Gold Mining Projects: What Drives Their Value?
November 13, 2025
Data Management for Mine Planners
February 10, 2026
Introduction
Our recent blog featured one of the most sought-after commodities in mining: Gold (check out the blog here: https://atlantech.com.au/2025/11/13/gold-mining-projects-what-drives-their-value/). Continuing with this series of blogs featuring different mining commodities, let’s deep dive into copper.
Amidst the rise and fall of commodity prices, copper has remained a dependable asset, thanks to its widespread applications in the fields of Electronics, Electrical, and Telecommunications due to its very high thermal and electrical conductivity, and in the fields of Automotive, Construction (including tubes, pipes, fittings, etc.), Marine, and Architecture due to its soft, malleable, corrosion-resistant, and ductile characteristics and its ability to combine with other metals to form an alloy.
1The “red metal” cracks the third spot in the world’s industrial metals consumption, behind only iron and aluminium. This ranking is expected to surge, driven by the adamant push for a green energy transition from electric vehicles to renewable energy infrastructure. Moreover, in this day and age, where data is more vital than ever in any decision-making, networking, electronics, telecommunication, and the expansion of data centres is yet to reach its peak. At the core of all this is none other than copper.
2 There are different views from several analysts on how the copper price will perform, with some forecasting, at least in the next five years, that the copper price will boost year-over-year. Unless the trend towards green energy transition changes its course, this upward forecast may very well come as no surprise.
Counties that contribute to copper production
The top 10 copper-producing countries in 2024 are listed in Table 1 below.
Table 1: Top Ten Copper Producing Countries in 2024
|
Country |
Copper Production (T) |
|
Chile |
5.3M |
|
Democratic Republic of Congo |
3.3M |
|
Peru |
2.6M |
|
China |
1.8M |
|
United States |
1.1M |
|
Indonesia |
1.1M |
|
Russia |
930K |
|
Australia |
800K |
|
Kazakhstan |
740K |
|
Mexico |
700K |
3 It is worth noting that Australia holds the second-most copper reserves in the world, and yet the country only ranks 8th in copper production. This could only mean that when the demand continues to surge, there is an available supply somewhere. On the other hand, Chile holds the world's largest copper reserves and has been the primary producer of copper for the longest time.
The Copper Extraction Process
The method for extracting copper is determined by two main types of ore: oxides and sulphides, and a third type called “refractory,” which has a complex mineral composition and is therefore not amenable to conventional beneficiation processes applied to oxides or sulphides.
4 The comparison between these types of ore is shown in Figure 1 below.
Figure 1: Comparison between Oxide, Sulphide, and Refractory Ore
Heap Leaching
Heap Leaching is a process of extracting valuable metals from low-grade oxide ores using chemical solutions such as sulfuric acid.
A simplified diagram of the heap leaching process is shown in Figure 2 below. Ore is crushed to a certain size and stacked on lifts (heap). A leaching solution, sulfuric acid in the case of copper leaching, is sprayed over the heap. The solution trickles down onto drainage pipes, dissolving the copper from the ore. The metal-rich solution collected at the bottom of the heap is called Pregnant Leach Solution (PLS) and is further processed via a SX-EW (Solvent Extraction and Electrowinning) circuit. 5 During the SX-EW process, copper is first upgraded and extracted from the PLS to a solvent that contains chemicals that bind the copper in the solvent. This process is called Solvent Extraction. Stripping is done to harvest the plated copper from the active cells in lots of 11 plates per extraction. The stripped cathode plates are returned to the cell before any other cathodes are removed to ensure a minimum of 22 plates remain in the cell at any given time to accommodate the current flow. Lastly, the solid metal is formed from the solvent that contains the dissolved metal by electrical deposition. Finally, direct current (DC) is passed from anodes to cathodes, depositing the copper at the surface of the cathode.
Figure 2: Copper Heap Leaching Process
Flotation
Copper flotation is another method of separating the copper metal from the gangue or waste portion of the sulphide ore by using flotation reagents.
A simplified diagram of the flotation is shown in Figure 3 below. 6 Ore is first crushed to reduce size and then pulverised to liberate the copper minerals from the gangue. In a roughing tank, pulverised ore is mixed with reagents such as collectors, frothers, and regulators to form a slurry. These reagents make the copper minerals hydrophobic (water-repellent). Air is introduced into the tank, and the hydrophobic copper minerals attach to and rise with the air bubbles, forming a froth layer at the top of the tank. The froth layer from the rougher tank is concentrated to further eliminate waste, while the tails from the concentrating tank go through another roughing stage. The tails from the initial roughing stage go to a scavenging tank to recover any residual copper minerals. The froth from the Scavenger tank goes through a second-stage roughing. The tails from both the Scavenging tank and the Stage 2 Rougher are treated before they are stored in a tailing storage facility. Finally, the froth from the Concentrating tank, called Wet/Damp Copper Concentrate, is thickened, filtered and dried to produce a dry copper concentrate cake that has low moisture content.
Figure 3: Flotation Process
Processing Refractory Copper Ores
There have been many technological advancements in recovering copper metal from complex refractory copper ores. However, it is still an evolving process to further address high cost, low recovery rate, and the environmental risks of arsenic and sulphur-containing harmful by-products of the process. Among the technologies developed to date is the 7 Intelligent Controlled Flotation Process, which is a flotation circuit that is integrated with PLC automatic control modules that monitor the feed concentration, reagent dosage, and flotation froth status in real time, dynamically adjusting process parameters to control the separation purity fluctuation range within ±0.3%. It is particularly suitable for refractory ores with high mud content and fine mineral particle size. Another technology is called Gravity-Flotation Combined Separation, where coarse-grained ore is first treated with a gravity separation equipment to remove low-density gangue, and then subsequently performs flotation to refine the enriched minerals.
Mine Planning Considerations
Understanding the different ore types when doing a study for a copper project is vital in getting the mine plan right. The following must be carefully considered.
1. The cost of mining the different copper ore types varies, with the oxides being relatively cheaper because they are closer to the surface.
2. The costs associated with processing each type of copper ore are also very different. As mentioned earlier, heap leaching is relatively less expensive than flotation because of the following:
a. Flotation requires finer particles and therefore the need for grinding. The energy used in the grinding stage contributes a large portion to the overall consumption of the entire flotation process.
b. Flotation requires more reagents and comes in different stages (roughing, concentrating, scavenging).
c. The tailings from flotation require transport to a storage facility, unlike in heap leach, where the tailings are already stacked on top of each other.
3. The processing recoveries between heap leaching and flotation are totally different, with the heap leach recovery usually ranging from 80-95% and the flotation between 60 and 80%. The in-situ ore grades can therefore likely drive the economic viability of the project.
4. The processing methods between oxides and sulphides can have different environmental impacts, and so the cost associated with mitigating these impacts, as well as mine closure, will also be different.
All these factors combined will influence the economic viability of a copper project. When comparing the two ore types, an open-pit copper project involving purely oxides will generate different pit limits compared to a project that involves sulphides only, or a combination of oxides and sulphides. Therefore, the pit designs and mining schedules will also be different between the two projects.
The Challenges Ahead
8 Sulphide and refractory copper ore account for a significant portion of the world’s copper reserve. As the oxides approach depletion, development of more efficient techniques to process sulphide and, more so, complex refractory ores becomes the focal objective for producers to ensure that the copper metal supply can be sustained, while dealing with the challenges surrounding processing these types of copper ore, such as environmental pollution due to harmful byproducts, low recovery rates, and extremely high energy consumption.
Conclusion
Copper has been and will continue to become a critical mineral due to its widespread application. The advent of the Green Energy Transition has only made copper more important than ever. Battery and Electrification are at the center of this revolutionary shift to green energy, and somehow, commodities like lithium, manganese, nickel, and rare earth elements have been the flavour of the conversations, while copper has been flying under the radar.
Sources
1 https://worldpopulationreview.com/country-rankings/copper-production-by-country
2 https://longforecast.com/copper
3 https://www.marketindex.com.au/copper
4 https://www.proactiveinvestors.com.au/companies/news/1032091/mining-101-understanding-sulphide-and-oxide-and-ores-1032091.html
5 https://www.australres.com/our-operations/our-copper-process/processing/
6 https://www.hongjigroup.com/copper-ore/copper-ore-flotation-production-line.html
7 https://mineraldressing.com/blog/refractory-copper-ores-types-processing-challenges-solutions-2025/
8https://mineraldressing.com/blog/refractory-copper-ores-types-processing-challenges-solutions-2025/