ITERAMS. Integrated Mineral Technologies for More Sustainable Raw Material Supply

Transcription

1 ITERAMS Integrated Mineral Technologies for More Sustainable Raw Material Supply Jukka Raatikainen (IMA, Finland), Robert Emler (Montanuniversität Leoben, Austria), Sylvain Guignot (BRGM, France), Kari Heiskanen (Outotec, Finland), Andreas Ciroth (GreenDelta, Germany), Jordi Guimerà (Amphos 21, Spain), Mika Paajanen and Päivi Kinnunen (VTT, Finland).

2 ITERAMS PROJECT Integrated Mineral Technologies for More Sustainable Raw Material Supply Addresses H2020 issue Sustainable selective low impact mining 3 years: M budget 16 partners 9 industrial partners, 2 RTOs and 5 universities From 7 EU Member States (Finland, France, Austria, Germany, United Kingdom, Spain and Portugal) Additionally from Turkey and South Africa VTT coordinates

3 PARTNERS

4 AMBITION To develop and obtain a NEW PARADIGM PROOF OF CONCEPT at mine sites to recycle water and valorise tailings for an improved environmental and economic result to enable future sustainable mineral supply in Europe.

5 NEW ROLE OF WATER AND WASTE IN MINING From water handling cost minimization to taking care of water properties and optimizing these properties for each process step. New water reuse concepts. From depositing waste rock and tailings to utilizing waste rock and tailings for added revenue as hardening mine fill or products. New ways of safe depositing of remaining tailings.

6 CHALLENGE Complete closure of water loops increases thermodynamical and kinetic unstability and process disturbance ITERAMS creates capabilities via laboratory experiments, modelling and validation at mine sites to tackle this complexicity GANGUE SOLIDS COLLOIDAL SPECIES TEMPERATURE IONIC STRENTGH MICROBES CLOSED WATER AND WASTE LOOPS DISSOLVED CHEMICAL SPECIES ph ORGANICS MATERIAL REACTIVITY REAGENT INTERACTIONS Eh

7 ITERAMS OBJECTIVES SUSTAINABLE MINERAL SUPPLY IN THE EU Economical, environmental and social sustainability EFFICIENT WATER RECYCLING Reduction of water consumption by >90% Water quality optimization for each process step Recovery of valuable constituents from water solutions Efficient and economical water treatment methods TAILINGS VALORIZATION Geopolymerization for water and oxygen tight covers on deposited tailings Waste rock and tailings as hardening mine fill or sold as products All remaining tailings safely deposited as a filter dry cake MINIMIZATION OF ENVIRONMENTAL FOOTPRINT No effluents to environment No fresh water intake No dam failures Area conserved Enhanced mining Enhanced tailings value 7

8 ITERAMS FRAMEWORK NO FRESHWATER INTAKE NO EFFLUENTS TO ENVIRONMENT FILTERING AND DRY STACKING OF TAILINGS WATER CIRCULATION BY STEPS SORTING OF MATERIAL REDUCED FOOTPRINT GEO-MODELLING HARD MINE FILL MATERIAL ENHANCED MINING NO DAM FAILURES GEOPOLYMERISATIO N AREA CONSERVED AMD MITIGATED GEOPOLYMER PRODUCTS ENHANCED TAILINGS VALUE NEEDS ENHANCES MAKES POSSIBLE

9 CONCEPT VALIDATION Development of test protocol for designing closed water loop systems Validation of ITERAMS water and waste efficient methods At sites of the mining company partners Boliden (Finland), Somincor (Portugal) and Anglo American (Chile or South Africa) Demonstration of environmental footprint of the ITERAMS approach

10 SOME ON-GOING WORKS

11 WP1: Sampling geopolymer candidates sampling in 2017 AIM to find high amphibolic materials from the blast benches AIM to study if tailings samples can be used as geopolymers (WP2) Prepared by Jukka Raatikainen (IMA)

12 WP1: On-line Big data collected from the plant feed in 2017 AIM to collect and study on-line elemental, oxides, power, tons/h, particle size to correlate with hardnss and/or minerals

13 WP 2 Geopolymers from mine tailings Approach Tailings Different types of tailings Alkaline solution + e.g. NaOH Chemical and mineralogical composition XRD XRF Quantitative mineralogical composition Particle size distribution Modelling Geopolymer Particle packing Properties Strength Density Permeability Additional species? Alkali silicate Alkali aluminate Leaching in alkaline solutions Dissolution of various species Which phases might precipitate P#

14 WP 2 Geopolymers from mine tailings Status Tailings Different types of tailings Alkaline solution + e.g. NaOH Precursors currently under investigation Kevitsa tailings and waste rock material (Finland Ni, Co) Mogalakwena tailings (South Africa Pt) Activators for geopolymerisation tested NaOH, KOH, Na2SiO3, K2SiO3, NaAlO2 Simulation Simulation of the batch leaching experiments in progress Geopolymer

15 Closed Water Circulation To develop and obtain a proof of concept at mine sites to recycle water up to the point that the use of process water is completely isolated from the adjacent water systems Develop water treatment processes to reach the water quality specifications of a given process unit in the plant Design a global Mine Water Management System, which comprises : Water balances : all of the waters and water cycles on a mine site + waters affected by the mine site Efficient and reliable monitoring (on-line if possible) technologies to measure suspended solids/residual reactants concentrations, Eh, ph variations Prepared by Sylvain Guignot (BRGM)

16 Focus on water recycling in the flotation stage Flotation selectivity and recovery highly sensitive to water quality Complex interactions among various components in water : ph, Eh, T, dissolved reagents, inorganic and organic colloidal species, and physical/chemical interactions between all of them define the properties of S/L and G/L interfaces. Recirculation = accumulation of the components, accumulation of microorganisms, modification of the impacts on flotation efficiency

17 Perceived challenges PROJECT approach Closed water recycling : High number of variables and interactions, multiple feed-back loops Complex dynamic multicomponent system No chemical and thermodynamic equilibrium Water quality? Quality is defined by the specifications of the process unit where water is recycled Need to develop on-line and continuous monitoring and control of water quality to assess and maintain a dynamic balance Deterministic Systemic Holistic Understanding of the final balance of a fully recycled water system Develop a Mine Site Water Model Provide a standardized protocol to help implementing recycling water concepts in mine and processing sites (guidelines for monitoring and evaluation of water related quality parameters) Replicable

18 Sustainability Life-Cycle assessment of the solutions adopted Modelling of the environmental impacts of the solutions

19 Sustainability Hydrogeochemical Modelling of the environmental impacts of the solutions Structure and distribution of materials Hydrogeological models

20 Sustainability Distribution of outflows and composition ,6% Flujo de salida (m3/día) Transient effects and time distribution of composition 9,5% 1 2 5,2% 3 0,8% 1,1% 4 5 Zona de salida 7,4% 9,4% 6 7

21 Clustering: Contacting and specifying mutual topics Other EU funded projects within this topic have been identified and contacted (see next slide) Clustering meetings Two topics of potential mutual interest have been suggested: 1) Sustainability in mining and 2) Communication with local communities. Working groud document has been intiated and contribution from clustering projects have been requested.

22 REINVENTING THE ROLE OF WATER AND WASTE IN MINING THANK YOU! This Project has received funding from the European Union H2020 programme under grant agreement nº

23 Kevitsa Final tailings Leaching results of individual fractions Batch leaching MUL R. Obenaus-Emler

24 Sample characteristics Particle size distribution 24

25 Sample characteristics Chemical composition XRF 25

26 Sample characteristics Mineralogical comp. XRD Tailings fraction 300/500 µm 26

27 Reactivity of solid raw materials Static batch leaching tests 2 g of sample added to 100 ml of NaOH solution with different molarity (1M, 5M, 10M, 15M) Leaching at RT for various time intervals (1h to 72h) NaOH M Leachate filtered and analysed by ICP Residue washed, dried and analysed by XRD Dissolution of individual elements Precipitation of mineral phases 27

28 Next steps Reactivity Additional experiments Further evaluation of static batch leaching tests (additional solvent concentrations and testing times) Dynamic dissolution tests with bottle roller (only lower T possible) Determination of specific surface area of tailings fractions dissolution in relation to specific surface area Additional experiments for geopolymerisation Geopolymers with different activator solutions and concentrations Compressive stress tests Mineralogical investigation of successful geopolymer mixes Rapid test on stability of successful geopolymer mixes 28