Refractory Backfill Composition for Molten Aluminum Corrosion Resistance

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Solution Overview

Problem

Existing refractory products used in the aluminum industry face challenges with corrosion resistance and infiltration resistance when exposed to liquid aluminum and aluminum alloys, particularly at high temperatures, leading to structural degradation and erosion.

Innovation Solution

A dry substance mixture comprising coarse- and fine-grained refractory aggregate materials with specific anti-corrosion agents, including mealy phosphates with controlled softening points and Al2O3 granular material, enhances corrosion resistance and infiltration resistance by forming protective layers and densifying the microstructure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional refractory products are used in contact with liquid aluminum and aluminum alloys, then they provide basic structural support, but they exhibit poor corrosion resistance and infiltration resistance leading to structural degradation

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidstructural degradation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a composite refractory material system consisting of multiple aggregate fractions (coarse-grained >2mm, fine-grained 0.2-2mm, and meal-grained ≤0.2mm) combined with specific binders and anti-corrosion additives. This multi-component composite structure creates a denser, more corrosion-resistant microstructure that resists liquid aluminum infiltration while maintaining structural integrity at high temperatures.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention applies different grain size distributions and material compositions to specific regions of the refractory product. The anti-corrosion agents and specific aggregate combinations are concentrated in zones most exposed to liquid aluminum contact, providing localized enhanced protection where it is most needed while optimizing overall structural performance.

Inventive Principle:

Principle #3Local quality

2Temperature

If refractory products are exposed to high temperatures in contact with liquid aluminum, then they maintain structural support, but they suffer from erosion and infiltration leading to reduced service life

Engineering Contradiction:

Improvehigh temperature resistanceVSAvoidservice life

Core Design Contradiction:

TemperatureVSDuration of action of stationary object

Solution Approach 1:

The patent modifies key material parameters including aggregate grain size distribution (using three distinct size ranges), chemical composition (specific Al2O3 content ≥70%, CaO content controlled at 5-15%), and binder characteristics. These parameter optimizations enable the refractory to maintain structural stability at temperatures up to 1200°C while resisting thermal cycling damage and extending service life.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The refractory mixture is pre-formulated with anti-corrosion agents and optimized aggregate distributions before installation. This preliminary preparation ensures that the protective microstructure is already in place before the refractory contacts liquid aluminum, preventing initial infiltration and erosion that would otherwise occur during early service periods.

Inventive Principle:

Principle #10Preliminary action

3Temperature

If refractory concrete is used to line industrial furnaces and transport systems, then it provides thermal protection, but it experiences corrosion and infiltration from molten aluminum reducing effectiveness

Engineering Contradiction:

Improvethermal protectionVSAvoidcorrosion resistance

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent introduces anti-corrosion agents and specifically formulated binder systems that act as intermediary protective layers between the refractory concrete matrix and the corrosive liquid aluminum environment. These intermediary components preferentially react with or resist aluminum infiltration, protecting the underlying refractory structure while maintaining thermal protection functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 mixture provides excellent corrosion resistance and infiltration resistance over a wide temperature range, maintaining structural integrity and reducing erosion in contact with liquid aluminum and alloys.

Implementation Method 1

at least one anti-corrosion agent to improve corrosion resistance to molten aluminum

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

for the production of a coarse ceramic, refractory, non-basic, shaped or unshaped product

Methodology Applied

Scientific EffectSintering: Sintering

Data Source

PatentUS12486201B2Dry material mixture for a backfill, preferably a refractory concrete backfill, for producing a heavy-clay refractory non-basic product, refractory concrete backfill and such a product, method for producing same, lining, and industrial furnace, channel transport system or mobile transport vessel

Publication Date: 2025.12.02 REFRATECHNIK HLDG GMBH

AI summary

A dry substance mixture for a batch, preferably a refractory batch, for the production of a coarse ceramic, refractory, non-basic, shaped or unshaped product, such a refractory batch, such a product as well as a method for its production and a lining of an industrial furnace for the aluminum industry, and such an industrial furnace as well as a lining of a launder transport system or a mobile transport vessel for the aluminum industry, and such a launder transport system and such a transport vessel.