Sludge Cementing via Dry Mixture for Waste Inerting

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Solution Overview

Problem

Current methods for inerting industrial and radioactive waste in the form of sludge face challenges due to their rheological properties and chemical reactivity, leading to difficulties in mixing and solidification, which results in suboptimal mechanical resistance and increased porosity.

Innovation Solution

A semi-homogeneous cementing process is developed, where waste is solidified with a dry cementitious mixture without additional water, allowing for the extemporaneous preparation of cement from waste water, thereby stabilizing and solidifying sludges that are difficult to mix conventionally, and maximizing the incorporation rate of dry matter into a cement matrix.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a high Water/Cement ratio is used to ensure workability and consistency of sludge suspension, then the rheological behavior is improved, but porosity increases and mechanical resistance decreases

Engineering Contradiction:
ImproveworkabilityVSAvoidmechanical resistance
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent changes the Water/Cement ratio parameter from high (conventional) to low (optimized), achieving both workability and mechanical resistance by using a controlled amount of water that enables mixing without creating excessive porosity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining sludge suspension with cement, where the interaction between the two components produces a optimized rheological behavior and mechanical properties that neither material alone could achieve

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If additional water is added to ensure suitable rheology of the paste, then the mixing process is improved, but the incorporation rate of waste decreases

Engineering Contradiction:
Improvemixing processVSAvoidincorporation rate
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The sludge suspension serves its own rheological needs by using its intrinsic water content, eliminating the need for external water addition and thereby maximizing waste incorporation without requiring additional liquid

Inventive Principle:
Principle #25Self-service

3Device complexity

If conventional cementing methods are used with sludge, then the process is simple, but the mixing quality and homogeneity are insufficient

Engineering Contradiction:
Improveprocess simplicityVSAvoidmixing quality
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary classification and separation of sludge components before cementing, preparing the sludge in advance to ensure optimal mixing quality and homogeneity while maintaining process simplicity

Inventive Principle:
Principle #10Preliminary action

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 process achieves stable and homogeneous composite materials with enhanced mechanical resistance and reduced hydrogen content, minimizing water usage and preventing re-dissolution of sludge, thus effectively inerting waste while limiting radionuclide release.

Implementation Method 1

a step consisting of bringing said waste in the form of sludge into contact with a dry cementitious mixture

Methodology Applied
Scientific EffectCement hydration: Chemical Bonding

Implementation Method 2

trapping mineral and organic pollutants by precipitation in the form of insoluble compounds

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

trapping mineral and organic pollutants by precipitation in the form of insoluble compounds

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Implementation Method 4

effectively inerting waste while limiting radionuclide release

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP2526073B1Method for preparing a composite material from waste and resulting material
Publication Date: 2016.04.06 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2526073B1 patent drawingFigure 1A~1B
  • EP2526073B1 patent drawingFigure 2~3
  • EP2526073B1 patent drawingFigure 4~5

AI summary

The present invention relates to a method for preparing a composite material from waste in the form of sludge, including a step of place said waste in the form of sludge in contact with a dry cement mixture. The present invention also relates to the resulting composite material and to the use of such a method for processing waste and/or rendering waste inert, in particular industrial and/or radioactive waste.