Continuous Smelting Reduction for Vortex-Assisted Iron and Slag Discharge
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Solution Overview
Problem
Existing iron making technologies face challenges in achieving continuous smelting reduction, with low utilization of reducing agents like pulverized coal, environmental pollution from unreacted dust, and the need for intermittent operations due to open molten iron and slag outlets.
Innovation Solution
A method involving continuous feeding, reduction, and metal slag separation, where iron-containing mineral powder is mixed with a reducing agent and slag former, heated to form a molten pool, and stirred to create a vortex for continuous discharge of molten iron and slag, using a screw feeder and paddle system to manage the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If pulverized coal is blown into a blast furnace from a tuyere, then the reducing agent can be supplied for iron making, but the low density causes large amount of pulverized coal to float on the surface and cannot react well with iron oxides
Solution Approach 1:
The patent changes the physical state parameter of the reducing agent from pulverized coal (low density) to iron-containing mineral powder mixed with reductant (controllable particle size and density). This parameter change allows the mixture to sink and react effectively with iron oxides in the molten pool, resolving the floating issue while maintaining reducing agent supply
Solution Approach 2:
The patent creates a composite material system by mixing iron-containing mineral powder with reductant and slag former in specific proportions. This composite approach combines the benefits of different materials to achieve both effective reduction reaction and proper settling behavior in the molten pool
2Productivity
If pulverized coal is used as reducing agent, then iron making can proceed, but the utilization rate of pulverized coal is low and generated flue gas contains large amount of unreacted dust
Solution Approach 1:
The patent changes the particle size parameter of the reducing agent from coarse pulverized coal to fine iron-containing mineral powder with controlled particle size distribution. This parameter change increases the specific surface area and improves reaction efficiency, allowing near-complete utilization of the reducing agent and minimizing unreacted dust in flue gas
Solution Approach 2:
The patent converts the previously harmful unreacted dust into beneficial fine powder that can fully react. By using fine iron-containing mineral powder mixed with reductant, the system transforms what was waste (unreacted dust) into effective reducing material, eliminating environmental pollution while maintaining productivity
3Ease of operation
If open molten iron outlet and slag outlet are used, then molten products can be discharged, but the outlets need to be blocked during feeding reduction refining process resulting in only intermittent operation
Solution Approach 1:
The patent implements continuous operation by maintaining covered outlets throughout the entire process. The reducing furnace continuously feeds mixed powder materials, performs reduction, and discharges molten iron and slag through covered outlets without interruption, eliminating the intermittent stop-start operation of previous systems
Solution Approach 2:
The patent uses a seal cover (flexible barrier) to close the molten iron outlet and slag outlet during the feeding and reduction process. This seal cover allows the system to maintain outlet closure while enabling continuous operation, as the cover can be maintained in place throughout the entire cycle without requiring opening and closing operations
4Productivity
If pellet sintering technology is used, then iron making can proceed, but the process complexity increases and cost rises
Solution Approach 1:
The patent extracts and eliminates the pellet sintering step from the traditional iron making process. By directly feeding mixed powder materials (iron-containing mineral powder, reductant, and slag former) into the reducing furnace, the system removes the intermediate pelletizing and sintering operations, significantly simplifying the process while maintaining iron making capacity
Solution Approach 2:
The patent performs preliminary mixing of iron-containing mineral powder, reductant, and slag former in the correct proportions before feeding into the reducing furnace. This preliminary preparation ensures proper reaction conditions are established, eliminating the need for subsequent pellet sintering to create suitable reactants, thus simplifying the overall process
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 method achieves stable continuous reduction operations, increases reducing agent utilization, reduces environmental impact, and allows for the use of low-grade iron ores and industrial waste, with efficient separation and discharge of molten products for further processing.
Implementation Method 1
a continuous feeding system which is a device capable of metering conveyed materials, and selects a screw feeder or a feeding bin with a metering pump
Implementation Method 2
stirred to create a vortex for continuous discharge of molten iron and slag
Implementation Method 3
Method for iron making by continuous smelting reduction
Implementation Method 4
heated to form a molten pool
Data Source
AI summary
A method for iron making by continuous smelting reduction, including: (1) mixing iron-containing mineral powder with a reducing agent and a slag former to obtain mixed powder materials; (2) placing furnace startup materials in a reducing furnace, and heating the furnace startup materials to be in a molten state to form a furnace startup molten pool; (3) conveying the mixed powder materials into the reducing furnace, and blowing oxidizing combustibles into the reducing furnace for heating; (4) performing stirring by a stirring paddle to form a molten slag layer and a molten iron layer; and performing stirring so that a vortex is formed in the molten slag layer; and (5) adjusting a position of the stirring paddle, a stirring speed and a conveying quantity of the mixed powder materials to enable the molten iron and the reduced molten slag to be respectively continuously discharged.