Copper Alloy Leaching with Redox Control for Nickel-Cobalt Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for recovering nickel and cobalt from waste lithium ion batteries face challenges such as high energy consumption, environmental hazards, and inefficient separation and purification, leading to high recovery losses and costly purification processes.
Innovation Solution
A method involving leaching treatment with a specific concentration of acid solution and a sulfurizing agent, controlled redox potential, and subsequent reduction and oxidative neutralization steps to obtain a high-concentration solution of nickel and cobalt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dry processing is used to recover valuable metals from waste LIBs, then various impurities can be separated at once and the process is simple, but most cobalt is distributed to the slag causing high recovery loss
Solution Approach 1:
The invention divides the recovery process into two distinct stages: (1) dry processing to separate impurities and obtain a copper-nickel-cobalt alloy, and (2) selective leaching to extract nickel and cobalt from the alloy. This segmentation allows each stage to optimize for its specific function, minimizing cobalt loss in the second stage through controlled chemical extraction.
Solution Approach 2:
The invention introduces an intermediary substance (sulfurizing agent) in the selective leaching step that selectively binds to copper while leaving nickel and cobalt in solution. This intermediary enables the separation of copper from the valuable metals without loss of nickel and cobalt to the slag phase.
2Manufacturing precision
If wet processing is used to separate and purify nickel and cobalt, then high purity can be achieved, but the process becomes complex and costly
Solution Approach 1:
The invention extracts only the essential purification step needed - selective leaching of nickel and cobalt from the copper-nickel-cobalt alloy using acid solution and sulfurizing agent. This targeted extraction approach achieves high purity without requiring the full suite of complex wet processing operations, thereby reducing overall process complexity while maintaining manufacturing precision.
3Productivity
If conventional leaching is used to extract nickel and cobalt, then recovery efficiency can be improved, but selective separation from copper remains difficult
Solution Approach 1:
The invention uses a sulfurizing agent as an intermediary that selectively reacts with copper to form copper sulfide precipitate, while nickel and cobalt remain in the aqueous phase. This intermediary enables simultaneous high leaching efficiency and excellent separation selectivity by exploiting the different chemical behaviors of the three metals toward sulfurizing agents.
Solution Approach 2:
The invention optimizes specific parameters including acid solution concentration (5-20% sulfuric acid), sulfurizing agent dosage (0.5-2 equivalents relative to copper), temperature (20-80°C), and liquid-to-solid ratio (5:1 to 20:1) to maximize both leaching efficiency and separation selectivity of nickel and cobalt from copper.
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
The method enables efficient and selective leaching of nickel and cobalt from alloys, achieving high concentrations and reducing recovery losses, while minimizing environmental impact and operational costs.
Implementation Method 1
a leaching step of applying leaching treatment with an acid solution to a slurry containing the alloy in a presence of a sulfurizing agent to obtain a leachate and a leached residue
Implementation Method 2
the leaching treatment is performed in a presence of a sulfurizing agent
Implementation Method 3
further comprising a reduction step of adding a reducing agent to the leachate obtained through the leaching step to perform reduction treatment
Implementation Method 4
further comprising an oxidative neutralization step of adding a neutralizer and an oxidant to the reduced solution obtained through the reduction step to perform oxidative neutralization treatment
Data Source
AI summary
Provided is a method for effectively obtaining a solution containing nickel and/or cobalt from an alloy that contains copper as well as nickel and/or cobalt, in a waste lithium-ion battery or the like. The present invention is an alloy processing method for obtaining a solution containing nickel and/or cobalt from an alloy that contains copper as well as nickel and/or cobalt, said method including a leaching step for carrying out an acid solution leaching treatment on an alloy-containing slurry in the presence of a sulfurising agent to obtain a leachate and a leaching residue. In the leaching step, the leaching treatment is carried out with the initial concentration of the alloy-containing slurry adjusted to between 100 g/L and 250 g/L. Moreover, in the leaching step, the leaching treatment is preferably carried out while controlling the redox potential (using a silver/silver chloride electrode as a reference electrode) to 200 mV or less. Furthermore, in the leaching step, the leaching treatment is preferably carried out in the presence of the sulfurising agent in an amount in the range of 1.05 to 1.25 equivalent weight (S-mol/Cu-mol) in relation to the amount of copper contained in the alloy.