Recovering precious
metals from
electronic
scrap and
catalytic
converters
from autos
has become
more profitable
than ever
before. That
may explain
why more and
more specialized
“niche” recyclers
and refiners
have sprung
up and the
sector has
really surged
over the past
several years.
Gold, which
traded at
an average
annual price
of $264 per
ounce in 2000,
has been trading
near $1,000
per ounce
in recent
days. Of course,
prices fluctuate,
but they have
been trending
steadily upward
for gold,
silver and
the platinum
group metals:
ruthenium,
rhodium, palladium,
osmium, iridium
and platinum.
The obvious
reason for
the sharp
price increases
is the economic
crisis; for
the feeling
of security
in uncertain
times and
as a hedge
against inflation.
Precious metals
do not even
have to be
converted
to cash –
they are tradable
as investment
or industrial
commodities
– gold, silver,
platinum,
and palladium
have an ISO
4217 currency
code.
There are scant amounts of
precious metals in e-wastes,
but more in catalytic
converters. When processed
in volume by an efficient
recycler, though, value
begins to add up. The
amounts of precious metals
alone found in e-wastes
do not even begin to
pay for the costs of
recycling and are subsidized
by disposal fees and
by other materials recovered
in the processes such
as copper, plastic, steel
and glass.
Precious metals from e-waste
“If you have a typical printed
circuit board (PCB) in your
hand, maybe 2 percent of the
weight is gold. Another 18
to 22 percent would be copper
and then you have trace amounts
of silver, palladium and things
of that nature,” said Bill
Rockett, vice president of
the M&K Recovery Group
in Boston.
M&K is a privately held
company with 30-years experience
in recovering precious metals
from electronic wastes. It
operates a 35,000 sq. ft.
state-of-the-art processing
facility in Boston and a 12,000
sq. ft. collection center
in Texas from which e-waste
is trucked to Boston. In Boston,
M&K uses a chemical refining
method to recover gold, silver
and platinum group metals
from encapsulated and clad
materials, and a cyanide strip
method for gold-plated scrap
products. Both processes are
zero-discharge, emission-free
and operate under a Massachusetts
B4 recycling permit.
While copper is the most common
material used to conduct electricity
in electronic circuitry, silver
and gold are also used in
thinly plated forms for better
conductivity in high-quality
surface-to-surface contacts.
In electronics recycling,
the primary sources of precious
metals are found in PCBs and
integrated circuits (ICs)
and vary in yields depending
on size and type of the board
or chip. The highest yields
come from personal computers,
laptops and cell phones in
the form of motherboards,
main boards, video and audio
boards, network cards and
related PCBs and ICs. Lower
value PCBs are found in monitors,
amplifiers, DVD players, printers,
speakers, VCRs, MP3 players,
cameras and the like. These
usually contain copper and
lead, but in much lower quantities
of precious metals than computers.
“In the average personal computer
there is, generally speaking,
20 percent copper, 2 percent
gold, 1 percent silver and
1 percent palladium. Beyond
that there’s iron and plastic
content that we recycle,”
Rockett stated.
After an electronic unit is
manually stripped at M&K,
PCBs and ICs and other precious
metal-bearing components are
set aside. An alligator shearing
machine is used to trim off
small precious metal-bearing
pieces from PCBs such as ICs,
fingers, connectors, plugs
and pins. The small pieces
are sent through M&K’s
chemical treatment process
where the precious metals
drop off the PCB fiberglass
substrate and are later cast
into bars. M&K holds pool
accounts with various bullion
dealers and bars of precious
metals are sold at the daily
spot price.
The stripped PCB fiberglass
is collected into 25,000 pound
lots and sent out to a smelter
where it is burned and scrubbed
to remove and recover copper.
Approximately 60 percent of
e-waste volume processed by
M&K comes from OEMs via
take-back programs and the
balance from corporate customers
and miscellaneous sources,
but not much from municipal
programs. In certain cases,
when a customer wants to dispose
of a large quantity of electronic
components, M&K will process
the materials at a contracted
price and return the redeemed
precious metals to the customer.
Precious metals from catalytic
converters
Replacing a catalytic converter
(CC) is expensive. Depending
on the auto’s make and model,
an OEM replacement part can
cost anywhere from $50 to
over $1,500. One muffler shop
estimate for a Subaru CC system
was for $1,300, not counting
installation labor. Aftermarket
CC prices are less, usually
because they are smaller and
contain less of the precious
metals used as catalysts,
such as platinum, rhodium
and palladium.
Depending on the size and
type of CC, a repair shop
can get $25 to $50 for a used
one. Increasingly, auto manufacturers
are asking dealers to return
used units so they can recycle
parts and recover precious
metals.
Most scrap recyclers accumulate
CCs and send them off in bulk
shipments to companies like
PMR Catalytic Converter Recycling
in Quebec that specializes
in recycling CCs. It is the
only company of its type in
Canada and bills itself as
the North American leader
in the analysis, cutting and
recycling of the metals and
ceramics found in all models
of catalytic converters. “I
buy in Canada and all over
the United States, anywhere,”
said Pierre Marchend, PMR’s
general manager and principal
buyer. “On average we pay
roughly $45 for each scrap
unit and process about 100,000
catalytic converters each
month.”
At PMR, the first step is
to “decan” or remove the auto
catalyst materials from the
whole steel converter unit.
This involves shearing open
the steel or stainless steel
case to release the bead or
honeycomb ceramic biscuits.
Since the recovery value is
in the Platinum Group Metals
(PGM) that coat the ceramic
catalyst material, all the
dust and small pieces are
collected. The catalyst material
is then crushed and milled
into a uniform powder. PMR’s
powder is then assayed to
determine the precious metal
content, but this is only
a conditional assay, a rough
approximation of content that
accompanies the material to
the next step in recovery.
PMR sends its catalyst powder
for refining to Techemet,
a technical, chemical and
metallurgic group headquartered
in Pasadena, Texas and one
of the top three companies
of its type in the world.
From Texas, Techemet directs
its international recycling
and refining operations in
the United Kingdom, continental
Europe, Mexico and Central
America. Catalytic converters
represent approximately 90
percent Techemet’s business,
but it also recovers platinum,
palladium, rhodium, gold and
silver from industrial catalysts
used in petroleum and chemical
processing as well as from
electronic, jewelry and dental
scrap.
“At the moment, business is
slow. Last year was our best
year ever in volume, but it
trailed off in November and
December, said Stewart Prentice,
a Techemet partner. “Currently,
everyone in our industry is
running about 50 percent of
the level of last year. There’s
a shortage of catalytic converters,
too, because a lot of auto
wreckers are not selling.
They are stockpiling, waiting
for prices to go up.”
Techemet takes in decanned
catalysts from companies like
PMR. While catalysts represent
the majority of Techemet’s
business, it also takes in
whole converters from scrap
dealers. Because there are
literally thousands of types
of catalytic converters in
a range of sizes, Techemet
pays anywhere from three dollars
to $120 for a whole unit.
To refine catalysts, Techemet
uses two submerged electric
arc furnaces that have a combined
capacity of 20 million pounds
of annual feed. Submerged
electric arc furnaces are
physically different from
steel-making furnaces. In
submerged arc furnaces the
electrode tips are buried
in the slag-charge and arcing
occurs through the slag between
a matte and an electrode.
Steelmaking arc furnaces arc
in the open and usually operate
on a continuous, rather than
on a batch basis like a submerged
arc furnace.
After the catalyst material
is refined in the arc furnace,
the extracted metal is called
“PGM alloy” and it contains
approximately 10 percent precious
metals. The remaining ceramic
material is of negligible
value and is used for road
fill. Techemet sends out its
PGM alloy to chemical refineries
for final processing into
99.99 percent pure platinum,
palladium and rhodium sponge.
Techemet’s smelter generates
no waste streams, nothing
that is processed is discarded
and everything is recycled.
