Mining faces a plethora of challenges including social license, decreasing grades, complex orebodies, and regulatory hurdles, among many others. Yet, there is an unparalleled opportunity as our society transitions to clean energy and an electrified world. For the transition to occur, we require significantly more minerals. The demand is outpacing supply. To date, the solution has been to continue to search for behemoth deposits even though they are becoming more elusive. S&P Global Market Intelligence notes that even though copper exploration budgets are at record levels only 5% of new copper resource discovered since 1990 have been novel and not an expansion of existing operations or brownfield developments1.
This is unprecedented. The industry is facing new problems that necessitate novel solutions.
For every large deposit, there are hundreds of small deposits. This is common knowledge but the industry has largely ignored these deposits. Novamera has estimated there is roughly $6 trillion of in-situ value in narrow vein deposits globally that are not currently being mined. Several commodities occur in small deposits and many types of these exist like orogenic gold, multi-metallic skarns or carbonate replacements, high and low sulfidation, and hydrothermal deposits.
If geologists know about these deposits and they are so often accompanying the large deposits, then why have they not been mined?
The simple answer is that, without specialized technologies, as ore deposits decrease in volume their geometry becomes harder to define, and dilution increases. For small greenfield deposits, the barriers to entry into mining can be too large to even consider a feasibility study.
This is unfortunate because small ore deposits represent a major opportunity. They can be high grade, relatively shallow (and oxidized), and enriched in the rarer commodities uncommon in large deposits. This results in high returns with significantly lower risk.
The concept of mining small deposits has implications for several players in the mining industry.
Lower Capital & Operating Costs
In addition, these deposits have low capital and operating costs. In other words, they can be mined with much higher efficiency. Mineral processing plants can be mobile, or ore can be transported to an existing plant which significantly reduces the capital costs. Active reclamation is easier to achieve, leaving no trace and reducing the closure costs. They are often high-grade, so they require lower levels of waste rock and ore extraction by volume when compared to a large low-grade deposit, hence minimizing operating costs.
Quickly Add to Production/Reduce time to Development
For large miners, they can maximize profitability, for junior companies, these small deposits represent easy access to early profit and a demonstration of resource. For others,-for turning a quick profit without the conventional hurdles of a large mine.
The efficiency of small deposits can also lower the barriers to earning social license to operate, a topic of ever-increasing importance.
Mining small deposits enables true temporary environmental and social disturbance that improves the sustainability of mining. By targeting small deposits, the mining operation can more readily achieve the goal of mining without having major impacts on water resources, changing the landscape, or leaving potentially hazardous tailings for future generations. Strengthening the Domestic Supply Chain
One of the key opportunities small deposits represent is to reduce dependency on imports. Many critical metals are exceedingly rare in large quantities but found in small deposits. Take, for example, tantalum, which the US and others are 100% import dependent2. This critical metal is found in LCT pegmatites and even though known deposits like Round Top in Texas or the Bokan Mountain deposit in Alaska contain enough tantalum to meet US demands for decades, neither have been mined because of their relatively small size. Tantalum is one critical metal among others that we are highly import dependent. Instead of ignoring these deposits, we should use our technical prowess to extract the resources efficiently and economically, regardless of the deposit size.
It is the right time to reconsider small deposits. With improved technologies and the invention of Novamera’s Surgical Mining Technologies, these deposits are no longer out of reach. We are now able to decrease the error when defining the ore body and utilize precise methods of ore extraction to overcome the barriers that have kept small deposits from being mined in the past. This can help meet demand by opening the doors to mine thousands of small deposits globally.
Writen by: Caelen Burand, ASM Consultant & Engineer
About: Caelen Burand is a mining engineer with a BSc in mining engineering and a BSc in geoscience from the University of Arizona. He works in mining operations throughout the globe within several technical and leadership roles with an interest in improving our ability to mine economically and responsibly.