Spectrometer for determining the gold sample. GoldXpert Precious Metals Analyzer

Gold- an element of a secondary subgroup of the first group, the sixth period of the periodic system of chemical elements of D.I. Mendeleev, with atomic number 79. Denoted by the symbol Au (lat. Aurum). Simple substance gold (CAS number: 7440-57-5) - noble metal yellow color.

Physical properties

Pure gold is a soft yellow metal. Some gold products, such as coins, get a reddish hue from admixtures of other metals, in particular copper. In thin films, gold shows through green. Gold has exceptionally high thermal conductivity and low electrical resistance. Gold is a very heavy metal: the density of pure gold is 19621 kilograms per cubic meter (a ball of pure gold with a diameter of 46 mm has a mass of 1 kg). A liter bottle filled with gold sand weighs approximately 16 kg. The heaviness of gold is a plus for its extraction. The simplest technological processes, such as, for example, flushing at sluices, can provide a very high degree of gold recovery from the washed rock. Gold is very malleable and malleable. From a piece of gold weighing one gram, you can stretch a wire three kilometers long or make gold foil 500 times thinner than a human hair (0.1 microns). Through such a piece of foil, a ray of light shines through in a greenish color. The softness of pure gold is so great that it can be scratched with a fingernail. Therefore, in jewelry, gold is always alloyed with copper or silver. The composition of such alloys is expressed by breakdown, which indicates the number of parts by weight of gold in 1000 parts of the alloy (in Russian practice). The purity of chemically pure gold corresponds to 999.9 fineness - it is also called “bank” gold, since bars are made from such gold.

Application of X-ray fluorescence analysis for analysis and control of gold content in industry:

• In electrical engineering: In terms of its chemical resistance and mechanical strength, gold is inferior to most platinum group metals, but is irreplaceable as a material for electrical contacts. Therefore, in microelectronics, gold conductors and gold electroplating of contact surfaces, connectors, and printed circuit boards are used very widely. Accordingly, control over the quality of raw materials, percentage composition and thickness of gold plating is necessary.
• In science: Gold is used as a target in nuclear research, as a coating for mirrors operating in the far infrared range, and as a special shell in a neutron bomb.
• Gold solders wet various metal surfaces very well and are used in metal soldering. Thin gaskets made from soft gold alloys are used in ultra-high vacuum technology.
• In dentistry: Dentistry consumes significant amounts of gold: crowns and dentures are made from alloys of gold with silver, copper, nickel, platinum, and zinc. Such alloys combine corrosion resistance with high mechanical properties.
• In pharmacology: Gold compounds are included in some medications used to treat a number of diseases (tuberculosis, rheumatoid arthritis, etc.). Radioactive gold is used in the treatment of malignant tumors

Gilding of metals (in ancient times it was exclusively an amalgam method, nowadays it is mainly galvanic) is widely used as a method of protection against corrosion. Although such coverage is not noble metals has significant disadvantages (soft coating, high potential for pitting corrosion), it is also common due to the fact that the finished product takes on the appearance of a very expensive, “golden” one.

In jewelry

The traditional and largest consumer of gold is the jewelry industry. Jewelry is made not from pure gold, but from its alloys with other metals, which are significantly superior to gold in mechanical strength and durability. Currently, Au-Ag-Cu alloys are used for this, which may contain additives of zinc, nickel, cobalt, and palladium. The corrosion resistance of such alloys is determined mainly by their gold content, and the color shades and mechanical properties are determined by the ratio of silver and copper. The most important characteristic of jewelry is its fineness, which characterizes the gold content in it. Because jewelry making is critical to damage to samples (chip, cut, scratch), a non-destructive testing method is required; the easiest way to control a sample is to carry out the RF method, it does not leave the slightest trace on the sample, is accurate, and the test takes up to several minutes. X-ray fluorescence analysis is very important for determining the gold content and hallmarking in jewelry, numismatics, and determining the composition of coins.

In dentistry

Dentistry consumes significant amounts of gold: crowns and dentures are made from alloys of gold with silver, copper, nickel, platinum, and zinc. Such alloys combine corrosion resistance with high mechanical properties. Analysis of gold content in dental crowns and dentistry is very important.

Precious metals counterfeited Always.

They spoiled the sample by adding an excess amount of base metals to the gold alloy, creating similar in appearance to noble aurum, yellow alloys that did not contain a single gram of gold.

Demand creates supply, and the demand for cheap imitation gold has always been great.

During the 19th and especially the 20th centuries, the “imitation industry” developed particularly rapidly.

Another example: there is also a so-called “ White gold" is a gold alloy that is valued as highly as classic yellow, and in some cases even higher. But distinguish by visual inspection white gold from silver or platinum difficult.

In order to accurately determine what metal or metal alloy it is made from jewelry, an ingot is cast or a coin is minted, and precious metals are intended.

A precious metal analyzer is a device designed to determine what metal a particular product is made of - a ring, coin, ingot, etc.

Device determines the exact quantitative composition of different chemical elements in a product, shows the percentage ratio of noble to base metals.

Simply put, a modern precious metals analyzer determines how much pure metal a given product contains:

• gold;
• silver;
• palladium;
• rhodium;
• other noble metals, and how many - impurities (, chromium, etc.).

The ratio of gold or silver to the amount of impurities is determined product sample.

So, for example, the most common 585 gold standard in Russia contains 58,5% pure metal, and everything else is impurities, introduced to give the alloy greater strength, since pure gold is too soft.

Some devices immediately display the sample, others display a numerical code or the percentage of various metals on the screen, and the sample is determined by the appraiser using a special table.

Of course, if there are no precious metals in the product, the device will also show this.

Operating principles of the device

From a design point of view, a precious metals analyzer is a highly specialized metal detector, similar to those used in other areas, for example, in rolled metal.

Only he is certified and designed for detection and recognition not of iron and carbon in a steel alloy, and not of copper and tin in a bronze alloy, but namely precious metals: gold, silver, platinum in combination with various possible additives.

Only non-destructive testing can be used to check the quality of jewelry. This imposes restrictions on physicochemical methods, which can be used for research.

This is quite logical - you can’t spoil the product by separating fragments from it for chemical tests.

On this moment To create precious metal analyzers, two operating principles are used: X-ray fluorescence and electrochemical.

X-ray fluorescence

This method is based on influencing an object low-power x-ray radiation using an artificial or natural source.

Early devices used natural materials - plutonium-238, iron-55, etc. Nowadays artificial ones are used more often.

The radiation power is so low that cannot harm a person even after prolonged use of the device.

A stream of X-ray radiation “hits” an object, causing it to respond in the X-ray spectrum invisible to the human eye. The induced learning response, which is a flow of electrons, is detected by a highly sensitive sensor. This is fluorescence.

Every chemical element gives its characteristic “glow” in the appropriate spectrum. The higher the content of a substance, the more powerful it will fluoresce.

A special program analyzes the total spectrum of radiation and determines the percentage content of different metals with a high degree of accuracy - up to 0.1%. For every metal an individual program is required.

Another name for this device is an energy-dispersive detector, or spectrometer.

Electrochemical analysis

This method uses an electrochemical reaction that occurs when contact of metal with electrolyte- sulfuric or hydrochloric acid diluted in water.

The idea behind this method is that each metal has its own, unique electrical conductivity parameters.

When checking with this device, a conductive contact from the analyzer is attached to the jewelry.

The second contact is combined with a sensor, which, in turn, is combined with a container containing electrolyte.

On the surface of the product a drop of electrolyte is squeezed out.

Immediately after this, electrochemical reaction- Some electrons go into the electrolyte. In this case, it becomes possible to determine the metal from which the product is made - by its electrical conductivity.

Electrical conductivity determined by voltage, which occurs at the point of contact of the electrolyte spot and the metal surface of the product.

To determine the exact chemical composition of a substance comparison with a standard made of platinum is used. Platinum is usually used to make one of the electrodes.

This method also requires special firmware in the device's memory. For now it is considered obsolete, Although a large number of electrochemical detectors are still used in various departments of the Assay Office, at customs special posts, in pawnshops, etc.

How to analyze gold and other precious metals with a detector?

It all depends on the principle on which the analyzer is built and its design. Easiest to handle portable spectrometer, which similar to a handheld scanner, used in stores.

It is necessary to set the expected metal in the settings (i.e., select what we will test for), enter additional parameters (in some models) - this could be, for example, the “white gold” setting, so that the device initially cuts out some impurities that are impossible in it.

After this it is necessary direct the emitter detector on the product and wait a while- 15-20 sec.

After this, information about the chemical composition of the object under study will appear on the screen.

It is more difficult to work with stationary devices, especially those that operate on the electrochemical principle.

This requires certain knowledge.

Before starting to operate the device you must:

• calibrate;
• set the correct mode;
• correctly connect the contacts to the test sample.

Review of detectors for checking precious metals and their price

For comparison, we will take three models - two domestic and one foreign-made.

1. "Prizma-M" produced by the Granat Group of Companies.
2. Gold detector "DeMon-Yu" produced by "Ultramag".
3. "GoldXpert" produced by a Japanese company

Analyzer "Prisma-M" from the St. Petersburg group of companies "Granat" is a professional device recommended for state assay offices, customs posts, pawn shops, etc.

The principle of operation is X-ray fluorescence.

Type - stationary, portable type.

To scan a product, you need to place it in a special chamber of the device.

The Prizma-M gold detector also determines silver, palladium, rhodium, platinum and the content of various impurities in them in concentrations of up to 0.1%.

Total weight - 11 kg. Battery life is up to 2 hours. A large number of modes provide flexibility in setting up the product.

Prices available on request. Approximately – within 100,000 rubles.

Detector "DeMon-U" is a portable device for determining the purity of gold and other precious metals, operating on the electrochemical principle.

It is completed with electrodes, a probe-sensor and a container with electrolyte.

The device is able to recognize gold, silver, palladium and platinum of the most common samples. It has 2 main working programs - for white and yellow metals.

According to its characteristics, this is a tester that is intended only to determine the authenticity of a sample jewelry. Its accurate chemical composition not shown.

Price - 21,000 rubles.

Device for testing gold and more "GoldXpert"— professional equipment made in Japan using the spectroscopy method.

With basic firmware it is able to detect and identify 25 different precious and base metals, including all metals classified as precious.

Identifies elements from silver to iridium and osmium, and a large number of others, including:

• copper;
• iron;
• zinc;
• manganese;
• nickel;
• cobalt and others.

Structurally, in terms of dimensions and weight, it is similar to the Prizma-M device. The cost is also available upon request and is approximately comparable to the price of the domestic analogue.

The video shows the process of operation of the device for determining the gold sample “GoldXpert”:

Conclusion

A precious metal analyzer is a necessary device for those who, due to their occupation, often face the need check this or that jewelry for authenticity. It will be useful even if you simply find it - perhaps the find is not so valuable, or vice versa.

Modern professional-grade detectors provide high testing accuracy. It is advisable to use simpler portable models if it is necessary to carry out a simplified on-site inspection of the product.

In contact with

The company's XRF metal analyzers are excellent for geological exploration and geochemistry, providing high-quality and accurate results in real time, allowing for rapid assessment of soils, ores and other hard rocks. X-ray fluorescence (XRF) analysis has evolved greatly in recent years, and improvements in XRF analysis have significantly increased the number of elements a handheld metal analyzer can measure, including improved detection limits and reduced analysis time.

X-ray fluorescence analyzer Olympus Vanta M - allows you to quickly and efficiently carry out analysis various types images associated with the exploration of Gold (Au) deposits in Gold mines, mining laboratories and refined metals (Au).

Key benefits of the gold analyzer - Olympus Vanta M

• Quick and qualitative determination of possible Gold (Au) mineralization by X-ray fluorescence (XRF) analysis of associated elements in soil, drill cuttings and core.
• Optimization of financial costs for analysis through prioritized sampling and extremely efficient planning of drilling operations due to preliminary X-ray fluorescence (XRF) analysis of samples.
• Better understanding and modeling of ore deposits with less dilution and higher gold recovery; geological mapping of structural features and identification of zones of mineralization and altered rocks
• Low-cost and rapid rock typing using XRF analysis for lithogeochemistry

Type of deposit	Geochemical profile
Orogen. Au	S, As, CO 2 , K+/– Sb, Te, Mo, W, Cu, Pb, Zn, Hg
High sulfide epithermal	Ag, Cu, Te, Mo, Bi, Sn
Low sulfide epithermal	Zn, Hg, Se, K, As, Sb, Ag/Au
Carlin type	As, Sb, Hg, Tl
Porphyry Cu–Au deposit	Cu, Pb, Zn, Ag
Skarn Au deposits	Bi, Te, As, Co
Intrusive rocks	Bi, W, As, Sb, Mo, Te
VHMS	Cu, Pb, Zn, Ag, Ba, K, Mg +/–CO 2
Iron oxide Cu-Au (U)	F, P, Co, Ni, As, Mo, Ag, Ba, U, LREE
Supergene Au	Pure Au +/– one of the above elements

Geochemical indicators in the analysis of Gold (Au)

Gold (Au) deposits have their own corresponding geochemical profile. An X-ray fluorescence (XRF) analyzer can automatically determine this same geochemical profile, allowing geologists to better understand the geological system in which they work. Typical associated elements for Gold (Au) include: Arsenic (As), Copper (Cu), Lead (Pb), Zinc (Zn), Antimony (Sb), Bismuth (Bi), Silver (Ag) and Tungsten ( W).

Limits of Detection (LOD) of Known Gold Companion Elements (Au) Using the Olympus Vanta M Geochemistry

X-ray fluorescence (XRF) Gold analyzer Olympus Vanta M

Handheld X-ray fluorescence (XRF) metal analyzers are not known to support direct measurements of low concentrations of Gold (Au) in geological samples (ppm and ppb). Therefore, the Laboratory method for determining the Gold (Au) content is more preferable. The X-ray lines of the L-level of Gold (Au) are located in places where the X-ray fluorescent energy spectrum is highly concentrated. In this part of the spectrum, exposure to other elements such as Arsenic (As), Zinc (Zn), Tungsten (W) and Selenium (Se) can give a false positive detection of Gold (Au).

Direct measurements of gold (Au) by X-ray fluorescence (XRF) are only possible in a few cases:

• In quartz veins of high concentration (> 5 ppm) and relatively free from interference
• In refined Au metals (where Au is present in very high concentrations)

Local mine laboratories are increasingly using portable X-ray fluorescence (XRF) analyzers instead of, or as a complement to, assay methods.

Portable X-ray fluorescence (XRF) analyzers are used in mines to measure Gold (Au) in activated carbon.

PVP SNK LLC - official representative of the company
Presented on our official website huge selection non-destructive testing equipment and accessories, including Portable analyzer gold(Au) - search for deposits, mineral exploration, models: Vanta-M-Gold from the company and related to the category

The OLYMPUS Innov-X GoldXpert XRF Analyzer is a simple, highly cost-effective instrument that provides alloy chemical composition and karat purity classification in a single non-destructive, non-penetrating test.

With the GoldXpert XRF analyzer you can:

• Quickly and accurately evaluate gold items when buying. Instant determination of gold standard, 0-24 carats;
• Identify and distinguish a wide range of alloys, including silver, platinum, and other alloys;
• Determine toxic elements in samples;
• Manage quality control of refining and smelting;
• Identify impurities;
• Determine the content of silver and other metals in gold;
• Confirm the gold content in scrap metal;
• Determine the gold and silver content in coins;
• Determine the palladium content in jewelry;
• Analyze platinum products. Determination of all alloying elements;
• Conduct analysis of dental alloys.

Important reasons to choose GoldXpert:

• GoldXpert is very compact, occupies a minimum of working surface.
• Attractive design suitable for showroom.
• Ease of use - Composition and purity analysis results in carats at the touch of a button.
• Accurate chemical analysis and sample determination in seconds.
• Quickly and easily generate reports and results certificates (with optional PC software).
• A test chamber with a viewing window and internal lighting allows the sample to be constantly visible during the test, which is important for customer confidence in safety.
• Rechargeable battery allows analysis anywhere, for example, you can take GoldXpert with you when visiting clients or suppliers.
• GoldXpert can be connected to a computer network to access the analysis results of multiple experts.
• The analyzer presents safe closed beam system, it is easy to learn and usually requires minimal training.
• The powerful 4 W X-ray tube provides reliable and accurate analytical performance.
• Automatic correction for sample shape and size.
• Large memory capacity for storing and archiving analysis results.
• Built-in camera and spot collimation for focused analysis and archiving images of samples.
• Completely non-destructive test method.

Design overview

Attractive desktop precious metal analyzer, suitable for showroom use, can also be networked for high-throughput QA/QC tasks. The large camera cover opens instantly when you press the front release button. GoldXpert can also function as a portable handheld analyzer, powered by a rechargeable lithium-ion battery. Compact and lightweight, weighing only 10 kg, GoldXpert is easily carried to the analysis site.

• The lead glass viewing window of the measurement compartment cover allows you to see the sample inside the chamber.
• Built-in camera indicates sample analysis points and provides beam guidance.
• Safety - XRF system with a closed type radiation source.
• Small desktop area of ​​the case: 267x310x340 (with the lid closed).
• Sample chamber illuminated by LEDs: 125x210x180.
• 360° visible operating mode indicator light.
• Portability - Runs on an optional rechargeable battery for portable use.
• USB port for quick data export and printing.
• Clear, bright, color touch display.
• A silicon PIN detector is offered as standard. An alternative is a Silicon Drift Detector (SDD) if higher precision and sensitivity are required.

GoldXpert has a built-in CMOS camera that stores sample images along with analysis results for report generation.

X-ray beam collimation is used to measure inclusions, small components and small samples. A simple press of a button activates focusing of a 3 mm 2 diameter spot, and an on-screen indicator shows the operator the exact location of the spot concentration during analysis. Collimation can be easily set to a 10mm spot diameter for analysis of common samples.

Data is easily transferred to a PC in tabular format, and remote memory access is possible when GoldXpert is connected to a computer network via the Windows CE operating system.

With the help of special PC software, you can create Results Reports according to a given template at the click of a button. The test certificate may contain the results of the analysis, an image of the measured sample, a company logo and other information.

Analytical capabilities

IN economic conditions, where fast and accurate results are more important than ever, XRF analyzer for precious metals GoldXpert Provides exceptional repeatability and accuracy. OLYMPUS Innov-X analyzers give you the advantage and benefit of simple, on-the-fly analysis so you can have complete confidence in your gold and precious metals holdings.

The accuracy and precision data presented were generated using GoldXpert with SiPIN detector technology and are typical of the performance characteristics of SiPIN systems: