Lattice-Strained Copper Sulfide for Atmospheric Leaching
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Solution Overview
Problem
Current methods for atmospheric leaching of primary metal sulfides like Chalcopyrite suffer from slow reaction kinetics and poor metal dissolution rates due to surface passivation, requiring high energy inputs and lengthy processing times, and previous attempts to address this have been inefficient or economically unviable.
Innovation Solution
The development of lattice-strained semiconductor compounds with a meta-stable, iron- and sulfur-depleted copper sulfide moiety, which exhibits enhanced oxidative leaching properties, allowing for rapid copper dissolution and recovery with reduced energy consumption and minimal side reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional atmospheric leaching methods are used on primary metal sulfides, then the process can proceed with simple equipment and操作流程, but the reaction kinetics are slow and metal dissolution rates are poor due to surface passivation
Solution Approach 1:
The patent applies preliminary action by mechanically activating the chalcopyrite concentrate before leaching through methods such as high-energy grinding, ultrasonic treatment, or ball milling. This pre-treatment creates surface defects, increases surface area, and disrupts the passive surface layer, preparing the material for faster subsequent leaching. The activation step is performed in advance to overcome the surface passivation problem that would otherwise slow down the leaching process.
Solution Approach 2:
The patent changes physical and chemical parameters of the leaching system to improve kinetics. This includes adjusting particle size distribution through classification, modifying surface chemistry through reagents, changing temperature, pH, and oxygen partial pressure conditions. These parameter changes are designed to enhance the dissolution rate while managing the trade-off with processing time and energy consumption.
2Area of stationary object
If ultra-fine grinding is applied to pretreat concentrates before leaching, then surface area increases, but leach times are reduced only marginally and surface passivation reactions continue to be problematic
Solution Approach 1:
The patent replaces or supplements mechanical grinding with alternative activation methods that are more effective at preventing surface passivation. These include ultrasonic cavitation, high-voltage electrical discharge, or chemical activation with specific reagents. These substitutions address the limitation of mechanical grinding where increased surface area is offset by concurrent surface passivation reactions.
Solution Approach 2:
The patent creates composite structures or combinations of treatment methods that synergistically improve leaching performance. This may involve combining mechanical activation with chemical reagents, or creating composite particle structures with enhanced reactivity. The composite approach allows simultaneous achievement of high surface area and resistance to passivation.
3Productivity
If chemical pre-treatment is used to convert chalcopyrite to more-readily-leached phases, then leaching efficiency improves, but the process requires quantitative conversion which is difficult to achieve and may require additional reagents
Solution Approach 1:
The patent employs self-service principles where the leaching process itself facilitates the necessary phase transformations without requiring extensive pre-treatment. The oxidative leaching conditions naturally promote the conversion of chalcopyrite to more reactive phases in-situ during the leaching process, eliminating the need for separate conversion steps and reducing overall process complexity.
Solution Approach 2:
The patent uses intermediary substances or conditions that facilitate the transition from chalcopyrite to leachable phases. Specific reagents or atmospheric conditions act as mediators that promote selective transformation of the mineral structure, enabling efficient copper recovery without requiring complete quantitative conversion or complex multi-step processes.
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 new compounds enable copper dissolution rates exceeding 90-95% within 3-6 hours at moderate temperatures, independent of chalcopyrite conversion to covellite, and maintain reactivity without parasitic side reactions, significantly improving metal recovery efficiency.
Implementation Method 1
enhanced oxidative leaching properties
Implementation Method 2
increased electrochemical reactivity
Data Source
AI summary
Disclosed are novel compounds which display enhanced reactive properties due, in part, to induced lattice strain. The new compounds demonstrate accelerated leaching of copper under oxidizing conditions. The activated compounds are produced under conditions of time, temperature, Eh, and pH which retard the rate of lattice strain relaxation. Further disclosed are methods of making and using the novel compounds.