Nickel Salt Purification Using Precipitation and Single Extraction
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Solution Overview
Problem
Conventional methods for producing battery-grade nickel salt solutions from mixed metal salt solutions require multiple liquid/liquid extraction steps, which are costly and inefficient, and often necessitate additional crystallization processes to achieve the required purity.
Innovation Solution
A method combining precipitation and a single liquid/liquid extraction process to produce battery-grade nickel salt solutions, involving the precipitation of impurity and manganese salts followed by a single extraction of cobalt and remaining impurities, reducing the number of extraction steps and eliminating the need for crystallization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple liquid/liquid extraction steps are used to separate nickel from mixed metal source, then nickel purity is improved, but process complexity and cost increase
Solution Approach 1:
The patent segments the impurity removal process into two distinct groups: (1) manganese and aluminum salts precipitated as hydroxides in the pH range of 8.5-9.5, and (2) cobalt and iron salts precipitated as hydroxides in the pH range of 10.5-11.5. This segmented approach achieves battery-grade nickel purity through controlled sequential precipitation rather than multiple liquid/liquid extraction steps, thereby reducing process complexity while maintaining high purity standards.
Solution Approach 2:
The patent utilizes parameter changes, specifically pH adjustment, to achieve selective precipitation of different metal salts. By controlling pH at different stages (first at 8.5-9.5 for manganese/aluminum, then at 10.5-11.5 for cobalt/iron), the process achieves high nickel purity through simple pH-controlled precipitation rather than complex multi-step extraction, resolving the contradiction between purity and process complexity.
2Productivity
If multiple liquid/liquid extraction steps are used for metal separation, then separation efficiency is improved, but operational cost increases
Solution Approach 1:
The patent replaces the mechanical/chemical complex process of multiple liquid/liquid extraction steps with a simpler pH-controlled precipitation system. By using pH adjustment to selectively precipitate different metal groups at different stages, the process achieves high separation efficiency while dramatically reducing operational costs associated with multiple extraction operations, solvents, and equipment.
Solution Approach 2:
The patent employs parameter changes (pH control) as the primary mechanism for metal separation. By adjusting pH to specific ranges (8.5-9.5 for first precipitation, 10.5-11.5 for second precipitation), the process achieves efficient separation of nickel from impurities through simple, low-cost precipitation reactions rather than expensive multi-step liquid/liquid extraction, thereby improving productivity while reducing operational cost.
3Manufacturing precision
If conventional extraction and crystallization processes are used, then nickel purity is achieved, but processing time increases
Solution Approach 1:
The patent performs preliminary pH adjustment and selective precipitation actions before final nickel solution preparation. By pre-precipitating manganese and aluminum salts at pH 8.5-9.5, then precipitating cobalt and iron salts at pH 10.5-11.5, the process eliminates the need for subsequent crystallization steps, achieving battery-grade nickel purity faster and reducing overall processing time.
Solution Approach 2:
The patent takes out (removes) impurity salts from the mixed metal solution through selective precipitation at controlled pH levels. By extracting manganese, aluminum, cobalt, and iron as hydroxide precipitates at different pH stages, the process achieves high nickel purity without requiring time-consuming crystallization operations, thereby reducing processing time while maintaining purity standards.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces capital and operational expenses while achieving battery-grade purity, enabling direct use of the nickel salt solution in cathode active material precursors without further purification.
Implementation Method 1
mixing the aqueous pre-extraction solution and an organic extractant to form an aqueous raffinate phase and a loaded organic phase
Implementation Method 2
precipitating a first group of the impurity salts and the manganese salt from the aqueous mixed metal salt solution to form one or more impurity precipitates, a manganese oxide precipitate
Data Source
AI summary
Methods are provided for preparing an aqueous nickel salt solution from an aqueous mixed metal salt solution comprising cobalt, manganese, and nickel salts and one or more impurity salts. The method includes precipitating a first group of impurity salts and the manganese salt to form an aqueous pre-extraction solution. The aqueous pre-extraction solution and an organic extractant solution are mixed to form an aqueous raffinate phase and a loaded organic phase, wherein the aqueous raffinate phase is the aqueous nickel salt solution.