Blogs
Effect of Pre-Aeration & Oxygen on Sodium Cyanide Consumption Gold Recovery
In your process development you may sometime want to test and see what effect (for your particular ore sample) would the use of oxygenation and pre-aeration have on silver and gold kinetics leach rates and recoveries. Some situations show improved precious metal recoveries, others show an impact of the leach agent’s consumption rate. Here, a flotation cleaner test was conducted
Effect of Regrind “Finer Grind” Gold Recovery
Regrinding a flotation concentrate (commonly the rougher or scavenger conc) can often produce gains in final concentrate grades and overall metal recoveries. What is also possible and not unfrequent that all you get is a better concentrate grade. If the valuable metal (in this case Au) is locked with other easy to float sulfides and were going to to be recovered
Selective Flotation
Who would think that Selective Flotation of copper, gold, zinc or any metal would required that one must be able to feel pain and recognized and/or admit when it hurts. Flotation mass-pull is a process that is often misunderstood; a learner’s mistake made by non-operating types. You do not need to pump anything in the lab. In selective flotation, less
Reduction Potential Gold
The oxidation-reduction (dissolution and precipitation) of gold from Au –> Au+ +e- is driven by this equation. Without using a gold periodic table or a oxidation potential chart, you can simply review the chemistry here: Figure 1 is Au–H2O system: No stability region for gold ions between lines; can’t dissolve Au in aqueous solutions (for now) Figure 2 shows why we can’t
Gold Oxidation States
With regards to the aqueous chemistry of gold and the various states of gold oxidation ( 5, 3, 2, 1, −1 (an amphoteric oxide)), we must look at the electronic presentation typical of transition metal elements (Copper, Silver, Gold) AKA Group 11 element from the periodic table, because they allow for the extraction of multi electrons. As shown in the red circle of Cu/Ag/Au below,
Gold Dissolution
Essentially state and corrosion resistant, gold dissolution is not easily obtained by just any acid. Use an oxidant like manganese dioxide, nitric acid, oxygen, ferric ions or cupric ions and you will dissolve gold. The formation of Aqua Regia by nitric and hydrochloric acids will break down gold and make it go into solution. In the presence of an oxidizing agent in
World’s Main Gold/Auriferous Mineral Deposits
Era Precambrian (3000-570)* Paleozoic (570-225)* Mesozoic (225-65)* Cenozoic (65-0)* Age of host rocks Gold-quartz deposits mainly in Archean rocks (>2500 m.y.); extensive deposits in Proterozoic quartz-pebble conglomerates; some large gold-quartz and varied stockwork deposits in Proterozoic rocks Mainly Paleozoic; some deposits in Precambrian or both Paleozoic and Precambrian rocks Mainly Mesozoic but also Paleozoic and Precambrian Mainly Tertiary but
World Gold Deposits Map
Here are 5 maps of where gold is found in the world while highlights zones where is the most gold found on the planet. http://www.nrcan.gc.ca/earth-sciences/science/geology/gsc/17100
Where are Vein Mineral Deposits Found
Where or how do vein mineral (gold, copper, nickel, silver, etc etc) are found is be exploring and sampling. As shown here, if you find some showings with increasing concentration, you are getting closer to the vein and maybe the Bonanza!
What Other Minerals are Found With Gold
Generalized paragenetic sequence of principal minerals and elements in epigenetic gold deposits. Minerals and elements shown include only those in veins, lodes, etc.; minerals and elements in wall-rock alteration zones are excluded. http://www.nrcan.gc.ca/home
Eluvial and Alluvial Placers and Gold-Quartz Vein
Sketch illustrating outcrop of a gold-quartz vein supplying material to form eluvial and alluvial placers. By one terminology, an eluvial placer embraces all materials not transported by streams. By another, only the placer materials over weathered and disintegrated deposits constitute an eluvial placer; downslope and other placer materials are classified as deluvial and proluvial as shown.
Effect of Clay on Flotation Recovery
Here is a classic relationship displaying how clays can affect/impact flotation recovery, copper rougher-scavenger recovery in the case.
Gold Processing Methods & Gold Ore Extraction
Of all the methods of extracting gold & processing it from its ore, I used a few to evaluate two principal flowsheets in this case study. The flowsheets utilized operations that involved flotation, cyanidation and gravity concentration. Tests that mirror each of these unit operations were utilized to evaluate the principal flowsheets. This page offers a comparative review of gold recovery methods:
Rare GOLD Minerals
This list of ores classified as natural and rare gold minerals are refractory to process. All these are sulphides refractory gold bearing minerals and will have a poor response behaviour to usual cyanidation extraction methods, and for the little guy, best used for exhibit or sold to rock collectors on eBay. Native Gold Au Formula Muthmannite Very Rare Crystal. Yellow white, opaque; Perfect
Sample Preparation and Analysis Methods
Geology and Mine Samples can usually be prepared and analized using techniques suggested in this Table. The Extractive Metallurgy of Gold
Ball Mill Motor/Power Sizing Calculation
A) Total Apparent Volumetric Charge Filling – including balls and excess slurry on top of the ball charge, plus the interstitial voids in between the balls – expressed as a percentage of the net internal mill volume (inside liners). B) Overflow Discharge Mills operating at low ball fillings – slurry may accumulate on top of the ball charge; causing, the
Radioactive Gold & Isotopes
The only natural gold isotope is 197Au. All others are radioactive ranging from 185Au to 203Au and are manmade. They dont make for good lasting investments since their half life goes from 1.35 sec to 185 days. The Extractive Metallurgy of Gold
High/Low Sulphidation Epithermal Silver/Gold Copper Porphyry Deposits
http://www.cec.uchile.cl