Document ID: EPA-HQ-RCRA-2010-0742-0016
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2011-07-22T04:00Z

Background Document 

June 2011

Providing Context – The Example of F006 Electroplating Sludges

		F006 electroplating sludges represents a common example in industry
where partial reclamation occurs prior to final reclamation at a primary
mineral processing smelter. F006 sludges are generated as part of an
electroplater’s on-site wastewater treatment system, and upon
generation, often contain 8 to 12 percent concentrations of recoverable
metals, such as copper, zinc, tin and nickel. The wastewater treatment
processes used by facilities generating F006 sludges are designed to
separate out contaminants and solids prior to discharge to a surface
water body or publicly owned treatment works (POTW). Most generators of
F006 use an on-site filter press to dewater their newly generated
wastes. These dewatered materials are indifferentiated because they
could either be disposed of, or sent to a facility for further
processing (e.g., partial reclamation) and subsequent recycling. Whether
sent off to be landfilled or subsequently recycled, the dewatering of
the sludges is meant to reduce the weight of the material, making it
less expensive to transport and subsequently manage.  Even after the
F006 sludges have been dewatered by the generator, they still contain
approximately 60-75 percent water unsuitable for final reclamation. 

Because of the composition of F006 sludges at electroplater facilities,
further processing is required before they can become commodity-like and
subsequently sent to a primary mineral processing facility where the
metals contained in them can be recovered or reclaimed.  Partial
reclamation facilities typically represent the facilitator or
intersecting entity between generators producing electroplating
residuals, and primary mineral processing facilities recycling
commodity-like, smelter ready F006 materials. 

Partial reclamation facilities seek out generators of F006 wastewater
treatment sludges containing specific characteristics, particularly high
metal content or precious metals that have the potential to meet the
contract specifications of primary mineral processing facilities and
produce commodity-like, smelter ready materials. Generators of
electroplating residuals or F006 sludges very often pay the partial
reclamation facility for its services, predicated on the amount of
recoverable metals contained in the electroplating residuals.   

Once generators of F006 sludges are found and contractual arrangements
are finalized, the partial reclamation facility will pick up the
generator’s shipment and transport it to its facility where the
electroplating sludges are processed (e.g., partially reclaimed) to
produce a commodity-like material. The processing steps include: (1)
sampling and analyzing the shipment to determine the concentration of
desirable, and possibly undesirable constituents that could adversely
impact the efficiency of the smelting process, (2) dewatering the 
residuals through thermal treatment (e.g., through use of a rotary kiln,
roaster, or calcination process), and (3) blending the shipment with
shipments from other generators in such a way as to meet the contract
specifications of  the primary mineral processing facility and produce a
smelter-ready material that will maximize potential metal recovery. By
meeting the contract specifications of its customer, the partial
reclamation facility is paid a fee by the primary mineral processing
facility usually predicated upon the price the smelter is paid for
delivery of their finished product. Primary mineral processing
facilities represent the end market where commodity-like F006 sludges
are sent for final recovery. These facilities produce metal products
from virgin ore containing particular metals, such as copper.  As an
example, copper ore when mined usually contains between 0.5 percent and
0.7 percent copper.   Once extracted, the copper ore undergoes a series
of beneficiation steps (e.g., crushing, grinding, and flotation) that
produces a virgin ore concentrate of between 28 - 30 percent copper.
This concentrate then enters the smelting process to produce a copper
anode with a concentration of at least 99 percent copper. This anode is
then sent to the electrolytic copper process where products, such as
billets or wire rod, are produced. The commodity-like F006 sludges
represent a viable substitute for virgin ore concentrate that both
reduces processing costs and increases smelter utilization. 

Applying the Revised Criteria to F006 Sludges Partially Reclaimed to
Produce a Commodity-like Material

Whether the degree of partial reclamation the material has undergone is
substantial. 

		In the case of F006 sludges, the processing required by a partial
reclamation facility to produce a commodity-like material first involves
sampling and analysis of incoming waste shipments to prescreen for
constituents or material characteristics that could adversely impact the
smelter process, and to measure the concentration of recoverable metals.
Once screened and  accepted, the F006 sludges are thermally dried, and
blended with other shipments of F006 sludges to produce a commodity-like
metal concentrate that is smelter- ready for final processing and
recovery by a primary mineral processing facility. This processing
occurs at a partial reclamation facility.

		Conversely, F006 sludges generated by an electroplater and
subsequently shipped to a partial reclamation facility can never be
commodity-like or smelter ready if the only processing involved by the
electroplater involves dewatering with a  filter press. As described
above, these sludges still contain 60-75% water – unacceptable to a
smelter, and often do not contain a sufficient concentration of
recoverable metals that a primary mineral processing facility will
purchase. These filter press processes are not designed to partially
reclaim the residual from the electroplating operation into a
commodity-like material. Additional processing steps after the filter
press are required before the material can be considered commodity-like.

Whether the partially-reclaimed material has sufficient economic value
that it will be purchased for final reclamation.

		An F006 sludge that has been partially reclaimed to produce a
commodity-like material will have sufficient economic value that a final
reclaimer (e.g., primary mineral processing facility) will enter into a
contract with the partial reclamation facility to purchase this
material. Evidence to support this criterion may include sales
information, business contracts, including quantities of the material
sold, additional demand for the material (if any), and the price paid
for the material by purchasers.

	However, an F006 sludge, as generated, very often will not contain a
concentration of recoverable metal that will be purchased by a primary
mineral processing facility. And, as stated above, a newly generated
F006 waste will contain significant amounts of water – thus severely
limiting the metal recovery process by the smelter.  In effect, the
value of the material produced by the electroplater will have no
positive economic value, nor will incoming shipments to partial
reclamation facilities. Hence, generators pay partial reclamation
facilities to process their wastes (e.g., F006 sludges). Therefore, only
when the F006 sludge has been thermally dried, and blended with other
shipments to produce a metal concentrate with high concentrations of
recoverable metal will a commodity-like material have been produced that
a primary mineral processing facility will purchase. 

Whether the partially-reclaimed material is a viable substitute for a
product or intermediate produced from virgin or raw materials which
feeds subsequent production steps.

		In the context of F006 sludges, this criterion would be met when a
commodity-like, smelter ready material can be substituted for a virgin
ore concentrate that is fed into the smelting process. For example,
virgin ore copper concentrate usually contains 28 to 30 percent copper.
A partially reclaimed  or commodity-like F006 sludge may not contain
that high a concentration of copper, but  other valuable metals
contained in the material, such as precious metals, may more than offset
the economic  difference in lower copper concentrations. Data collected
by EPA have found a copper primary mineral processing facility willing
to pay for concentrations of 18 percent or higher, provided the incoming
material satisfies the other minimum or maximum concentrations for
specified constituents identified in business contracts. Although lower
than normal virgin ore concentrate, these incoming materials represent
levels that can be processed at a profit by the mineral processing
facility.

Conversely, comparing the concentration of an incoming shipment of F006
waste to a partial reclamation facility (8-12% copper on average) with
virgin ore (i.e., greater than 0.5% for nickel and 0.7% for copper)
would not satisfy this criterion. Neither the incoming F006 to the
partial reclamation facility nor the virgin ore represent a viable
substitute for virgin ore concentrate (28 to 30%) which is fed into the
smelting process because neither of these material are commodity-like. 

4)  Whether there is a guaranteed end market for the partially-reclaimed
material.

		The end market for partially reclaimed F006 that is also
commodity-like would be a primary mineral processing facility.
Conversely, the end market would not be another intermediate processing
or partial reclamation facility. Almost all F006 sludges generated must
undergo additional processing steps (e.g., additional de-watering and
blending) by a intermediate processing facility to derive a
commodity-like material that a primary mineral processing facility will
purchase and recycle.  

5) Whether the partially-reclaimed material is handled to minimize loss.

		F006 wastes sent to a partial reclamation facility must be managed in
compliance with all applicable RCRA Subtitle C regulations, including
RCRA Part B storage and treatment permits and financial assurance.  The
majority of F006 wastewater treatment sludges are stored and transported
in closed containers such as drums, cinched super-sacks (large synthetic
bags generally moved by fork-lift) on pallets, and roll-on/roll-off
containers.  Wastewater treatment sludges are generally a moist
cake-like particulate material that is relatively non-dispersible and
with care is easy to manage in a way that minimizes loss by using these
non-leaking closed containers. 

		Similarly, we would expect a partial reclamation facility to manage
any commodity-like materials produced from their operations so as to
eliminate, if not, minimize any releases to the environment because of
the economic value attached to them. Failure to do so suggests the
materials are not valuable or commodity-like.     

		

		

 Dewatering is a form of reclamation.