Lime-Based Refining Agent for Hot Metal Dephosphorization
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Solution Overview
Problem
Current dephosphorization methods using a hot metal ladle are inefficient without CaF2-based flux, resulting in a lower dephosphorization rate compared to methods using CaF2-based flux.
Innovation Solution
A method employing a lime-based refining agent with an Ig-loss value of 4.0% to 35% by mass, containing 60% or more quick lime, is used for dephosphorization treatment, where the refining agent is injected with a carrier gas from an immersed lance, and gaseous oxygen is blown to enhance slag formation and reaction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CaF2-based flux is used to improve slag melting properties, then dephosphorization reactivity is improved, but treatment cost increases and environmental burden increases
Solution Approach 1:
The invention changes the chemical composition parameters of the refining agent by specifying an Ig-loss value of 4.0-35% and quick lime content of 60% or more, which fundamentally alters the slag formation characteristics and enables efficient dephosphorization without CaF2-based flux
Solution Approach 2:
The invention extracts and eliminates the need for CaF2-based flux from the refining process, achieving dephosphorization efficiency improvement through optimized lime-based refining agent composition and properties alone
2Ease of manufacture
If existing converter is used for dephosphorization treatment, then facility cost is reduced, but dephosphorization efficiency is insufficient
Solution Approach 1:
The invention optimizes the parameters of the refining agent (Ig-loss value and quick lime content) to achieve superior dephosphorization efficiency in existing hot metal treating facilities without requiring converter replacement
Solution Approach 2:
The invention enables the existing hot metal treating facility to perform efficient dephosphorization treatment by optimizing the refining agent properties, making the facility self-sufficient without external converter equipment
3Loss of substance
If lime-based refining agent is used without CaF2-based flux, then treatment cost is reduced, but slag melting properties deteriorate
Solution Approach 1:
The invention changes the chemical composition parameters of the refining agent by specifying an Ig-loss value of 4.0-35% and quick lime content of 60% or more, which fundamentally alters the slag formation characteristics and enables efficient dephosphorization without CaF2-based flux
Solution Approach 2:
The invention creates a composite refining agent system combining specific proportions of quick lime with controlled Ig-loss properties, achieving both cost reduction and adequate slag melting properties through the synergistic effect of the optimized composition
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 approach significantly improves dephosphorization efficiency without using CaF2-based flux, reducing slag generation, treatment costs, and foaming, while maintaining effective phosphorus removal from hot metal.
Implementation Method 1
An oxygen source such as gaseous oxygen (an oxygen gas) or a solid iron oxide is supplied as a dephosphorizing agent to the hot metal to oxidize phosphorus in the hot metal with oxygen in the dephosphorizing agent so as to produce phosphorus oxide (P2O5)
Implementation Method 2
the refining agent is injected with a carrier gas from an immersed lance
Implementation Method 3
gaseous oxygen is blown to enhance slag formation and reaction efficiency
Data Source
AI summary
When performing dephosphorization treatment of hot metal by adding a refining agent as a lime source and an oxygen source (dephosphorizing agent(s) and a gaseous oxygen source into the hot metal accommodated in a hot metal holding container, the refining agent used is a refining agent having an Ig-loss value of from 4.0% by mass to 35.0% by mass and including 60% by mass or more of quicklime.