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6 results for “Cut-off grade” in Industry
Industry · 28 July 2026
Urban Mining: The Richest Gold Ore on Earth Is in Your Old Phone
…than gold ore? By concentration, frequently yes. Modern underground ore is often mined at grades measured in single-digit grams of gold per tonne, while sorted, high-grade circuit boards can run into the hundreds of grams per tonne. What e-waste lacks is a deposit: the material a…
Tomas Herrera · 13 min read
Industry · 7 August 2026
After the Cyanide
…he risk lies in handling and storage, not in the chemistry being exotic. · Free cyanide degrades in sunlit water over weeks; the durable hazards at a closed mine are usually metals and acidity, not the reagent itself. · Acid mine drainage generates when sulphide minerals meet air…
Tomas Herrera · 17 min read
Industry · 4 August 2026
The Gold Inside Your Phone
…rth a few dollars at prevailing prices. · Gold is specified where a connection must not degrade: it does not form an insulating oxide, so contact resistance stays stable for decades. · Substitution is real and mostly already happened — copper bonding wire displaced gold across hi…
Tomas Herrera · 15 min read
Industry · 6 August 2026
The Scrap Trade
…hod still in daily use. The item is rubbed on a fine-grained stone to leave a streak, and graded acids are applied to the streak: an acid formulated for 14k will dissolve a 9k streak and leave an 18k one intact. It is cheap, fast, destructive only to a microscopic smear, and read…
Ingrid Sørensen · 15 min read
Industry · 2 July 2026
Nine Nines: Inside a Modern Gold Refinery
…nomics can be better than mined feed because the concentration is higher. A tonne of high-grade ore might carry a few grams of gold. A tonne of sorted circuit-board connectors carries orders of magnitude more. · Handling scrap is messier work. Feedstock arrives as everything from…
Tomas Herrera · 12 min read
Industry · 7 August 2026
How Fake Gold Is Detected
Counterfeiting gold is not about making something that looks right. It is about defeating a specific test, and the industry's defences are an escalating conversation between forgers and instruments. ·…
Tomas Herrera · 15 min read
