Lithium Brine Projects: there is a resource, but is there a reserve?

Author(s): 
Pablo Cortegoso, Terry Braun
Date: 
Thursday, April 7, 2016
First presented: 
LITIO Conference, April 7, 2016, Jujuy, Argentina
Type: 
Presentation
Category: 
Mining
Civil Engineering

Brine extraction for surface process and recovery of potash, lithium and industrial salt requires the application of traditional hydrogeological theories to hyper-saline solutions. Such brines present additional technical challenges in comparison to fresh water due to density effects (e.g., 1.2 gram/cm3), density driven multi-chemical composition flow on a large scale, and interaction between brines and fresh water over the course of the production period. Surface production facilities require estimation of brine composition over time. Therefore, the hydrogeologist is tasked with balancing extraction rates from multiple production wells, locating the production wells in space (and time), predicting chemical composition of the pre-pumping and extracted brines and monitoring depletion of a “dynamic” resource. Each of these parameters can have a significant impact on project economics. The parameters such as effective porosity, permeability (“hydraulic conductivity” adjusted by density and dynamic viscosity), anisotropy, aquifer configuration (extent, thickness and heterogeneity), and wellfield efficiency are key in the estimation of resources and reserves for a brine extraction project. During the stages of prefeasibility and feasibility, an accurately built numerical groundwater model is required in order to develop a production plan. Recent guidance from the Ontario Securities Commission provides an indication of how to disclose brine resource and reserve estimates according to the Standards of Disclosure for Mineral Projects, namely National Instrument 43-101. This paper examines the technical aspects of estimating extractable brine resources and reserves, and current public disclosure guidance.

Feature Author

Pablo Cortegoso
Pablo Cortegoso is a Civil Engineer with over 8 years of experience in civil and mining projects; specializing in lithium brine projects. His main areas of focus are surface water hydrology and modeling, project management, design and implementation of field programs and data collection and analysis for hydrogeological and geotechnical studies. Mr. Cortegoso has extensive experience in hydrogeological field programs, with an emphasis on lithium brine deposits, including well designs, packer testing and aquifer tests. Mr. Cortegoso expertise includes solar pond evaporation design, modeling and operation for lithium and potassium brine projects. Mr. Cortegoso has been a key member in the preparation and completion of Technical Due Diligences, Technical Reports (Mineral Resource and Reserve Statements), Preliminary Economic Assessments, Pre-Feasibility and Definitive Feasibility Studies in accordance with NI 43-101 and JORC Guidelines for lithium brine projects throughout Argentina, Chile, USA, UK and Botswana.

 

Lithium Project Development Specialist
MSc Civil Engineering
SRK Denver
Terry Braun

Terry Braun has over 25 years of professional experience in mining and environmental projects. His practice incorporates various elements of environmental compliance activities as well as engineered solutions to potential environmental liabilities at mining and other industrial operations. He develops and often implements projects that require negotiations with regulatory agencies and other stakeholders to achieve client objectives. Terry leads multi-disciplinary project teams tasked with producing engineering studies in accordance with public disclosure requirements (i.e., Canada and U.S.) as well as internal due diligence reviews on behalf of clients. His project experience includes planning, permitting and implementing the large-scale closure program for the BHP Copper San Manuel mine and plant sites in Arizona. He has also led teams in mitigating legacy mining impacts at active and inactive mine properties in the western U.S.

Principal GeoEnvironmentalist
MSc, PE
SRK Denver
SRK Turkey