Intro
As promised in our published article “TOP 10 TIPS FOR MINERAL RESOURCE ESTIMATION” This is the first of a series of articles named Journey to a Mineral Resource Estimate. All the materials intend to discuss the various aspects of the multiple tasks typically undertaken to complete a Mineral Resource Estimate successfully for any given mineral deposit. The current article discusses the importance of data and why it is so critical.
Data, the foundation of everything
Every Journey has a beginning; data collection is the first step in Mineral Resource Estimation. However, most of the time, due to discouraging results, not every mineral exploration program reaches the end of this Journey.
In the Mineral Exploration business, all of the collected data comprise the most valuable asset. It must be carefully handled because the purpose of mineral exploration is to obtain the necessary data to assess a mineral deposit. It takes much effort to complete the process. Regardless of how exciting the data content could be, it should be organized and stored correctly in a structured and secured relational database. Data provides the building blocks to create information, and it is the basis for interpretations and decision making. Data, the intangible asset, is often taken for granted: end-users overlook its importance, focusing instead on information and reports because those are what people understand and communicate.
Figure 1: Data, Information and Knowledge Pyramid
Source: Micon, 2020.
Standard Data Transfer Proceedings in Consultancy
When mining consultants receive a geological database with which to conduct a mineral resource estimate, it usually takes a lot of effort and time to compile, clean and organize the data in good order to support the mineral estimate. All metadata details are ignored or lost in the handling process and may even never be captured. Consultants may simply receive a copy of the dataset, which is often a filtered or partial version of the entire existing database.
After due diligence checks have been carried out, the geological data is accepted “as is” subject to the client warranting its accuracy and completeness; however, every database contains qualitative and quantitative variables, which have a history that consultants rarely get to know.
Upon receipt and curation of the data, all standard proceedings for resource estimation are completed presenting the results in a mineral resource statement with tonnage and average grade for the given mineral deposit. That is often the extent of a consultant’s involvement.
The Subject Matter
All of the described procedures above are standard practice in mining consultancy.
Data plays a pivotal role in mineral resource estimation. Experienced consultants know how important and valuable a geological database is, and terms like corrupted, lost, unreliable, incomplete, insufficient, unsuitable are often mentioned when dealing with them. Usually, by the time consultants are involved, it is too late to make corrections leading to costly solutions and sometimes an impediment to doing the work.
All of these hassles and wastes of time and money can be avoided. This requires that consultants conducting a mineral resource estimate be involved in the data capturing process at an early stage and be the independent observers of the “data gestation”. This will ensure that this costly but essential operation is properly done once.
This will increase the level of confidence of all interested parties such as the exploration companies, shareholders, investors, analysts, lenders, the public and ultimately, consultants who take responsibility for the estimates.
This recommended modus operandi does not mean costly consulting fees at an early stage of exploration. With a proper database management system, a consultant can spend 1 or 2 hours looking at your database settings and provide the required advice when needed.
The Geological Database
Most of the exploration and mining companies running exploration projects struggle to build a new geological database, and everyone does it differently with the available computer software they have. The most used is Microsoft Excel because it is affordable; however, Excel is not a database manager.
There are some general aspects to consider when building a geological database:
- The database must be unique and stored to / shared from a single permanent source.
- Data must be properly organized, representative, reliable, accessible, auditable, and secure.
- The database must contain at least location, geology, and sampling data, see Table 1 for details.
Table 1: Essential Data to Support a Mineral Resource Estimate
Source: Micon, 2020.
In summary, we need:
- location data to define the geometry of the mineral deposit,
- geology data to determine the geological framework of the mineral deposit,
- assay data to assess the grade distribution and quantities of the contained commodity,
- density data to calculate the tonnage, and,
- metallurgical recovery data along with economic parameters to determine prospects for economic extraction.
All these dataset components are critical and must be collected.
Data Verification
Data errors are pervasive; it is almost guaranteed you will catch an error in the database. For this reason, the company collecting the data and the consultants using the data should make great efforts to have an error-free geological database. Among the many verification steps performed thoroughly on the entire database the most common include: revision of QA/QC data, assay values checks, assay units, element (field) switch, samples switch, negative values, detection limits symbols, assay results versions, interval sequences, interval gaps/overlaps, missing data, duplicated data, pending results, suspicious down the hole deviations, coordinates datum, survey discrepancies, collar locations, topographic surface, and many more. Also, plotting the data in a 3D viewer software is a practical way to catch errors quickly, especially those related to location data.
In conclusion, the collection and verification of data is a tremendous task and it is the most important step to begin your Journey to a Mineral Resource Estimate, talk to Micon before you get started.
Next time we will discuss our second article “Journey to a Mineral Resource Estimate: Statistics.”
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Excelent publication Alan.
One comment on the importance of data and why it is so critical:
When verifying a database of a technical report, it is very common to find phrases such as:
“The database was examined and minor issues were found that were resolved.”
“The geology and chemical analysis database was reviewed, with overlaps and duplications identified and removed.”
“The differences between the checks and the original results are small, and the checked trials are not consistently higher or lower than the original trials.”
“Migration from the current Excel database to an SQL database has validated the integrity and quality of all the drill-hole data. Minimal errors or deviations were observed during this migration process ”.
And so we can continue with a fairly extensive list.
What is happening?
It turns out that high, low, small, minimal, etc. are interpretations, therefore they are subjective and correspond to the subject who issued them. The errors are not high, low, minimal, or small, they are simply errors and must be quantified in% since they are associated with risks, which they will have positive or negative effects on the mining asset. If the error is quantified, the information provided in the reports will comply with the principle of Transparency.