Battery Smelting Flux Composition for Slag-Alloy Separation
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Solution Overview
Problem
The existing dry processes for recycling lithium-ion batteries face challenges in separating valuable metals from slag due to high viscosity and melting point issues, particularly with the oxidation of aluminum, which increases the melting point and viscosity of slag, making it difficult to recover valuable metals efficiently.
Innovation Solution
A method involving the addition of SiO2 and CaO as fluxes to control the composition of slag with specific ranges of alumina and iron content, reducing the melting point and viscosity, allowing for efficient separation of slag and alloy at lower temperatures between 1,500°C and 1,650°C in an electric furnace.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the melting temperature is increased to separate slag and alloy, then the separation reliability is improved, but the energy consumption and operational costs increase
Solution Approach 1:
The invention changes the chemical composition parameters of the slag system by adding specific fluxes (CaO, SiO2, Al2O3, MgO) to modify the physical properties of slag, enabling effective separation at lower temperatures (1200-1450°C) while maintaining separation reliability
Solution Approach 2:
The invention introduces fluxes as intermediary substances that mediate between the high-melting-point alumina-containing waste battery materials and the separation process, lowering the overall melting point and viscosity to enable efficient separation at reduced temperatures
2Use of energy by stationary object
If the melting temperature is decreased to improve operational efficiency, then the energy consumption is reduced, but the slag viscosity increases and separation becomes difficult
Solution Approach 1:
The invention modifies the slag composition parameters by adding specific fluxes that reduce viscosity at lower temperatures, enabling easy separation operations while maintaining lower energy consumption
Solution Approach 2:
The invention creates a composite slag system combining multiple oxides (CaO, SiO2, Al2O3, MgO) with waste battery materials, where the flux components work synergistically to maintain low viscosity and facilitate separation at reduced temperatures
3Quantity of substance
If alumina content in slag is increased due to aluminum oxidation, then the melting point and viscosity of slag increase, but the separation of alloy from slag becomes poor
Solution Approach 1:
The invention introduces fluxes as intermediary substances that interact with alumina to form a eutectic system, lowering the melting point and viscosity of alumina-rich slag and enabling effective separation despite high alumina content
Solution Approach 2:
The invention changes the slag composition parameters by adding fluxes that modify the physical and chemical properties of alumina-containing slag, reducing its melting point and viscosity to enable effective separation
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 a lower-temperature process with reduced viscosity, facilitating reliable separation and efficient recovery of valuable metals from lithium-ion batteries, increasing throughput and reducing operational costs while maintaining alloy purity.
Implementation Method 1
silicon dioxide and calcium oxide are added as fluxes in the melting step, the slag has an aluminium oxide content of 25% by weight to 75% by weight and an iron content of 5% by weight to 40% by weight
Implementation Method 2
a melting step including melting the waste battery to form a melt
Implementation Method 3
the melting step is performed at at least 1,500°C and at most 1,650°C, and wherein the melting step is performed in an electric furnace
Implementation Method 4
a slag separation step including separating slag from the melt; and an alloy separation step including separating an alloy of a valuable metal from the melt
Data Source
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AI summary
Provided is a method for increasing the rate of recovery of valuable metals when waste batteries batteries are treated by a dry process. The valuable metal recovery method in the dry step S20 includes a melting step ST21 including melting waste batteries to form a melt, a slag separation step ST22 including separating slag from the melt, and an alloy separation step ST23 including separating an alloy of valuable metals from the melt, wherein the slag has an aluminium oxide content of 20% by weight to less than 75% by weight and an iron content of 5% by weight to 40% by weight, calculated as metallic iron, and silicon oxide and calcium oxide are added as fluxes in the melting step ST21 so that the slag can have a melting point of at least 1,500°C, preferably at most 1,650°C.