Reduced Iron Pellet Composition for Clustering Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for producing reduced iron in vertical shaft furnaces face challenges with iron ore pellet clustering, which reduces productivity and requires inefficient temperature control to suppress clustering, and existing solutions like adding impurities or focusing on iron grade are not comprehensive enough.

Innovation Solution

A method that involves producing iron ore pellets with specific oxide and oxide content ratios (SiO2, Al2O3, CaO, MgO, and FeO) and setting metallization rates to satisfy the clustering index (SiO2+Al2O3+CaO+MgO+FeO)/M.Fe ≥ 0.15, ensuring optimal conditions for reducing gas temperature and metallization rates to suppress clustering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the maximum temperature in the furnace is controlled to suppress clustering, then clustering is suppressed, but the reduction rate decreases due to insufficient temperature

Engineering Contradiction:

ImproveclusteringVSAvoidreduction rate

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent changes the chemical composition parameters of the iron ore pellets by controlling the ratios of SiO2, Al2O3, CaO, MgO, FeO, and M.Fe. Specifically, it establishes a composition range where (SiO2+Al2O3+CaO+MgO+FeO)/M.Fe is within a specific range, which fundamentally alters the material properties to suppress clustering without requiring temperature restriction

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by carefully combining multiple oxide components (SiO2, Al2O3, CaO, MgO, FeO) with metallic iron (M.Fe) in specific proportions. This composite structure of reduced iron pellets provides both the desired clustering suppression and high-temperature stability, resolving the contradiction between suppressing clustering and maintaining high reduction rate

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If impurities are added to suppress clustering, then clustering is suppressed, but electric power consumption increases due to increased slag ratio

Engineering Contradiction:

ImproveclusteringVSAvoidelectric power consumption

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

Instead of adding external impurities, the patent changes the inherent composition parameters of the iron ore pellets by controlling the ratios of natural oxides (SiO2, Al2O3, CaO, MgO, FeO) and metallic iron content. This approach suppresses clustering through optimized material composition rather than adding unnecessary impurities, thereby avoiding increased slag ratio and electric power consumption

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If focus is placed only on iron grade to control clustering, then iron grade is optimized, but other factors like metallization rate and basicity are overlooked

Engineering Contradiction:

Improveiron gradeVSAvoidcomprehensive control of clustering

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent establishes a comprehensive set of composition parameters including SiO2, Al2O3, CaO, MgO, FeO, and M.Fe content, and defines their interrelationships through the ratio (SiO2+Al2O3+CaO+MgO+FeO)/M.Fe. This multi-parameter approach ensures comprehensive control of clustering by considering all relevant material properties simultaneously, rather than focusing on iron grade alone

Inventive Principle:

Principle #35Parameter changes

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 method effectively suppresses iron ore pellet clustering, allowing for higher furnace temperatures and improved productivity by adjusting raw material composition and process parameters, thereby enhancing reduction efficiency.

Implementation Method 1

directly reducing the iron ore pellets via a reducing gas to obtain reduced iron pellets

Methodology Applied

Scientific EffectReduction: Reduction

Data Source

PatentUS20260071287A1Method of producing reduced iron

Publication Date: 2026.03.12 JFE STEEL CORP

AI summary

Provided is a method of producing reduced iron that can suppress clustering of iron ore pellets. The method of producing reduced iron ore includes: a pellet production process of mixing iron ore powder, binder, and auxiliary material, granulating to obtain green pellets, and then firing the green pellets to obtain iron ore pellets; and a reduction process of charging the iron ore pellets into a vertical shaft furnace and directly reducing the iron ore pellets via a reducing gas to obtain reduced iron pellets. Raw material of the iron ore powder includes iron ore having a composition in which total Fe content is 63 mass % or less and the sum of SiO2 and Al2O3 is 4 mass % or more. The reduced iron pellets satisfy the following Expression. (SiO2+Al2O3+CaO+MgO+FeO)/M.Fe≥0.15