington, DC The Occupational Health and
Safety Ad-ministration (OSHA) of the Department of Labor plans to
propose reduction of the current chromium permissible exposure limit
(PEL) to one of the lowest in the industrialized nations. It is
believed that OSHA is considering a PEL proposal of 0.5 mg/m 3 to 1.0
mg/m 3 . OSHA is under great pressure from the Public Citizen's
Health Research Group and the Oil, Chemical and Atomic Workers
International Union to lower the PEL from the current allowable
ceiling limit of 100 mg/ mg 3 (micrograms per cubic meter as chro-mic
acid) to an 8-hr time-weighted aver-age (TWA) of 0.5 mg/mg 3 as
hexavalent chromium. The primary adverse health ef-fect under
consideration is lung cancer.
This presentation will discuss industry activities regarding this
rule, including actions taken by the Joint Government Relations
Program since 1994, anticipated projects to develop cost, exposure
and technical data for the industry and the an-ticipated timetable
and actions of OSHA.
10 a.m.-Break
10:30 a.m.-A Perspective on the Changing Chromium Air Emission
Standards
Thomas E. Miles, Conserve Engineering, Laguna Beach, CA
Eight years ago, California adopted chro-mium emission standards
that demand control efficiencies of 95 to 99.8 percent for hard
chromium plating facilities. The current EPA MACT standard demands
control efficiencies on the order of 98 to 99.9 percent for
large-sized hard chromium plating facilities. Within eight years, EPA
is required to implement risk-based standards that will demand
control efficiencies on the order of 99.99 to 99.999 percent. Several
states have already imple-mented emission limits comparable to the
future EPA standard. Control technologies capable of meeting current
and future emission limits will be described and compared. The case
history of one Cali-fornia company that adopted a goal to achieve
"near zero" emissions to meet future regulations will be described in
detail. Equipment selection criteria, implementation costs, operating
costs and test results will be presented.
11 a.m.-Conducting Surface Tension Measurements for Compliance
with Chromium MACT Standard
Joelie Hill, Scientific Control Laboratories, Chicago, IL
Conducting surface tension measure-ments to consistently meet 45
dynes/cen-timeter is a compliance option for decorative chromium
plating facilities under the U.S. EPA's National Emission Stan-dards
for Chromium Emissions (the MACT Standard). It is important to
understand the various techniques and procedures for measuring
surface tension in order to find a suitable method for your facility.
This paper will cover methods with ten-siometers (DuNouy ring and
Wilhelmy plate), stalagmometers, capillary tubes, and various other
methods. Cleaning, calibration and recordkeeping procedures for all
methods will also be covered.
11:30 a.m.-Lunch
Session Co-Chairmen: Myron Browning, CEF, Matrix
Technologies, West Hills, CA, & Steve Schachameyer, Eaton
Corporation, Milwaukee, WI
1 p.m.-Advances in Decorative Trivalent Chromium Plating
Nabil Zaki, Frederick Gumm Chemical Company, Inc., Kearny,
NJ
For the past 15 years, the shielded anode concept made it
possible to use a stable non-halogen-type electrolyte plating
solution to great advantages to the plater: High tolerance to
metallic impurities, a light chrome deposit and high tempera-ture
applications. A new insoluble anode has now been identified for use
with the same electrolyte. The new anode is used in direct contact
with the solution with no generation of hexavalent chrome, while
maintaining all the advantages of the shielded anode process. This
paper will review the properties of the new an-ode and the results of
12 months of field testing.
1:30 p.m.-Hard Trivalent Chromium Plating: New Improvements &
Results
Dr. Patrick Benaben, E.N.S. Mines, Saint-Etienne, France
Results will be presented on hard, thick chromium deposits
obtained from an aqueous trivalent chromium bath by chemical
reduction of hexavalent chromium with methanol alcohol. At a
thickness of 100 mm, these deposits have a hardness of about 1000
Hv/100g and the deposition rate is 3 mm/mn at 80 A/Dm 2 .
Microhardness obtained on ther-mal treatment of these chromium layers
(400 °C to 700 °C) will be compared to that of hexavalent
(sulfate and fluosilicate) baths. Results will also be presented on
the chromium-nickel multilayer com-posite deposits obtained by the
single bath method.
2 p.m.-Break
2:30 p.m.-A Review of Decorative Trivalent Chromium
Electroplating
Dr. Donald L. Snyder,
Atotech USA, Inc.,
Cleveland, OH
Over the last 20 years, trivalent chromium electrplating has been
shown to be an environmentally friendly and productive process when
compared to hexavalent chromium plating. The factors contribut-ing to
this success will be discussed.
3 p.m.-Hard Chrome Plating & Alternatives: How, When, Why
&Where?
George Nichols, Mike Graham & Keith Legg, BIRL,
Northwestern University, Evanston, IL
There are now various viable dry-coating alternatives for
replacing electrolytic hard chromium (EHC) plating, but because none
of them is universal, there are many applications in which EHC
remains the most cost-effective technology.
This paper will discuss which re-placement options are best for
certain applications, and what considerations should enter decisions
on whether (and with what) to replace EHC. Where EHC is to be
retained, there are now tech-nologies available to reduce its
environmental impact, and these will be discussed.
Session Chairman: Dr. Kenneth R. Newby,
Atotech USA, Inc.,
Somerset, NJ
Open question-and-answer period; expected to run approximately
one-and-a-half hr.
Open Forum 3:30 p.m., Friday, May 31