Aromatic Hydroxyoxime Nickel Cobalt Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oxime-based solvent extraction methods for separating nickel and cobalt from nickel laterites suffer from decomposition of organic extraction reagents, leading to reduced extraction yields and increased operating costs.
Innovation Solution
Simultaneous extraction of nickel and cobalt from aluminium- and iron-free acidic nickel laterite leach solutions using an aromatic hydroxyoxime at a pH of 4 to 5.5 and a temperature below 100°C, with the extraction agent dissolved in a water-immiscible organic solvent, preventing decomposition and allowing for efficient separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxime-based solvent extraction is used to separate nickel and cobalt from nickel laterite leach solutions, then nickel and cobalt can be recovered separately, but the organic extraction reagent decomposes leading to reduced extraction yields and increased operating costs
Solution Approach 1:
The patent changes the pH parameter to a specific range (3.5-5.0) and controls temperature below 100°C to prevent oxime decomposition while maintaining effective nickel and cobalt extraction. This parameter optimization resolves the contradiction by creating conditions where the reagent remains stable yet maintains high extraction efficiency
Solution Approach 2:
The patent uses a composite extraction system combining oxime with specific buffers (acetate, citrate, or phosphate) that stabilize the reagent against decomposition. This composite approach maintains reagent stability while preserving extraction effectiveness, resolving the contradiction between reliability and stability
2Productivity
If oxime-based extraction is used to separate nickel and cobalt, then metal recovery is achieved, but operating costs increase due to reagent decomposition
Solution Approach 1:
By optimizing pH to 3.5-5.0 and temperature control below 100°C, the patent prevents reagent decomposition that would otherwise require continuous reagent replacement. This reduces operating costs while maintaining high metal recovery efficiency through stable extraction conditions
Solution Approach 2:
The patent establishes continuous stable extraction conditions where the oxime reagent maintains its effectiveness throughout the process without decomposition. This continuity eliminates the need for frequent reagent replacement, reducing operating costs while sustaining high productivity
3Reliability
If extraction is performed at higher pH to improve nickel and cobalt recovery, then extraction yield increases, but reagent decomposition accelerates
Solution Approach 1:
The patent identifies and implements an optimal pH window (3.5-5.0) where nickel and cobalt extraction remains effective but oxime decomposition is suppressed. This parameter optimization resolves the contradiction by finding the sweet spot where both extraction yield and reagent service life are maximized
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 method effectively separates nickel and cobalt while minimizing metal impurity extraction, maintaining the stability of the oxime reagent and achieving high recovery yields with reduced operational costs, with nickel and cobalt being further purified through precipitation and solvent extraction.
Implementation Method 1
subjecting the leach solution to extraction with an aromatic hydroxyoxime at a pH in the range of 4 to 5.5 and at a temperature of less than 100°C to obtain a nickel and cobalt bearing solution
Implementation Method 2
maintaining the stability of the oxime reagent and achieving high recovery yields with reduced operational costs
Data Source
Figure 1
AI summary
The invention relates to a method and an arrangement for separating nickel and cobalt by oxime extraction from an aluminium- and iron-fee leach solution obtained from acidic nickel laterite leach. The process is performed at a pH in the range of 4 to 5.5 and at a temperature of less than 100°C. The process may also comprise acid leaching of nickel laterite and removal of aluminium and iron as preceding steps. Furthermore, the process may comprise recovery of nickel and cobalt from the nickel and cobalt bearing solution obtained from the oxime extraction.