Itabirite iron ore mines produce concentrates, which form the main source of revenue for their mining operation. In order to generate the desired levels of quantity and quality of concentrate that are required to maximize the DCF (Discounted Cash Flow) of the project, these mines seek the optimization of the blocks to be mined.
This blog describes an optimization technique where you create the CONC attribute (concentrate) to be valued and allow for a pit optimization based on this variable in GEOVIA Whittle.
An attribute, in this example, a variable “conc” should be created in your General Mine Planning software (eg Surpac etc.), where the Mass Recovery (MR) – percentage values for mass of concentrate will be stored in each block of ore generated. These equations are inherent to each process and may have constant values, depending on the approach that one wishes to take (Scoping Study, Preliminary Economic Assessment, etc.).
To export to Whittle this variable should be considered as a variable quality in the block (%), and thus defined in the software.
In the New Pit Shells node, Processing tab, the cost equations should represent the process (s) for the production of concentrate to be obtained in each block, allowing the product valuation, and the plant feed specifications must be entered in the Min Grade, Max Grade, and Tresh fields.
In the New Pit Shells node, Selling tab assign price $ / t conc and change unit to tonnes, thus we guarantee the optimization of the pits according to the value of the concentrate to be produced and we obtain the family of nested pits for the continuity of the studies of definition of Final pit and strategic long-term planning scenarios.
GEOVIA Whittle is the standard and world leader optimization software, generating optimized pits (nested cavas) using the Lerchs-Grossman (LG) algorithm or Pseudoflow, considering the physical characteristics of the mineral deposit (resource block model ), economic scenarios, geotechnical constraints (maximum slope angles) and other constraints. With GEOVIA Whittle, you have all the strategic mine planning tools you need to devise pit optimization at all levels:
- Strategic Sequencing
- Detail of costs
- Price and recovery modeling
- Stocks
- Multiple mines
- Blending and cutting contents for optimization
And more recently,
- Simultaneous optimization – an innovative tool from a methodology that offers an exchange of steps in improving NPV over previous approaches.
Kessel brings 28 years of experience in Technical and Management career working with a wide variety of mining companies such as producers like Samarco (the first Surpac customer in Brazil), Rio Tinto and Vale and Consultants such as Coffey Mining and GE21. He is Member of AusImm since 2007 and he was the Competent Person for Samarco in 2004 for reporting reserves. He works as as Process Consultant in the Americas CoE Team, based in Belo Horizonte, Brazil.