Copper Sulfide Leaching for Copper-Nickel-Cobalt Alloy Separation
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Solution Overview
Problem
Current methods for separating copper, nickel, and cobalt from alloys, particularly those obtained from waste lithium ion cells, face challenges such as high energy consumption, recovery losses, and environmental concerns due to the use of toxic gases or unstable slags, and existing separation techniques are inefficient and costly.
Innovation Solution
A method involving the use of sulfuric acid in conjunction with a sulfurizing agent, such as sulfur, hydrogen sulfide, or sodium sulfide, to selectively precipitate copper as copper sulfide while leaving nickel and cobalt in a leachate, allowing for efficient separation and purification of these metals from alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dry treatment (smelting) is used to recover valuable metals from waste LIB, then the treatment process is simple and slag is chemically stable, but most cobalt is distributed to the slag causing recovery loss
Solution Approach 1:
The patent applies preliminary action by performing selective leaching of cobalt and nickel from the copper alloy using sulfuric acid before the final smelting process. This preliminary separation step prevents cobalt from being distributed to the slag during smelting, thereby reducing recovery loss while maintaining the simplicity of the overall process
Solution Approach 2:
The patent segments the recovery process into distinct stages: selective leaching of cobalt and nickel using sulfuric acid, filtration to separate the leached metals, and then smelting of the remaining copper alloy. This segmentation allows each stage to be optimized independently, preventing cobalt loss while maintaining process simplicity
2Ease of manufacture
If slow cooling from fused state is used to separate copper and nickel, then the separation process is simple, but copper and nickel are mixed and solidified into a layer and cannot be separated
Solution Approach 1:
The patent changes the chemical parameters by introducing sulfuric acid to selectively leach cobalt and nickel from the copper alloy. This chemical parameter change enables separation based on differential solubility rather than relying on physical cooling processes, achieving both simplicity and high separation efficiency
Solution Approach 2:
The patent uses sulfuric acid as an intermediary substance to facilitate the separation of cobalt and nickel from copper. The acid selectively reacts with and dissolves cobalt and nickel, allowing them to be separated from copper through filtration, thereby achieving precise separation without complex cooling processes
3Manufacturing precision
If nickel is subjected to disproportionation reaction using carbon monoxide gas, then nickel is volatilized and separated from copper or cobalt, but very toxic CO gas is used making it difficult to ensure safety
Solution Approach 1:
The patent converts the harmful effect of using toxic CO gas into a beneficial process by replacing it with sulfuric acid leaching. The acid selectively dissolves cobalt and nickel without requiring toxic gases, maintaining high separation efficiency while eliminating safety hazards associated with CO toxicity
Solution Approach 2:
The patent uses sulfuric acid, a relatively safe and inexpensive reagent, as a disposable leaching agent that can be easily handled and disposed of compared to toxic CO gas. This replacement maintains nickel and cobalt separation efficiency while eliminating the need for complex safety measures
4Productivity
If mat containing copper and nickel is slowly cooled to separate into sulfides, then rough separation is achieved, but copper and nickel are only roughly separated and separate electrolytic purification is required
Solution Approach 1:
The patent changes the separation mechanism from physical cooling-based sulfide formation to chemical leaching using sulfuric acid. This parameter change enables selective dissolution of cobalt and nickel at controlled rates, achieving both high productivity and high purity in a single step without requiring subsequent electrolytic purification
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 enables the selective and efficient separation of copper from nickel and cobalt, resulting in high-purity metals that can be reused, with copper being suitable for smelting and nickel/cobalt being recoverable through known processes, thereby addressing the inefficiencies and environmental issues of previous methods.
Implementation Method 1
an alloy containing copper, nickel, and cobalt is brought into contact with sulfuric acid in the joint presence of a sulfurizing agent, thereby copper is precipitated from the alloy in a form of copper sulfide
Implementation Method 2
copper is precipitated from the alloy in a form of copper sulfide
Data Source
AI summary
Provided is a method for separating copper from nickel and cobalt with which it is possible to selectively and efficiently separate copper, as well as nickel and cobalt, from an alloy including copper, nickel, and cobalt such as an alloy having high corrosion resistance that includes copper, nickel, and cobalt obtained by dry treatment of waste lithium ion cells. An alloy including copper, nickel, and cobalt is brought into contact with sulfuric acid in the joint presence of a sulfurizing agent, and a solid containing copper and a leachate containing nickel and cobalt are obtained.