Fluxing And Smelting Silver Ore
Equipment Used For Firing/Smelting Ore Furnace Or Oven For Firing/Smelting: It must heat to 1950 degrees F for gold and 2100 degrees F for silver. A muffle furnace is best. It fires to about 2300 degrees F and the ingredients can be easily added to the ore while firing. Crucible: Clay or graphite crucible to use in […]
Nitric Acid To Purify and Separate Silver/Gold
THE DANGERS OF NITRIC ACID Nitric acid can be absorbed through the skin, causing nitric acid poisoning. WEAR RUBBER GLOVES! Nitric acid cannot be boiled or simmered in the house or where it is not well ventilated. It causes nitric poisoning. You will hurt in every joint of your body and it can kill you. […]
How To Clean Gold with Nitric Acid
Gold acts like a sponge and absorbs nitric acid. This enables the nitric acid to clean the gold, such as gold nuggets or free gold taken from black sands. Most gold found in nature contains other metals, but some of these cannot be taken down in nitric acid (such as the platinum family). First; The […]
How To Use Nitric Acid To Purify Silver
Here is the recipe/method if you want to use Nitric Acid To Purify Silver: First; The Dangers of Nitric Acid Place the silver in a beaker or Pyrex container. Add 3 parts distilled water to 1 part nitric acid. Place on stove or hot plate and simmer until all of the metals are gone. Take un-iodized […]
Recover Gold/Silver in Jewelry/Electronics eScrap by Aqua Regia
The Dangers Of Aqua Regia: Aqua regia cannot be boiled or simmered in the house or where it is not well ventilated. This can cause serious illness or KILL YOU! Use a vent hood with an exhaust fan or simmer in the open. Hydrochloric acid is very dangerous. It CAN BURN TO THE BONE and is […]
Gold Rocker Box
One of the first devices used after the gold pan was the gold rocker box. The rocker allowed small operators to increase the amount of gravel handled in a shift, with a minimum investment in equipment. Rockers vary in size, shape, and general construction, depending upon available construction materials, size of gold recovered, and the […]
Rate of Gold Recovery by Size of Particle
Here is a review of various gold recovery machines/methods and the gold particle size they are best suited to recover. Compare Jig, shaker tables, dry washer, sluice box, spirals, bowl concentrators, falcon, Knelson and leaching. The size distribution of the raw material will also determine if classification of the ore is necessary for better recovery. […]
Cyanide Leaching and Decomposition of Pyrrhotite
Research on cyanidation methods brought considerable discussion on the reactions involved in the leaching and decomposition of pyrrhotite in cyanide solutions. Pyrrhotite has one loosely held sulphur atom which readily reacts with cyanide to form thiocyanate: Fe5S6 + NaCN = NaCNS + 5 FeS The ferrous sulphide oxidizes rapidly to the sulphate which reacts with cyanide to […]
Eliminating Copper from Gold Ore
When reviewing Methods of Eliminating Copper from Gold Ores we see that several methods have been suggested to eliminate copper from ores prior to cyanidation. Preliminary extraction of the copper with sulphuric or sulphurous acids may be applicable to ores containing oxidized copper minerals such as malachite, azurite and chrysocolla but these acids have but little […]
Gravity Recoverable Gold (GRG) Test
The GRG test is used to determine the theoretical maximum amount of gold that can be recovered from a sample. The testing scheme consists of three sequential liberation and recovery stages , the progressive size reduction allowing for the determination of the precious metal recovery as liberated without over-grinding and smearing coarse precious metal particles. […]