APPROACHES TO MAKE STRATEGIC MINE PLANNING SUCCESSFUL

Part 2: Production-scale Plan, Optimized Production Schedule, SMP’s Risk Assessment

Ensuring optimal resource extraction, maximizing value of increasingly scarce resources, and having confidence in mine plans amid market uncertainties is possible through DS GEOVIA’s SMP solutions.

In Part 1, we elucidate differences between mine plan and schedule, and strategic and tactical mine planning. We covered the approach in defining reserves and directional strategies.

Establishing the Optimal Scale of Production

After determining the best starting region and corresponding pushback directions, mine planners need to create a production-scale plan that can adapt to shifts in demand over life-of-mine and make three (3) major decisions: mine sequences, cut-off grade and production rate. These decisions are correlated, thus, changing one will alter the other two decisions.

With the Hill of Value, we can visualize a value surface based on cut-off grade and production rate at the same time identify the point in the value surface that generates maximum value.

Using the GEOVIA Whittle and SIMULIA process-automation tools, mine planners can run 9,680 sequences with various production rates, cut-off grades, and economic and market prices in less than a day.

Optimizing Strategic Production Schedule

In this approach, the mine planner can now identify which (blocks) to mine, when to mine and is left with a question: “How to optimize strategic production schedule that aligns with constraints, both technical and operational, and also maximize value (net present value)?”

The answer? The need to understand what can be optimized in the mine production schedule— the schedule itself, cut-off grade, stockpiling and blending.

Optimizing schedule can maximize net present value (NPV) by identifying what material to mine from generated pushback and when these will affect mine’s revenue and cost orders. The use of Milawa algorithm in GEOVIA Whittle helps determine the “what and when.”

The widely used cut-off grade optimization is Lane’s theory. It states, “Low-value material is discarded even if it is above the marginal cut-off grade. It will increase the mine’s NPV because the mine will spend more time early on processing higher-grade ore that otherwise would have been mined and processed later.”

Extractive blending maximizes value. GEOVIA Whittle provides “blend bins”, allowing mine planner to utilize the existing model without needing to manually re-classify block model data to achieve the most suitable blending.

Assessing Risks of Your Strategic Mine Plan

Mine planners assess risks in the plan using multiple scenarios. GEOVIA Whittle alone produces tens of scenarios. Thousands scenarios can be produced using GEOVIA’s SMP Workflow, and a combination of GEOVIA Whittle and SIMULIA tools.

Moreover, GEOVIA’s SMP Workflow enables planners assess risks in each workflow’s steps by incorporating uncontrolled variables’ sets. It also allows mine planners to “use uncertainty analysis to determine the accuracy of the definition of the final pit and pushbacks as well as the production scale and schedule,” said Romero.

Further, Monkhouse and Yeates, in Beyond Naïve Optimization (2007), identified five (5) sources of these uncertainties: • Orebody • Processing • Market • Discount rate • Changing technologies

Assessing the risks associated in processing, market and discount rate is easier compared to orebody uncertainty for it does not require the use of conditional simulations.

However, it was found that the use of Monte Carlo simulation enables to address orebody uncertainty easily by incorporating to pit optimization routine the “to-beassessed” input variables along with performing optimization routine for each scenario, resulting to pit shell sets.

From some studies, GEOVIA SMP enabled customers to improve NPV from 10% to 50% and reduce stripping ratio by 16-20%, resulting lower mining costs. It also improved grade forecasting accuracy by 30%, reduced development cost by 10%, revealed best possible performance scenarios, and saved time by converting manual one-month process to semi-automatic process of three days.

With Dassault Systèmes GEOVIA’s SMP, customers can focus on the importance of analyzing results and making decisions. To know more about SMP and other Dassault Systèmes Solutions and Services, contact DS Value Solutions partner Paramina Earth Technologies, Inc. through paramina_solutions@paramina.com or visit www.paramina.com.

REFERENCE:

Dassault Systemes. (2022). Strategic Mine Planning Articles 1-4.

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fully fabricated one-piece hopper hood, with a wear resistant skin rather than wear liners reduces the risk of liners falling off due to high impacts. This skin is replicated on the hopper itself, along with a Tshaped lattice design in the impact area to combat high impacts from the truck dump. Adaptations such as these ensure MMD machines are designed to endure the harsh mining environment and are built to last.

MMD Sizer stations undergo rigorous FEA, DEM and Explicit Dynamics analysis at the design stage. This examination provides data on impact forces, load conditions, fatigue cycles, as well as material flow characteristics, which assist in optimising the design. This is particularly useful for wet and sticky applications where material hang-up and blockages could be problematic in features such as hoppers and chutework. At MMD, analysis and design work is undertaken by experienced, fully qualified engineers who combine their technical know-how with industry leading software to design the best solution for customer specific challenges.

Case Study

In 2014, MMD delivered two compact semi-mobile Sizer stations to an island in the Philippines. These bespoke designs were installed to handle lateritic nickel ore. The material within the mine is generally very sticky with hard rock inclusions, however during the wet season the material characteristics change to become extremely wet. The turnkey Sizer stations featured 625 series Sizers with side cleaning combs and D4 Apron Plate Feeders along with supporting steelwork and electrical package. Run of Mine material is directly fed by dump trucks in to the apron feeder which in turn draws material into the sizer controlled rate of up to 500TPH. Lumps of up to 800mm can enter the Sizer chamber, which is then efficiently reduced down to 150mm product. Both these machines remain active, providing trouble-free operation and minimal maintenance.

Watch the unit in action here: https://www.youtube.com/ watch?v=DSLdwNoAY80

One of the SemiMobile Sizer Stations processing Lateritic Nickel Ore.

2GO: Best positioned for special handling, custom processing

2GO, the largest and most integrated logistics and transportation services provider in the Philippines and a subsidiary of SM Investments Corporation, is best positioned to provide special handling and custom processing to serve various industries such as mining, power, telecommunications and infrastructure.

With its own assets for endto-end solutions, 2GO’s Special Containers and Value-Added Services (SCVASI) is backed by 25 years of experience in moving all types of cargo.

Leveraging on the shipping business’s strength of schedule, reliability, and speed, 2GO SCVASI continues to expand its capabilities and offer borderless solutions.

Apart from pioneering Less than Container-Load (LCL) reefer and isotanks in the country, 2GO SCVASI has proven expertise in its Project Logistics service—loading and unloading deliveries of oversized and overweight cargos for power generation, transmission lines, mining operations, cement manufacturing, pipes for geothermal operations and government infrastructure to the most remote areas in the country. 2GO SCVASI is manned by professionals to survey efficient routes, presenting methodologies on safe conduct of lifting of transformers, generators, railways, cement manufacturing equipment, solar and other industrial goods, and other equipment that require special handling.

It currently has two customized 25-tonner Boom Trucks that will eliminate mobilization and demobilization of forklift on these weight categories. 2GO SCVASI, the Philippines’ leading provider of reefers, flexibags, isotanks, and project logistics, continues to make significant investments to soon deliver long dimension wind-power propellers.

To know more about 2GO SCVASI, visit https://www.2go. com.ph/scvasi/