Advances in Pyrometallurgy: Developing Low Carbon Pathways: Energy Valorization in Metallurgy
Sponsored by: TMS Extraction and Processing Division, TMS: Pyrometallurgy Committee
Program Organizers: Camille Fleuriault, Eramet Norway; Joalet Steenkamp, XPS Glencore; Dean Gregurek, RHI Magnesita; Jesse White, Kanthal AB; Quinn Reynolds, Mintek; Phillip Mackey, P.J. Mackey Technology, Inc.; Susanna Hockaday, Curtin University, WASM
Tuesday 2:30 PM
March 21, 2023
Room: 29B
Location: SDCC
Session Chair: Camille Fleuriault, Eramet Norway; Quinn Reynolds, Mintek
2:30 PM Invited
The Use of Concentrating Solar Energy for Thermal Decomposition in Oxide and Carbonate Minerals: Susanna Hockaday1; Quinn Reynolds2; 1Gam Aesa; 2Mintek
Concentrating solar energy can deliver high temperature process heat to metallurgical processes. An overview of mineral resources in South Africa and Australia and the possibilities of using concentrating solar thermal energy for thermal decomposition as novel low-carbon pretreatment processes are investigated. The paper will consider the thermodynamics of oxide and carbonate minerals and evaluate the potential carbon emission reductions as well as changes in energy demand of such processes.The state of the art of concentrating solar technologies for materials treatment will be reviewed.
3:00 PM
Linde’s Industrial Gas Technology in Nonferrous Processing: Combining CFD with Partial Experimental Verification & Validation: William Mahoney1; Adrian Deneys2; Ahmed Abdelwahab1; Jiaye Gan1; 1Linde Technology Center; 2Linde, Inc.
In primary and secondary nonferrous sectors, industrial gases and associated injection equipment are applied to oxyfuel and pneumatic injection technologies. The former is applied to decarbonization through the improved utilization of alternative fuels, including a growing interest in hydrogen. The latter is concerned with gas jetting for metal mixing and refining. CFD is used to support the design, installation, start-up of oxyfuel burners and gases injection equipment. Verification and validation (V&V) in CFD output can be enhanced via experimental efforts; however, the extraordinary difficulty in taking measurements in production furnaces under hot conditions is fully appreciated. We present an approach on a partial V&V method relying on basic assumptions in the computational and experimental domains, wherein posteriori error estimation is partially fulfilled through experiment. We draw upon industrial installations in the following reactors: fluidized bed roaster (g-g), cylindrical-horizontal furnaces (g-l) (top-blown and submerged) and straight grate / rotary kilns (g-s).
3:20 PM
Sulphuric Acid Plants in Metallurgical Facilities: Options for Energy Optimization: Shailesh Sampat1; Joseph Kelly1; Maria De Campos1; Sina Mostaghel1; 1SNC-Lavalin
Highly exothermic reactions in a Sulphuric Acid Plant are sources of energy that can be used effectively in metallurgical facilities. Unfortunately, this aspect does not receive the attention that it deserves while designing metallurgical facilities. High temperatures in gas circuit allow heat recovery as steam which is a very valuable source of energy. Over the last two decades, development of better materials of construction has allowed operation of acid circuits at high temperatures, resulting in increased opportunity of heat recovery as steam. This paper discusses various options for recovering heat and utilizing it effectively in metallurgical facilities.
3:40 PM
Experimental Analysis of Zinc Melting Using CSP: Pieter Bezuidenhout1; Willem le Roux2; Joalet Steenkamp3; 1Mintek; 2University of Pretoria; 3University of the Witwatersrand
The industrial sector is expected to be a large greenhouse gas producer in the future, with the majority of emissions being attributed to fossil fuel-based heat generation. By directly applying solar thermal energy to a high-temperature industrial process, the reliance of the industrial processes on fossil fuel-based energy sources can be lessened or completely removed. Preliminary investigations into the production and beneficiation of zinc using concentrated solar power (CSP), in a South African environment, show promise and even more so with a focus only on the cathode casting operations. To evaluate the practical implications of directly applying CSP to a high-temperature materials processing application, a study was launched into the direct solar melting of zinc metal. In this study, the set-up and performance of a novel cavity receiver for zinc melting using CSP are discussed.
4:00 PM Break
4:20 PM
Effect of Ore Pre-heating on Furnace Operation in High Carbon Ferromanganese Production - Lessons Learnt from Pilot-scale Testwork: Samuel Moholwa1; Sello Tsebe1; Derek Hayman1; Pieter Bezuidenhout1; Martin Sitefane1; Joalet Steenkamp2; 1Mintek; 2University of the Witwatersrand
The EU-funded PreMa project investigated the potential for a preheating stage to reduce the electrical energy requirement and CO2 emissions produced, during the production of high-carbon ferromanganese in a submerged arc furnace. Pilot-scale testwork was conducted at MINTEK in South Africa to demonstrate the potential effect of preheating on furnace operation. The 300 kVA AC-furnace facility at Mintek was upgraded extensively for this purpose. The paper reports on the lessons learnt from the pilot-scale testwork.
4:40 PM
A Desktop Study on the Potential use of South African Slags as Thermal Storage Medium: Sifiso Sambo1; Joalet Steenkamp2; Pieter Bezuidenhout1; 1Mintek; 2University of the Witwatersrand
Waste slag sources from South African pyrometallurgical smelters are evaluated to determine their potential for use as sensible heat storage media in Concentrated Solar Power applications. This offers the possibility of repurposing slag waste materials while tackling their environmental and handling problem. This work studies the key performance indicators of thermal energy storage systems to assess the suitability of pyrometallurgical slag for use as filling materials in packed bed thermal energy storage. The thermophysical properties of selected slags and their potential for long-term thermal stability are studied through the equilibrium module of FactSage 8.0 from 100℃ to 1000℃. A validated model is employed to study the heat transport process in the fluid-solid interface with air as the heat transfer fluid. The maximum temperature of the studied thermal storage cycles is 750℃. The overall system performance shows that pyrometallurgical slags have potential as energy storage materials.
5:00 PM
CO2 Free FeMn/Mn Production through Molten Oxide Electrolysis: Karen Osen1; Halvor Dalaker1; Ana Maria Martinez1; Henrik Gudbrandsen1; Ida Kero1; Zhaohiu Wang1; 1SINTEF
Ferromanganese production by carbothermic reduction in Submerged Arc Furnaces (SAF) is a productive and efficient process with energy consumption around 2.4 kWh/kg Mn, however, in the reduction step 1-1.6 kg CO2/kg Mn is generated. Molten Oxide Electrolysis (MOE) has been put forward as a possible CO2-free break-through technology to alleviate the environmental impact of steel and ferroalloy production. Electrons are the reducing agent, and with an oxygen evolving anode, the chemical energy in the carbon will be completely replaced with electrical energy. In the current work, Mn was reduced by electrolysis in a molten oxide electrolyte (MnO-SiO2-Al2O3-CaO) on various cathode materials, using a commercial alloy as inert oxygen evolving anode. The paper also includes theoretical mass and energy balances for an envisioned industrial MOE Mn process, comparing two different cases of Mn ore pretreatment (pre-reduced only and pre-reduced and purified).
5:20 PM
Ferronickel Production from Nickel Laterite via Sulfide Chemistry: Caspar Stinn1; Antoine Allanore1; 1Massachusetts Institute of Technology
Stainless steel exhibits among the highest rates of demand growth of all the commodity metals, yet its production remains burdened by carbon, energy, and water intensive legacy technologies. These alloys are made from a blending of ferronickel, ferrochromium, iron, and other components, with each feedstock exhibiting a range of technoeconomic bottlenecks to sustainability. New sulfide process chemistries have been developed as platform technologies to decarbonize mining, materials separations, impurity management, and metals production. Herein, we apply selective sulfidation as a means to produce ferronickel and stainless steel directly from mineral feedstocks. We first demonstrate production of iron-nickel sulfide and iron-nickel-chromium sulfide from laterite and blended laterite-chromite minerals and concentrates. We then develop electrolytic and metallothermic techniques for carbon-free production of stainless steel from these sulfide feedstocks. Technoeconomic and life cycle assessment reveals that sulfide-based chemistries for stainless steel production are cost competitive and enable a step change in environmental impact.
5:40 PM Invited
Application and Results of MPOT Diluted Combustion in Aluminum Furnaces and the Complete Carbon Free Future Technology: Curtis Bermel1; Michael Potesser1; 1MPOT LLC
Diluted or flameless oxy-fuel combustion has shown in the past year’s huge successes as an optimization tool for a variety of high temperature applications. This innovative combustion technology has a lower flame temperature, more uniform temperature distribution, and with MPOTŪ burners, utilizes air participation, leading to lower fuel consumption and ultra-low NOx levels. MPOTŪ burners are designed to minimize pure oxygen participation, which reduces oxygen costs, and results in an overall higher melt efficiency. The carbon-free future will be CCU, in the purest sense, the process of capturing CO2 at the point of generation and utilizing that CO2 within the boundaries of said facility. MPOT engineers embraced this challenge with these solution tenants: Utilize at least 95% of process generated CO2 inhouse, improve heat flux in process, improve fuel efficiency, decrease turnaround time, and improve product quality with this solution.