NetWork
Progress in Lithium Extraction Technologies from Salt Lake Brines
QI Tao;SU Hui;ZHOU Binbin;HU Yaoxian;XIAO Xinyu;LIU Wensen;MA Tianfang;ZHU Zhaowu;WANG Lina;Lithium is a critical strategic metal underpinning the development of new energy and strategic emerging industries, and its global demand has surged dramatically with the advancement of the "dual-carbon" strategy. China accounts for 80% of the world's total lithium consumption, yet its dependence on imported lithium resources exceeds 60%, resulting in a prominent supply-demand imbalance. Notably, 80% of China's lithium reserves are distributed in the brines of salt lakes in Qinghai and Xizang, characterized by high Mg/Li ratio and alkaline carbonate-type properties. Efficient Li/Mg separation and low-energy-consumption clean production have become core priorities for new technology development, as traditional technologies face limitations including long salt lake evaporation cycles, high lithium loss rates, and difficulties in achieving efficient ion separation. To address these challenges and promote the sustainable development of the lithium industry chain, this study comprehensively reviews the latest advancements, research status, and application progress of mainstream lithium extraction technologies worldwide by integrating research achievements and industrial practices in the field. The reviewed technologies include precipitation, adsorption, solvent extraction, membrane separation, and electrochemical methods. For precipitation—the most mature industrialized approach— progress in subtypes such as carbonate precipitation and aluminate precipitation was analyzed. Regarding adsorption technology, the current status of lithium extraction using inorganic adsorbents(aluminum-based, manganese-based, titanium-based) and organic adsorbents was summarized. For solvent extraction systems, both neutral(phosphate esters, amides) and alkaline(β-diketone) systems were discussed,verifying their feasibility in industrialization. Membrane separation technologies, such as nanofiltration and electrodialysis, exhibit advantages in efficient separation but are confronted with challenges like membrane fouling.Electrochemical methods have evolved from ion-capture and "rocking-chair" systems to innovative Decoupled Membrane-Free(DCMF) systems, demonstrating broad adaptability to brines while facing bottlenecks such as high electrode costs. Systematic analysis of key performance indicators reveals the differentiated characteristics of each technology: precipitation is mature and efficient for low Mg/Li ratio brines, yet inefficient for high Mg/Li ratio brines; adsorption offers high selectivity but is hindered by adsorbent dissolution; solvent extraction enables largescale production but carries risks of organic loss; membrane separation achieves excellent selectivity but is limited by membrane fouling; electrochemical methods are adaptable but require electrode optimization. By addressing inherent limitations and application bottlenecks, this study further outlines targeted future development directions,including the development of low-dissolution adsorbents, anti-fouling composite membranes, and low-cost electrode materials; the design of coupled processes(e.g., precipitation-adsorption, nanofiltration-electrodialysis) tailored to brine characteristics; and the acceleration of engineering transformation from pilot-scale to large-scale production.This review provides comprehensive theoretical references and technical support for the efficient development of lithium resources in China's high Mg/Li ratio salt lakes, contributing to safeguarding the security of the global lithium supply chain and advancing the sustainable development of the "dual-carbon" goal.
Research on the Construction of Carbon Management System and Technological and Economic Optimization Path for Electrolytic Aluminum Enterprises Based on Carbon Emission Dual Control Background
WEI Yuwei;ZHU Xishan;CUI Yufeng;HUANG Fengxiao;WEI Dezhi;YANG Yong;TANG Jianghua;ZHOU Ming;YANG Tongyuan;QIN Feng;In the context of the dual control policy on carbon emissions, the electrolytic aluminum industry, as a key industry with high energy consumption and high emissions, building a systematic and standardized carbon management system is of great significance for achieving the "dual carbon" goal. This article systematically reviews the current status of carbon management systems and standards at home and abroad, analyzes the advantages and disadvantages of existing carbon management system rules, and focuses on proposing a carbon management system construction path and implementation steps applicable to electrolytic aluminum enterprises. Innovatively incorporating product carbon footprint management into the carbon management system, and conducting a preliminary accounting of the carbon footprint of electrolytic aluminum based on the full life cycle assessment(LCA)method, and an aluminum electrolysis LCA model for carbon footprint sensitivity analysis was established. It is clarified that electricity consumption is the main source of the carbon footprint of electrolytic aluminum, accounting for 65% to 85%. The study also proposes a marginal emission reduction cost curve and technology economic optimization model, explores the potential and cost of different emission reduction technologies. According to the marginal cost emission reduction curve, the emission reduction cost is lower when the CO2 initial emission reduction is between 0–0.5 t, sharply increases when the emission reduction is between 0.5–4.5 t, and shows a lower trend when the emission reduction exceeds 4.5 t. Based on the study of marginal emission reduction costs, a multi-objective optimization model for technical and economic efficiency was established, seeking a systematic and adaptable optimal equilibrium solution set(Pareto optimal frontier) between multiple interrelated or even conflicting goals such as economic costs, emission reduction benefits, technological feasibility, and operational stability, to adapt to future changes. According to the model, the specific optimization path for carbon management in the electrolytic aluminum industry from 2024 to 2035 is as follows: Before 2026, the focus will be on optimizing operational processes and waste heat recovery; From 2025 to 2028, the main focus will be on the renovation of high-efficiency electrolytic cells; From 2026 to 2030, the focus will be on replacing green electricity; From 2028 to 2033, focus on self built new energy; From 2030 to 2033, demonstrate the application of inert anodes; From 2032 to 2035, we will focus on integrating CCUS technology. Based on the above marginal emission reduction curve and multi-objective optimization research results, on the basis of establishing a corporate carbon management system, standardizing carbon footprint management and emission data management, from a technical and economic analysis, the current optimal way to reduce carbon emissions is to adopt process improvement and green energy substitution models.Considering the high proportion of hydropower in Guangxi, green power can be achieved through hydropower. In terms of technology, large-scale electrolytic cells can be used, stable current insulation technology can be promoted,and inert anode application process control such as real-time monitoring of PFC(perfluorocarbon) emissions can be applied. After implementing the above technical measures, a certain enterprise reduces its carbon intensity by 8.9 t CO2e/t-Al and saves more than 200 million yuan in annual carbon quota expenditure by implementing the combination plan of "green electricity+process upgrading". An AI driven digital carbon management platform to achieve digital empowerment of carbon management is introduced. The platform collects key operational data of electrolytic cells in real time through the Internet of Things, such as power consumption, current efficiency, material dosage, and process parameter fluctuations, and integrates data from bauxite mining to aluminum liquid ingots throughout the entire industry chain. Combined with blockchain technology, the data is tamper proof and traceable throughout the entire process. On this basis, an AI algorithm engine is introduced to establish a large-scale model for optimizing electrolytic cell parameters. By aligning with national and international accounting standards, dynamic accounting of carbon footprint, intelligent warning of anomalies, and process optimization decision-making are achieved, supporting the full process of carbon quantification and precise management from cradle to gate. The research results can provide theoretical support and practical reference for the construction of carbon management system in electrolytic aluminum enterprises, seeking the optimal technological and economic carbon reduction path,empowering digital carbon management, standardizing carbon management, and future certification.