Gold, the dazzling light that has traveled for thousands of years, not only carries the symbol of wealth,
but also unites the extraordinary wisdom of mankind in exploring nature and technology. Have you ever
wondered how gold, hidden deep in rocks or river gravel, has traveled so far to become a treasure in our
hands? Today, we will unravel the mystery of gold mining and reveal an extraordinary journey that combines
technology, courage and responsibility.
Treasure hunt in the depths of the earth
Locking the target area: Geologists, like “treasure hunters”, use geological principles to analyze the rock structure,
mineral distribution and other clues to lock the target area that may be rich in gold.
Scientific and technological eyes to see through the earth's crust: professional equipment on the scene:
Geophysical Prospecting: Utilizing magnetic, electrical or gravitational methods to detect differences in the physical
properties of underground rocks and search for tectonic zones that may contain gold.
Geochemical exploration: Systematically collect samples of rocks, soil or water system sediments for precise chemical
analysis, detect trace gold anomalies and draw “treasure maps”.
Drilling: Drilling in the most prospective areas to obtain deep core samples. This is the most direct evidence used to
accurately determine the location, size and shape of the ore body, as well as the grade of the gold (the amount of
gold per unit of ore). Drilling data is the central basis for assessing the economic viability of the mine.
Resource and economic considerations: All exploration data is combined to produce a detailed resource estimate and
a rigorous economic assessment. Only when the gold reserves are large enough, the grade is high enough, and the
mining and refining costs are manageable enough to be economically viable, will the project proceed to the actual
development stage.
Knocking on the door of the earth to get the treasure
Depending on the geological conditions and the environment in which the ore body exists, two distinct
mining methods are used:
Rock gold mining: deep into the earth
Open pit mining: When the ore body is close to the surface, large and thinly covered, it is like peeling back the earth's
veneer. Using giant electric shovels, hydraulic shovels and mining trucks, the overburden of rock and soil is stripped
away layer by layer to reach the ore body. This method is efficient, relatively inexpensive and suitable for specific terrains.
Underground mining: When an ore body is buried deep underground, it is necessary to build a “labyrinth” that leads
to the depths of the earth. Shafts, inclined shafts, or flat caves are drilled as access points, creating a complex network
of tunnels within the ore body. Miners or modern machinery work in the tunnels, blasting and mechanically cutting
the ore, which is then transported to the surface by hoisting equipment. Underground mining is technically complex
and costly, and safety is a constant theme.
Alluvial Gold Mining: Panning the Gifts of History
Rivers and ancient riverbeds: Alluvial gold is mainly found in the gravel layers of modern rivers or in ancient riverbeds
and terrace deposits formed during the geological past. Because of their high density, gold particles are often enriched
in specific layers after being transported over long distances by water currents.
Amalgamation and sieving: Traditional methods such as gold panning utilize water scouring and density differences
to separate gold particles. Modern large-scale mining uses large-scale excavation equipment (e.g., excavators,
bulldozers) to dig up gold-bearing gravels, which are crushed, screened, and gravity sorted by washing plants
(washing machines, vibrating screens, chutes, jigging machines, etc.), and ultimately get heavy sand concentrates
(enriched with heavy minerals such as gold, platinum, and other heavy minerals).
Turning ore into gold, refining and purification
The mined ore or alluvial gold concentrate needs to go through a complex process to refine high purity gold:
Crushing and Grinding: Crushing and grinding the large ore into a very fine powder (as fine as flour), the purpose is
to fully dissociate the chalcopyrite minerals that encapsulate the gold, and increase the surface area of the gold
particles that come into contact with the chemical reagents.
Core extraction process:
Cyanidation (mainstream): A finely ground slurry is mixed with a low concentration of sodium cyanide solution. Under
oxygen-filled conditions, the gold reacts with the cyanide to form a soluble gold-cyanide complex into the solution,
realizing the separation of gold from most solid impurities.
Gravity Separation (Auxiliary/Pre-treatment): Utilizing the high-density nature of gold, some of the coarse-grained
gold is recovered in advance through centrifuges, chutes, etc., before or after the grinding process to reduce the
amount of subsequent processing and increase the recovery rate.
Flotation: For certain specific types of gold ores (e.g., closely symbiotic with sulfide minerals), special agents are
added after milling so that gold-bearing mineral particles attach to air bubbles and float to the surface of the
slurry to form a froth, thus separating them.
From solution to gold ingot:
Adsorption: Activated carbon or resin is used to efficiently adsorb the gold-cyanide complex from the cyanide
leach solution. The gold-carrying carbon or resin is subsequently desorbed.
Electrolytic deposition/zinc replacement: Reduction of gold from the desorbed gold-rich solution (precious liquid).
Electrolysis results in the deposition of a gold sludge at the cathode; zinc replacement results in the reduction of
the gold by zinc to a metallic state precipitate (sludge).
Refining: Sublimation of purity
Gold Mud Smelting: Gold mud is mixed with flux and smelted in a high-temperature furnace to remove most of the
impurities and produce crude gold ingots (doré alloys) with a gold content of about 90%.
Electrolytic refining: The crude gold ingot is cast into an anode plate and placed in a special electrolyzer. After direct
current is applied, pure gold is precipitated at the cathode, with a purity of over 99.99% (international standard delivery
gold ingot). Silver, platinum, palladium and other precious metals are enriched in the anode mud, which can be
further recovered. Refining can also be carried out by chemical methods (e.g. aqua regia dissolution-reduction).
Green and Responsible: The Way to Mining
Modern gold mining is deeply aware of its impact on the environment and actively takes on social responsibility:
Environmental management:
Waste Material Disposal: Scientific planning and stockpiling of waste rock stripped from open-pit mines and tailings
(fine-grained waste residue) from ore dressing. Construct tailing ponds that meet the highest environmental standards,
adopt impermeable liners, leachate collection and treatment systems, and implement strict stability monitoring.
Mulching and greening of waste rock piles.
Water Resource Protection: The recycling rate of beneficiation wastewater is extremely high. Wastewater that must be
treated (e.g., cyanide-containing wastewater) is subject to strict purification (e.g., natural degradation, chemical oxidation,
biological treatment, etc.) to ensure that it meets the standards for discharge or is safely reused. Prevent acidic mine
wastewater from being generated.
Land reclamation: After the mine pit is closed, carry out terrain remodeling, soil improvement and vegetation
restoration for the disturbed areas (quarry pits, waste rock quarries, tailing pond surfaces, etc.) to rebuild the
ecosystem.
Community Building: Respect the rights and interests of local communities, create employment opportunities, support
community development programs, maintain transparent communication, and strive to make the mine a positive
force in the sustainable development of the community.
Safety: We invest heavily in the safety of our miners, applying automation and remote control technology to
minimize exposure in hazardous areas, and continuously improving safety procedures and training.
Conclusion: A modern chapter in an eternal light
The light of gold, from the masks of ancient Egyptian pharaohs to the cornerstone of modern financial markets,
has never dimmed. When we gaze upon a fine piece of gold jewelry or a standard gold ingot, it carries not only
a rare substance, but also the crystallization of human wisdom, technological innovation and responsibility. Modern
gold mining is striving to find a more sustainable and responsible balance between discovering the earth's treasures
and guarding the earth's homeland, so that this gift from the depths of the earth will continue to glow with its due
splendor and value.