Empirical models to determine ions concentrations in lithium brines with high ionic strength

Argentina Puna brines are complex systems in which ions such as Na+, K+, Li+, Mg2+, Ca2+, SO42−, and B4O72− are presents. To obtain lithium carbonate from brines, they must be treated in order to increase its lithium concentrations and to eliminate the others ions that are presents in the brines. Du...

Full description

Bibliographic Details
Main Authors: Silvana K. Valdez, Agustina M. Orce Schwarz, Martín I. Thames Cantolla
Format: Article
Language:English
Published: Elsevier 2023-06-01
Series:Results in Engineering
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2590123023002724
_version_ 1797802777498353664
author Silvana K. Valdez
Agustina M. Orce Schwarz
Martín I. Thames Cantolla
author_facet Silvana K. Valdez
Agustina M. Orce Schwarz
Martín I. Thames Cantolla
author_sort Silvana K. Valdez
collection DOAJ
description Argentina Puna brines are complex systems in which ions such as Na+, K+, Li+, Mg2+, Ca2+, SO42−, and B4O72− are presents. To obtain lithium carbonate from brines, they must be treated in order to increase its lithium concentrations and to eliminate the others ions that are presents in the brines. During concentration some salts can reach their solubility products (kps) and crystallize, producing different solid-liquid equilibriums. In order to design and select the process to purify the brine before lithium salts precipitation, it is necessary to know the other ions concentrations.Ion concentrations in solutions can be calculated based on the salts coefficient activities using Pitzer's model and its modifications. These methods have the restriction that can only be applied to solutions with ionic strength values up to 6 molal. The state of the art shows that the approach to study the equilibrium in complex system is to consider it as binary, ternary, quaternary and quinary systems. When ionic strength values are higher than 6 m the systems studied are binaries or have symmetrical ions.Brines of the Argentina Puna have, in general, initial ionic strength values around 6 molal and it increases when the brine is concentrated by evaporation, so the available thermodynamical models cannot be used to determine, beforehand, the final composition of a certain brine. In this work four different brines from four different Puna plateau in Argentina were evaporated to several degrees and ionic strength was calculated from the chemical brine's composition after each evaporation test. Ionic strength was found to correlate with the percentage of eliminated water following two different simple mathematical models, depending on the initial sulphate concentration of the brine and the possibility of its precipitation. Models to estimate the concentration of diluted ions of commercial value such as Li+, K+, and Mg2+ as function of ionic strength were also proposed. Ion concentrations could be modeled as function of the amount of eliminated water, once the correct relationship between this parameter and the ionic strength of the brine is established. These models correlate accurately ionic strength and ion concentrations for an ionic strength range from 4.8 to 15.4 molal; corresponding to percentages of water evaporated from 0% up to 60%.With these models it is possible to calculate beforehand the final ions concentrations after a given percentage of evaporated water. It allows to design brines processing and select the purification techniques without exhausting and time-consuming tests. Nowadays there are no tools that allows to do that, in consequence, each company must perform rigorous and numerous tests with its brines. Results of these work show that ionic strength is the parameter that unified brines behavior even if initial composition could be different. In consequence, it could be used as a parameter to describe brine behavior during evaporations.
first_indexed 2024-03-13T05:10:47Z
format Article
id doaj.art-4a10954d929a46f29f842ab90243cb67
institution Directory Open Access Journal
issn 2590-1230
language English
last_indexed 2024-03-13T05:10:47Z
publishDate 2023-06-01
publisher Elsevier
record_format Article
series Results in Engineering
spelling doaj.art-4a10954d929a46f29f842ab90243cb672023-06-16T05:11:05ZengElsevierResults in Engineering2590-12302023-06-0118101145Empirical models to determine ions concentrations in lithium brines with high ionic strengthSilvana K. Valdez0Agustina M. Orce Schwarz1Martín I. Thames Cantolla2Universidad Nacional de Salta, Facultad de Ingeniería, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Consejo de Investigación de La Universidad Nacional de Salta (CIUNSa), ArgentinaUniversidad Nacional de Salta, Facultad de Ingeniería, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina; Consejo de Investigación de La Universidad Nacional de Salta (CIUNSa), ArgentinaUniversidad Nacional de Salta, Facultad de Ingeniería, Argentina; Consejo de Investigación de La Universidad Nacional de Salta (CIUNSa), Argentina; Corresponding author. Av. Bolivia 5150, Salta, Argentina.Argentina Puna brines are complex systems in which ions such as Na+, K+, Li+, Mg2+, Ca2+, SO42−, and B4O72− are presents. To obtain lithium carbonate from brines, they must be treated in order to increase its lithium concentrations and to eliminate the others ions that are presents in the brines. During concentration some salts can reach their solubility products (kps) and crystallize, producing different solid-liquid equilibriums. In order to design and select the process to purify the brine before lithium salts precipitation, it is necessary to know the other ions concentrations.Ion concentrations in solutions can be calculated based on the salts coefficient activities using Pitzer's model and its modifications. These methods have the restriction that can only be applied to solutions with ionic strength values up to 6 molal. The state of the art shows that the approach to study the equilibrium in complex system is to consider it as binary, ternary, quaternary and quinary systems. When ionic strength values are higher than 6 m the systems studied are binaries or have symmetrical ions.Brines of the Argentina Puna have, in general, initial ionic strength values around 6 molal and it increases when the brine is concentrated by evaporation, so the available thermodynamical models cannot be used to determine, beforehand, the final composition of a certain brine. In this work four different brines from four different Puna plateau in Argentina were evaporated to several degrees and ionic strength was calculated from the chemical brine's composition after each evaporation test. Ionic strength was found to correlate with the percentage of eliminated water following two different simple mathematical models, depending on the initial sulphate concentration of the brine and the possibility of its precipitation. Models to estimate the concentration of diluted ions of commercial value such as Li+, K+, and Mg2+ as function of ionic strength were also proposed. Ion concentrations could be modeled as function of the amount of eliminated water, once the correct relationship between this parameter and the ionic strength of the brine is established. These models correlate accurately ionic strength and ion concentrations for an ionic strength range from 4.8 to 15.4 molal; corresponding to percentages of water evaporated from 0% up to 60%.With these models it is possible to calculate beforehand the final ions concentrations after a given percentage of evaporated water. It allows to design brines processing and select the purification techniques without exhausting and time-consuming tests. Nowadays there are no tools that allows to do that, in consequence, each company must perform rigorous and numerous tests with its brines. Results of these work show that ionic strength is the parameter that unified brines behavior even if initial composition could be different. In consequence, it could be used as a parameter to describe brine behavior during evaporations.http://www.sciencedirect.com/science/article/pii/S2590123023002724BrinesEvaporationIonic strengthIons concentrations
spellingShingle Silvana K. Valdez
Agustina M. Orce Schwarz
Martín I. Thames Cantolla
Empirical models to determine ions concentrations in lithium brines with high ionic strength
Results in Engineering
Brines
Evaporation
Ionic strength
Ions concentrations
title Empirical models to determine ions concentrations in lithium brines with high ionic strength
title_full Empirical models to determine ions concentrations in lithium brines with high ionic strength
title_fullStr Empirical models to determine ions concentrations in lithium brines with high ionic strength
title_full_unstemmed Empirical models to determine ions concentrations in lithium brines with high ionic strength
title_short Empirical models to determine ions concentrations in lithium brines with high ionic strength
title_sort empirical models to determine ions concentrations in lithium brines with high ionic strength
topic Brines
Evaporation
Ionic strength
Ions concentrations
url http://www.sciencedirect.com/science/article/pii/S2590123023002724
work_keys_str_mv AT silvanakvaldez empiricalmodelstodetermineionsconcentrationsinlithiumbrineswithhighionicstrength
AT agustinamorceschwarz empiricalmodelstodetermineionsconcentrationsinlithiumbrineswithhighionicstrength
AT martinithamescantolla empiricalmodelstodetermineionsconcentrationsinlithiumbrineswithhighionicstrength