Progressive Copper Heap Leaching for Refractory Chalcopyrite
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Solution Overview
Problem
Conventional leaching processes for copper sulfide ores, particularly those containing chalcopyrite, suffer from slow dissolution rates and low extraction efficiency, necessitating high energy and water consumption, and are challenged by environmental emissions, especially NOx, making them unsuitable for industrial-scale applications.
Innovation Solution
A dynamic oxidative process involving sequential irrigations with reactive liquid mixtures containing sulfuric acid, nitrate ions, and oxidizing agents like hydrogen peroxide, combined with controlled irrigation rates and rest periods, to create a dynamic moisture state in the heap, enhancing copper recovery through electrochemical transformations and minimizing passivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional acid leaching is used for copper sulfide ores, then the process is simple to operate, but copper extraction efficiency is low and dissolution rate is slow
Solution Approach 1:
The patent changes the chemical parameters of the leaching solution by adding oxidizing agents (ferric sulfate, hydrogen peroxide, nitrate) to conventional sulfuric acid, transforming the leaching environment from reducing to oxidative. This parameter change enables efficient copper extraction from refractory sulfide ores while maintaining heap leaching simplicity
Solution Approach 2:
The patent creates a composite leaching solution combining sulfuric acid with multiple oxidizing agents (ferric sulfate, hydrogen peroxide, nitrate). This composite chemical system synergistically attacks refractory copper sulfide minerals, achieving high extraction efficiency without requiring complex pyrometallurgical processes
2Productivity
If pyrometallurgical techniques are used for chalcopyrite processing, then copper extraction efficiency is high, but energy consumption and water consumption are high
Solution Approach 1:
The patent replaces the high-energy pyrometallurgical mechanical/thermal system with a chemical hydrometallurgical system using oxidative leaching. The chemical reactions occur at ambient or near-ambient temperatures, dramatically reducing energy consumption while maintaining high copper extraction efficiency from chalcopyrite
Solution Approach 2:
The patent changes the temperature parameter from high-temperature pyrometallurgical processing to ambient/near-ambient temperature hydrometallurgical processing. This parameter change, combined with the introduction of oxidizing agents, enables efficient copper recovery without the high energy input required by traditional pyrometallurgy
3Productivity
If high irrigation rates are used for leaching, then copper recovery rate is improved, but water consumption increases and surface passivation occurs
Solution Approach 1:
The patent changes the chemical composition parameter of the leaching solution by adding oxidizing agents, which enables effective copper dissolution at lower irrigation rates. The oxidizing environment prevents surface passivation, allowing sustained copper recovery rates with reduced water consumption compared to conventional acid leaching
4Object-affected harmful factors
If conventional acid leaching is used for refractory copper sulfide ores, then the process is environmentally friendly, but dissolution rate is slow and extraction efficiency is low
Solution Approach 1:
The patent changes the redox potential parameter of the leaching solution by introducing oxidizing agents (ferric sulfate, hydrogen peroxide, nitrate). This creates an oxidative environment that efficiently dissolves refractory copper sulfide minerals while maintaining environmental benefits of heap leaching, avoiding both pyrometallurgical emissions and conventional leaching inefficiency
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 process achieves high copper recovery rates with reduced water and energy consumption, minimal NOx emissions, and prevents surface passivation, effectively addressing the refractory nature of copper sulfide ores.
Implementation Method 1
A dynamic oxidative process involving sequential irrigations with reactive liquid mixtures containing sulfuric acid, nitrate ions, and oxidizing agents like hydrogen peroxide
Implementation Method 2
enhancing copper recovery through electrochemical transformations
Implementation Method 3
Conventional copper leaching was primarily developed for the extraction of copper from oxide ores... The dissolution of copper from such sources is readily initiated by the application of acid
Implementation Method 4
oxidizing agents like hydrogen peroxide
Data Source
AI summary
A hydrometallurgical process for processing metal ore includes a dynamic oxidative step in which the ore is irrigated with specific reactive liquid mixtures at low flow rates to progressively transform the ore and maintain conditions for enhanced recovery of metal from the ore by solvent-extraction/electrowinning. In embodiments, the systems and methods described herein may be used for obtaining copper metal from the refractory copper mineral chalcopyrite. A copper heap subjected to the electrochemical regimes established and maintained in the heap using these methods exhibit novel kinetics.