Jensen Technologies, LLC

Laboratory Services Au-Ag-PGM Fire Assay Effective Date: January 1, 2012

15985 South Golden Road, Unit H Golden, CO 80401 Phone: (303) 478-3929 E-mail:[email protected] Website: www.jensentechnologiesllc.com

1 FIRE ASSAYING J-Tech and others highly recommends analysis of samples by the fire assay method to determine precious metal content Fire assaying, in use for thousands of years, still stands the test of time. Jim Steinberg in Mining Artifact Collector principally takes the following summary of the process from “Assaying,” The article was written from a historical viewpoint, but the process is the same as the fire assaying of today except for the use of electronic balances, mechanical pulverizers, and so forth. In Webster’s dictionary assay is defined as follows: in metallurgy, the determination of the quantity of any particular metal in an ore or alloy; especially, the determination of the quantity of gold or silver in coin or bullion. While the most common definitions of the word assay do revolve around the determination of gold or silver in ore or alloys, assay is itself a much broader subject that involves the quantitative analysis of chemical substances both organic and inorganic. The primary interest of this article is the assay of metalliferous ores. Because even this is a broad subject that has filled a large number of books, the highlights of fire assay by the scorification process in gold bearing samples are going to be summarized here. Initially, the sample must be reduced to a powder so that it can be tested. This powder is often called “pulp” and the scales to weigh it are called “pulp scales.’ The assayer begins by running the sample through a crusher. With many crushers, the fineness of the output is adjustable. The sample is still not sufficiently fine after initial crushing, so the assayer then puts it onto a “buck board” for further pulverization under a muller that rubs the material into a finer state with a sliding motion. Harder samples are made finer using a device called a “rocker” that uses a heavier weight upon the sample being pulverized. Assayers doing a smaller volume of work might use an iron mortar and pestle, although it requires considerably more effort. As the pulverization of the ore sample proceeds, the assayer mixes and then divides the sample into smaller and smaller portions until he has reduced the amount of the sample to the size that he will actually process (Splitting). This can be done manually or by using devices designed to assist in the sampling process. This is done to assure uniformity within the sample and to increase the accuracy of the assay to be performed. When the sample has been sufficiently pulverized it must be run through sieves of the appropriate size. Material that does not pass through must be further ground until the entire sample will pass through the sieve (Sieving). What has passed through the sieves must then be carefully mixed and then stored in a marked container. The contents of these containers should not be shaken or agitated as this can cause the materials to begin stratifying according to their masses and upset the accuracy of the process. From various parts of the container (Cone & Quartering), selected portions of the sample are taken and weighed. The weighed sample is then placed in a scorifier, a dish that can sustain the heat of the assayers oven. Along with the sample litharge (a form of lead), various chemicals that will assist in allowing the metals in the sample to separate from the slag are included. This mixture is roasted in the assayer’s oven (Assay Furnace) until the melted slag completely covers the lead bead that forms in the scorifier. The sample in the scorifier is next poured into the cup of the scorification mold. Here it is allowed to remain until it is cold. Once cold, the sample is removed from the mold. It is cone-shaped, with the metal at the apex of the cone and the slag forming the bottom. The metal part, or lead button, is detached from the slag. This button may then be hammered into a cube with no sharp corners. The button is placed into a cupel of appropriate size that is then placed in the furnace. Cupels are comprised of a material called bone ash. When it has come up to heat, the button is placed in the cupel. In this process lead and other impurities within the button are both oxidized and driven into the material of the cupel itself a good cupel is capable of absorbing its own weight in litharge (the lead in the sample). The metal in the cupel melts and will be observed to become smaller as the process proceeds.

2 Towards the end of the process, the surface tension of the metal will draw it into the shape of a bead. The bead will appear to be in rapid motion and at the moment the process is complete, an optical energy release will sometimes be visible as a “flash” or “blick.” At this point, the cupellation is complete and the cupel with its bead may be removed from the oven. Now the bead is removed from the cupel. The composition of the bead should now be gold and silver. The bead is weighed in a type of scale made specifically for this task called a button scale. Button scales, because they are measuring something so small, must also be very accurate and are thus always enclosed, while analytical or pulp scales do not always require enclosure. Weighing the bead has shown how much metal is there, but has not told how much is gold and how much is silver. The next step of assaying is called “parting.” In this step the gold and silver are separated from each other by solution. The weighed bead is flattened, placed in a porcelain capsule and treated with a solution of water and nitric acid. Once reaction begins, the capsule is warmed. Silver in the bead forms a solution of silver nitrate that is carefully washed away until only the gold, if any, remains. This is gently dried in the porcelain capsule and then removed. The final sample of gold is again weighed in the button balance, unless it is too small to be weighed, in which case it is simply described as a “trace” or “color.” From the weight of this bead the assayer will then calculate the gold and silver ore value per ton of ore. The assayer may use a special set of assay ton weights when weighing the gold to more easily calculate the assay value of the ore. In Summary, Fire Assaying is a three-step process: Fusion - The sample is mixed with flux, and then heated to 1095 C. A slag containing the unwanted elements and a lead button containing the gold and silver are formed. Cupelling - The lead button is heated and oxidized in a bone ash cupel that adsorbs the lead oxide, leaving a precious metal bead in the cupel. Parting and Weighing - In this part of the process, the gold is separated from the silver. Two weighing steps are involved. Discussion of Fire Assaying’s Purported Problems Fire assaying is a series of chemical steps that takes advantage of the precious metal’s chemical behavior. Those who claim they have non-fire assayable gold are saying they have a substance that chemically does not behave like gold. Arguments used to explain why fire assay is not applicable to their “Colloidal” or “Micron” gold generally falls into one of the three categories discussed below. “The particles are so small they vaporize and so are not in the button.” 1063° C is below the melting point of gold. Even if the temperature goes above this, the vapor temperature of gold is 2808 C. So very little is lost. H2O, for example, has vapor pressure 6 orders of magnitude higher. “Small particles of gold float on the surface of water so they float on the slag.” This ignores the process that goes on. It is not dependent on gravity. The Pb02, now Pb, dissolves the gold. It is the Pb that collects at the bottom of the crucible. “Interfering elements mask the gold.” The London Mint ran an assay of 1000 mg tellurium, I g Au, 25 g Pb and skipped the fusion step! Even so the “worst” they could do was to lose about half the gold. These conditions are highly unlikely in a rock sample. What about the platinum group metals? These, if present, report with the gold in the bead.

3 Conclusion Fire assaying, in use for thousands of years, still stands the test of time.

Reprinted and edited from the Arizona Department of Mines and Minerals Resources website.

Fire Assay Procedure (General)

Classification of ores:

Using a 100 X shop Microscope, carefully examine and classify the ore according to the amount of silicates, sulfides, and lead that it contains. Class I: High in silicates and carbonates: Has no oxidizing or reducing power. If an appreciable amount of silicate, such as quartz, is present giving the ore a glassy or vitreous luster, do not add more silica or glass (borax glass) to the basic flux used. Quartz (Si02) is the strongest acid in its molten state. Class 2: High in sulfides, carbonates and lead: If the ore is rich in sulfides (pyrite, galena, tellurides, sulfur, etc.), it should first be ground, then roasted. Place it in a roasting dish and roast in an oven until all of the sulfide fumes are driven off. If the ore contains only a small amount of sulfides, these can be removed by placing a 16d (penny) steel nail in the crucible with the assay. If low in lead, add an additional 12g of litharge to the standard flux. Class 3: Iron, manganese, etc.

Assay Procedure

• Examine ore and adjust flux as explained, then pulverize as finely as possible, at least 100 mesh (finer the better).

• Weigh out one assay ton, 29.2 g (1/2 AT or 14.58g) of ore, mix thoroughly with appropriate amount of flux and place in a 20g or 30g crucible. This is your assay.

• If sulfides are present, roast ore or use niter with the charge.

• Place the crucible in the furnace and turn to high heat. When the furnace reaches 1095°C. Note the time or set a timer. The assay must remain in the oven at this temperature for 60 minutes.

• Remove the crucible from the oven. Pour the entire molten assay into a pouring mold and allow it to cool. • When the assay has cooled, remove the lead button from the bottom of the mold. • Pound the button into a cube breaking away the slag. It is all right if a little slag adheres to the button. Brush off the button with a button brush. • Put the button in a cupel, and place it in the furnace at 950 °C until the cupel has absorbed all the lead. The remaining bead contains all of the gold, silver, and PGM’s in the assay. • Examine the bead carefully with a magnifier. Its color and surface appearance will tell you

4 something about the ratio of gold/silver/PGM’s present and whether these elements should be parted as described below.

• Weigh the bead. Each milligram (mg) in weight represents I troy ounce of precious metals in each ton of the original ore, or: I mg = I oz/T.

Parting

If your bead appears to be relatively pure gold, no parting is necessary. If the presence a significant amount of silver and/or PGM’s is indicated, proceed as follows: To part the silver from the gold, the button must contain at least 3 times as much silver as gold. If it does not, add sufficient assay silver to make this ratio. This is called INQUARTATION. Then proceed to ANNEAL the button as follows:

Annealing

Anneal by repeatedly hammering the bead flat and heating it in a flame until it’s red-hot. Repeat heating after every couple of blows with the hammer. The annealed strip is then rolled into a loose coil or Coronet, placed in a parting cup and covered with a parting solution, a mixture of chemically pure nitric acid and distilled water, 6 parts water to I part acid, or a 6/1 ratio. Heat the flask gently. The coronet will blacken as the hydrogen bubbles off. Do not allow it to boil too fast. If the coronet becomes immediately black, add a little more distilled water to slow the action.

Finish

Gravimetric

Instrumental: Flame AAS, GA-AAS

Priority Service Routine analyses are normally completed within 5 working days. Samples arriving after 3:00 pm are logged into our system on the following business day.

When our analysis load permits, priority services are available for an additional charge. These services do not guarantee Results within the number of days specified as some procedures or combinations of procedures require additional time. Priority service does insure that your samples will be prioritized over standard service samples. Priority services require prior arrangement to insure availability. Projects requiring exceptional levels of effort may be subject to additional surcharges.

Priority Service $Quote

Results are delivered by mail or email, typically within 5 working days after sample receipt.

Quality Assurance / Quality Control We maintain a QA/QC program to assure reliable results. We have certified standard reference materials for a variety of matrices and analytes, allowing us to provide better matching between reference material and samples. In some cases, we have alternate methods that can be used to confirm values obtained by our standard methods. We strive to make

5 results that are very reliable, but we encourage customers to contact us if data does not meet expectations. Since quality is very important to us, we within reason, verify results at no additional charge.

Quality control (QC) data is available as a part of your results. The data includes blanks, laboratory control samples (LCS), matrix spikes, and associated raw data. Contact Jensen Technologies for more information regarding your quality assurance requirements.

Duplicate Analysis

Duplicate analysts are usually charged at the normal rate of a single analysis. Some services have special rates for duplicate (or multiple) analyses.

Special Handling

Hazardous Material Handling requires special personal protective equipment or monitoring.

6 Sample Preparation

Routine

Rock and ore: $25 for first 2 pounds (0.9 kg) + $2.50/pound (0.45 kg) for each additional pound (0.45 kg). Includes splitting and pulverization to –200 mesh (74 μm). This is for material ¼ inch or less.

Crushing: Greater than 3/8 inch material $25 for first 2 pounds (0.9 kg) + $2.50/pound (0.45 kg) for each additional pound (0.45 kg).

Wet Gravity Concentration RP-4 Gravity Table

Tabling: $50 plus $2.00 / Kg ($1.00/lbs) 1 Kg. = 2.2 lbs. 200 lbs = $50 + $200 = $250 100 lbs = $50 + $100 = $150

Introduction Global Mining Solutions is dedicated to producing the ultimate gravity concentrating equipment on the world market. Combining the world’s most used and successful gravity- concentrating table, with a “unique” reverse polarity magnetic separator, achieved this. "Designed for hard rock gold mines, placer gold deposits, or heavy mineral separations. Spinning rare earth magnets are placed underneath the deck surface of concentrating shaker table. Reversing the magnetic polarity of magnetite at about 800 cycles per minute (Elliptical polarization of the magnetite) magnetite will rise to the surface of the feed material and will be washed into the tails by the transverse flow of wash water. Magnetite has the ability to create more magnetism than the applied magnetism and will align their magnetic poles with each other in long chains. This basic concept was invented by Darvin P. Wade and has revolutionized placer concentrating equipment and the minerals concentrating equipment. An ABS plastic (truck bed liner material) one piece molded riffled deck and launder tray is incorporated into the RP-4 gold shaker table. RP-4 shaker concentrating tables will process up to eight hundred pounds or more per hour (average 400 lbs. black sands) of sand sized feed with little or no loss of gold. Four hundred pounds of river gravel with a maximum size of 3/4" inch can be processed when using a submerged deck screen. With the factory installed deck screen the RP-4 gold separating table will operate as a shaker screen, a magnetite separator and gold gravity concentrator. The submerged deck screen is just one of many new and innovative techniques incorporated into the new line of heavy mineral concentrators. gravity concentrators will recover 99% of microscopic gold from your magnetite concentrates and is designed to run continuously ". We have users claiming the heavy mineral concentrators are saving down to one micron. Competitive tests with drum magnetic separators, spiral separators, concentrating bowls, gold centrifuges, vanners, micron tables, static charges, etc., prove the RP Gravity Concentrating Tables to be superior in speed, recovery and economics. (Reduce tons to pounds, without losses). RP-4 mineral concentrating tables are factory designed with a raised riffle for maximum recovery of micron sized gold and platinum metals.

7 RP-4 gravity concentration tables weigh 60 lbs. and require about 8 to 14 gallons of water per minute. Table comes equipped with a 1/2 HP motor and uses 8.6 amps. "1/3 HP motor is optional at 6.8 amps.

Precious Metals Au-Ag-PGM Fire Assay, Instrumental

Flame Atomic Absorption Spectrometry (AA)

Gold (Au) Flame AA-Aqua Regia $50 Palladium (Pd) Flame AA $50 Platinum (Pt) Flame AA $50 Silver (Ag) Flame AA-Aqua Regia $25 Silver (Ag) Flame AA-PPVD (HNO3-HCl-HF) $25 Rhodium (Rh) Flame AA $50 Cyanide, Ag Hot Cyanide AA $50 Cyanide, Au Hot Cyanide AA $50

Graphite Furnace Atomic Absorption Spectrometry (GF-AAS)

Ruthenium (Ru), GF-AAS $50 Gold (Au), GF-AAS $50 Silver (Ag), GF-AAS $50 Platinum (Pt), GF-AAS $50 Palladium (Pd), GF-AAS $50 Rhodium (Rh), GF-AAS $50 Fire Assay (FA)

8 Au, FA, Gravimetric, 15g $50 Ag + Ag, FA, Gravimetric, 15g (inquart) $50 Au, FA, GA-AAS, 15g $50 Ag, FA, GA-AAS, 15g $50

Au Pt Pd Rh, FA, GA-AAS, 15g* $100 Au Pt Pd, FA, GA-AAS, 15g* $75

*Au, Ag, Pt, Pd, Rh, Ru GA-AAS, Tellurium Coprecipitation Collection available $250

Microscope Digital Photos of FA Prills $25/Sample

The minimum charge is $50 for Fire Assaying

9 ORDERING INFORMATION GENERAL Please, complete either our Analysis Request Form, (photocopy the form on page 11.) or supply the following information on your company's stationery: 1. Purchase Order Number. 2. Reporting and billing addresses. 3. Reporting phone number, FAX number and/or email address 4. Street address for sample return. 5. Sample I.D. 6. Analyses requested. 7. Information about the chemical structure and physical properties of all samples submitted for analysis 8. The expected levels and required detection limits of requested analytes 9. Any hazards associated with the samples 10. Sample disposal information (see below)

Samples arriving after 3:00 pm. will be logged into our system on the next business day. Jensen Technologies reserves the right to refuse to receive or analyze samples that are deemed to be unsafe to handle in our facilities or for any other reason.

SAMPLE QUANTITY REOUIRED Except for some physical tests, 100 grams of sample are typically an adequate amount for most analyses. Check with Jensen Technologies to verify the sample quantities and/or handling required for analysis. .

ANALYSIS REPORTS Analysis reports are normally sent by e-mail. Upon request, reports will be provided by telephone, hard copy, or FAX at no additional charge. Inquire about other reporting formats. All results are held in strict confidence. Results will be released to a third party only when authorized by the original client.

QUOTATIONS Written quotations are available to secure pricing for projects and special analyses. These quotations are valid for 30 days unless otherwise noted. .

SAMPLE STORAGE, RETURN and DISPOSAL All samples remain the property of the client Any unused portion of a sample will be returned unless the client certifies that the sample can properly be disposed of in the municipal waste system (landfill or sewer). A fee of $3.00 per sample (minimum $10.00 per order) will be billed for all returned samples. A minimum $50.00 surcharge will be added to orders requiring special packaging and labeling as hazardous materials. Samples are normally held for 30 days after reporting. Perishable samples will be returned to the customer or discarded after allowed holding times have elapsed.

10 PRICING POLICY

It is the policy of Jensen Technologies to set prices at a fair and equitable level for quality analytical services. While we attempt to maintain the listed rates, the prices are subject to change without notice. Specific test methods and pricing may not be applicable to all sample types. In these cases the customer will be notified and, if appropriate, a special price quotation will be provided.

DISCOUNTS Discounts may be available for large quantities of samples. Contact Jensen Technologies for more information.

TERMS Payment for services must accompany order unless credit is arranged.

PAYMENT

We accept cash or check for payment of services.

11 Jensen Technologies, LLC Assay Lab

Website: jensentechnologiesllc.com 15985 South Golden Road, Unit H Golden, CO 80401 Cell: 303-478-3929 E-mail: [email protected] Sample Submission Form Please include this form with samples (please print)

Today’s date: Project No: Purchase order number: Date results are required: Project Name: Price: Company information (or include business card) Company name: Contact for report: Phone number: Fax number: Street address: P.O. box: City: State: ZIP Code: Description of work requested Sample # Matrix Sample/Reference description Analytes Cost/Sample (used in final report) $ 1 Au Au, FA, 15g Grav 50.00 2 Ag Ag, AAS-PPVD 25.00 3 EDXRF 75.00 30 elements 4 Sample 25.00 Prep 5

Number of Samples: Date Received: reporting (standard turnaround for results are 5 working days after receipt of sample)  No report X Standard turnaround Disposition of samples after analysis

 Discard samples after 3 months X Return samples after analysis Forward samples on to:

Include Contact: * Extra charge Authorization Signature: Received Payment of $ for services rendered on ___/___/___

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Carl M. Jensen Payment for services must accompany order unless credit is arranged.