The dies can be identified by removing the cap and observing the die body. The standard die will have a smooth cylinder, where the premium die will have a cutout for the accommodation of a plastic ring. Remove the ring from the die and extend the die shaft until it clicks into place. The shaft … Read more
Precious Metal Analysis and Karat Classification: XRF is a widely used, reliable, and recommended method for chemical analysis and determination of purity and fineness of precious metals. This analysis technique is a multi-elemental test that is quicker and less expensive than fire assay and chemical tests. Benchtop XRF provides on the-spot analysis of gold, silver, platinum, … Read more
Whether you’re sampling for exploration, development or production, getting asset data is a critical part of your workflow. Traditionally, it can take weeks to access this data, causing delays and drastically affecting productivity. Portable XRF Gun X-ray technologies have made it possible to achieve real-time chemical and elemental analysis in the field, but despite all of the … Read more
It is essential for the assayer to be assured of the fact that his reagents are pure, or at least to know to what extent they are impure and what the impurity consists of. For this reason it is necessary to examine lots of reagents from time to time, as they come into the laboratory, … Read more
We have developed an improved method for determining dissolved helium in water in the concentration range of 4.0 x 10 -8 to 270 x 10 -8 cm³ He (STP)/cm³ H2O. The method is a modification of a previously reported method that was developed for analyzing surface and subsurface waters in geochemical survey work. Water samples … Read more
The principle of the sample flows of the analyzer system is shown in Figure 4. As the analyzers are located in a separate room, many of the primary lines require pumping. The samples are returned mostly by gravity to the corresponding process pump sumps. The primary sample lines have a diverter that feeds the stream … Read more
The Bureau of Mines once modified a commercial atomic absorption spectrophotometer to rapidly determine trace levels of mercury by cold-vapor atomic absorption spectrophotometry AA. Such diverse materials as ores, mill products, stream water, sediments, and flue dust have been analyzed. A very high dynamic range of 0.2 ng/ml to 1 µg/ml of mercury in solutions … Read more
Sample Preparation: Aqua regia with, occasionally, the addition of hydrofluoric acid is the most used lixiviant, and is applicable to most ore types. Other combinations of acids as well as cyanides are also used, and pre-roasting is sometimes applied. Digestion time and amount of reagent vary, quite naturally, with the amount of acid consuming materials … Read more
I have always been amazed at the amount of knowledge the Alchemists in the Middle Ages possessed regarding chemistry, metallurgy and the precious metals. Yet they did not realise that the fleas of rats were transmitting the plague that killed literally millions of people in Europe during the 1300’s, nor that the earth was round. … Read more
The simplest form of aspirator consists of two large bottles, a, Fig. 98, both of which are tightly stoppered with rubber stoppers. Through each of these stoppers pass two tubes, one reaching from a few inches outside to within a fraction of an inch of the bottom of the bottle, the other reaching to just … Read more