Subject: Mineral processingDate/time: 08/11/2021, 1:00 pm (Melbourne time zone, Australia)Duration: 1 hour and 30 minutes
Mineral processing_lecture notes_2021/MNE4040 Week 1 Lecture 3_Nawshad Haque.pdf Engineering RSE 4040 Mineral Processing Sustainable Mineral processing Dr Nawshad Haque Senior Scientist CSIRO Energy Week 1, Semester 2, 29 July, 2021 Learning Objectives: • What is sustainable Mineral Processing? • How do we develop and evaluate a flowsheet? • What are the economic and sustainability indicators? • What are the main purposes of flowsheet development and technology evaluation? • Learn about case-studies for metals Nawshad Haque | Mineral Processing 2 Process flow Nawshad Haque | Mineral Processing 3 Deposit and resource characterisation (metals and grade) Metallurgical test work (recovery) Flowsheet development (milling and plant) Evaluation (generally financial (+environmental)) • Various process design and optimisation software • In-house equipment sizing and costing database • Online sources • Supplier’s quote • Yearly subscription to Cost Estimation Handbooks • SimaPro software for LCA work • European Eco-invent and other Australian databases Process evaluation (economic & environmental) Inputs Develop flowsheet, mass & energy balance Equipment sizing Estimate CAPEX, OPEX Process economics Sensitivity analysis LCA studies Process improvement Nawshad Haque | Mineral Processing Challenges for mineral industries – require action ▪ Declining ore grades, deeper ore bodies, complex minerology ▪ Increasing production cost ▪ Global competition ▪ Increasing pressure to reduce industry’s environmental footprint • Energy • Carbon emission • Water • Waste Nawshad Haque | Mineral Processing 5 | Grinding energy estimate Nawshad Haque | Mineral Processing 6 | 397 793 1,020 1,247 467 933 1,200 1,467 - 500 1,000 1,500 2,000 2,500 3,000 Soft Medium Hard Very hard Po w er r eq u ir ed ( kW ) 150 micron to 75 micron 1,000 Micron to 150 micron What are the tools to assess sustainability? ▪ Process auditing for energy and water ▪ Life cycle costing (LCC) ▪ Environmental Life cycle assessment (eLCA) ▪ Social life cycle assessment (SLCA) ▪ Organisation LCA (O-LCA) – Scope 1, 2 & 3 emission ▪ Environmental impact assessment (EIA) ▪ Environmental management system ▪ Material flow analysis ▪ International Standards for LCA and Water Nawshad Haque | Mineral Processing 7 | Life cycle Extraction Processing& Manufacturing Transport Use phase Resource Landfill 8 | Nawshad Haque | Mineral Processing Organisational LCA Nawshad Haque | Mineral Processing 9 (source: WRI GHG Protocol) Metrics of sustainable processes Metrics Unit (per tonne of ore, concentrate or metal) Changes compared with conventional Embodied energy MJ or GJ Close to theoretical, Practically minimum Carbon footprint kg-equivalent CO2 Minimum through best combination of technology Water footprint kL or ML of water Minimum with recycling and reuse Waste footprint Tonne Approaching zero by means of reducing or adding value as input for other processes Other environmental impact Depending on impact Minimise Nawshad Haque | Mineral Processing 10 | CO2 conc. measurement by CSIRO/BOM Source: State of the Climate - CSIRO and The Bureau of Meteorology, Australia - http://www.csiro.au/greenhouse-gases/. Station at Cape Grim, Tasmania Courtesy: Google Maps 11 | Nawshad Haque | Mineral Processing LCA studies in CSIRO using flowsheeting approach Nawshad Haque | Mineral Processing 12 | Mining methods/configuratio n Open pit, underground, in-situ leaching, heap leaching, Truck-shovel system, in-pit crushing and conveying, ore- sorting Mineral processing Screening, crushing, grinding, flotation, dewatering Metal making Blast furnace, electric arc furnace, SX, EW, refining Metals studied Cu, Au, Ni, Pb, Zn Al, Mg, Ti Fe, Steel, FeSi, FeMn, SiMn, FeNi, FeCr REE, U LCA studies at CSIRO Nawshad Haque | CSIRO Mineral Processing 13 | ▪ Environmental score card is required for social licence to operate ▪ Currently lack of data for understanding variability of impact from metal production ▪ Does not help greatly in decision making Nawshad Haque | Mineral Processing 14 | Metals used in iPhone LCA of products What are the requirements ▪ Input data (also called Life Cycle Inventory – LCI) – Materials use – Chemicals – Fuel (natural gas, coal) – Electricity ▪ Outputs (called functional unit) – Concentrate product – Metals – By-product or co-product Nawshad Haque | Mineral Processing 15 | Metals – “Cradle-to-Gate” – GWP specific 16 | Nawshad Haque | Mineral Processing 0 2 4 6 8 10 12 14 16 18 20 22 24 t C O 2 e /t o f m e ta l Norgate et al. (2007) J of Cleaner Production, 15:838-848. Pyro Hydro BF ISF PyroHydro Electrolytic ISF Variability reported by companies (limited data) Impact ▪ To understand variability in environmental impact of metal production (specific and global): • Energy • Greenhouse gas • Water • Solid waste Nawshad Haque | Mineral Processing 17 | 0 50 100 150 200 250 Energy (GJ/t) CO2-e (t/t) Water (t/t) Waste (t/t) Aluminium Steel Stainless steel Copper Pyro Total global impact in 2015 (rough estimate) Nawshad Haque | Mineral Processing 18 | - 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 Energy (PJ) CO2-e (Mt) Water (Mt) Waste (Mt) Aluminium Steel Stainless steel Copper Pyro Aluminium Nawshad Haque | Mineral Processing 19 | GHG Impact – Iron ore Source: Norgate, T. and Haque, N. Journal of Cleaner Production 18(2010):266-274. 0 2 4 6 8 10 12 14 D rill ing Bl as tin g Lo ad ing a nd h au lin g C ru sh in g an d sc re en in g St ac ki ng a nd re cl ai m ing R ai l t ra ns po rt Po rt op er at io ns To ta l k g C O 2 /t i ro n o re 20 | Nawshad Haque | Mineral Processing Global warming potential of 1 kg Steel 0.0 0.5 1.0 1.5 2.0 Iron ore Sintering Blast Furnace Iron Basic Oxygen Furnace Casting G W P ( k g C O 2 e q ) 21 | Nawshad Haque | Mineral Processing What is the carbon footprint of a car? Nawshad Haque | CSIRO Mineral Processing 22 | What is the carbon footprint of a car? Dr Nawshad Haque | Team Leader Process Evaluation | CSIRO 23 | What is the carbon footprint of a car? Dr Nawshad Haque | Team Leader Process Evaluation | CSIRO 24 | Solar panels on roof Dr Nawshad Haque | Team Leader Process Evaluation | CSIRO 25 | Implications for car manufacture – exploded view & composition Nawshad Haque | Mineral Processing 26 | UNEP (2013) Metal recycling report Image source: http://www.merchantcircle.com/business/Junkyard.Jungle.2104174242/picture/view/3893831 Average petrol vehicle - 1.24 t weight, 2/3 metal 500 242 42 26 9 0.5 0.001 0.0003 0.0002 420 BOF Steel EAF Steel Primary Al Secondary Al Copper Magnesium Platinum Palladium Rhodium Other materials Gold flowsheet GOLD ORE Comminution (crushing & grinding) Refractory ores Non-refractory/ Gravity concentration free-milling ores Flotation (coarse gold) Roasting Pressure oxidation Amalgamation Bio-oxidation Mercury Extraction process Regrinding Retorting (cyanidation) (distillation) - tank - heap Recovery process - carbon adsorption (CIL, CIP) - Merrill-Crowe Stripping Electrowinning Steel removal Smelting Refining Refined gold Acid washing Re-activation Activated carbon Eluate solution Concentrate Cathodes Dore Cathodes Gold ore Comminution FlotationGravity Cyanidation Recovery process Refined gold 27 | Nawshad Haque | Mineral Processing What is the price of love? = Energy: 800 – 1200 MJ Greenhouse Gases: 70 – 107 kg CO2-e Solid Waste: 5 tonnes Water: ~ 1,000 L 18 Carat Gold Ring 28 | Nawshad Haque | Mineral Processing Work with Industry - Outotec ▪ Outotecs’ HSC 9 software ▪ Thermodynamic database ▪ Flowsheeting capability ▪ Additional tool for sustainability assessment Nawshad Haque | Mineral Processing 29 | Financial indicator of an example project Nawshad Haque | Mineral Processing 30 Items Value Unit Mine total production 762,950 t Cu Mine life 20 Years Mine average yearly production 38,148 t Cu/y SX-EW PLS 1.5 g/L Cu Recovery 40.0 % Long term average price over life of mine 6,063 $/t Cu Operating cash cost 1,499 $/t Cu Total production cost reported 1,808 $/t Cu Total production estimated by Nawshad Haque based on their number 2,028 $/t Cu Initial capital investment 284.4 $M Sustaining on-going capital investment over 20 years 598.8 $M After tax estimate NPV at 7.5% interest 490.6 $M IRR at 7.5% 30.3 % Payback (discounted) 6.3 years Cost data Nawshad Haque | Mineral Processing 31 Opportunites for energy savings for mining and mineral processing ▪ Grinding – new comminution devices – HPGR, stirred mills ▪ Loading, hauling and dumping – advances in diesel engine technology, larger haul/dump trucks ▪ More advanced blasting techniques ▪ Alternative processing routes for ores – heap leaching, in-situ leaching ▪ Ore sorting, gangue rejection and pre-concentration – reduce amount of material to grinding circuit ▪ In-pit crushing, conveying, grinding and in-place ore smelting 32 | Nawshad Haque | Mineral Processing Underground gold mine – for data 33 | Nawshad Haque | Mineral Processing Open cut – Gold mine, Kalgoorlie, WA 34 | Nawshad Haque | Mineral Processing Open cut coal mine 35 | Nawshad Haque | Mineral Processing Coal conveying system for powerplant 36 | Nawshad Haque | Mineral Processing Powerplant complex 3 units (3000 MW) 37 | Nawshad Haque | Mineral Processing Powerplant generation unit (500 MW) 38 | Nawshad Haque | Mineral Processing Coal processing flowsheet Nawshad Haque | Mineral Processing 39 Coal Seam Gas to LNG Nawshad Haque | Mineral Processing 40 In-situ Leaching (ISL) recovery Source: Australian Government 41 | Nawshad Haque | Mineral Processing Sea-floor mining robot – “Minero” Korea Nawshad Haque | Mineral Processing 42 Example Question and Answer ▪ Q: Name four important metrics for assessing sustainability of a process ▪ A: Embodied energy, carbon, waste and water (ECWW). ▪ Q: List five major metals and their specific energy and carbon footprints on life cycle basis ▪ Hint: Read Norgate et al (2007) JCP paper and prepare your table. ▪ Q:Come up with at least three measures that would reduce energy and greenhouse gas emission from metal production for your selected metals ▪ A: Smart blasting, energy efficient comminution technologies (e.g. High pressure grinding rolls), ore-sorting or pre-concentration Nawshad Haque | Mineral Processing 43 | Key messages ▪ Flowsheeting is an important tool to develop conceptual scenarios for processing complex ores ▪ Key contributing items on operating and capital cost can easily be identified ▪ Sensitivity of these key inputs on CAPEX and OPEX