Recon #13 of 17. F2 – Building Relationships with the Metallurgy Team

Hi everyone and thanks for your interest in mining geology!

In previous posts, we discussed how to develop a robust checkpoint system to ensure all bases are covered regarding ore control. Some of these areas are within our immediate control (such as block models and polygon design), while others require extensive communication with the mining team (such as dispatch and blast planning). However, so far we are all working together on the production side of the process.

When the ore is dumped into the crusher feeder, it marks the end of the grade control team's control and transfers it to the processing or metallurgy team. Although this demarcation line is imaginary from the perspective of overall mine success (at the end of the day, we all want more metal to be produced), it is very real in terms of the general attitudes of the ore control team at one side of the fence and processing team on another.

The simple generic formula for F2 reconciliation is Mill Feed Reconciled / Mill Feed Produced, where the denominator is the sum of Ore Produced (Pre- or Post-blast Polygons) + Delta Stockpile. We will focus on the grade part of this metric in the next post and address the tonnage problems in the post after that. In this discussion though, I’d like to focus more on the quality of the plant-produced grade information and the critical importance of building healthy and transparent relationships with the metallurgy team.

Ironically enough, although half of the information in F2 comes from the plant team, the reconciled tonnes and grades are typically considered accurate, and it is usually the ore control team's responsibility to explain the root causes of any variations. While it is true that, as discussed in previous posts, the production data has more variables and it is more challenging to ensure a consistent metal stream without losses compared to the controlled environment of the plant, the latter also requires verification. The best course of action for the chief operational geologist is usually to first ensure that all checks and balances on the mining end are in place. If discrepancies in F2 persist, the next step is to work closely with the metallurgists to determine the cause.

This collaboration is very important. Although in many mines the processing and mining teams tend to operate in silos, this is a suboptimal practice that leads to tension, conflicts of interest, and overprotection of individual kingdoms. A better approach for geologists is to understand, at least at a high level, the source data for everything related to reconciled information. This means you need to be familiar with the sampling practices of the head/tail samples (and possibly offer to independently check them in the geo lab or another lab regularly), have open discussions about the details of crusher and mill weightometer calibration practices, and monitor the Gold-in-Circulation (GIC) balances on a month-to-month basis. In other words, apply the “Extreme Ownership” (total responsibility for the success of the mission, a term popularized by Jocko Willink in his book of the same name) concept to everything related to the mine's success in delivering the final product.

None of this is possible without real, trustful, and transparent communication between the geology and metallurgy teams, and developing these relationships is vital. If ore control holds shift calls with processing about ore delivery plans, proactively addresses or changes the blend in case of emerging issues, helps in modeling and tracking variables that can aid processing in optimizing their workflows, and meet at least monthly to discuss reconciliation results and potential improvements, it can have a tremendous impact on the mine's ultimate revenue. Conversely, if relationships are poor and everyone is focused solely on their own interests, it will have a disastrous impact on the mine's profitability.

I think this is an unusually vague post without any clear tips and tricks. However, when it comes to F2, I truly believe that removing informational barriers and establishing healthy, professional, and clear communication with the processing team is a paramount step for any technical checks we will discuss in the next couple of posts. So, if you find yourself in a position where grade is somehow magically lost between the crusher feed and reconciled head while all your F1 metrics are performing well, first grab lunch or dinner with your chief metallurgist and discuss the issue. You may not become best friends (it's not easy with so many conflicts of interest), but healthy and respectful professional relationships will be the cornerstone for everything we discuss next on that topic.

#mining #mininggeology #resourcegeology #geology #resourcemodel #resourcemodelgeology