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REMOVE THE GUESSWORK: UNDERSTANDING THE REFINING PROCESS
For the Best Value, Stick to Well-Established Alloy Companies

The process of refining dental scrap may seem mysterious to some lab technicians. Every so often, metal scrap and dust are collected and shipped off to a refiner to face an uncertain outcome. A short time later, you receive a gold coin or a check in return.

There is no magic or alchemy involved. Instead, there is a painstaking process - part science, part art - involved in transforming your scrap into an accurate settlement. The science can be learned from any textbook, but correctly applying science and art in the correct measure can be learned only through years of experience.

Collecting
Dental lab scrap comes in many different shapes and forms - some you may not have considered. Scrap is generally classified into the following major categories: Solid metallics, semi-metallics, higher-grade combustibles/sweeps, lower-grade combustibles/sweeps and low-grade refractory. These are further described below, according to the metallic versus non-metallic composition of their contents:

Solid Metallics
• Crowns & bridges, facings, castings, sprues, buttons, snips, wire, flashing, foil and even old ingots and damaged bullion coins – all virtually 100% solid metal, except for any incidental sweeps, facings and natural teeth that find their way into this category. After-process metal recoveries are usually 85-95%.

Semi-Metallics
• Bits of metal and abrasive materials remaining after the finishing process, which primarily consist of grindings and filings. Care should be taken here to remove any magnetic contamination with a magnet prior to shipment and after-process metal recovery is typically less than 90%.

Higher-grade Combustibles/Sweeps
• Residues remaining after polishing, which are commonly referred to as Polishing Dust and Vacuum bags containing more valuable (“richer”) sweeps. After-process metal recovery here is typically less than 75%.

Lower-grade Combustibles/Sweeps
• Shop dust, floor and rug sweepings, toweling, papers, air filters, low-grade vacuum bags and occasionally even carpeting. After-process metal recovery here is typically well below 50% and can often times fall to as low at 5-15%.

Low-grade Refractory
• Investment, crucibles, graphite parts and aluminum oxide suspected of being contaminated with trace precious metals. After process metal recoveries here are highly unpredictable, but generally below 5%.

In general, metallics and semi-metallics will have higher values than the other categories mentioned above and will invariably have a higher recovery or “yield” (equates to more alloy recovered “after-processing” as a percentage of the original weight received) than combustibles, sweeps and refractory. The combustibles and sweeps, for their part, are prone to be mixed with other non-metallics, including rouge, polishing media, floor dust, towels, filters, etc., which have no precious metal content in and of themselves, but which are impregnated or co-mingled with the waste precious metal alloys.

Solid metallic scrap from a casting operation or rejects from the lab’s quality control process are relatively easy to collect. Semi-metallics and higher grade sweeps, such as grindings and polishings, can be collected with any vacuum system that is equipped with filters or waste storage receptacles. Because the majority of your value tends to be in these two or three categories, it is incumbent that these materials are routinely collected, accounted for and stored securely until the materials are dispatched for refining. Do not expose yourself to internal pilferage; collect and secure your valuable scrap to the best of your abilities.

Larger scrap generators should endeavor to separate solid metallics from grindings, grindings from polishing, etc. In doing so, you will have a better idea of what your refiner is recovering by material category over time. Since minimum lot charges are usually only applied to very small lots failing to generate a minimum refining fee, larger shipments will avoid this penalty and still provide valuable historical settlement information that can be utilized for comparisons. For all shippers, it is very important that you do not mix mercury-bearing amalgam or any base metal alloys containing nickel beryllium with the rest of your scrap shipment. Mercury and nickel-beryllium alloys are hazardous to your refiner’s technicians, in the event that these elements vaporize during processing. They should not be shipped without proper hazardous materials documentation and then only to a legitimate reclamation company.

Always remember to legibly label your scrap lot with your name, address, phone number, and any special instructions regarding your scrap. Your scrap is money! Each year, we receive several lots without proper identification, which forces us to postpone processing until the shipper can be properly located and identified.

Sampling-Assaying
Sampling and assaying are the most important aspects of the refining process, bar none, because they form the basis of your settlement. Refiners “sample” each lot under tight controls in order to preserve economies of scale and to provide customers with a faster turnaround. The ultimate goal is to homogenize your lot in such a way as to obtain a sample that is truly representative of the lot from which it was extracted.

Solids and semi-solids can be readily melted into a homogeneous form and at Jensen we easily pin sample these materials thanks to our electric induction furnace capabilities. However, lots containing non-metallic or combustible content or those posing a bio-hazard due to the presence of tissue and teeth typically undergo additional processes, which include incineration and smelting. Incineration reduces both the non-metallic bulk of the lot and simultaneously eliminates any downstream handling risks. Once incinerated, the residual ash will either be routed to a pulverization and blending step, which reduces the lot into a homogeneous powder at a minimum or to a foundry where the ash will be mixed with flux and smelted, often multiple times, and cast into a intermediate production ingot.

A representative sample allows for the most accurate assessment of the contents during assaying. After the sampling process has been completed, the laboratory must maintain this same precision during assaying, in which a combination of time-honored labor intensive methods with rather sophisticated automated instrumentation are used to arrive at the precious metal determinations.

The advent of so many new dental alloys on the market has considerably complicated the sampling and assaying process. Many alloys embrace a wide range of precious and non-precious metal contents and therefore each lot presents new challenge to the refiner. In addition to gold, palladium, platinum and silver, we also contend with a host of base metals, including nickel, chrome, iron, monel, molybdenum, tin and tungsten, which find their way into scrap lots from time to time by simple cross-contamination.

As these alloys add new complexity to the dental refining industry, the activities involved in the sampling and assaying processes demand careful attention. The care with which sampling and assaying are performed is very much dependent upon the individual performing the task. Ultimately it is the precision with which these tasks are completed that determines the accuracy of your settlement.

To begin the sampling process for metallics, your lot is placed in a crucible and melted. When the homogenized metal reaches a given temperature above its molten point, a sample is taken via vacuum pin tube. The metal remaining in the crucible is cast into a bar. At Jensen, both the sample and the bar are then weighed and then we endeavor to hold both within reason until the customer approves the settlement, which is an accommodation that is somewhat unique for the industry.

There are several processes that can be used to determine the percentage of precious metals in your lot. Among the available analytical choices are fire and gravimetric assay, X-ray fluorescence, atomic absorption and ICP optical emission spectrometry. At Jensen, we use an industry-standard fire assay for gold, as it is still considered the most accurate method to date, however we also employ other corroborating methods for determining the remaining payable precious metals. We then run blind samples using two independent technicians, who are not at liberty to exchange information with each other. In the event that the assays fall outside lab tolerances, they are either repeated, or in cases of demonstrable segregation, the material is re-sampled in its entirety and then re-assayed once again.

The fire assay begins by combining your sample with pure silver and pure lead in a process called cupelling. The silver/lead sample combination is placed in a cupel (a small bone-ash bowl) where it is heated in a temperature-controlled furnace until the non-precious metals are absorbed, leaving a small button of precious metal. This button is combined with nitric acid and de-ionized water and heated. The acid slowly dissolves all metals, except gold. This process is called parting. Any other precious metals present can be selectively precipitated from the solution or subsequently analyzed in mass using either XRF or ICP instrumentation.

This detailed methodology is designed to protect both your vital interests and those of your refiner by creating the means to arrive at the most accurate and fair outcome as possible. While the system is relatively foolproof, there is still the issue of finding the right refiner for your needs.


Choosing A Good Refiner

Finding a refiner with whom you feel comfortable - someone who is honest, reliable and creditworthy - is paramount. While no checklist can verify individual integrity, there are some qualities and features you can look for to separate the wheat from the chaff.

Many refiners also manufacture and sell dental casting alloys. Refiners with alloy manufacturing facilities generally have all the technologies to process your scrap lot in house, as well as the metallurgical expertise (in the form of full-time metallurgists, chemists and technicians) to do the job correctly. These firms understand the material you are sending in, because they work with it everyday. Check to see if your refiner is in the alloy business. Those that are have a host of quality and audit requirements that they are mandated to supply to the FDA, the International Organization for Standardization (ISO), and/or MDD/EU.

As a group, they are required - by virtue of their medical device credentials - to painstakingly maintain their production, quality control and systems standards. Since these alloy companies would like you to purchase alloys from them, they have an equally compelling interest in satisfying your expectations and providing the best possible refining yields. Furthermore, Jensen is very flexible with regards to how alloy customers, with A/R balances, use their refining settlements. Provided that customers have not repeatedly abused their credit provisions or are not extensively past due, there are no restrictions against taking back a settlement check. If the refiner is not affiliated with an FDA and ISO-approved organization, you should proactively seek to assess their qualifications by other means.

Remember, when you are sending scrap to a refiner, you are also making an important credit decision. Above all else, you want to ensure that you are dealing with a refining organization that has strong financial credentials, where your material is not at risk. Here are just few helpful ideas:

• Larger shippers should consider accessing Dunn & Bradstreet, the Better Business Bureau or Secretary of State to determine whether the refiner is rated as being in good standing.

• Request a customer reference or two, so that you can gauge the types of labs that the refiner services.

• Prior to shipping your scrap, take the time to contact any new refining vendor to discuss and confirm their published processing rates and terms and do not ship without this confirmation. Ask them to spell out all aspects of the charges including their published (yields) payable returns; their processing and analytical fees; whether they discount the payable market prices and their refining fees or percentages, etc. Request a copy of a sample settlement in order to review its format and determine whether the information that is provided is sufficient.

• Determine how any disputes are handled and resolved. Do you have recourse to obtain your material back, if you contest the outcome?

• Ask for a brochure outlining their capabilities to make sure that they have the credentials to handle your valuables. Some refiners and independent brokers can attend trade shows, have websites and produce ads, but still run on a shoe-string. What checks and balances do they have in place to insure that errors are minimized and that there is demonstrated professionalism throughout the organization?

• Each time your scrap moves at the refinery, there is a potential for loss from theft or spillage. What security measures are taken to protect your assets? Tight internal security, like documented weigh-ins at each stage of a receiving/sampling process, video camera monitoring, locked storage and limited access areas can help prevent loss and ensure a fair settlement. Also, ask the refiner if they adhere to federal EPA and state environmental agency regulations. If they are less than vigilant in this area, it is possible that you might be held liable.

Personal Attention

Your refiner should contact you when your lot is received to confirm its safe arrival. They should provide you with literature about their company and their methodology, detailed shipping and rate information and free shipping containers. Ideally, your refiner should make a technical person available to discuss any questions you might have about your particular lot. Is the refining manager, general manager, or other senior management personnel available to help you when a problem arises?

Performed properly, a scrap-refining job takes time. If your refiner settles your lot overnight or on the spot, chances are that they are not sampling your scrap to the degree that is required, but estimating the value of your lot (and probably not in your favor). If your refiner takes a month to turn your metallics and high grade scrap around, they are inefficient and probably costing you money. A reasonable time expectation to process and settle your scrap is 10 to 15 days from its arrival, unless you ship an unusually large low-grade lot requiring additional incineration or processing. When you settle, a good refiner should offer you the option of receiving your payment in gold coin, alloy, or check and provide you with a detailed report. We would dissuade you from accepting a cash settlement(1) due to the newly enacted U.S. Patriot Act.

This detailed report, commonly referred to as a Settlement, should include a comparison of your original receiving weight to the after-processed or recovered weight and clearly demonstrate the payable results for each metal, as well as the refining fees and all other applicable charges. Merely showing you the net paid metals at their applied market rates, in absence of other details, is insufficient and leaves you guessing as to whether your process losses were acceptable. It also prevents you from making intelligent historical comparisons from one lot to the next or even contrasting different lots between different refiners.

Lastly, in the unlikely event that you do contest the outcome, the refiner should also give you satisfaction in knowing that you have a few different avenues of recourse. This recourse could include requesting a simple re-assay, requesting that the material be totally re-sampled and then re-assayed, or as a last resort, obtaining the return of your material, slag and all prior samples - even though the material has been converted to a homogenous ingot or powder form.
Your refining relationship should be an open book. We hope these tips act as a useful guide in choosing the best refiner for your business and we hope your next refining experience is a pleasant one.

For more information about how Jensen could play a contributing role to your successful scrap program, please call your Jensen Account Manager at 800-243-2000. We appreciate your consideration.

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(1) Postscript: A Note About Cash Settlements
With the passage of the U.S. Patriot Act, cash payments – which had been a traditional form of payment in the dental industry - have come under heightened scrutiny. Cash payments are no longer under the radar screen of the U.S. government. A refining company is now considered a precious metal dealer, under the letter of the Act, and is now required to maintain adequate records, have a compliance officer and full fledged Anti-Money Laundering program. As such…..the US Patriot Act (of 2001), Section 5318(h) requires a “dealer in precious metals” to institute an effective Anti-Money Laundering (AML) Program, designed to best detect and deter money laundering and terrorist financing from abuse of our industry. The US Treasury deems you to be a “dealer in precious metals” and have a AML Program IF: (a) Your are in the business of purchasing and selling precious metals of .500 fineness purity or higher; (b) Your purchase and sell more than $50,000 per annum of those precious metals; (c) You are not a qualified retail seller buying almost exclusively from “dealers;” and (d) You are not a manufacturer of fabricated goods with minor precious metal content. By this definition, all U.S. Refining companies fall into the “dealer’s definition” and will be required to put a AML Program into place and to monitor all suspect cash transitions, as well as the parties associated with those transactions.