Modified Biochar Adsorption for Reduced-Sludge Critical Mineral Recovery
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Solution Overview
Problem
Existing methods for recovering critical minerals from acid mine drainage (AMD) are costly and environmentally detrimental, producing high volumes of sludge that require further management, while AMD and its treatment products contain valuable critical minerals like aluminum, cobalt, and rare earth elements (REEs).
Innovation Solution
A method involving adjusting the pH of a critical mineral solution with acid or base to 2 to 7, contacting it with modified biochar, and desorbing the saturated biochar to form a critical mineral precipitate, using biochar modified by physical and chemical treatments to enhance adsorption and desorption efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional pH control with neutralization reagents is used for AMD remediation, then treatment cost is reduced, but sludge volume increases requiring further management and disposal
Solution Approach 1:
The patent employs modified biochar with porous structure as an adsorbent to capture critical minerals from AMD. The porous material provides high surface area for adsorption, enabling concentration of minerals from large volumes of AMD into small amounts of saturated biochar, thus reducing the volume of waste requiring disposal while maintaining cost-effective treatment
Solution Approach 2:
The patent transforms the conventional approach by recovering valuable critical minerals (aluminum, cobalt, manganese, REEs) from the AMD treatment process. Instead of discarding the treatment product as waste sludge, the minerals are adsorbed onto biochar and then desorbed using acid/base solutions, converting waste into recoverable resources that can be processed further
2Quantity of substance
If common extraction techniques are used to recover critical minerals from AMD, then mineral recovery is achieved, but treatment cost increases and environmental impacts worsen
Solution Approach 1:
The patent uses modified biochar as a low-cost, disposable adsorbent that can be easily prepared from biomass waste. The biochar is used once to adsorb critical minerals, then discarded after simple acid/base washing to recover the minerals. This avoids the need for expensive, complex extraction equipment and chemicals while maintaining effective mineral recovery
Solution Approach 2:
The patent converts the harmful AMD waste stream into a valuable resource by using the acidic solution itself to desorb and recover critical minerals from the saturated biochar. The same acid that causes environmental harm is repurposed as a tool for mineral recovery, eliminating the need for additional harsh chemicals and reducing overall environmental impact
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 recovers critical minerals in a cost-effective and environmentally sustainable manner, reducing the volume of sludge and minimizing environmental impact by utilizing biochar's porous structure and functional groups for selective adsorption and desorption.
Implementation Method 1
contacting the critical mineral solution with a first modified biochar, forming a first saturated biochar
Implementation Method 2
desorbing the first saturated biochar, thereby forming a first critical mineral precipitate, a first stripped biochar, and a first aqueous phase
Data Source
AI summary
In one aspect, the disclosure relates to a method for recovering critical minerals from a solution, the method comprising: (a) providing a critical mineral solution comprising at least one critical mineral and water; (b) contacting the critical mineral solution with an acid or a base in an amount sufficient enough to adjust the pH to a value of about 2 to about 7; (c) contacting the critical mineral solution with a first modified biochar, forming a first saturated biochar; and (d) desorbing the first saturated biochar, thereby forming a first critical mineral precipitate, a first stripped biochar, and a first aqueous phase. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.