1996 N.H. Pollution Prevention Internship Program
Internship Project Final Report
Project Title:
Copper Recovery and Water Recycling
Intern:
Jason Shiepe
Home Phone: 508-352-6925
378 Main St.
Work Phone: 603-791-3799
Boxford, MA 01921 Fax: 603-791-3080
Contact Person:
DeWayne Howell
Environmental Engineer
Phone: 603-791-3817; Fax: 603-791-3080
Executive Summary:
Teradyne Circuits Operation in Nashua, NH used its participation in the 1996
N.H. Pollution Prevention Program to explore the recovery and recycling of copper from
its waste streams, as well as to investigate increasing the overall capacity of its waste
treatment facilities.
The first project involved research into technologies which could recover copper
from existing waste streams. Their current waste treatment system produces a sludge
which contains 16-20% copper. The sludge is dried, and shipped offsite for disposal. Last
year, Teradyne disposed of 20,000 pounds of sludge. It was discovered that the process
which accounted for the largest percentage of the copper waste at Teradyne was the inner
layer etcher. The etcher uses cupric chloride to remove copper from the layer, which in
turn is sent into an FSL regeneration system to plate out the etched copper. This
regeneration system contains a bleed-off stream which accounts for five-hundred gallons
of cupric chloride etchant every week. Traditionally, copper solution can be easily plated
out in an electrolytic recovery cell. This is called electrowinning. Unfortunately, cupric
chloride produces toxic chlorine gas when electrolytic recovery is attempted. Therefore,
initial research was directed toward recent technologies which can recover the copper out
of cupric chloride without producing chlorine gas.
The second project is absolutely necessary in the upcoming months. Recently,
management had approved a request for a larger plating line and two additional scrubbers.
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Teradyne is currently running its waste treatment processes at full capacity. When these
new processes are installed, the existing waste treatment processes will not be able to
handle the additional hydraulic and solids loading. Shortly before I arrived at Teradyne,
an engineering consultant firm had reviewed Teradyne’s waste treatment system and
suggested several possible technologies. I have since investigated options such as reverse
osmosis and ionic exchange. Teradyne would like to ultimately recycle its water back to
the process rinses, and also run its existing waste treatment system to handle upsets, and
accept reject bleed streams off of the new equipment involved.
It should be noted that while working on these projects, much guidance and
teamwork was provided by both my facility advisor, DeWayne Howell and the Waste
Treatment technician, Emile Laplante. We held meetings on a regular basis to decide
which direction was the most beneficial for Teradyne.
Background:
“Teradyne was founded in 1960 by two MIT graduates, Alex d’ Arbeloff and
Nick DeWolf. The first product was an automatic tester for semiconductor diodes, and
was followed by automatic testers for resistors, transistors, and, in 1967, industry’s first
computer-operated integrated-circuit test system. In the 1970’s, the company’s product
line expanded to include test systems for circuit boards and other electronic
subassemblies, as well as an automated test system for telephone subscriber lines.
Teradyne Connection Systems, launched as Teradyne Components in 1968, grew to
become the world’s largest merchant supplier of backplane connection systems. Today
Teradyne is the world’s largest manufacturer of automated test equipment (ATE), with
sales (1994) exceeding $670 million. Teradyne recently received the Boston Globe 100’s
top award, Company of the year. With 1,600 employees at its downtown Boston
headquarters (and 5,200 worldwide), Teradyne is the third largest manufacturing
employer in Boston. `` (Teradyne Homepage, www.Teradyne.com)
Teradyne Corporation is well noted for its pollution prevention history. Recently,
Teradyne Circuits Operation, in Nashua, N.H., has expanded its plant size and plans to
install a new printed circuit board line to supplement its existing processes. Much of the
waste generated from the existing line is composed of copper in solution. At present, the
waste waters are pH adjusted and treated using traditional metal hydroxide precipitation
methods. The sludge is settled through a 4000 gallon Lamella Clarifier. A filter press
captures the sludge which is then dried to 95% solids. This solid, among other things,
contains high levels of copper.
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If this copper could be recovered and separated from the existing streams, it could
then be recycled instead of being sent out as hazardous waste. This modification, if
successful will be used on the new circuit line as well.
The new plating line will increase flow of untreated water to the existing waste
treatment system. The waste treatment system is currently running at full capacity,
handling 120 gallons per minute. Present waste treatment would not be able to handle an
estimated 50 gallon per minute additional influent. Ultimately, Teradyne would prefer to
install a process which would recycle their rinse streams and recover copper. This would
reduce water and sewer costs and reduce annual sludge production, while recovering
copper for resale.
A large amount of data collection and technology investigation was performed by
myself, with the help of DeWayne and Emile, to analyze Teradyne’s options.
Approach:
The approach taken to complete these projects, which began on Monday, June 3,
consisted of several phases. My orientation consisted of a survey of operating procedures
and plant tours which helped to develop an understanding of the overall flow of
Teradyne’s backplane product.
For most of the processes, the concentration of copper in the waste or rinse streams was
unknown. As a result of my subsequent research, several processes were determined to
be the main culprits of copper waste generation. It became evident that a majority of
copper waste was stemming from the Layer Etch process in the DES room (Develop,
Etch, Strip). This process etches the inner layer of a backplane assembly board. At this
etcher, the concentration of copper is approximately 230 grams/liter. Possible methods to
isolate the copper waste and plate out the copper for reclaim were reviewed.
I met with Miles Walker at the Department of Environmental Services in
Concord, N.H. He provided information about possible vendors and technology options.
This was soon followed by a meeting with DeWayne Howell, my facility advisor, myself,
and a representative of Memtek, a company with a good reputation for producing
machinery related to metal recovery and water recycling. Many possible copper recycling
methods were discussed. The information requested by the vendor had long-term benefits
as it provided my project a direction for what type of data was needed for the evaluation
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These interviews, which provided the involved engineers a general overview of
project goals, consisted primarily of specific questions about each process. This in turn
clarified process functions from a pollution prevention standpoint. A database was then
put together which outlined this data in relation to tank location and station number.
By the end of June, I had finished most of the data collection that was necessary
for an accurate evaluation, while DeWayne and I continued to meet with various vendors.
At these meetings, a copy of the information gathered was distributed to each company
representative. The availability of this information expedited the generation of proposals
which was met with surprise and pleasure by the various vendors. Among the vendors
interviewed were: Larson Technologies, U.S. Filter, Kinetico Incorporated,
Environmental Control Systems Incorporated, Atlantic Sales Engineering, Compliance
and Recycling Incorporated, Dynamic Automation, and Manchester Corporation.
Once proposals were received from the vendors, an economic evaluation began.
This consisted of totaling the capital cost of the equipment that was proposed, and
calculating the depreciation value over a five year period.
The copper recovery estimate, when added to sludge disposal savings and water recycling
savings, formulated the basis of our annual savings based on the proposed systems.
Conservative estimates for savings were calculated. ]Copper recovery savings
were based on half of the commodity listing multiplied by the amount proposed to be
recovered. Sludge disposal savings were determined by the net amount in weight times
the price per a pound to send it out as F006 sludge. While these two savings would
definitely contribute to a payback, the main source of a payback would be found in water
cost and chemical usage to treat the influent in the waste water treatment system. Based
on current operation it was estimated that approximately 30,000,000 gallons of water
could be recycled annually. Most of this water to be recycled originates from the plating
line rinses. Teradyne pays approximately $ 3.32 per 1000 gallons of water, this includes
city water purchase as well as sanitary discharge. Teradyne also pays approximately $6.00
per one thousand gallons for chemical treatment in the batch treatment process.
Teradyne Circuits Operation is planning to install a brand new plating line larger
in size than the current “Auto line“, with a 24 gallon per minute rinse flowrate. Also two
new scrubbers, will be installed with approximately 20 gallons per minute flowrates.
Another 6 gallons per minute will be contributed by a fume scrubber, which will be
installed. With these expected rates added to the influent of the waste treatment process,
it is estimated that approximately 50,000,000 gallons of water has the potential to be
recycled. There are also projections that more equipment might be purchased, in the next
five years.
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It has been mentioned that the new plating line is scheduled for operation by April
of 1997.
Therefore, any new waste treatment system must be installed and running by March first.
During the middle and the end of July, meetings to begin a formal decision process were
held between Mark Cappi Division Environmental and Safety Manager, DeWayne
Howell, Emile Laplante and myself. These meetings consisted of discussions about
waste treatment upgrade plans as well as preparing a proposal to Teradyne management.
Other sessions included the design of a selection matrix which aided discussion of what
type of equipment and or systems which would best complement Teradyne’s proposed
waste treatment upgrade.
On August 8, 1996, DeWayne Howell, Emile Laplante and myself met with
arepresentative from Memtek at Altron, a circuit board shop located in Wilmington, MA.
Memtek has designed and installed waste treatment equipment similar to the types being
investigated by Teradyne. At Altron, we were shown their ion exchange units and copper
plate out cells in a functioning environment by their Waste Treatment and Hazardous
Waste Manager, Peter Muto. Viewing the system, provided us with a practical
examination of an impressive ion exchange and copper recovery system. They also
described the waste water segregation necessary to successfully operate this type of
system.
Equipment Needs:
Teradyne Circuits Operation at this time would like to recover copper out of its
water waste streams. Teradyne would also like to recycle water off of its process rinses
and at the same time reduce the production of F006 sludge.
There are many types of technologies which can accomplish this but which types
seem to display the best outcome? Should a point source system be installed or an end of
pipe system? What types of technologies are offered? One of the technologies which I
investigated was electrolytic recovery. Electrolytic recovery at Teradyne would be used
when trying to plate out copper from solution. It involves a cathode and an anode subject
to about 7 volts and 3500 amperes. When a metal solution is placed in a recovery cell,
DC current is applied and the metal is electrolytically reduced and deposited on the
cathode surfaces within the plate out cell. The recovered metal can then be resold.
Teradyne would use this method when trying to recover copper. There is, however, a
problem when trying to plate copper out of cupric chloride solution. Along with the
recovery of copper metal, chlorine gas will also be discharged. Chlorine gas is very toxic
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and would require a fume scrubber if this process was chosen.
At this time, Teradyne wanted to avoid chlorine gas production. One alternative
that was found suggested to pre-treat cupric chloride with NaOH to form Cu(OH)2, the
precipitate could be rinsed and re-dissolved in H2SO4. This would result in copper sulfate
which can be easily plated out to recover copper without the worry of chlorine gas.
Another alternative suggested was a specially designed electrowinning cell that contains a
membrane. The membrane would allow copper to pass through it and plate out onto the
cathode while the chlorine will stay in solution, resulting in the production of copper
metal and chlorine bleach. However, this technology has never been used in a production
setting for copper recovery.
Other technologies investigated were ionic exchange and reverse osmosis. Ion
exchange is a technology which removes dissolved ions from solutions by using synthetic
resins. Synthetic resins, which are selected based on the metal to be removed and the pH
of the solution, trap metal ions. Ions can be released during a regeneration cycle where
usually an acid displaces the ions. The ions are now concentrated and can be removed
from the acid in an electrowinning cell. This allows the acid to be used indefinately to
regenerate the columns. If ion exchange was applied to Teradyne Circuits Operation
correctly, water and copper could be recycled. Reverse Osmosis was also investigated. In
this process the influent wastewater is passed through a membrane. Reverse osmosis
accomplishes almost the same outcome as ion exchange except that the permeate results
in very pure water. The largest pores on a reverse osmosis membrane range up to 0.2
microns. The reject stream which contains a higher concentration of metals must be
further treated, to remove the metals.
Ultimately, if the above technologies were coupled, water could be recycled at a
level purer than drinking water. Copper could also be recovered at a high percentage. One
of the systems proposed to Teradyne would accomplish this. A reverse osmosis, coupled
with an ion exchange could be used. Both of these concentrated streams could be sent to
a holding vessel to be chemically converted to copper sulfate and then copper could be
plated out in an electrowinning cell.
Chemical Usage :
PROCESS
DES
DESCRIPTION
CHEMICAL SPECIES
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TANK
DUMP FREQUENCY
etcher
etcher rinse
stripper waste
Cupric Chloride
650 gal
^^^^^^^^^^^
Copper,Potassium Hydroxide ^^^^^^^^^^^
500 gal/week
^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^
develop
strip
Copper,Potassium Carbonate ^^^^^^^^^^^
Copper,amines
^^^^^^^^^^^
^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^
etcher
etcher rinse
Copper, ammonia
Copper, Pb
^^^^^^^^^^^
^^^^^^^^^^^
off site recycling
^^^^^^^^^^^^^^^^
rinse
final rinse
Copper,Pb
Copper,Pb
^^^^^^^^^^^
^
^^^^^^^^^^^
^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^
system
Copper, Pb
^^^^^^^^
^^^^^^^^^^^^^^^^^^^
electroless
rinse
microetch
glass etch
rack strip
sodium hydroxide, formaldehyde
microetch
rinse
durabond
chiller
rinse
Copper, Persulfate
plating
rinse
microetch
microetch decant
nitric
Copper Sulfate
residual
Copper, Sodium persulfate
Copper,Sodium persulfate
Copper, Nitric Acid
# 10 rinse
# 143 microetch
microetch decant
residual
Copper, Sodium persulfate
Copper,Sodium persulfate
^^^^^^^^
195 gal
195 gal
^^^^^^^^^^^^^^^^^^^^^^
195 gal/ ^6months
49 gal/ 2 weeks
schmid
century
Copper,Pumice,Citric Acid
Copper,Pumice, sulfuric
p sump
75 gal
once a month
75 gal/day
COMPOSITE
COMPOSITE
Hot Oil Reflow
Sir Cleaning
DEP
Copper,electroless residue
Copper, Sodium persulfate
Copper, Ammonium Bifluoride,Peroxide
Copper,Nitric Acid
220 gal recycled copper onsite
multi tank
feed and bleed
220 gal
220 gal/week
220 gal
220 gal/ 2 weeks
220 gal
220 gal/ 6months
Durabond
residual
Copper(thiourea)sulfate
Copper(thiourea)sulfate
residual
170 gal
^^^^^^^^^
220 gal
15 gal
^^^^^^^^
170gal/ 2days
^^^^^^^^^^^^^^^^^^
220 gal/2weeks
10 gal/2hours
^^^^^^^^^^^^^^^^^
AutoPlate
8( 975 gal)
^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^
350 gal
350 gal/ 6 months
350 gal
175 gal/ week
270 gal
270 gal/ 6 months
ManualPlate
Scrub
CHEMICAL SPECIES
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PLATING LINES
Sensitizer-
sodium hydroxide,glycol ethers
Permanganate- potassium permanganate, sodium hydroxide, potassium
fluoroalkyl carboxylates
Neutralizer-
MSA + nitrates, Ammonium bifluoride
Conditioner- sulfonic acid, sulfuric acid, isopropyl alcohol,
hydroxyacetic
Predipsodium bisulfate
Catalyst-
sodium bisulfate,hydrochloric acid, stannous chloride as tin
Palladium
Anti Tarnish - potassium hydroxide
PC4 Cleaner - phosphoric acid
Wastes Generated :
F006 sludge is the largest waste stream generated at Teradyne. Approximately 80
tons of F006 sludge is produced each year on a 95% dry basis.
Details of work accomplished : Most of the details can be found in packet provided but
also in approach section.
. Researched possible technologies
. Gathered information of prospective vendors
.
.
.
.
.
.
.
Conducted process interviews
Collected data for every rinse and metal bearing stream at Teradyne
Arranged vendor contacts/meetings
Created process variable database
Evaluated vendor proposals
Evaluated Teradyne’s water treatment and purchase costs
Conducted an economical evaluation on proposals
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. Provided Teradyne with a practical evaluation of their pollution prevention options
Pollution Prevention Benefits :
There are many pollution prevention benefits associated with recycling water and
recovering copper. Water, which is normally discharged and not reused, requires further
treatment at the Publicly Owned Treatment Works before it can be reused. Last year
Teradyne discharged 50 million gallons of water. Every year, approximately 80 tons of
F006 sludge is sent out for disposal. This is from the copper removed from concentrates
and rinses.
Economical advantages to water recycling include allowing Teradyne to purchase
less water, since more would be recycled and reused. Also, the amount of chemicals used
in the treatment process will decrease. Further, Teradyne will discharge a cleaner water
stream to the local Publicly Owned Treatment Works.
From a production standpoint, a higher quality of water would be supplied to
rinses, most likely reducing the number of defects and possible shorts. This will result in
a better product, with better customer appeal and cost savings related to the decrease in
defective boards. At this time, it is hard to determine the magnitude of the affect this will
have on production quality, but it is expected to be significant.
Copper recovery has many additional benefits. Twenty percent of the dry sludge
is composed of copper. Cement is mixed with the sludge to form large concrete blocks,
which are then buried. Consequently, when the sludge is sent out for disposal all of its
copper content is wasted. It has been calculated that Teradyne can produce an annual
savings of approximately $35,000 dollars from copper recovery resale and decreased
sludge disposal from the DES room etcher alone.
Consequently, when a company improves its process from an environmental
standpoint, customer outlook and corporate appeal greatly increase. From a pollution
prevention standpoint, a better platform will be set for future efforts.
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Recommendations for Future Efforts:
I am very confident that when my internship is completed at Teradyne Circuits
Operation, that the projects will still continue. It appears Teradyne will definitely install a
system which will recycle water and reduce the amount of sludge currently generated at
the facility. While I am finishing my internship the project is currently being reviewed by
Teradyne management. A request for proposal is in the process of completion, to be
approved. When the request is finally approved, Teradyne can choose the most suitable
equipment for their needs based on performance, technical response, costs, and
availability. This is just a brief outline. The company best suited for Teradyne’s needs
will be chosen based on a more detailed selection matrix. The waste treatment upgrade
will be installed sometime before April of 1997.
References :
Desilva, Francis; Essentials of Ion Exchange; Water Quality Association; Illinois; 1995.
Plambeck, James; Applications of Electrochemistry; 1995.
Auerbach, Jon; Time-Tested Teradyne is Company of Year ; Boston Globe ; May 21, 1996.
DeWayne Howell
Emile Laplante
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