Zirconium Adsorbent Mo-99 Purification Process
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Solution Overview
Problem
Current methods for purifying Mo-99 from acidic solutions obtained after uranium irradiation in nuclear reactors face challenges such as high retention on alumina, loss of Mo-99, and contamination by chemical impurities, especially when using acid dissolution processes, which are not compatible with subsequent purification steps.
Innovation Solution
A process involving an adsorbent comprising zirconium oxide, zirconium hydroxide, zirconium alkoxide, zirconium halide, and zirconium oxide halide, which contacts the acidic solution and elutes Mo-99 using a strong base, followed by an alkaline-based chromatographic recovery step on an anion exchange material for further purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If alumina is used to adsorb Mo-99 from acidic solution, then Mo-99 can be concentrated, but Mo-99 retention is too high causing losses during recovery
Solution Approach 1:
The patent changes the chemical parameters of the solution by converting from acidic medium to alkaline medium (pH adjustment). This parameter change fundamentally alters the adsorption characteristics of Mo-99 on alumina, reducing excessive retention and enabling efficient elution while maintaining concentration capability.
Solution Approach 2:
The patent inverts the conventional approach by performing adsorption in alkaline medium rather than acidic medium. This inversion of the chemical environment allows Mo-99 to be adsorbed onto alumina with optimal retention characteristics that enable both concentration and subsequent easy recovery without excessive loss.
2Manufacturing precision
If alumina is used for Mo-99 adsorption, then purification can be achieved, but chemical impurities leach into the Mo-99 eluate causing contamination
Solution Approach 1:
The patent changes the pH parameter from acidic to alkaline, which prevents the leaching of chemical impurities from alumina into the Mo-99 eluate. This parameter change eliminates the contamination problem while preserving the purification function of alumina.
3Productivity
If acid dissolution is used for target processing, then Mo-99 can be extracted from uranium, but the acidic stream is incompatible with subsequent purification steps
Solution Approach 1:
The patent performs a preliminary neutralization action by adding base to convert the acidic stream to alkaline medium before Mo-99 adsorption. This preliminary action makes the stream compatible with subsequent purification steps on alumina and other adsorbents that require alkaline conditions.
Solution Approach 2:
The patent changes the chemical parameter (pH) of the solution from acidic to alkaline, transforming the stream into a form that is compatible with standard purification procedures using alumina and other adsorbents, thereby enabling multi-step purification while maintaining extraction efficiency.
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 purifies Mo-99 from acidic solutions, reducing losses and contamination, and allows for the use of acid-based output streams in Mo-99 production, achieving high purity Mo-99 suitable for Tc-99m generator preparation.
Implementation Method 1
contacting the acidic solution with an adsorbent comprising a zirconium oxide, zirconium hydroxide, zirconium alkoxide, zirconium halide and/or zirconium oxide halide
Implementation Method 2
eluting the Mo-99 from the adsorbent using a solution of a strong base
Implementation Method 3
an alkaline-based Mo-99 chromatographic recovery step on an anion exchange material
Data Source
AI summary
A process for purifying Mo-99 from an acidic solution obtained by dissolving an irradiated solid target comprising uranium in an acidic medium, or from an acidic solution comprising uranium and which has previously been irradiated in a nuclear reactor, or from an acidic solution comprising uranium and which has been used as reactor fuel in a homogeneous reactor, the process comprising contacting the acidic solution with an adsorbent comprising a zirconium oxide, zirconium hydroxide, zirconium alkoxide, zirconium halide and/or zirconium oxide halide, and eluting the Mo-99 from the adsorbent using a solution of a strong base, the eluate then being subjected to a subsequent purification process involving an alkaline-based Mo-99 chromatographic recovery step on an anion exchange material. Also provided is apparatus for carrying out the process.