Process for the Depletion of Magnesium and the Enrichment of Lithium in Saline Solutions, which Comprises Adding KCl to the Solution to be Further Dried by Evaporation, which is Transformed with the MgCl2 of the Solution into Potassium Carnallite and is Added in the Form of Potassium Carnallite

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This patent describes a method for enriching lithium and reducing magnesium content in saline (brine) solutions, particularly useful for brines with high magnesium-to-lithium ratios. The invention achieves this by adding potassium chloride (KCl) to the solution, which then reacts with magnesium chloride to precipitate potassium carnallite, allowing removal of magnesium and preventing lithium losses during further evaporation.

Use CasesContent extracted from patent full text and abstract with AI.

• Extraction of lithium from brines with high magnesium content, such as those found in the Salar de Uyuni (Bolivia) and Qaidam Basin (China)
• Industrial production of battery-grade lithium salts (e.g., lithium carbonate)
• Production of high-purity lithium chloride solutions for use in chemical and energy industries
• Improvement of lithium recovery processes in solar evaporation ponds
• Scaling up magnesium removal in salt lake resource development

BenefitsContent extracted from patent full text and abstract with AI.

• Reduces lithium losses typically encountered in magnesium removal processes
• Enables effective lithium extraction from brines with high magnesium-to-lithium ratios, previously considered uneconomical
• Minimizes the use of chemicals that can introduce impurities or require complex waste management (e.g., avoids excess use of lime)
• Allows recycling of potassium chloride, reducing raw material costs
• Improves purity of recovered lithium solutions, facilitating subsequent processing
• Operational flexibility with both batch and continuous process options

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Patent Abstract

The invention relates to a method for increasing lithium content while at the same time decreasing magnesium content from chloridic solutions which have high magnesium contents in relation to the lithium content. In accordance with the invention this is achieved by metering KCl into the solution intended for further evaporation, this solution containing at least 4 g/l Li+ and 60 g/l Mg2+, this KCl reacting with the MgCl2 in the solution, at least partially, to form potassium carnallite and is deposited in the form of potassium carnallite, the amount of KCl added being calculated such that the composition of the mother solution is close to saturation with carnallite (potassium carnallite) and KCl and hence the formation of lithium carnallite is prevented.