Chromium Oxide Refractory Powder for Molten Glass Corrosion

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Solution Overview

Problem

There is a need for refractory products based on chromium oxide with high resistance to thermal shock and corrosion, particularly when in contact with molten glass, as existing products face challenges with mechanical and thermal stresses, and corrosion resistance in such environments.

Innovation Solution

A powder with a specific chemical composition comprising Cr2O3, Al2O3, ZrO2, MgO, Fe2O3, SiO2, and TiO2, with a median circularity greater than 0.87 and at least 90% of particles larger than 100 µm, providing excellent corrosion resistance and thermal shock resistance when sintered.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional refractory products are used in contact with molten glass, then they provide basic corrosion protection, but they suffer from poor thermal shock resistance and reduced mechanical strength

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidmechanical strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the particle size parameters by using exclusively large particles (>100 μm, preferably >200 μm) with high circularity (>0.87), and controls the chemical composition parameters (Cr2O3: 10-50%, Al2O3: 40-80%, SiO2: 5-20%) to achieve both corrosion resistance and thermal shock resistance in the sintered product

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite refractory material combining chromium oxide (Cr2O3) and alumina (Al2O3) in specific proportions, where Cr2O3 provides corrosion resistance to molten glass and Al2O3 provides mechanical strength and thermal shock resistance, forming a synergistic composite structure

Inventive Principle:
Principle #40Composite materials

2Temperature

If refractory products are exposed to thermal cycling, then they experience repeated temperature changes, but this generates cracks that reduce mechanical resistance

Engineering Contradiction:
Improvethermal cycling resistanceVSAvoidmechanical resistance
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent uses large particle sizes (>100 μm) with high circularity (>0.87) to reduce stress concentration points, and controls the chemical composition (Cr2O3: 10-50%, Al2O3: 40-80%) to achieve low thermal expansion and high thermal shock resistance, preventing crack formation during thermal cycling

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses particles with uniform large size distribution (>100 μm) and high circularity (>0.87) to create a homogeneous microstructure that minimizes stress concentrations and prevents crack initiation during thermal cycling

Inventive Principle:
Principle #33Homogeneity

3Ease of manufacture

If conventional powder compositions are used, then they can be manufactured easily, but they do not achieve high corrosion resistance in molten glass environments

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidcorrosion resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters to Cr2O3: 10-50%, Al2O3: 40-80%, SiO2: 5-20% and particle size parameters (>100 μm, circularity >0.87) to achieve high corrosion resistance to molten glass while maintaining ease of manufacture through standard sintering processes

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

The sintered product exhibits improved corrosion resistance and thermal shock resistance, maintaining performance when exposed to molten glass, extending the lifespan of refractory products.

Implementation Method 1

refractory products based on chromium oxide with high resistance to thermal shock and corrosion, particularly when in contact with molten glass

Methodology Applied
Scientific EffectChemical stability:

Implementation Method 2

exhibits improved corrosion resistance and thermal shock resistance, maintaining performance when exposed to molten glass

Methodology Applied
Scientific EffectThermal shock resistance: Thermal Shock

Data Source

PatentEP2603466B1Powder on the basis of chromic oxide
Publication Date: 2018.09.12 SAINT GOBAIN CENT DE RES & DEVS & DETUD EUROEN
  • EP2603466B1 patent drawingFigure 1a~1b
  • EP2603466B1 patent drawingFigure 2
  • EP2603466B1 patent drawing

AI summary

The invention relates to a particulate powder, said powder having a median circularity of greater than 0.87 wt % and less than 9.0 wt % of particles having a size greater than 100 µm. The powder and at least 80 wt % of the particles have a chemical composition such that, in wt % on the basis of the oxides and for a total of 100%: Cr2O3 + Al2O3 + ZrO2 + MgO + Fe2O3 + SiO2 + TiO2 = 90%; Cr2O3 + Al2O3 + MgO = 60%; Cr2O3 = 9%; 20% = SiO2 = 0,5%; and other oxides: = 10%. The invention can be used for a glass furnace.