A series of tests were undertaken for the Aurora Partnership-Aurora Project to solve inter-laboratory variations in the analyses of blast hole cuttings. Initial concern was centered on the probability that free gold occurrence was resulting in erratic results for the mine’s cyanide shake assays and outside laboratory fire assays. Test Procedure A 50 kilogram bulk … Read more
Early laboratory balling and pelletizing tests resulted in balls or pellets superior in quality as compared to production pellets, no matter what the variable being tested. In order to indicate more closely what a material would do for balling and pelletizing in a plant we felt it was necessary to approach the plant conditions. When … Read more
Liberation data were obtained from polished mounts made from the various size fractions produced during the batch grinding experiments. Representative portions of each size fraction were first treated with ethanol and then mounted in a cold setting resin (EPOFIX Epoxy). To minimize segregation of particles on the basis of mass or density, the particles were … Read more
Three gold sensing electrodes were made from 3 mm gold rod. The rod was cut with a diamond wafering saw into 3 mm lengths, soldered to insulated copper wire, placed inside 9 cm lengths of 1 cm (outside diameter) Plexiglas tubing, and cast inside the tubing with epoxy. After the epoxy was set, the gold … Read more
Discussion flotation and mineral processing with industry metallurgist from around the world. Wetting and not wetting or water-absorbing is the principle of flotation. Some minerals are wetted, whereas others are not wetted. Wetting is a variable property of minerals and depends upon the surface properties of the solid, liquid, and gaseous conditions. Minerals that are … Read more
Size is crucial to virtually all mineral processing A size range in a standard series is generally identified by the bottom size in the range A single size parameter is not enough to define a size distribution Narrow size ranges are generally best for following separation processes Sizes are usually arranged in a ratio series … Read more
It is important to have Assay Laboratory standards over a range of grades. This alone may preclude the material being sampled from serving exclusively for the preparation of standard material. One of the standards must have as close to an absolute zero value as possible. At least three and if possible five other standards should … Read more
In the 1940’s a top blown water-cooled oxygen lance was developed to inject oxygen into liquid iron. This process, the LD or BOF process technique, today is used in 65% of the world’s steel production, and represents the largest oxygen market for temperature enhancement in steel and non-ferrous smelting applications. There are three major approaches … Read more
Zirconium crucibles are rapidly becoming a standard piece of equipment, particularly in laboratories where fusions using strongly alkaline fluxes are common. This Center has found no better material to use for the thousands of sodium peroxide fusions that are done here every year. Zirconium crucibles usually arrive from their suppliers in a polished, silvery state. … Read more
At times it may be necessary or desirable to dissolve a ferrochrome sample in acid rather than fusing it in sodium peroxide. Acid digestion methods are slow, but require little in the way of attention. Two alternative methods are described here. The A method is the basic method to use for most ferrochrome samples. The … Read more