What you will learn
- How grade is measured, and where it is measured
- How loads are tracked from face to crusher or stockpile
- How blending decisions use grade data
- What happens when grade data is late or missing
- Where grade tracking ends and resource modelling begins
What this project is
Grade is what makes ore valuable, and it varies across a deposit. One load may be high grade, the next waste-like. If the plant receives loads without knowing their grade, it cannot blend feed to a consistent quality, and recovery suffers. A grade tracking system records the grade of each load or batch, links it to where it was mined, and follows it through haulage to the crusher, stockpile or waste dump. The plant then knows, load by load, what is arriving.
The system depends on sampling and assaying. Face samples, blast hole samples, truck load samples or on-belt analysers each give grade information at a different point, with different accuracy and delay. The system should record which method produced each grade value, because a face estimate and a laboratory assay are not equally trustworthy, and blending decisions should weigh them differently.
Core features
- Load and batch records with source location, material type and grade values
- Sampling and assay tracking, recording method, laboratory and result date for each value
- Stockpile tracking by grade category, so each stockpile's average grade is known
- Blending guidance that shows the effect of adding a load or stockpile draw on feed grade
- Reconciliation between planned grade from the resource model and actual grade mined
- Reporting by shift, bench or stope, showing grade variation over time
How it is built
- Map the material flow first: faces, stockpiles, crusher and waste, and where grade is measured at each step
- Build load tracking and stockpile records, then the blending view the plant uses daily
- Add assay tracking with method and laboratory recorded for every value
- Add reconciliation against the resource model, so systematic differences become visible
- Pilot on one pit area or stope, checking tracked grade against laboratory results before wider use
Technology considerations
Grade data is always an estimate with error, and the system should be honest about that. A value from a face sample carries more uncertainty than a laboratory assay, and the system should carry that uncertainty with the value rather than presenting every number as equally precise. Timing matters too: a laboratory result that arrives days after the load was processed cannot guide blending, so the system needs to distinguish fast estimates used for operations from slow assays used for reconciliation.
Stockpile tracking is a common failure point. If loads are added to a stockpile without recording grade, the stockpile's average grade becomes a guess, and blending from it becomes a guess too. The system should enforce stockpile recording at the point of dumping, when the information is available, rather than reconstructing it later from memory.
For the first version, track grade for one pit area or stope: load records with source and method-labelled grade values, stockpile averages, and blending guidance the plant actually uses daily. Plant managers judge the system on whether the feed grade it predicts matches what the plant receives. A system that does that for one area, with fast estimates distinguished from laboratory assays, proves the approach before it covers the whole mine.
Challenges to plan for
- Grade values that arrive too late to guide blending decisions
- Stockpiles whose recorded grade no longer matches what is actually in them
- Different sampling methods giving different grades for the same material
- Reconciliation gaps between modelled grade and mined grade that nobody investigates
Who it is for, and its limits
This suits a mine operator or a processing plant that blends feed from multiple sources. It fits operations where grade varies enough that blending matters. It does not fit a deposit with uniform grade, where tracking adds little, and it is not a resource model: it tracks grade actually mined, it does not estimate what remains in the ground.
A grade tracking system does not improve grade. It stops good ore being diluted with waste and stops the plant being surprised by feed it was not expecting. Costs vary with sampling methods and material flow complexity, so confirm with a quote after the flow is mapped.
Frequently asked questions
Where is grade measured?
At several points: face or blast hole sampling before mining, load sampling during haulage, and on-belt or laboratory analysis at the plant. Each point gives a different view, and the system records which method produced each value.
What is blending?
Mixing high-grade and low-grade material to produce a consistent feed grade for the plant. Consistent feed improves recovery and avoids swings that damage plant performance.
Why track stockpiles by grade?
Because a stockpile is a blending tool. Knowing each stockpile's average grade lets the plant draw from the right stockpiles to hit the target feed grade.
What is reconciliation?
Comparing planned grade from the resource model with actual grade mined and processed. Persistent gaps mean the model, the sampling or the mining selectivity needs attention.
What if assay results are late?
Operations use the fast estimate available at the time, and reconciliation later corrects the record with laboratory results. The system keeps both, labelled, so nobody mistakes an estimate for an assay.