Battery Waste Heat Treatment to Prevent Leaching Foam
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The recovery of valuable metals from battery waste is hindered by the foaming phenomenon during acid leaching, which occurs when battery waste is heat-treated in a nitrogen atmosphere, and the explosive combustion of organic electrolytes in oxygen-rich environments, leading to difficulties in temperature control and reduced metal recovery rates.
Innovation Solution
A two-step heat treatment process is employed, where the battery waste is initially heated in a nitrogen, carbon dioxide, or water vapor atmosphere to control oxygen partial pressure and prevent explosive combustion, followed by a second heat treatment in an atmosphere with a higher oxygen content to suppress foaming during acid leaching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat treatment is carried out in a nitrogen atmosphere to prevent explosive combustion of organic electrolyte, then safety and temperature control are improved, but foaming phenomenon occurs during subsequent acid leaching
Solution Approach 1:
The heat treatment process is divided into two distinct stages: first heat treatment in a nitrogen atmosphere to remove organic electrolyte and prevent explosion, followed by second heat treatment in an air atmosphere to eliminate carbon residues. This segmentation allows each stage to address specific problems without causing the foaming issue that would occur with a single nitrogen-only treatment.
Solution Approach 2:
The first heat treatment in nitrogen atmosphere is performed as a preliminary action to remove the organic electrolyte before the main processing. This preliminary removal of the explosive component enables safe subsequent treatments and prevents the foaming problem by ensuring organic residues are eliminated before acid leaching.
2Productivity
If heat treatment is carried out in an oxygen-rich atmosphere to improve metal recovery rates, then valuable metals can be effectively recovered, but organic electrolyte explosively burns and temperature control becomes difficult
Solution Approach 1:
The heat treatment is segmented into two atmospheric conditions: initial nitrogen atmosphere to safely remove organic electrolyte without explosive combustion, followed by air atmosphere to oxidize carbon residues and prepare for effective metal recovery. This segmentation eliminates the temperature control issues while maintaining high metal recovery rates.
Solution Approach 2:
The first heat treatment in nitrogen atmosphere serves as a preliminary safety step that removes the explosive organic electrolyte before the second heat treatment in air atmosphere. This preliminary action prevents explosive combustion while enabling subsequent effective metal recovery through proper oxidation of carbon residues.
3Reliability
If single heat treatment in nitrogen atmosphere is used to prevent explosion, then safety is improved, but foaming during acid leaching reduces processing efficiency
Solution Approach 1:
The heat treatment process is segmented into two atmospheric stages: nitrogen atmosphere for safety and organic electrolyte removal, followed by air atmosphere to eliminate carbon residues. This segmentation maintains safety while preventing the foaming phenomenon that would reduce processing efficiency during acid leaching.
Solution Approach 2:
The nitrogen atmosphere heat treatment is performed as a preliminary safety step to remove organic electrolyte, followed by air atmosphere treatment to prepare the material for efficient acid leaching. This two-stage preliminary preparation ensures both safety and processing efficiency by eliminating both organic electrolyte and carbon residues before leaching.
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 suppresses the foaming phenomenon during acid leaching, improving the recovery rates of valuable metals like cobalt, nickel, and lithium by controlling the heat treatment conditions and atmosphere changes.
Implementation Method 1
a first heat treatment step of heating the battery waste in an atmosphere comprising at least one selected from the group consisting of nitrogen, carbon dioxide and water vapor
Implementation Method 2
a second heat treatment step of changing the atmosphere in the first heat treatment step and heating the battery waste in an atmosphere which is different from the atmosphere in the first heat treatment step and which comprises a larger amount of oxygen than that in the first heat treatment step
Data Source
AI summary
A method for treating battery waste includes: a first heat treatment step of heating the battery waste in an atmosphere containing at least one selected from the group consisting of nitrogen, carbon dioxide and water vapor; and after the first heat treatment step, a second heat treatment step of changing the atmosphere in the first heat treatment step and heating the battery waste in an atmosphere which is different from the atmosphere in the first heat treatment step and which contains a larger amount of oxygen than that in the first heat treatment step.