Magnesium Titanate Sintering Aid for Chromium Oxide Refractories
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sintering refractory materials with high chromium oxide content is challenging due to the formation of volatile chromium oxides with high vapor pressure, requiring precise control of firing conditions and the use of sintering aids, which can be costly and inefficient, especially when attempting to achieve high density and high chromium oxide content.
Innovation Solution
Incorporating magnesium titanate as a sintering aid in the refractory blend, which suppresses the formation of volatile chromium oxides and reacts with chromium oxide to form stable phases like magnesium chromite and magnesium oxide, allowing for densification and achieving high sintered chromium oxide content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional sintering aids (zirconium dioxide, titanium dioxide, magnesium oxide, or silicates) are used in the blend, then sintering of chromium oxide is facilitated, but it is still very difficult to fire the blend to a refractory material or sinter the chromium oxide to sufficient density
Solution Approach 1:
The invention uses a composite sintering aid system comprising magnesium titanate and/or magnesium chromite in combination with chromium oxide. This composite approach creates synergistic effects where magnesium titanate reacts with chromium oxide to form magnesium chromite and other stable phases, enabling both facilitated sintering and achievement of high density simultaneously. The composite material system allows for optimized interaction between components during firing.
Solution Approach 2:
The invention changes the chemical composition parameters of the sintering aid from conventional single-oxide aids to magnesium titanate-based compounds with specific stoichiometric ratios. By adjusting the magnesium-to-titanium ratio and the amount of magnesium chromite present, the system optimizes both the ease of sintering and the final density, transforming the sintering aid into a multi-functional additive that addresses both contradictions.
2Reliability
If high chromium oxide content is used to increase corrosion resistance, then corrosion resistance is improved, but volatile chromium oxides with high vapor pressure are formed during firing, making densification difficult
Solution Approach 1:
The invention converts the harmful volatility of chromium oxides into a beneficial reaction process. Magnesium titanate reacts with volatile chromium oxide species during firing to form stable magnesium chromite and other non-volatile compounds. This transformation turns the harmful vapor pressure issue into a driving force for forming stable, corrosion-resistant phases in the final material.
Solution Approach 2:
Magnesium titanate acts as an intermediary substance that mediates between the volatile chromium oxide and the final stable product. During firing, magnesium titanate reacts with chromium oxide to form magnesium chromite and titanium dioxide, serving as a chemical bridge that transforms volatile species into stable phases, thereby suppressing harmful volatility while maintaining high chromium content.
3Object-generated harmful factors
If precise control of firing conditions and partial pressure of oxygen is implemented to manage volatile chromium oxides, then formation of volatile chromium oxides is controlled, but the process complexity and cost increase
Solution Approach 1:
The magnesium titanate-based sintering aid system performs self-regulation during the firing process. The reaction between magnesium titanate and chromium oxide occurs spontaneously under standard firing conditions, automatically suppressing volatility without requiring external control mechanisms. The system self-adjusts the chemical reactions to minimize harmful emissions while achieving the desired density and corrosion resistance.
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 use of magnesium titanate enables the production of very dense sintered refractory ceramic materials with high chromium oxide content, exceeding 80% by weight, which was previously difficult to achieve with existing techniques, resulting in improved corrosion resistance and reduced production costs.
Implementation Method 1
reacts with chromium oxide to form stable phases like magnesium chromite and magnesium oxide
Implementation Method 2
enables the production of very dense sintered refractory ceramic materials with high chromium oxide content
Data Source
AI summary
The invention relates to a blend for the production of a sintered refractory material containing chromium oxide, a sintered refractory material containing chromium oxide, a method for the manufacture of a sintered refractory material containing chromium oxide and to a use of magnesium titanate.