THE PRACTICAL GUIDE TO MASS FINISHING OF PRECIOUS AND COSTUME JEWELRY: METHODS AND MYTHS |
Steven R. Alviti, Bel Air Finishing Supply Inc.
ABSTRACT
A microscopic and technical view of mass finishing presented in layman's terms. Understanding of mass finishing must start at the very basic level of what happens microscopically to the surface of various materials. All the variables will be discussed, such as the media, compounds and the effect of various types of machinery on the finishing process. Practical techniques and the associated costs will be presented for pre-finishing of precious metal jewelry as well as costume or imitation jewelry
INTRODUCTION
This article is an explanation of Mass Finishing from a practical standpoint. The views discussed here are a result of 30 years of experience in manufacturing jewelry, job shop processing for many diverse manufacturing industries as well as experience in designing and manufacturing of finishing equipment. Historically, the mass finishing department of many companies have not received the attention or understanding required to serve the best interests of the manufacturer's finished product. Typically, manufacturers migrate to opposite ends of the spectrum with regards to their finishing department. It is either in the remotest location of their facility and the attitude is "well that's the way we have always done it" or they have instituted a sophisticated system without the proper understanding of the economics or the reality of everyday jewelry manufacturing. There is no best way of finishing a product. Before any changes are made to a finishing department, the manufacturer must address the importance of several aspects before making a decision. Most Important Semi Important Least Important Processing Time Quality of Finish Cost of Finishing Training Employees Maintenance Cost of Equipment Loss of Material from Product
III MEDIA - COMPOUNDS
A. DEFINITION
The word media is used to describe the material that is used in mass finishing to actually do the work on the surface of the part that is being finished. The compound refers to the different types of chemicals used during wet mass finishing operations.
B. FUNCTION OF MEDIA
The functions of media are varied and range from rough cutting to polishing. ROUGH CUTTING of the raw product is to remove all possible surface imperfections. Depending upon the manufacturing process, some hand work may be necessary prior to this mass finishing step. Raw gold casting must have the sprue cut off and ground down to the surface. In the case of a white metal rubber molded piece, usually no hand operation is necessary. However, each case depends on the manufacturing process. The rough cut is to remove the surface imperfections of the material due to its fabrication technique. (i.e. casting, rolling, forming, etc.) This is the stage where mass finishing plays its biggest role in labor savings. Typically, mass finishing can save 50 - 75% of the hand labor used to finish a piece of jewelry. FIG. 1-3
|



The rough cut is almost always done as a wet operation with media, water and compound. The labor savings is most obvious for cast materials due to the inherent roughness of the "as cast" surface. PRE-FINISHING is the term used for the operation following the rough cut stage. The pre-finishing step is usually done prior to machine polishing, hand polishing or electroplating. The purpose is to increase the smoothness of the "rough cut" surface so as to make the polishing or electroplating procedure more effective. In order for a product to be machine polished or a combination of machine and hand polished, this step is most necessary. If the product is going to be hand polished or electroplated, this step may or may not be necessary. This would depend upon whether the labor saving is worth the time investment. A question quality versus cost must also be taken into consideration. The pre-finishing operation is almost always done as a wet operation with media, water and a compound. MACHINE POLISHING is very economical where applicable. It can save up to 95% of hand finishing labor costs; however, many facto must be considered for this step to be viable. This is usually a dry procedure using a natural carrier and a powdered compound without water. Fig. 4 BURNISHING is used to render the surface of a product bright by J means of rolling over a surface with a non-abrasive media such as steel or porcelain. This method physically peens the surface in order to increase light reflectivity which, in turn, will make the surface appear bright. This media is the heaviest available and is used with water and compound.
C. MEDIA TYPES
There are a variety of different media for different applications:
|




Normally, there are two components of CUTTING MEDIA:
1) abrasive grains and
2) carrier or bonding agents
Abrasive grains for cutting media can be any of the following:
- Silicone carbide - most aggressive
- Aluminum oxide - moderately aggressive
- Silica- least aggressive
Bonding materials can be (FIG
8 ):
- Ceramic - hard
- Plastic - soft
- Natural - range soft to hard
PRE-POLISHING MEDIA is much the same as cutting media with exception of the size of the grain that is bound into the media. Pre-finishing media is also used to perform a cutting operation; however, much more gentle and finer than the rough cut media.
BURNISHING MEDIA has no abrasive grain. This media is used simply to roll over or hammer away at the surface with the sole purpose of making it bright. This media is typically made from either very heavy lain or solid steel.
POLISHING MEDIA is generally made of a natural base material as wood, shell or corn cob. Polishing compounds, very similar to used in hand polishing bars, are bound to the natural base by means wax or oil based product.
|

D. MEDIA SIZES AND SHAPES.
The various types of media are available in many shapes and sizes. When choosing sizes and shapes, one must consider the geometry of the being processed and choose the largest media possible that will fulfill the following criteria: 1. The shape chosen will best be able to touch every part of the surface of the work pieces. 2. The size will facilitate easy separation (i.e. either the media or the piece can be sifted through an existing separating screen).
E. FINISHING COMPOUNDS
Finishing compounds are either liquid or powder and are as additives to the water being used during any of the mass finishing operations There are three purposes for compounds (1) The compound is form of soap used to suspend the solids being removed from the surface the product (much like dishwashing soap). (2) The prevention of oxidation or discoloration of the metals being processed. (3) The addition lubricity to the process. The proper compounds form a cushion between the media and the work piece, which allows a sliding action which in turn, reduces impingement of the abrasive. Compounds are used both types of processing. The first is called a batch operation where a prescribed amount of media, water and compound are placed in a sealed process chamber. The second is called a flow-thru operation where a prescribed amount of water and compound continuously flow in and out of open processing chamber of media. Theoretically, compounds are most likely to be changed for a particular metal being processed as well as for a particular step (i.e. rough cut, pre-finish etc.) In reality; however, this is less likely to be specifically matched to the purpose. Most manufacturers settle on one "all purpose compound" best suited for their needs.
|
Pre-tumbled Resin Bonded Preformed Media |
PYRAMIDS
|
SPEC
|
A
|
B
|
C
|
P0
|
3/8
|
5/8
|
5/8
|
P1
|
1-5/8
|
1
|
1
|
P2
|
2
|
1-1/2
|
1
|
TETRAHEDRON
|
SPEC
|
A
|
B
|
C
|
TH1
|
3/4
|
3/4
|
3/4
|
TH2
|
1-1/8
|
1-1/8
|
1-1/8
|
TH3
|
1-1/4
|
1-1/4
|
1-1/4
|
TH4
|
1-3/8
|
1-3/8
|
1-3/8
|
TRIANGLE
|
SPEC
|
A
|
B
|
C
|
TR0
|
1/4
|
1/4
|
1/4
|
TR1
|
5/8
|
1/2
|
3/8
|
TR2
|
11/16
|
7/16
|
5/8
|
TR3
|
1
|
5/8
|
9/16
|
TR4
|
1-1/4
|
5/8
|
5/8
|
TR5
|
1-3/4
|
1-1/4
|
1-1/4
|
TR6
|
2-1/2
|
2-1/2
|
2-1/2
|
|
|
CONE
|
SPEC
|
A
|
B
|
C1
|
3/8
|
3/8
|
C2
|
1/2
|
9/16
|
C3
|
3/4
|
3/4
|
C4
|
1
|
1-1/4
|
C5
|
1-1/4
|
1-1/4
|
C6
|
1-1/4
|
1-1/2
|
C7
|
1-1/2
|
1-1/2
|
C8
|
1-3/4
|
1-3/4
|
C9
|
2
|
2
|
C10
|
2
|
2-1/2
|
C11
|
2-1/2
|
2-1/2
|
|
|
|
ANGLE CUT TRIANGLE
|
SPEC
|
A
|
B
|
ATR1
|
1
|
1-1/8
|
CYLINDER WEDGE
|
SPEC
|
A
|
B
|
ATR1
|
1-1/4
|
1-1/4
|
ATR2
|
1-1/2
|
1-1/2
|
|
|
TRI-STARS
|
SPEC
|
A
|
B
|
TS1
|
1-3/8
|
1/2
|
TS2
|
1-3/4
|
3/4
|
TS3
|
2
|
3/4
|
WEDGES
|
SPEC
|
A
|
B
|
C
|
W1
|
1-5/8
|
1
|
1
|
W2
|
2
|
1-1/4
|
1-1/8
|
ANGLE CUT CYLINDERS
|
SPEC
|
A
|
B
|
C
|
AC1
|
1
|
9/16
|
|
TRIANGLE
|
SPEC
|
A
|
B
|
C
|
TR0
|
1/4
|
1/4
|
1/4
|
TR1
|
5/8
|
1/2
|
3/8
|
TR2
|
11/16
|
7/16
|
5/8
|
TR3
|
1
|
5/8
|
9/16
|
TR4
|
1-1/4
|
5/8
|
5/8
|
TR5
|
1-3/4
|
1-1/4
|
1-1/4
|
TR6
|
2-1/2
|
2-1/2
|
2-1/2
|
|
|
|
|
|
|
F. HOW MEDIA AND COMPOUNDS WORK
Mass finishing media works basically in the
same manner as the materials used in hand finishing. FIG 10
a-d
The main difference is that a machine is used to apply the
force through the tool to the work piece. The other difference
is that a mass of pieces are being processed rather than one
piece at a time. Hence, the name Mass Finishing. FIG 11
In order to perform the CUTTING OPERATION, we must choose
the best combination of abrasive grain, bonding material,
size, shape and the proper compound to use during the process.
The cutting media works in the same manner as a grinding wheel.
A force is required to rub the media across the surface of
the work piece. FIG 12
At the point of contact of media and the work piece, abrasive
grains are exposed at the surface of the media and rubbed
across the work piece, microscopically cutting material from
its surface. As material is being cut away from the work piece,
the abrasive grains are becoming dull as they do their job.
FIG 13a,b
Meanwhile, the bonding material is wearing away so as to rid
the media of these dull abrasive grains and to expose new
sharp grains to continue the cutting process. The water and
compound are used to cushion this effect as well as to remove
all of the waste (used abrasive grains, bonding material,
work piece surface material) from the operation. Economics
now come into play when choosing the proper cutting media.
The faster a media cuts, the faster it normally wears which
equates to dollars per finishing operation. If the bonding
agent of the media does not wear fast enough, the abrasive
grains may not perform as effective as they should. There
is an optimal wear ratio between the bond and the grain. If
this ratio is not correct, the media is less cost effective.
Regardless of these microscopic costs, the overall economic
scale of labor saving, material loss and overall time savings
make mass finishing a sure bet.
|







THE PRE-POLISHING OPERATION is practically the same
as the cutting media except the bonding material is usually
harder and the abrasive grain size is smaller. In some cases,
the abrasive grain is in the form of slender finer shape.
By rubbing over the surface with a greater low of water and
a compound that lubricates more effectively, a gentle honing
action occurs. The purpose is to reduce the surface to a finer/smoother
finish. Typically, the wear of pre-polishing media is much
less than that of cutting media. We are less interested in
removing metal, than we are in reducing the surface finish.
The POLISHING OPERATION is normally done as a dry process,
the media in this case is either of several natural products
like wood round up corn cob or nut shells. In this case, there
is no water flow and, the compound is dry and bonded to the
carrier. Some typical compounds are alumina and tin oxide,
which are the same compounds used for hand polishing In this
case, the rubbing action of the media is meant to -plicate
the action of a polishing wheel rubbing polishing compound
over the surface of the work piece. As long as the surface
has previously been rendered smooth and flat, this process
will now produce a high luster to the surface. This operation
usually takes a much longer time than the rough cut and pre-polish.
The finish that is achieved with this method is very good;
however, it will never be equal to that of a hand polished
finish No mass finishing machine has been able to duplicate
the force and action necessary to compare to hand polishing.
Hand polishing actually over the surface of the work piece
by dragging metal whereas machine polishing only glosses the
existing surface. During this operation, due tog the fact
that it is a dry process, heat is generated by the friction
of the in moving This heat is beneficial to the process because
it helps activate it polishing compound itself; therefore,
it is helpful to retain as much of the .at generated by covering
the process. Unlike cutting and pre-polishing' media, the
polishing media has a life span, after which it is no longer
effective This is due to the fact that the polishing compound
is only bonded to the surface of the media as opposed to the
abrasive grain being 81 bound throughout the whole composition.
However, once this media has been expended, it can be re-charged
for several more cycles before being discarded.
BURNISHING MEDIA is typified by the lack of abrasives
and a hard and extremely smooth surface. The purpose of burnishing
is to brighten the surface of a material by means of peening
the surface. The correlation that we use to explain this is
if one took a plain dull piece of brass and a ball peen hammer.
After repeatedly hammering the surface, it will then take
on brightness imparted by the surface of the ball peen will
hammer.
|

Steel or stainless shot as well as porcelain balls are the
typical media of choice for burnishing. These are usually
the heaviest materials available and they are processed to
have a microscopically smooth and shiny surface finish.
|
IV MACHINES
The media is what actually performs the surface
finishing. The compound allows this work to be done efficiently
but it is the machine that provides the energy to do all the
work. There are several different types of mass finishing
machines, all of which have a different method of transferring
energy from an electric motor to the media to the work piece.
The TUMBLING MACHINE is the oldest form of mass finishing
equipment. A motor is attached to the gear box by means of
a pulley and belt. The gear box rotates an octagonal finishing
chamber which is either submerged in water or contains water
in its chamber. The chamber should be loaded with between
50% and 60% of the total chamber volume. About 15% to 25%
of the total mass should be work pieces In this equipment,
the pieces are only being worked on as the media and pieces
tumble down the incline of the rotating barrel. Meanwhile,
as the mass rotates up to the top of the incline, there is
no movement of media with respect to workpiece; therefore,
no work is (D 83 being done. This type of operation is still
effective for limited applications with longer time cycles
and a low quality finish.
|
Efficiencies of Tumblers:
Good for low cost, low quality finishes Good
for cutting & de-burring flat stackable work pieces Good for
low cost, low quality burnishing Deficiencies of Tumblers:
Labor intense for volume processing Not effective for polishing
Not effective to pre-polishing Flow-through compound system
not available More apt to get part on part impingement Will
not finish parts with deep recesses
THE VIBRATORY TUB MACHINE was the next generation of mass
finishing equipment. It took the same basic idea of the tumbling
machine but created a new and more efficient means of transferring
energy from the motor to the tub. The chamber is "U" shaped
and suspended on springs. The shaft with eccentric weights
is attached to the chamber and is rotated by means of a belt
and pulley attached to the motor. There are still some of
the same inherent problems in this process as in tumbling
but now we have incorporated a flow-through compound system
and vibratory action for more efficiency.
|

The VIBRATORY BOWL machine was the next generation
of mass finishing and remains the most popular and most effective
to date. The processing chamber is the shape of a hollowed
doughnut laying on its side. A motor is attached to a shaft
with eccentric weights which is fixed to the bowl shaped chamber
which is suspended on springs. The ensuing action causes the
mass to travel in a three dimensional toroidal motion.
|
This type of action allows for the most efficient
processing of work pieces. The work chamber can almost be
filled to capacity as well as allowing the high concentration
of work pieces in relationship to the mass.
Efficiencies of Vibratory Bowl:
- Highest quality finish
- Low maintenance
- Allows flow-through operation
- Low labor cost for operating
- Minimizes processing load
HIGH ENERGY BARREL MACHINES operate basically the same
as tumbling barrels with one major difference - centrifugal
energy is added to the process to dramatically reduce the
processing time. This is accomplished by mounting several
barrels in a ferris wheel type arrangement and spinning the
complete apparatus as each barrel is rotating.
|
Except for the extra force applied to the media
and work piece, all the draw-backs of tumbling are still inherent.
An additional drawback is that the equipment now becomes very
expensive as well. Processing time is one positive feature
of the apparatus.
The HIGH ENERGY DISC finishing machines have been developed
to take advantage of the three dimensional action of a vibratory
bowl and the reduced processing time of centrifugal force
machines. The energy is transferred from a motor to a gear
box in order to rotate a central disc at the bottom of a round
stationary chamber. Centrifugal force and the rotating action
sends the mass outward towards the stationary wall. The mass
then slows down and returns to the center to complete the
cycle.
|
This method incorporates the ability to have
flow-through processing and high energy. The major drawback
to this equipment lies in the disc seal. This is the machine
part that lies between the stationary bowl and rotating center.
A precision opening must be maintained so as to allow the
flow-through water and debris to escape. The inherent problem
is that abrasives are constantly flowing through a moving
seal. This makes for a maintenance nightmare besides the high
initial expense of the equipment. Process time reduction is
the benefit derived from this equipment. The latest development
in mass finishing equipment is a machine designed for the
specific purpose of burnishing.
The ROLL BURNISHING machine is a completely new drive
mechanism for the oldest of techniques, burnishing.
|

This new machine is a form of high energy ball
burnishing. It operates by rotating a belt in a tub shape
configuration while submerged in a rectangular tub of water
and compound. Not only does this facilitate a much faster
cycle, there is also the point of impingement on all tubs,
which has been eliminated because of the roll under effect
created by the belt This is also the only tub style burnisher
that allows the possibility of a flow-through compound system.
Beyond this, the system has a unique unload system that is
incredibly labor saving. A specially made sieving basket is
emerged into the mass and removed with just the work pieces.
No media has to ever be handled by the operator. It takes
less than one minute to completely unload work pieces.
The MAGNETIC PIN FINISHER has been developed to burnish
the nooks and crannies and far reaches of jewelry products.
The machine uses a motor to spin a magnet beneath a flat table.
The finishing chamber contains very fine steel needles or
pins with the water and compound mix. The work pieces are
placed in the chamber and covered. The cylindrical chamber
is placed on top of the table. The magnets are rotated in
a circular path that matches the bottom of the chamber. This
causes the steel pins to stand up and rotate. The collision
of the magnet driven pins with the work piece causes the mass
to rotate at the same time as the pins hammer the surface
of the work piece.
|
V. MACHINE EFFECTIVENESS / COST RELATIONSHIP
A. MACHINE COST EFFECTIVENESS
The main purpose of mass finishing is to economize
the finishing operation of all jewelry products. Other reasons
vary according to the situation. In Italy and the U.S., hand
finishing labor is very costly. In China, the labor is cheap.
The worker training and consistency are the issues . In some
other countries, the main issue is the loss of gold from the
raw casting to the finished product. The type of mass finishing
is determined by these and other parameters:
|
AVERAGE COSTS PER I CUBIC FOOT (40 LITERS) CHAMBER SIZE |
MACHINE TYPE
|
|
COST
|
|
|
$ 1000
|
|
|
$ 4000
|
|
|
$ 3200
|
|
|
$ 37000
|
|
|
$ 24000
|
|
|
$ 7000
|
Magnetic Pin
|
|
$ 17000
|
B. COMMON FINISHING MYTHS
1. Many customers purchase plastic
media based on lowest cost
Plastic media is made of two parts, a polyester
resin bonding agent and abrasive grain. The most expensive
part of the media is the resin bonding agent. In order to
decrease the cost of selling plastic media, an increase percentage
of abrasive can be mixed into the media. The problem is -
the more grain, the faster the media wears, which actually
makes it more expensive to operate. Another way to decrease
the cost of selling plastic media is to use a less expensive
bonding agent. Urea Formaldehyde has been used as a less expensive
bonding agent, which again increases the wear rate and hence
is more expensive to operate with this media.
2. Urea Formaldehyde bonded plastic
media is cheaper to use and easier to settle out in your waste
water system
Urea Formaldehyde or UF media was developed
to fight the increased cost of using the standard polyester
based resin bonding agents. Because it obviously wears out
faster, some other benefit must have to be touted to over-ride
this defect. Actually its initial cost is less. It does not
make waste treatment any easier and it is more expensive to
operate.
3. Ceramic cutting media costs
less and wears longer
This is a true statement. We see this approach
quite often in the Far East. The fact is that, because the
media is harder and does not wear out, it does not cut the
surface. If you are dealing with soft metals, as we often
do for jewelry products, ceramic media for cutting is not
practical because the surface of the media "loads up" with
metal before it can wear to the next level of cutting. Therefore,
the media only works in a manner of burnishing the surface.
4. High energy disc finishers give
a better finish than Vibratory
The action of both a disc finisher and a vibratory
finisher is basically the same with respect of the mass traveling
in a three dimensional motion. Assuming the media and compound
are the same, the only difference is t some added centrifugal
force is being used in the operation. That alone cannot produce
a better finish. Faster - yes, but not better. The simple
fact that a particular grit media is rubbed over a work piece
surface is what defines the degree of smoothness achieved.
An example would be rubbing a 200 grit sand paper on a surface.
No matter how hard or how t it was rubbed, it still remains
a fact that you could not get better than 00 grit finish.
5. "After casting, put your
piece in a pin machine and it is finished"
I heard this absurd statement from finished
goods manufacturers coming out a seminar at a trade show.
The statement may be true for the purpose of cleaning a raw
casting; however, it actually deteriorates any broad surface
t needs polishing. A pin machine is strictly for pronged and
recessed as or the lowest quality bright finish. This is used
to finish these hard to reach areas in conjunction with other
mass finishing or hand finishing.
6. The European technique saves
time
This technique is to use a plain media with
no abrasive as a carrier and then to add abrasive grit for
.ting. This is done in a batch operation as a slurry. Once
the first cycle complete, it is then flushed. The batch is
then run with a finer grit led and flushed again. This system
saves an unloading operation; however, it sacrifices results.
Finishing by this method would be as if one took a piece of
paper and a sprinkle of sand and started to rub a piece as
posed to using a piece of sandpaper. Although the unloading
between finishing steps has been eliminated, the operation
itself is very inefficient.
7. The machine does not work
Many times, after a manufacturer has purchased
a machine and has embarked on mass finishing, they call and
say "the machine does not work". My response is to ask several
questions: a. Did you plug the machine in? b. Did you turn
the machine on? c. Does the machine shake? or spin? If they
answer yes to all of these questions, my response is "the
machine works". The problem is that the technique the manufacturer
is using is not producing what the manufacturer expected.
He may have been misinformed, uninformed or misdirected. It
is important to remember, although mass finishing is relatively
straightforward once a process has been established, there
are many variables to consider. The technology is the most
important thing to consider when making a purchase. Just as
in making a decision to purchase jewelry software, you should
be dealing with a supplier who concentrates in the industry
and is always updating their technology.
8. Internal separation in a vibratory
machine saves time
Some vibratory finishing machines have a built
in dam that, when closed, allows the mass to rise and pass
over a screen which allows the media to return into the bowl
and the work pieces shake across the screen and out of the
bowl. The idea seems efficient; however, in reality, there
is so much variation in jewelry components that it becomes
a laborer's nightmare to change screens and find missing parts
that never rise over the screen. internal separation is never
100% effective. It reduces the capacity of the machine and
it causes longer down time for the unload cycle. An operator
should be able to unload and reload a vibratory bowl up to
3 cubic feet in less than 10 minutes using an external separator.
VI CONSUMER EXPECTATIONS DICTATE TECHNIQUES
Ther is no best way to mass finish. The consumer
who will eventually purchase the finished jewelry product
is the one who actually dictates the finishing technique to
be used by the manufacturer. For instance, let's manufacture
a pair of gold earrings set with diamonds. The estimated retail
value will be $2000 US dollars and it will be sold in an upscale
jewelry store. The gold castings would probably be run in
some type of mass finishing cutting cycle and then hand polished
with several steps: the settings may be hand burnished and
then the stones would be hand set and, finally, hand glossed
again. Now let's use that same wax model and make a $ 100
US dollar pair of gold earrings with a cast in CZ that will
be sold to Wal-Mart Stores. We would probably run that same
gold casting through a three step mass finishing process that
would give us a "near" polished finish. The final operation
may be a quick hand gloss with a polishing wheel. Next, let's
take the same wax model and make a pair of gold earrings to
sell one of the world's latest consumers, a Mainland Chinese
laborer. First, we will move the stone and now have a target
retail of $40.00 US dollars. The manufacturer now may only
have to do a simple burnishing operation to bring up the shine
and color of the gold. Each one of the above consumer has
a different level of expectation with regards to the product
resulting in each product being processed by a different mass
finishing technique. The end result is that each consumer
is equally pleased with his or her purchase. The same scenario
is true for costume jewelry. There is no best way. ere are
many techniques developed for varying degrees of quality and
economy Whether the product has been stamped, cast, machined
or molded be it made from precious metal, base metal, plastic
or wood, there are many machines and media available for mass
finishing. The most effective to date remains the Vibratory
Bowl Finisher.
NEW DEVELOPMENTS IN WASTE WATER TREATMENTS
New developments in treating effluent have
progressed nicely from the set of jewelry mass finishing.
In the early days, environmental restrictions were tremendous
hurdles to overcome for many manufacturers. In most recent
years, systems have been developed that make it a lot easier
for manufacturers to efficiently process their vibratory me.
The following are some methods currently used in many systems.
1. Polymer Flocculation
2. Filter Presses
3. Ultra Filtration
4. Resin Columns
Recycling Methods
The current technology now allows for the effluent to RECYCLE
thru vibratory system. This eliminated the need to discharge
water while saving in compound cost at the same time. In some
parts of the world, the laws are not strict enough to make
this necessary but we would hope that manufacturers will be
environmentally responsible. Once the effluent has been treated,
costume jewelry manufacturers now must deal with the disposal
of sludge waste that has been extracted from the water. This
sludge has typically been defined as hazardous waste and trucked
away at about $200 per drum.
The latest development in WATER TREATMENT CHEMISTRY now
encapsulates up to 99% of the soluble and insoluble metals
from the effluent. The sludge, after air drying, now transforms
into cement like material. In most cases, this allows the
waste to be classified as non hazardous which allows dumping
in land fills. For precious jewelry manufacturers, this simple
15 minute procedure allows them to recover the most gold or
platinum ever attainable without waiting for days of natural
settling or messy evaporation techniques.
|
VIII
FUTURE ARTICLES
Costume Jewelry Finishing Techniques
Precious Jewelry Finishing Techniques
New Developments in Waste Water Treatment Technology
|