Contents
Mineral exploration is the search for evidence of mineralization hosted in surrounding rocks, a process where geological data is extracted from ores in mineral deposits. An intensive, organized, and professional mineral exploration effort requires a comprehensive understanding of geology, the use of advanced technologies, and a highly skilled team is required for a successful mining project.
What is mineral exploration?
Mineral exploration is the process of searching for concentrated deposits for minerals. It precedes mining and is used to identify sites that could be mined for economic benefit, contributing to resource allocation, and, ideally, sustainable outcomes.
Mineral exploration covers all activities leading up to the actual decision to mine, from exploratory phase, geophysical testing and analysis, to modeling, reporting, and informing a mineral production decision.
The search for ore
The goal of mineral exploration is to find ore, which is a commercially viable concentration of minerals. Ore contains valuable minerals from which metal or other commodities can be profitably extracted through mining and geological or industrial processing.
Which materials can be found in ores?
Searching for ores can lead to the exploration of various metals and resources, such as:
- Extracted metals like iron, copper, or zinc
- Industrial raw materials like limestone or salts
- Gemstones like diamonds
- Solid fuels like coal
Two ways of exploring minerals
Greenfield exploration
If one is doing exploration in so-called Greenfield projects, one is exploring areas where there have not yet been exploration work.
Brownfield exploration
As opposed to Greenfield projects, Brownfield projects are done in areas in vicinity to existing mine sites or known mineral deposits. In other words, the likelihood of there being ores in these sites are greater than in Greenfield projects.
The process explained in 8 stages
Stage 1: Research and permitting
The starting point for mineral exploration is identifying relevant areas with potential for mineral deposits. Locating these deposits requires research and should be done in a strategic and efficient manner. This includes ensuring records and information on the area, collecting relevant permitting, and doing any other vital research for the specific project.
Depending on whether it is a Greenfield project or a Brownfield project, the research phase can be guided by whether there are existing mine sites nearby. Mineral deposits tend to form in clusters, meaning that prospective areas are likely close to existing areas for mineralization.
Stage 2: Surface exploration and geological mapping
Next is surface exploration, which involves geological sampling and analysis to get a sense of where the minerals are located. A key method for surface exploration is geological mapping, which is the foundation for all mining processes. After the area is mapped out and all the relevant research has been completed, one uses geological mapping to specifically identify the mineral deposits in the area. Geological mapping provides a base-level perspective on the geology in the specific areas.
Stage 3: Early-stage exploration and geophysical studies
The actual first steps of mineral exploration begin in stage 3, which is characterized by doing geophysical studies. Compared to geological mapping, geophysics go more in depth and are used to test for the physical properties of the specific rock that is collected in the deposit.
Geophysical studies can include:
- Gravitational survey: Measuring variations in the Earth, including gravity, density variations in rocks, and density in various features.
- Magnetic survey: Measuring variations in the Earth’s magnetic field, like disturbances created by magnetic minerals (iron ore).
- Electromagnetic survey (EM): Mapping subsurface electrical conductivity variations, measures the response of an electromagnetic field to uncover the impact of the electrically induced currents.
Early-stage exploration includes finding, testing, and surveying the deposit, where the end goal is to determine the value and cost of exploiting it. In other words, this is the final step for deciding whether to drill or not. Therefore it is likely that there will be done other surveys as well, for examples the ones listed in bullet points below:
- Geological data review: A comprehensive evaluation of geological information that assesses the reliability and relevance of sourced data.
- Remote sensing: Collection of data from a distance without physical contact to the relevant object.
- Soil sampling: Collection of portions of soil that are analyzed to give representative information on its physical, chemical, and biological properties. Knowledge about the layers in the soil is an essential to catch the metal ions.
- Stream sediment geochemistry: Analysis of the chemical composition of sediments found in stream beds. The stream beds derive from erosion of rocks and are a source for identifying anomalous element concentrations that are indicative of a valuable mineral deposit.
Stage 4: Data integration and drill planning
Before starting to drill, all the information collected in the previous stages should be processed and assessed in a holistic manner. This means that one does an overall assessment of the deposit size, grade, and economic viability based on the insights one has gotten from the surveys, assessments, and studies. This makes planning for the mine development and securing financing and obtaining permits much more streamlined.
Stage 5: Core drilling
Drilling commences when the geophysical studies, soil sampling, and other relevant surveys are completed and have given a direction for the project. Core drilling is used to prove and analyze mineral deposits, and core drilling is a method that is characterized by drilling a small diameter of rock from the earth. One can drill these core holes in hundreds of meters, for which directional core drilling is an especially useful method.
Directional drilling, sometimes referred to as borehole steering or slant drilling, is a technique that drills bores or wells along a curved path. In practice, it is a type of angled or curved drilling that aims to reach a specific target. Therefore, directional drilling provides access to underground areas that are not accessible through conventional drilling with minimal disturbance to the surface. After drilling, the cores are collected, logged, and analyzed for potential minerals. At the lab, the core samples are assayed and measured for an estimate of how much metal exists in the rock.
Stage 6: Resource modeling and de-risking
Once the amount of metal in the rock is determined, the core drilling continues, which benefits from doing some extra modeling for efficient time utilization. This involves de-risking, which is the process of carrying out various assessments and tests to determine the costs, required investments, and resource allocation required to complete the project.
De-risking might include these tests:
- Follow-up drilling: Any other additional drilling that is required by the project.
- Environmental assessments: Analyses that are used to identify and predict the potential outcome of drilling and mining in the specific area.
- Risk assessment: Analyses that identifies potential or likely hazards of doing the project that also highlights potential consequences of doing so. It also outlines actions that mitigate or eliminate the risks.
- Metallurgical tests: A set of analyses that outline the different properties of metals.
- Mine design and strategy: A comprehensive process of planning, designing, and optimizing a mining project. The goal is to maximise the operational outcomes and limit the environmental impact of the mining.
- Feasibility study: An assessment of the practicality and proposed project plan that in the case of mineral exploration outlines the factors that influence the success of the exploratory process.
- Preliminary Economic Assessment (PEA): An initial study that specifically outlines the economic viability of a mining project. It highlights the potential risks and uncertainties in the project.
Stage 7: Production
The final step is reached when a confident decision is made regarding the amount of potential metal that can be discovered in the mineral deposits and a plan for how to collect it has been made. Once that is done, the full-scale production process can commence and the mining can begin.
Stage 8: Closure
A quick note on stage 8 of the mineral exploration process, which may also be considered a new process altogether. Once the mining is completed, there must be a process for closing down the mine and restoring the community and area to a functioning site. This includes post-closure surveillance where one ensures long-term environmental stability through close site monitoring.
The potential outcomes of doing mineral exploration
Together with the improved geological knowledge and exploration techniques in the field, mineral exploration has become an increasingly important service with economical benefits and sustainably-aligned objectives.
For economic development
Mineral exploration is the first step to mining, where one sources mineral resources and produces economically profitable outcomes. One, the minerals sourced is used in production, and two, the actual on-site mining operations provide job opportunities and infrastructure opportunities.
For improved supply chain security
Minerals are important for energy production and resource allocation. By accessing minerals such as iron or coal, countries can for instance reduce their dependence on other suppliers and strengthen their own resource security.
For industrial use
- Technological advancement: Minerals are crucial components in for example electronics, batteries, and renewable energy production.
- Production: Minerals are used in a wide range of production and in various industries, for example sand and limestone in construction and sulfur in chemical production.
- Energy: Exploration for coal, oil, and gas can be covered in mineral exploration. As mentioned, minerals like copper and lithium are vital for solar and wind energy production. Both energy sources are essential in everything from domestic energy use to global trade, industry, and transportation.
A trifecta for success
When doing mineral exploration, all activities and every step have to work effortlessly together. In essence, there must be a clear understanding of the project and its challenges and opportunities, which can be supported by the proper equipment, technology, and knowledge. Successful exploratory mineral projects - and mining projects as a whole, relies on a solid geological foundation, the use of precise drilling techniques, and collaboration between geologists, engineers, environmental scientists, and project managers.
Geological knowledge
Mineral exploration can only be done with the likelihood and knowledge of there being mineral deposits available, including the knowledge of how to extract these minerals from the ores. This requires insight into regional geology, the design and implementation of mineral deposit models, and the use of historical data. For this, advanced technology, such as remote sensing or geophysical equipment, is necessary.
Borehole steering technology
Advanced technology, such as borehole steering, is essential for a successful project. Directional drilling, or borehole steering, is a practice that controls the direction of the wellbore to follow a predetermined path. There are several reasons to drill directionally, such as to intersect underground targets at a specific angle. Additionally, directional drilling allows for the grouping of several wellheads which is beneficial for the efficiency in complex drilling programs.
Collaboration
Utilizing the expertise that exists in the team, from geologists to project managers, is at the backbone of a successful mining project. Success also depends on data management, funding, and environmental, social, and government-related (ESG) considerations. For this reason, the exact data collection, allocation of financial resources, and adherence to regulation and risk assessment, are crucial. This can only be accomplished through close collaboration and communication.
Summary
Mineral exploration is the necessary step before starting mining and exploiting mineral deposits. It is defined as the search for minerals in concentrated deposits of minerals. The process for exploration can be covered in 8 steps, where the first six steps cover the stages of assessment, analysis, and exploration, and the final two steps outline the post-exploration phase and are part of the mining process. Mineral exploration is in other words a vital step that is achieved through collaboration between geologists, engineers, and project managers who use their expertise and experience to collect valuable minerals that can be used for industrial products and in later processing.
