Refining

Anyone who works with dental alloys has to be vigilant about collecting scrap alloy. Particularly since some forms of valuable scrap are not very obvious. In your own office, you might be able to benefit from some of the techniques used by laboratories to manage and maximize scrap metal recovery.

Save Everything
Though gold crowns are obvious "keepers", the alloys used for porcelain fused-to-metal crowns often contain Gold, Platinum and Palladium.

Collect All Metal Dust and Grindings.
Two types of often-overlooked scrap are dust and grindings, even by some labs. A single cut of alloy can create $1.00 or $2.00 worth of "dust". There are two excellent tools and techniques that can be used to aid collection of these types of valuable waste in a laboratory environment.

TIP #1. If you grind or cut alloy, then it is important to use an accumulator with your vacuum (shown at right). This simple collection device separates all heavy particulates before they are sucked into the vacuum. (Don't forget to save the paper vacuum filters for refining as well.) When dedicated to collecting metal grindings, an accumulator's contents can yield over 50% alloy. The small expense of an accumulator can pay for itself very quickly.

Lab type accumulator shown with
vacuum from Vaniman.

TIP #2. If you cut or grind metal with a high-speed lathe, put a shallow tray or saucer of water directly under the cutting disk. The high-speed metal particulates can escape a vacuum, but will penetrate and be trapped in the water, rather than scatter as dust on the bench top. It seems insignificant, but this "dust" is actually a relatively coarse grind of metal that is 75% alloy.

Document Your Scrap
It is a good idea to divide the crowns, grindings, and dust into separate zip-loc type bags. Weigh and label the individual bags and record the information in a transmittal document to the refiner, and keep a copy for your records. Also, this information can give you a good idea about the value of your scrap. Full cast crowns and PFMs can yield over 90% alloy, grindings 75%, and dust up to 50% alloy after melt. Always send a copy of your documentation to the refiner along with the scrap.

What's it worth?
That is the “big question”, and you will find that no two refiners will agree on the answer. What can you do? Here are two ideas:

1. You can split your batch between two different refiners and ask for an assay only. If one refiner's assay and settlement seem too small compared to the other, then you can ask for your metal back, which you can send to the other refiner for a second opinion. In theory this is a good verification technique, however it is very difficult to split a batch exactly in half. To successfully use this technique, you must be able to separate not only by weight but also by metal content.

2. Keep a record of your past assays and settlements. You can estimate the value of your scrap by comparing it to the weights and compositions of past scrap batches. Microsoft Excel is an excellent tool for recording settlement data and then using the information to estimate the value of future scrap batches.

Select a Reputable Refiner
Interview prospective refiners before you use them. Ask questions about their receiving and refining processes, the assay, security measures, quality assurance, and settlement options. Also, ask to see a sample settlement statement. The statement should be a comprehensive document with the following information: before-melt weight, after-melt weight, the assay percentages (Au, Ag, Pt, Pd), the market value of the metals, and a clear accounting of all charges and fees.

What Does Refining Cost?
Costs will vary from refiner to refiner and with the size of the batch. You can expect to pay a different percentage for the recovery of each metal, Gold (Au), Silver (Ag), Palladium (Pd), and Platinum (Pt). Bottom line…you should receive approximately 90% of market value for after-melt weights of approximately 5 ounces or more. If you have a small amount of metal, then recovery fees and expenses could reduce your settlement to only 65% of the market value. It is best to accumulate a larger amount of scrap for the greatest return.

Settlement
Cash, Check, Gold or Other Metal
As payment for your scrap, most refiners will allow you to select check, cash, or metal. Metal is unique, because some refiners will buy back your metal any time you choose at current market prices. If you like to trade in the markets, and are confident in predicting the trend of precious metal prices, then you may be able to take special advantage of this payment option. Visit www.kitco.com for comprehensive market information.

With the conscientious implementation of a comprehensive scrap recovery plan, you will be surprised at how much money you will receive from scrap metal grindings, dust, metal crowns, and porcelain fused-to-metal crowns