Lithium Iron Phosphate Precursor from Red Mud Without Additives
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Solution Overview
Problem
The existing methods for preparing lithium iron phosphate precursor from red mud are complicated and require the addition of exogenous substances, lacking consideration for the characteristics of the iron phosphate material, and there is a shortage in the supply of this new energy material.
Innovation Solution
A method involving mixing high-iron red mud with an acid solution, followed by leaching, homogeneous reactions, and controlled pH and iron-phosphorus ratio adjustments to produce a lithium iron phosphate precursor without the need for exogenous substances, utilizing the red mud's inherent properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If concentrated acid leaching method is used to convert iron compounds into trivalent iron ions and divalent iron ions to react with phosphoric acid, then iron(III) phosphate dihydrate can be formed, but the process becomes complicated and requires adding additives and extractants in multiple steps
Solution Approach 1:
The patent extracts and utilizes the inherent phosphorus-containing substances already present in the red mud system, eliminating the need to add external phosphoric acid and other additives. This is achieved by directly reacting iron compounds in the red mud with internally present phosphorus substances under controlled pH conditions, thereby simplifying the process while maintaining product formation reliability
Solution Approach 2:
The method enables the red mud system to self-generate the necessary chemical environment for iron(III) phosphate dihydrate formation by utilizing its own phosphorus-containing components. The process leverages the self-contained chemical resources within the red mud to complete the reaction without requiring external additives or extractants, thus reducing process complexity
2Quantity of substance
If conventional magnetic separation method is used to recover iron minerals from red mud, then a small portion of iron can be recovered, but the recovery efficiency is low
Solution Approach 1:
The patent changes the chemical state of iron from its original mineral form (hematite, goethite) to soluble iron ions through acid leaching, fundamentally altering the physical and chemical parameters of iron. This transformation enables much higher recovery efficiency compared to conventional magnetic separation, as it converts insoluble iron minerals into bioavailable and reactable iron ions that can be fully utilized in subsequent precipitation reactions
3Quantity of substance
If high-intensity magnetic separation and magnetic roasting method is used to recover iron from red mud, then iron recovery can be improved, but investment and energy consumption increase significantly
Solution Approach 1:
The patent replaces the mechanical and high-energy magnetic roasting methods with a chemical leaching approach using acid solutions. This substitution eliminates the need for high-intensity magnetic fields and extensive roasting energy input, achieving iron extraction through chemical dissolution at lower energy costs while maintaining high recovery quantities
4Ease of manufacture
If red mud is used as raw material for preparing ferric phosphate, then cost advantages and reserve advantages are achieved, but exogenous substances need to be added in conventional methods
Solution Approach 1:
The method enables the red mud system to self-supply all necessary chemical components for iron(III) phosphate dihydrate formation. The phosphorus-containing substances required for the reaction are already present within the red mud, eliminating the need to add external phosphoric acid or other reagents. This self-sufficiency maximizes cost advantages by utilizing only the red mud resource without requiring additional chemical inputs
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 simplifies the process, reduces costs, and achieves high-value utilization of red mud by producing a lithium iron phosphate precursor efficiently, meeting industry standards for purity and quality.
Implementation Method 1
mixing the high-iron red mud and an acid solution, and then leaching to obtain a red mud leachate
Implementation Method 2
mixing the red mud leachate and a phosphate, and then performing a first homogeneous reaction to obtain a primary homogeneous solution
Implementation Method 3
adjusting a pH value and iron-phosphorus ratio of the primary homogeneous solution
Implementation Method 4
precipitating the secondary homogeneous solution to obtain the lithium iron phosphate precursor
Data Source
Figure 1
AI summary
A method for preparing a lithium iron phosphate precursor from a high-iron red mud is provided according to the invention, comprising: mixing the high-iron red mud and an acid solution, and then leaching to obtain a red mud leachate; mixing the red mud leachate and a phosphate, and then performing a first homogeneous reaction to obtain a primary homogeneous solution; adjusting a pH value and iron-phosphorus ratio of the primary homogeneous solution, and then performing a second homogeneous reaction to obtain a secondary homogeneous solution; and precipitating the secondary homogeneous solution to obtain the lithium iron phosphate precursor.