Precious Metals Refining
Recovering
value from your scrap
Since precious metals-gold, silver and platinum group metals-are your principal raw materials, the scrap generated in your manufacturing operations contains considerable value. This value can be recovered for you by a precious metal refiner. The return you receive from your refiner constitutes an important part of your business income, and you are justifiably concerned to recover the fullest possible value for every pennyweight of precious metal in your scrap.
The principal steps in a profitable precious metals recovery program can be summarized in four words Detection, Collection, Protection and Selection. In the following discussion we’ll offer suggestions for the efficient performance of each of these steps, based on our century of experience in the refining of manufacturers’ scrap.
Detection-learning the hiding places
Precious metal scrap can hide in a thousand places. Make sure you know all those places in your own manufacturing operation. Abrasive procedures, for example (grinding, sanding, buffing), generate valuable scrap in dust form. So you’ll use collector hoods and bags in those operations to trap the dust, and you’ll save the used wheels and belts themselves. You’ll be aware of your valuable scrap in liquid form the wet sludge from sink traps, floor drains and rinse tanks, and the spent plating and stripping solutions. If you’re plating precious metals, don’t overlook the holding fixtures, clips and hooks, or the used anodes.
Precious metal dust settles on walls and floors. Vacuum them regularly. Save the dust filters from ventilation fans. Save used crucibles and pay special attention to such high-value scrap as bench filings and clippings, lathe chips, production rejects, spinning and blanking scrap.
Above all, create awareness of the value of your scrap among all your people-from management to machine operators, bench workers and sweepers. Make sure everyone handling precious metal materials knows their value-and their hiding places.
Collection - getting it all
together
In collecting your scrap, segregate it according to type. The more you segregate your scrap, the more efficiently your refiner can process it. The result is a lower refining cost and the highest possible return for the precious metal content of the scrap.
Use special care in the handling of high-value scrap. Keep this scrap separate from the lower value sweeps. Keep gold, silver and platinum group metal scrap in separate containers. If you generate large amounts of scrap it is to your advantage to segregate it wherever practical. Segregate plated from filled scrap, high-karat scrap from low-karat scrap. Separate solids from liquids, magnetic from nonmagnetic and ferrous from nonferrous scrap. Use special devices for trapping valuable dust-disposable smocks, shoe covers and inexpensive floor coverings. In short segregate, and save.
Protection -stopping the leaks
Arrange scrap collection procedures in each department where precious metals are handled. For high-value scrap use theft-proof containers with small openings. And as an added precaution, weigh the containers periodically to make sure their contents are increasing, not decreasing.
Store all filled containers in a secured area, under lock and key. Before shipping your scrap to a refiner, weigh every container. Weigh it empty and then full, to determine net weight. Keep a careful record of net weights as a basis for checking your return, and possibly comparing refiners.
When you ship your scrap containers to your refiner, use numbered seals. Don’t use labels that advertise the containers’ contents. Instead, send along a covering order slip, noting the seal number, weight and contents of each container. Your refiner’s inspection of your lot should conform to this information. If it does not, you should be notified immediately, so that any discrepancy can be resolved before refining begins.
Selection-choosing the right refiner
Your choice of a refiner will have a direct bearing on the amount of your return. You’re dealing with a “blind” item, whose exact value is unknown to you, and you’ll be concerned to choose a refiner with an established reputation for competence, experience and business integrity.
We’d like to indicate briefly how Handy & Harman fulfills each of these requirements.
We’re competent. With seven modern refineries in
North America and abroad, and sales offices in key manufacturing areas, we can
supply prompt and total service. We have the most advanced technology for the
efficient processing of precious metal scrap in any quantity, from a palm-sized
package to a truckload.
We’re experienced. We’ve been leaders in precious metal refining, as well as fabrication, since the beginning of this century. And we were the innovators of many of the refining procedures and standards in general use today.
We’re trustworthy. In the course of more than a century of business dealings with manufacturing jewelers and silversmiths, our name has become a byword in the trade. We have established an unsurpassed reputation for fair dealing and business integrity.
Handy & Harman’s refining specialists will be happy to work with you, to help in setting up a systematic scrap recovery program that will enable you to recover the highest possible value from your precious metal scrap.
Precious Metal Determination
A quick test to determine the gold, silver or platinum group metal content of an article: At times you may find it necessary to determine the gold, silver platinum content of an article of jewelry. The procedures described below will enable you to make a quick test for each of these metals.
Gold
in testing for gold, the equipment you need includes a black stone slab, testing needles of different karats and colors, a bottle of nitric acid, one of aqua regia, and a bottle each of diluted nitric acid and aqua regia.
The first step in the testing procedure is to file a deep notch in the piece. Apply a drop of nitric acid to the notch. A bright green reaction indicates plated gold, while a pinkish cream color indicates gold plate on silver. Ten-karat solid gold will show a slight reaction. Over 10 karat will show little or no reaction.
To find the karat, file a clean spot on the article. Rub this spot on the stone slab, making a distinct mark. Alongside it make a mark that is equally heavy, using a test needle nearest in karat and color to what you suppose the gold to be. Apply acid to both markings at the same time. Use nitric acid to 10 karat and less, and aqua regia for higher karats. If the test needle marking reacts sooner than the other, wipe the stone dry and retest with a higher karat needle. If the reaction is slower, try a lower karat needle. When you have matched the two reactions, you will have determined the karat.
Green gold will react more slowly than yellow gold because it contains more silver. White gold will react slowly because of its nickel or palladium content.
Silver
The method for testing silver is basically the same as testing for gold. File a deep notch in the article and apply nitric acid. If’ the article is plated, a green color will appear. Sterling silver will produce a cloudy cream color, and in the case of coin silver the reaction will be dark or blackish. Silver of 750 fineness and lower reacts with varying degrees of green, becoming darker in color as the fineness is reduced. To be absolutely sure of the fineness make comparative tests with silver of known fineness.
Platinum metals
In testing for platinum metals follow the same basic procedure used for gold, employing test needles made of platinum, iridio-platinum, and palladium-platinum (various proportions). Apply aqua regia and compare reactions.
Iridio-platinum and platinum react very slowly. Lower grade alloys containing palladium, gold and base metals react rapidly. To speed up the testing procedure, heat the stone slab until it is uncomfortable to hold, or use a white stone which may show reactions better. Porcelain plates called “spotplates” are available for this purpose.