DRI Pig Iron Desulphurization Inside an Electrical Smelting Furnace
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current steel production methods, particularly the BF-BOF route and direct reduction methods, result in significant CO2 emissions and require heavy investments for impurity removal in liquid steel, limiting the production of high-quality steel grades.
Innovation Solution
A method and apparatus for manufacturing pig iron in an electrical smelting furnace using DRI products, involving melting DRI to form a pig iron layer with a slag layer and injecting a desulphurizing reagent directly into the pig iron layer, followed by transferring the pig iron to a converter for decarburization to produce low-carbon liquid steel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If DRI product is used in classical electrical furnaces with ferrous scraps, then CO2 emissions are reduced, but impurities in the liquid steel increase requiring further processing
Solution Approach 1:
The invention performs desulphurization in advance during the pig iron production stage by injecting desulphurizing reagents directly into the pig iron layer in the electrical smelting furnace. This preliminary action removes sulphur impurities before the steelmaking process, preventing them from contaminating the final steel product and eliminating the need for additional liquid steel treatment facilities.
2Manufacturing precision
If additional liquid steel treatment tools are installed to process impurities, then steel quality improves, but investment costs increase
Solution Approach 1:
The invention extracts the desulphurization function from the traditional post-melting treatment stage and relocates it to the pig iron production stage. By injecting desulphurizing reagents (such as calcium carbide, calcium oxide, or calcium carbonate) directly into the pig iron layer during electrical smelting, the process removes sulphur impurities early, eliminating the need for complex and expensive liquid steel treatment facilities while maintaining high steel quality.
3Productivity
If desulphurizing reagent is injected directly in pig iron layer, then sulphur removal efficiency increases, but process complexity increases
Solution Approach 1:
The invention uses a lance as an intermediary device to inject desulphurizing reagents directly into the pig iron layer through the slag layer. This intermediary mechanism enables precise delivery of reagents to the pig iron layer without requiring complex processing equipment, as the lance system leverages the existing furnace structure and the natural layering of molten materials to achieve efficient desulphurization.
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
Minimizes environmental impact by reducing CO2 emissions and eliminates the need for additional desulphurization and decarburization steps, enabling the production of high-quality steel with reduced investment costs.
Implementation Method 1
melting said DRI product to form a pig iron layer topped by a slag layer
Implementation Method 2
injecting a desulphurizing reagent material directly in said pig iron layer
Implementation Method 3
the carbon content of said pig iron is then lowered to a value below 2.1 percent in weight by oxygen blowing, so as to obtain liquid steel
Data Source
AI summary
A method for manufacturing pig iron in an electrical smelting furnace including a vessel, the method including the following successive steps: loading DRI product in the vessel, melting the DRI product to form a pig iron layer topped by a slag layer, and injecting a desulphurizing reagent directly in the pig iron layer. It also deals with the manufacturing of steel from the pig iron and the associated electrical smelting furnace.