Geochemical Model and Simulation of Water Balance for Mining Operations: Svappavaara Iron Mine

Maria Sinche-Gonzalez1*, Pertti Lamberg2, and Malin Suup3

1. Oulu Mining School Faculty, University of Oulu, Oulu, Finland

2. Division of Minerals and Metallurgical Engineering Luleå University of Technology, Luleå, Sweden

3. Environmental Department, Luossavaara-Kiirunavaara AB, Kiruna, Sweden

Abstract: A model and simulation of water balance for Svappavaara iron mining operation were carried out. This water balance is an accounting in quantity and quality of all water inputs and outputs and includes a detailed collection of information on raw material and various water quality streams in the whole operation. The first objective was to simulate changes in solution composition as mineral undergoes transformation in contact with the water (e.g. dissolution or precipitation) by incorporating a reaction path modeling. The distribution of species in water streams was calculated by solving the set of mass balance equations, transformation reactions of the solid phase, given water and ore composition, percentage of water recirculation and using the simulation software HSC Chemistry. The reactions were defined for the raw material, i.e. ore, and products (concentrate, tail), in contact with water, air, gases, reagents and other input components. Therefore, various parameters were considered such as changes in pH, temperature, storage and processes, seasonal variation (precipitation and evaporation), variation in characteristics of the mined ore, recycling water percentage, and raw water quality.

The predicted water quality of a facility determines the mitigation measures to implement in order to prevent pollution in the discharge or negative effect in treatment processes. Therefore, a second objective was the simulation of a water balance after a water treatment was implemented targeting one of the main undesirable species in water such as sulfate.

Key words: modelling, simulation, water balance, mining operations