Tempered Refractory Concrete Block Deformation Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Refractory concretes with low alkaline earth oxide content face challenges in corrosion resistance and deformation under load, particularly in blast furnace environments, where they develop internal cracks due to temperature gradients, limiting their lifespan.
Innovation Solution
A refractory concrete composition with a matrix comprising high moisture uptake alumina, silica, and silicon carbide, along with an aggregate of corundum or mullite, and minimal alkaline earth oxides, which provides excellent corrosion resistance and controlled deformability under linear load, achieved through a tempering process at moderate temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If refractory concrete uses low alkaline earth oxide content, then corrosion resistance is improved, but deformation under load becomes difficult to control
Solution Approach 1:
The patent changes the chemical composition parameters by replacing alkaline earth oxides (CaO, MgO) with alumina (Al2O3) as the binding phase. This substitution maintains low alkaline earth oxide content for corrosion resistance while using alumina's thermal expansion characteristics to control deformation under load through adjusted alumina content and particle size distribution.
Solution Approach 2:
The patent creates a composite refractory concrete using alumina particles combined with silicate binders and optional additives. This composite structure achieves both corrosion resistance from the alumina-rich composition and controlled deformation through the synergistic interaction of alumina particles with the silicate matrix, overcoming the limitations of conventional single-phase materials.
2Reliability
If refractory concrete uses low or zero alkaline earth oxides, then resistance to corrosion and oxidation is improved, but internal cracks develop under temperature gradients
Solution Approach 1:
The patent adjusts the alumina content and particle size distribution parameters to control thermal expansion characteristics. By optimizing these parameters, the material maintains low alkaline earth oxide content for corrosion resistance while preventing internal cracks through controlled thermal stress distribution under temperature gradients.
Solution Approach 2:
The patent introduces silicate binders as intermediary substances that mediate between alumina particles. These silicate binders act as a flexible matrix that accommodates thermal expansion differences and prevents crack formation, while still maintaining the low alkaline earth oxide composition required for corrosion resistance.
3Temperature
If carbon blocks are used for furnace lining, then high temperature resistance is achieved, but oxidation resistance and erosion resistance are reduced
Solution Approach 1:
The patent changes the chemical composition from carbon-based to alumina-based materials. This parameter change eliminates the oxidation and erosion problems inherent in carbon blocks while maintaining high temperature resistance through alumina's exceptional thermal stability and chemical inertness at elevated temperatures.
Solution Approach 2:
The patent creates a composite alumina-rich material that combines the high temperature resistance of alumina with improved oxidation and erosion resistance. The silicate binder matrix provides additional protection against erosion while the alumina particles maintain thermal stability, creating a material superior to conventional carbon blocks in oxidizing environments.
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 concrete exhibits remarkable corrosion resistance, linear thermal expansion, and improved mechanical strength, reducing wear and extending the lifespan of furnace linings while maintaining low permeability and porosity.
Implementation Method 1
The matrix contains more than 1.5%, preferably more than 2%, or even more than 5% of hydratable alumina. These contents are higher than those conventionally required when hydratable alumina is used to fluidize a starting charge.
Implementation Method 2
The concrete exhibits linear thermal expansion, and the coefficient of thermal expansion is substantially constant between 20°C and 1600°C.
Data Source
AI summary
Refractory concrete comprising a refractory aggregate bound by a binder matrix, the concrete comprising at least 0.5 % by mass of SiC based on the mass of concrete, the matrix representing between 10 and 60% by weight of the concrete and having a composition such that, in percentages by mass based on the matrix: - Al2O3 + SiO2 > 70%, 50 % > SiO2 > 10%, hydratable Al2O3and/or with a water content greater than 3%: > 1% and alkaline-earth oxides: < 0.2%.