Carbon-Coated Granules for Sintered Ore Production

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing sintered ore in blast furnaces face challenges such as poor wettability of carbon materials, high production costs due to oxidation treatments, and restricted production volume, as well as issues with the strength and stability of carbon material-containing agglomerated ores when using metallic iron-containing iron oxide powders.

Innovation Solution

The use of carbon material-containing granulated particles with a small lump coke core and an outer layer of iron ore powder and CaO-containing material, where the iron ore powder has a particle size of 10-1000 µm and a melting point between 1200°C and 1500°C, allowing for stable production of sintered ore without the need for metallic iron-containing iron oxide powders and reducing production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If metallic iron-containing iron oxide powders are used to coat carbon material cores, then the carbon material can be closely arranged with iron-containing material, but the production cost increases due to oxidation treatments and production volume is restricted

Engineering Contradiction:
Improveproduction volume of sintered oreVSAvoidproduction cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The invention changes the material parameters by replacing metallic iron-containing iron oxide powders with ordinary iron ore powders having specific particle size (10-1000 µm) and melting point (1200-1500°C) characteristics. This parameter change eliminates the need for oxidation treatments while maintaining the functional requirements for carbon material arrangement and sintering performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention substitutes expensive metallic iron-containing powders with cheaper ordinary iron ore powders. The iron ore powder serves as a disposable coating material that fulfills its function during sintering and does not require recovery or reuse, thereby reducing production costs while maintaining productivity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Productivity

If iron ore powder with small particle size is used to coat carbon material, then the carbon material and iron-containing material are closely arranged, but the outer layer strength decreases

Engineering Contradiction:
Improveiron-making reaction rateVSAvoidouter layer strength of granulated particles
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The invention optimizes the particle size parameter of iron ore powder to the specific range of 10-1000 µm. This parameter range achieves an optimal balance between close arrangement for high reaction rates and sufficient outer layer strength to maintain particle integrity during handling and charging.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure consisting of a carbon material core coated with iron ore powder outer layer. This composite granulated particle combines the reactive carbon core with the protective and structurally sound iron ore coating, achieving both high reaction rates and adequate strength.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If the iron ore powder melting point is below 1200°C, then the coating process is easier, but the granulated particles lack strength and powder excessively during charging

Engineering Contradiction:
Improvecoating process easeVSAvoidparticle strength during charging
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention sets the melting point parameter of iron ore powder within the specific range of 1200-1500°C. This parameter ensures that the outer layer maintains sufficient strength during charging operations while still being compatible with the sintering process, preventing excessive powdering.

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

This approach enables the production of sintered ore with improved strength and efficiency, allowing for increased iron-making reaction rates, reduced furnace temperatures, and lower production costs, while avoiding the limitations of previous methods.

Implementation Method 1

adding CaO-containing material of a melting point conditioner

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

burning the carbon material contained in the quasi particles to perform sintering

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 3

burning the carbon material contained in the quasi particles to perform sintering

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

reduction reaction (exothermic reaction) at the side of the iron source

Methodology Applied
Scientific EffectReduction reaction: Reduction

Implementation Method 5

gasification reaction (endothermic reaction) at the side of the carbon material

Methodology Applied
Scientific EffectGasification reaction: Chemical Bonding

Data Source

PatentEP3020834B1Carbon material-containing granulated particles in production of sintered ore, method for producing the same and method for producing sintered ore
Publication Date: 2017.11.01 JFE STEEL CORP
  • EP3020834B1 patent drawingFigure 1~2(b)
  • EP3020834B1 patent drawingFigure 3(a)~4
  • EP3020834B1 patent drawingFigure 5~6

AI summary

Small lump coke having a particle size of 3-15 mm as a carbon material core, iron ore powder having a particle size of not more than 250 µm to be an outer layer and CaO-containing raw material are charged into a pelletizer and mixed and granulated therein to obtain quasi particles formed by coating the carbon material core with the outer layer (carbon material-containing granulated particles). Also, a sintering raw material obtained by mixing the carbon material-containing granulated particles with normal granulated particles is charged onto a pallet of a sintering machine to form a charged layer, and a sintered ore (carbon material-containing sintered ore) is produced by sintering heat of a carbon material included in the normal granulated particles. Thus, the carbon material-containing sintered ore having the iron-containing raw material and the carbon material arranged close to each other is obtained without using metallic iron-containing iron oxide powder such as iron-making dust, mill scale or the like and without restricting production volume.