Lithium Battery Separator Paper Recycling via Flotation and Hydrometallurgy

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Solution Overview

Problem

Current methods for treating waste lithium battery diaphragm paper, such as incineration, result in low metal recycling rates, high energy consumption, and environmental pollution, failing to effectively recover valuable metals like copper, aluminum, nickel, and cobalt.

Innovation Solution

A method combining physics and chemistry techniques, involving shearing and crushing, pneumatic separation, eddy-current separation, flotation, pickling, and hydrometallurgy to separate and recover metallic copper, aluminum, and cobalt from the diaphragm paper, achieving high recycling rates and reducing environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If incineration method is used to treat diaphragm paper, then the treatment process is simple, but the metal recycling rate is low and valuable metals are lost

Engineering Contradiction:
Improvetreatment process simplicityVSAvoidvaluable metals loss
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The treatment process is divided into multiple stages: incineration to remove organic matter, followed by separation processes (magnetic separation, eddy current separation, gravity separation) to recover different metals. This segmentation allows both simple initial treatment and comprehensive metal recovery, resolving the contradiction between process simplicity and metal recycling rate.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If incineration method is used to treat diaphragm paper, then the treatment process is straightforward, but the energy consumption is high

Engineering Contradiction:
Improvetreatment process straightforwardnessVSAvoidenergy consumption
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The diaphragm paper undergoes preliminary incineration to remove organic matter before metal separation. This preliminary action simplifies subsequent separation processes and reduces energy consumption during metal recovery stages, as the material to be separated is already pre-treated and more easily separable.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If incineration method is used to treat diaphragm paper, then the process is simple, but environmental pollution occurs

Engineering Contradiction:
Improveprocess simplicityVSAvoidenvironmental pollution
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The incineration process, which initially causes pollution, is converted into a beneficial step by controlling it to selectively remove organic matter while preserving metals. The resulting ash and gases are then processed through separation techniques that recover valuable metals, transforming the harmful incineration byproduct into a source of recoverable resources.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Ease of operation

If aluminum is melted during treatment, then the aluminum can be separated, but the aluminum penetrates into battery powder causing separation difficulties

Engineering Contradiction:
Improvealuminum separationVSAvoidseparation process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The melting point parameter of aluminum is utilized by controlling the incineration temperature to melt aluminum (660°C) without melting other battery components. This parameter change allows aluminum to be separated in liquid form while other materials remain solid, simplifying the separation process and avoiding contamination of battery powder.

Inventive Principle:
Principle #35Parameter changes

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 achieves high recycling rates for metallic copper and aluminum (>98% and >90% respectively) and allows for the recovery of nickel and cobalt, enabling the reuse of diaphragm paper and reducing energy consumption and environmental pollution.

Implementation Method 1

putting the same into a cyclone separator with an airflow speed of 2.2 m/s for pneumatic separation to obtain a light material and a copper-aluminum mixture

Methodology Applied
Scientific EffectPneumatic separation: Cyclone Separation

Implementation Method 2

putting the copper-aluminum mixture into an eddy-current separator with a rotor speed of 40 Hz and a belt speed of 12 Hz for separation to obtain metallic copper and metallic aluminum

Methodology Applied
Scientific EffectEddy-current separation: Eddy Currents

Implementation Method 3

putting the light material into a flotation machine with a stirring speed of 300 r/min and a scraper speed of 50 r/min for separation to obtain diaphragm paper and battery powder

Methodology Applied
Scientific EffectFlotation: Froth Floatation

Implementation Method 4

filtering with a 60-mesh linear sieve, and spin-drying with a horizontal spiral discharge centrifuge with a rotating speed of 5,000 r/min, thus obtaining the diaphragm paper

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Force

Data Source

PatentEP4199184B1Method for processing waste lithium battery separator paper
Publication Date: 2024.10.30 HUNAN BRUNP RECYCLING TECH CO LTD
  • EP4199184B1 patent drawingFigure 1

AI summary

The present invention relates to the field of waste battery recycling, and discloses a method for treating waste diaphragm paper of a lithium battery, which includes the following steps of: (1) shearing and crushing waste diaphragm paper, and then carrying out pneumatic separation to obtain a light material and a copper-aluminum mixture; (2) putting the light material into a flotation machine for separation to obtain diaphragm paper and battery powder; and (3) pulping the battery powder, and then carrying out leaching of hydrometallurgy, pickling the diaphragm paper, and then filtering and spin-drying to obtain the diaphragm paper. According to the method, the diaphragm paper is treated by a method combining physics and chemistry, so that valuable metals in the waste diaphragm paper of the lithium battery are effectively recycled, and the industrial production requirements of environmental friendliness, low energy consumption and high resource recycling are satisfied.