12th International Copper Conference

Table of Contents

1. Mining Projects

   1. Frontmatter

   2. High Angle Conveying the Vital (Missing) Link to In-Pit Crushing and Conveying Systems

      Joseph A. Dos Santos, Amy Duncan

      Abstract

      Dramatic reduction in energy use and environmental impact can be achieved with sandwich belt high angle conveyors that serve as the vital link in any In-Pit Crushing and Conveying (IPCC) system. These high angle conveyors are not new at all, but have not found wide use in IPCC systems where they can realize the greatest advantage. IPCC systems were already realized in the 1970s. With the bulk material haulage limited to conventional open trough conveyors, the most direct path out of the open pit was not possible, requiring low angle spiral ramps and/or deep slots and/or tunnels through the high wall of the open pit. These excavations, to accommodate the low angle limitations, represented undesirable impact on cost and on the environment. Against this backdrop, a major study in 1979 sought to develop high angle conveying systems that could continuously haul the mined bulk material directly out of the pit, along the high wall—the shortest distance between the two end points. Between 1979 and 1982, that study developed sandwich belt high angle conveying systems that utilized all conventional conveyor equipment, including smooth surfaced rubber belts that could be continuously scraped clean. These systems had all of the positive features of conventional conveyors but overcame the angle limitation. By hugging the bulk material between two belts, the material’s internal friction could be developed to facilitate conveying at any high angle up to 90° (vertical). In 1984, the Majdanpek copper mine in Serbia, already using pit perimeter crushing and conveying, decided to move their primary crusher deep into the pit and to use a sandwich belt high angle conveying system to elevate the ore continuously, directly out of the pit, along the high wall to the pit perimeter where it then transferred to a conventional conveyor for the remaining haul to the plant. This significant sandwich belt high angle conveyor was only the second commercial sale. Many successful sandwich belt high angle conveyors followed with the current count of commercial installations at more than 200. Despite the great success in the Majdanpek system, its use has not been repeated as part of an IPCC system. The high angle conveyor offers the link to optimization of any IPCC system, yet that industry continues to struggle with the use of conventional conveyors and haul trucks to achieve the high angle function. The results are sluggish low angle conveyor systems of limited flexibility requiring excessive maneuvering time, excessive excavation and fill, re-handling and grading in order to accommodate the low angle limitations. Recent studies have represented resurgence in interest in high angle conveying and have demonstrated the technical and economic advantages along with the reduced environmental footprint. Though the primary purpose is to demonstrate suitability for open pit mining applications, this writing will first recap the early development of the latest sandwich belt high angle conveyors and their commercialization over the last 40 years. Particular emphasis will be on who did what, and when, giving due credit. This will show that since 1979, the constant of the development is the invention and the work of the writer. We will highlight the features that make Dos Santos Sandwich Belt high angle conveyors particularly energy efficient and suitable for use in the harsh requirements of the IPCC systems, highlighting the success in Serbia and in the latest studies. Finally, we introduce the latest structural support systems for long span, high lift high angle conveyors. These wire rope suspended systems, we call Flying Sandwich Belts.

   3. Applying Machine Learning Techniques to Decarbonize Mine Haulage and Accelerate the Transition to Zero Emission Mining

      Kevin Dagenais

      Abstract

      The mining industry is under increasing pressure to meet aggressive decarbonization targets, driven by both regulatory frameworks and corporate sustainability goals.

   4. Non-intrusive Flow Measurement of Compressed Air in a Deep-Level Underground Platinum Mine

      Victor K. Mwaba

      Abstract

      Compressed air systems are one of the most significant energy users in underground mines, with a contribution of about 20% to the total electrical energy consumption. As a matter of fact, compressed air is considered to be a 4th utility in many industrial settings, in the same category as water, electricity and gas. In underground mine settings, compressed air is used to power pneumatic tools, mainly rock drills. Also, it is used to provide respirable air for underground workings ventilation systems. Surface compression facilities supply air to an underground network of pipes laid in vertical shafts and horizontal adits. The air is typically provided from a 24″ supply line to 12″ and 6″ feeder pipes at around 90 PSI. As various sections of the ore body are extracted, air supply is needed in different locations of the mine. The electricity costs associated with supplying compressed air are significant. In the case of a platinum mine in South Africa, it was approximately $25 K per day. Flow measurement is needed for the following objectives:

      • To identify if there is flow in inactive areas, isolate the piping, and stop wastage.
      • To identify high consumers of compressed air in active areas. This may indicate equipment wear and therefore able to prioritize these for repair.
      • To identify leaks; it is estimated a punch hole caused by a nail can result in the loss of $36 K per year while open ends can be as much as $715 K per year.
      • To supply data to compressed air simulation models. The operators of the platinum mine were therefore looking for a suitable way to monitor the compressed air flows using measurement technology.

      One may note that traditional leak detection technologies are more suitable for commercial building settings such as warehouses where compressed air piping is within line of sight. A mine being a complex web of shafts and adits, leak detection instruments need to be more innovative. Also, some compressed air audits and surveys include opening up of electrical panels, which may include disruption of production to conduct electrical energy isolation safety procedures lock out tag out try out (LOTOTO).

   5. Cactus Mine Update—from a Taxpayer Liability to a Top Copper Producer

      Travis Snider

      Abstract

      The Cactus Project (Cactus), historically the Sacaton Mine, is a prime example showing that it is possible to turn an environmental clean-up into a sustainable mining operation. It demonstrates how government agencies and private industry can work together to benefit the local community. Arizona Sonoran Copper Company Inc. is proposing to restart Cactus, located in a previously heavily developed area. Instead of disturbing an untouched greenfield area, the company is proposing to use an historical mining site. It will also bring an historic location, from circa 1970s and 1980s, up to the modern environmental requirements that the State of Arizona requires for modern mines, including Arizona Aquifer Protection Permit Requirements. Prior to the Arizona Sonoran Copper Company Inc. acquiring this project from an Environmental Trust and the State of Arizona, this site was a taxpayer liability. Now it is on track to being a top 10 copper producer in Arizona while supplying a critical mineral, copper, for the U.S. supply chain as well as for national security requirements. This site will also provide meaningful jobs to the host community of Casa Grande and surrounding cities and Pinal County as a whole. Over the three plus decades this mine will be in operation, the Economic Output from the operation will be US$15 billion, equivalent to the City of Casa Grande hosting a Super Bowl every year for almost four decades.

   6. Analysis of Alternatives to Diesel Fuel Use in Mining Trucks

      Diego Canullan, Angelina Anani, Sefiu Adewuyi

      Abstract

      The increasing effects of climate change have resulted in a global agreement on the urgent need for decarbonization, with governments establishing ambitious emissions reduction targets, such as those set in the 2016 Paris Agreement. The main activities in the mining sector that contribute to greenhouse gas emissions are loading and transportation. Minerals are typically transported on large trucks with diesel engines. In order to meet the urgent need to reduce CO₂ emissions in the mining industry, this study examines diesel fuel substitutes for use in mining vehicles. The research analyzed the feasibility of using electricity, renewable diesel, and liquefied natural gas (LNG) as alternatives to diesel fuel. We used discrete event simulation to compare these energy alternatives across various parameters and scenarios. The analysis was performed on data from an open pit mining operation over a 24-h period. Our results showed that short-term production levels remained largely unaffected by the type of energy used. However, the electric truck scenario required 13 additional trucks to match the production levels of diesel fuels due to the smaller size of electric trucks. LNG trucks demonstrated a significant increase in fuel consumption (+50%) compared to diesel trucks, leading to higher operational costs (+46%). In terms of emissions, electric trucks achieved a 95% reduction in CO₂ emissions, while renewable diesel trucks reduced emissions by 90%. On the other hand, an increase in fuel consumption by LNG trucks compared to diesel trucks resulted in a 30% increase in CO₂ emissions. In addition, simulations with LNG and electric trucks resulted in longer cycle times and queue lengths. The results showed that the assumptions used in this analysis have a major impact on the outcomes, indicating the need for further research as the industry continues to investigate and implement these technologies.

   7. Master Planning for End-Of-Life Concentrator Asset Replacement

      Ewan Wingate, Bill Van Butzelaar, Ranjit Prasad, Ivan Sanhueza, David Meadows

      Abstract

      Copper concentrator equipment life cycle replacement master planning is a vital strategic process aimed at de risking operations, optimizing asset performance, improving cost-efficiency, ensuring capital planning and increasing operational longevity of machinery and equipment within copper concentrators. This comprehensive planning approach considers the entire life cycle of key equipment, including crushers, mills, flotation cells, thickeners, filters, pumps, conveyors and supporting non-process infrastructure (e.g., desalination plants and ports), from design and acquisition, through operations to final disposal, with a focus on minimizing downtime, reducing maintenance costs, and enhancing overall production efficiency. The unique operational environment and demands of copper concentrators necessitate a tailored multivariate approach to equipment life cycle management, factoring in variables such as equipment wear, maintenance strategies, production capacity and operating conditions. By considering all aspects of asset ownership and implementing strategies to optimize each component, mining companies can significantly improve their bottom line. A holistic approach to equipment management is essential for sustainable and profitable mining operations.

   8. Standardizing the Mine-Call-Factor for Three (3) Generational Models—A Case Study for ASARCO Mission Mine, AZ

      William Zutah, Jose Quispe

      Abstract

      Mine reconciliation is the comparison of an estimate of a long-range resource model, short-range model, ore control model, or a mine production plans, or schedule measured against survey measurements of stockpiles and dumps and production records, usually compared with the final processing metal produced. Mission Mine’s current reconciliation system does not take into consideration the establishment of reconciliation factors, or it nominally assists in confirming the grade and tonnage estimation efficiency of long-range, short-range, and ore control models or diligently estimate resource/reserve models and survey pick-ups compared to actual or budgeted production. The main objective of the project is to establish an automated reconciliation processing system and implement a new system to measure the operation's performance against targets, confirm the grade and tonnage estimation efficiency of mineral resource and ore control models, ensure the accurate valuation of mineral assets, and provide key performance indicators for ore control predictions. Establishing reconciliation factors often takes a rigorous process and over an extended period to arrive at appropriate values/factors for a deposit. The presentation summarizes the case study of the reconciliation evaluation between three long-range models produced from 2019 and 2025 for Mission Pit. Mine reconciliation factors for F1, F4, FLTM, FSRM and FMRLR evaluated for the process indicated varying variances for all three models. Results from evaluation consistently showed acceptable predictions with tonnage, grade and contained copper predicting averages within 0% to 10% for all models within a twelve-month period for F1. FLTM factors showed variances of 10% to 17% lower for tonnages and contained metal within the twelve-month period for all three models but the grade was within acceptable limits. FMRLR factors consistently showed lower percentage variance in tonnages, high variance in grade and lower variance in contained metal for all three models. The contained metal variance predicted for all three models by production were 9%, 8% and 10% lower for 2019, 2022 and 2025 respectively.

   9. Rigorous Financial Discipline in the Copper Mining Industry: Strategies for Sustainable Profitability and Long-Term Success

      Isaac Osei, Bob McCarthy

      Abstract

      The copper mining industry operates in a multifaceted environment characterized by fluctuating commodity prices, stringent regulatory pressures, and increasing demands for sustainable practices to improve profitability for long-term success. This paper explores the role of rigorous financial discipline as a cornerstone for achieving sustainable profitability. It outlines strategies for effective financial management that mining companies can adopt to effectively navigate these challenges by emphasizing on cost control, risk management, and investment in technology to capitalize on opportunities (Smith and Brown in J Min Econ 15:45–67, 2022).

   10. Florence Copper: Creating 360 Degrees of Value Through Sustainable Copper Mining

       Sophie Dessart

       Abstract

       Unlike conventional mining, Florence Copper uses ISCR technology—a low-impact method of copper extraction with significant environmental advantages. The process eliminates the need for open-pit or underground excavation, waste rock piles and tailings storage facilities. By eliminating the need for blasting, hauling and crushing massive volumes of mineralized and non-mineralized material, Florence Copper is forecast to consume 78% less water and 65% less energy per unit of production compared to traditional open-pit copper mines in Arizona. Greenhouse gas (GHG) emissions at Florence Copper will also be 75% lower than conventional open-pit mines in Arizona per pound of copper produced. The project is expected to be the lowest GHG and energy intensive copper producer in North America, supporting the global transition to a low-carbon economy with responsibly sourced copper. Once operational, Florence Copper’s ISCR wellfield and SX/EW processing plant will have an annual production capacity of 85 million pounds of LME Grade A copper per year for 22 years, generating significant economic benefits for Florence, Pinal County and the State of Arizona. These include $4.3 billion in economic activity and nearly 820 total jobs (direct, indirect and induced) over the project life.

   11. A Case Study of the Trolley Assist System at the Copper Mountain Mine

       Kota Fujimaki

       Abstract

       The trolley assist system enables the supply of electric power directly to the drive system of diesel-electric haul trucks, thereby increasing productivity, reducing diesel consumption, and reducing CO₂ emissions. Copper Mountain Mine in British Columbia, the first mine in North America to install the trolley assist system, has installed an overhead power supply system along an inclined haul road segment stretching approximately 1 km and operates 28 diesel-electric haul trucks, 7 of which are equipped with pantographs to receive electricity. The purpose of this paper is to report the actual improvements at the mine by comparing operating results of trolley assisted and non-trolley assisted haul trucks. There was a 10% increase in the productivity of the haulage operation as a contribution of 59% increase in the climbing speed on the segment with the trolly assist system. In addition, the operating cost per tonne moved was reduced by 16% and CO₂ emissions per cycle were reduced by 42%.

   12. Comprehensive Overview of Los Azules Copper Project Metallurgical Test Work

       Nicole Cheishvili, Marcela Medina

       Abstract

       Los Azules, an advanced-stage porphyry copper project in the Andes Mountains of San Juan, Argentina, is focused on evaluating leachable copper potential across multiple different lithologies. A three-phase metallurgical program was conducted using both historical and newly-drilled core samples to assess leaching performance through bottle rolls and column leach tests. The testing explored ore from multiple mineralization zones and lithologies to evaluate copper recovery, acid consumption, and leach kinetics. Ongoing experiments in Santiago are testing additives like wetting agents and sulfur substitution to enhance copper recovery while potentially reducing acid consumption. Preliminary results from ongoing tests have informed process design and identified strategies to optimize economics while maintaining environmental responsibility. The findings will ultimately contribute to improving test methodologies for the Los Azules project.

   13. Rethinking Copper Extraction

       Doris Hiam-Galvez, Nathan Stubina, Egardt Gerber

       Abstract

       The global pursuit of copper has resulted in significant environmental impacts, such as vast open-pit mines that scar the Earth’s surface. As we confront this legacy, it’s imperative to explore innovative extraction methods that minimize environmental disruptions. Copper sulfide deposits present significant challenges due to their depth, complexity, and operational constraints. These deposits require advanced infrastructure, specialized technologies, and substantial capital investment. This paper examines advanced techniques such as in-situ recovery and block caving, alongside emerging hybrid systems, to propose a holistic approach that reduces ecological footprints. By integrating sustainable practices and fostering community trust through Designing Sustainable Prosperity (DSP), we can transform mining into a catalyst for regional prosperity.