Reduced Iron Recovery via Segmented Magnetic Separation
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Solution Overview
Problem
Conventional reduced iron production methods face challenges in recovering high-purity metallic iron due to slag contamination and inefficient crushing processes, which increase equipment load and waste production.
Innovation Solution
A two-stage magnetic separation process is implemented to separate granular metallic iron from slag, followed by crushing only the second slag containing fine-granular metallic iron, reducing equipment load and enhancing purity recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the whole discharged material is crushed by a crusher to separate metallic iron, then fine-granular metallic iron can be recovered, but granular metallic iron that can be shipped as product is wastefully crushed and equipment load increases
Solution Approach 1:
The discharged material is divided into two streams: granular metallic iron (5mm or more) is separated and shipped as product without crushing, while the remaining material containing fine-granular metallic iron is crushed for further processing. This segmentation prevents waste of recoverable granular iron while enabling recovery of fine-granular iron.
Solution Approach 2:
Granular metallic iron (5mm or more) is extracted from the discharged material before the crushing process using a separator. This extracted granular iron is then shipped as product without undergoing crushing, thereby avoiding unnecessary waste and equipment load.
2Manufacturing precision
If granular metallic iron is separated from slag by magnetic separator, then high-purity granular metallic iron can be recovered, but slag containing fine-granular metallic iron is mixed into the recovered iron group reducing purity
Solution Approach 1:
The discharged material is preliminarily separated into granular metallic iron (5mm or more) and other material before magnetic separation. This preliminary action ensures that only the appropriate fraction undergoes magnetic separation, preventing fine-granular iron-containing slag from contaminating the granular iron product.
Solution Approach 2:
The separation process is segmented into two stages: first separating granular metallic iron (5mm or more) by size, then performing magnetic separation on the remaining material to recover fine-granular metallic iron. This segmentation allows each stage to optimize for its specific function without compromising the other.
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 efficiently recovers high-purity metallic iron while minimizing the load on crushing equipment by effectively separating and processing fine-granular metallic iron from slag, thereby improving the overall recovery rate and reducing waste.
Implementation Method 1
separating at least the granular metallic iron from the first slag by use of a first magnetic separator
Implementation Method 2
separating the second slag from a substance containing the second slag among the first slag containing substance and the granular metallic iron containing substance that are separated from each other by the first magnetic separation step by use of a second magnetic separator
Data Source
AI summary
A reduced iron production method includes: a reduction-step of producing reduced iron by heating an agglomerate containing iron oxide and carbonaceous reducing agent to reduce the iron oxide and solidifying a product produced by melting the reduced iron; a first-magnetic-separation-step of separating, among granular metallic iron, first slag, and second slag containing more fine-granular metallic iron than the first slag that are contained in the product, at least the granular metallic iron from the first slag by use of a first magnetic separator to separate first slag containing substance and a granular metallic iron containing substance from each other; a second-magnetic-separation-step of separating the second slag from the first slag containing substance or the granular metallic iron containing substance by use of a second magnetic separator having attraction force different from attraction force of the first magnetic separator; and a crushing-step of crushing the second slag.