Ruthenium Collection via Dissolving Inorganic Adsorbent

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Solution Overview

Problem

Current methods for collecting ruthenium or ruthenium compounds from aqueous solutions are inefficient, particularly when the solutions contain water-soluble salts, lower alcohols, or organic acids, due to instability and corrosion issues with existing adsorbents, and are not optimized for low concentration solutions.

Innovation Solution

A method involving the use of an inorganic adsorbent, such as calcium phosphate, talcite, or amorphous aluminosilicate, which is dissolved under acidic conditions and then deposited in an alkaline environment to enhance adsorbability, with the pH adjusted to 7 or higher to improve collection efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If calcium phosphate compounds are used as adsorbents under neutral or alkaline conditions to maintain solid state, then structural stability is improved, but adsorbability is insufficient due to restricted ion release

Engineering Contradiction:
Improvestructural stabilityVSAvoidadsorbability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies preliminary action by dissolving the calcium phosphate adsorbent in acid before use, releasing ions in advance. This pre-treatment step transforms the solid adsorbent into an ionic form that can effectively adsorb ruthenium, then the solution is neutralized to precipitate the adsorbent for recovery. This resolves the contradiction by enabling ion release (improving adsorbability) while maintaining structural stability through controlled dissolution and reprecipitation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the adsorbent is dissolved to release ions for adsorption, then adsorbability is improved, but the adsorbent structure is destroyed

Engineering Contradiction:
ImproveadsorbabilityVSAvoidstructural stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies discarding and recovering by intentionally dissolving the calcium phosphate adsorbent in acid to release ions for ruthenium adsorption, then recovering the adsorbent by neutralizing the solution to precipitate the calcium phosphate again. This cycle allows the adsorbent to be reused multiple times, resolving the contradiction between destroying structure for adsorption and maintaining structure for stability.

Inventive Principle:
Principle #34Discarding and recovering

3Device complexity

If existing adsorbents are used for ruthenium collection, then collection process is simplified, but collection ratio is insufficient due to instability and corrosion issues

Engineering Contradiction:
Improveprocess complexityVSAvoidcollection ratio
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling pH levels throughout the process: acidifying to dissolve the adsorbent and release ions, then neutralizing to precipitate the adsorbent for recovery. This systematic pH control transforms the collection process into a reliable method that achieves high collection ratios while maintaining simplicity, resolving the contradiction between process simplicity and collection efficiency.

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

This method significantly improves the collection ratio of ruthenium or ruthenium compounds from aqueous solutions containing water-soluble salts, lower alcohols, or organic acids, allowing for efficient separation and reuse of the adsorbent, even in the presence of inhibitors that reduce oxidation-reduction or ionization operations.

Implementation Method 1

putting an aqueous solution containing ruthenium or a ruthenium compound into contact with an inorganic adsorbent

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

hydroxyapatite, which is one type of calcium phosphate, is known as a compound having a cation exchange capability and adsorbability

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Implementation Method 3

dissolving the entirety or a part of the inorganic adsorbent under an acidic condition

Methodology Applied
Scientific EffectDissolution:

Implementation Method 4

adding an alkali to deposit the dissolved inorganic adsorbent while causing the inorganic adsorbent to adsorb ruthenium or the ruthenium compound

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP2677047B1Method for collection of ruthenium or ruthenium compound
Publication Date: 2019.09.11 MITSUBISHI GAS CHEM CO INC

AI summary

According to the present invention, ruthenium or a ruthenium compound, which is expensive, can be collected with high efficiency even from an aqueous solution containing a water-soluble salt, a lower alcohol, an organic acid or the like, by adding at least one specific inorganic adsorbent to an aqueous solution containing ruthenium or the ruthenium compound, dissolving the entirety or a part of the inorganic adsorbent under an acidic condition, and then adding an alkali to adjust the solution to be an alkaline solution having a pH value of 7 or higher, thereby depositing the inorganic adsorbent while causing the inorganic adsorbent to adsorb ruthenium or the ruthenium compound.