Seven decades of precious metals refining with response and responsibility

Yield…Yield…Yield.

yield...yield...yield.Yield. . .yield. . .yield.

An alternative approach to enhanced profits.

Guest Editor Richard DeSantis, Sabin Metal Corporation


The benefits of increased yields are obvious both for producers of hybrid micro-electronic materials, circuits, and packages as well as for their users. And we all do what we can to maximize yields. But if you can stretch the word a bit, you could say that increased yields might also he obtained by methods other than reducing waste at the materials formulation stage by printing and firing only perfect thick film circuits, or by producing hybrid packages that always meet precise performance specifications.

In fact, if you equate "yield" with profitability, we can look at another approach to increasing yield that has nothing to do with production efficiencies. And that is the ability to recover the lost dollars from the precious metals contained in hybrid circuits, ICs, interconnects, ceramic packages, and thick- and thin-film materials.

Hybrid microelectronic devices including parts rejects, customer returns, production and plating clippings, drillings, blankings, stampings, sweeps, solutions, resins, and wipes contain precious metals such as gold, silver platinum, palladium, and others. There are many precious metals refiners around the country whose business is to recover these precious metals from hybrid microelectronic products. In many cases, selecting a refiner for your returns is merely a matter of finding one whom you trust, and in whom you have confidence.

The most important considerations with regard to selecting a refiner are the company’s concern for the environment, the size of the organization (does it have the financial resources to assure payment either in returned materials or dollars?), and the techniques and equipment used to determine the precious metal content in your returns. You should also evaluate the processing methods employed to maximize "yield" with regard to recoverable material and thus maximize profits for your business.

For example, with regard to determining precious metals content, you should seek a refiner with a modern, well-equipped analytical laboratory, preferably one that uses classic volumetric, gravimetric, and fire assay techniques as well as advanced technology X-ray fluorescence, atomic absorption, and ICP emission spectroscopy. These techniques—when used in combination, depending upon hybrid product or precious metals content—are the most exact for determining actual precious metals content, and have been approved by the American Bureau of Standards and NYMEX/ COMEX (internationally recognized precious metals trading organizations). This information should he provided to you through detailed weight and analysis reports; in fact, you should be offered the opportunity to follow your shipment of returned materials throughout the process. Some laboratories assay samples in triplicate so is to cross check procedures as well as technicians.

There are many different kinds of equipment and procedures used during the actual refining process. These include rotary and crucible furnaces, kilns, roasters, thermal processors, pulverizers, granulators, screens, blenders, auto samplers, reactors, dissolvers, precipitators, electrolytic cells, and filter presses, among others. Again, depending upon hybrid product and specific precious metal content, the refiner generally should use a combination of pyro-metallurgical and hydrometallurgical processes to achieve the highest possible metal recovery at the lowest possible processing cost. It is also in your best interest that these procedures are handled "in-house" by the refiner, as opposed to subcontracting them outside. This is a key issue: Keep in mind that the more it costs your refiner to process your materials, the less return you’ll likely get.

Another issue with regard to returns concerns acceptance of the refiner’s materials by "sanctioned" trading organizations such as NYMEX/COMEX and other internationally recognized metal exchanges. This assures you of receiving the highest quality materials in return for your products or processes, in addition to enhancing your confidence in the refiner’s integrity.

Now that you’ve looked at the business and technical (recovery) sides of a refining organization, as well as its capabilities, there is another consideration which can be significant, based upon today’s focus on the environment at virtually all levels of government. This concerns the policies and procedures of the refiner with regard to generating (or eliminating) air or water pollution — and the possible implications you, as a customer, may face if there is an enforcement action against the refiner. Today, it is not uncommon for the customer of a precious metal refiner to be named in a lawsuit.

Before getting involved with a precious metal refiner, you’d want to know exactly what the organizations policies and procedures are with regard to environmental protection and related issues. Not only should you know precisely how your precious metals are being processed, but those of other customers as well. Most important, you want to know the disposition of any atmospheric or effluent discharges. Only with this information can you enter into a relationship with a refiner with peace of mind and he assured that the environment will not be violated, exposing your firm to possible serious negative financial consequences.

It is in your best interest to seek a refiner who you are comfortable with, and who can provide assistance with regard to understanding environmental regulations that may affect your waste materials. The refiner should work closely with local, state, and federal agencies on issues such as environmental compliance, licensing, and documentation, among others.

In choosing a refiner you should select one that operates a "zero discharge" facility, eliminating all possibility of creating pollution problems in the first place. A zero dis-charge facility typically evaporates process water (the most common source of pollution) and reprocesses any residue, thereby eliminating any discharge of materials, chemicals, or residues in the atmosphere.

To help determine this, when you look at your refiner’s facility, notice baghouses, wet scrubbers, and waste liquid neutralization equipment along with the ability to process waste liquid thermally. The baghouses should he equipped with afterburners to further reduce pollution possibilities.

Asking the right questions of a prospective precious metal refiner may pay big dividends in the long run, both from the perspective of enhancing your profits through maximum recovery of precious metals from scrap hybrid products, as well as the peace of mind you’ll have by working with an environmentally conscious refiner.