The block model provides a three-dimensional, spatial interpretation of the ore body that is fundamental to the mine planning process. Typically, the block model will include the following information:
- Centroid position and blockA spatially constrained unit within the resource model. dimensions,
- Interpolated geology, estimation and/or processing domainGeological, statistical or spatial groupings used for modelling.s and rock typeGeological classification of material into discrete groups.s,
- Estimated grade and density of the block,
- geotechnicalStructural properties of a given material. estimates for mine design, and
- geometallurgical estimates for processing throughputMetric for overall tonnage moving through a system within a specified time.s and recoveries.
- The interpolated natural deportment Response Ranking (required for GE-screening assessments),
- Estimated heterogeneity of blocks or panelA discrete section within a resource model (i.e. block).s at relevant SMUs (required for Induced deportment and bulk ore sorting assessments),
- Estimated screening and particle sorting response, and
- Estimated gravity separation response.
These Grade Engineering parameters are combined with blast fragmentationDistribution of rock created through the application of explosives. models and selected GE plantA preconcentration circuit. settings (screening aperture, ore sorting Cut-Off grades) to populate the Grade Engineering block model with the proportion of mass and metal reporting to upgrade and downgrade products of GEGrade Engineering options. Process modelling and simulations are required to estimate changes to plant throughputMetric for overall tonnage moving through a system within a specified time. for GE-screening options, that alter the PSDParticle Size Distribution of material sent to processing, and estimate changes to processing recoveries based on the increased grade of GEGrade Engineering products to the plant. A trade-off exists between the number of GE-options assessed and the computation time required for scheduling and Cut-Off optimisation. The complexities of GEGrade Engineering options for the evaluation of natural and Induced deportment and bulk ore sorting are depicted in the image below.
The Grade Engineering block model is combined with GEGrade Engineering cost models and economic and financial assumptions to calculate the value of each blockA spatially constrained unit within the resource model. if processed via all treatment and storage options. The resultant Grade Engineering economic block model forms the basis for defining the ultimate pit or underground mining shapes. An example of treatment and storage options for a GEGrade Engineering operation with a processing plant and heap leach are presented in the picture below. Please note that high-value and barrenMaterial void of any valuable elements. material mined may bypass Grade Engineering and be sent directly to a treatment or storage destination to yield the greatest possible value for the block.