Blast Furnace Ore Layer Segmentation for CO2 Conversion

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Solution Overview

Problem

The challenge is to effectively increase the concentration of carbon iron composite in regions with high CO2 concentration within a blast furnace to enhance the conversion of CO2 to CO gas, which is hindered by uniform mixing of the composite throughout the ore layer, leading to inefficient reduction of ore.

Innovation Solution

A method involving the strategic division of ore into batches and varying the carbon iron composite mixing ratio in the radius and height directions to concentrate it in regions with high CO2 concentrations, specifically positioning it in ore layers with higher thickness ratios or upper layers to maximize its reactivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If carbon iron composite is uniformly mixed throughout the ore layer, then the mixing operation is simple, but the concentration of carbon iron composite in high CO2 regions is insufficient, reducing the effectiveness of CO2 conversion to CO

Engineering Contradiction:
Improvemixing operation simplicityVSAvoidCO2 conversion efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent applies local quality by varying the mixing ratio of carbon iron composite in different regions of the ore layer. Specifically, the carbon iron composite is mixed at a higher ratio in upper ore layers where CO2 concentration is higher, and at a lower ratio in lower ore layers. This regional variation in composition optimizes the local chemical reaction conditions to maximize CO2 conversion efficiency while maintaining operational feasibility.

Inventive Principle:
Principle #3Local quality

2Productivity

If carbon iron composite concentration is increased in high CO2 regions, then CO2 to CO conversion is accelerated, but the charging and mixing process becomes more complex

Engineering Contradiction:
Improveore reduction rateVSAvoidcharging process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the ore layer charging process into multiple stages or zones. The ore layer is divided into upper and lower portions, with carbon iron composite added selectively to the upper portion. This segmentation of the charging process allows for optimized material distribution without requiring overly complex mixing equipment, as the stratified charging approach can be implemented through controlled material feeding sequences.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the ore layer thickness ratio is varied in the furnace radius direction, then gas flow distribution is improved, but the charging process requires more precise control

Engineering Contradiction:
Improvegas flow efficiencyVSAvoidcharging control difficulty
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies local quality by varying the ore layer thickness ratio in different radial positions within the furnace. In regions where gas flow is restricted, the ore layer thickness is adjusted to create more permeable zones. This local adjustment of physical parameters optimizes gas distribution and flow patterns throughout the furnace cross-section, improving overall gas flow efficiency while accommodating the inherent complexity of three-dimensional charging control.

Inventive Principle:
Principle #3Local quality

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 increases the carbon iron composite concentration in high CO2 regions, accelerating ore reduction and reducing the reducing agent rate, thereby improving the blast furnace's operational efficiency.

Implementation Method 1

The reaction of formula (a) is a reaction through which CO2 generated by reduction of ore shown in formula (b) below is recycled into CO gas having a reducing ability. CO2 + C → 2CO

Methodology Applied
Scientific EffectGasification reaction: Chemical Transport Reactions

Implementation Method 2

FeO + CO → Fe + CO2

Methodology Applied
Scientific EffectReduction reaction: Reduction

Data Source

PatentEP2840152B1Blast furnace operation method using ferrocoke
Publication Date: 2018.10.17 JFE STEEL CORP
  • EP2840152B1 patent drawingFigure 1
  • EP2840152B1 patent drawingFigure 2
  • EP2840152B1 patent drawingFigure 3

AI summary

In a method for operating a blast furnace by forming a coke layer 1 and an ore layer in a blast furnace, an ore layer is formed as ore layer 2 and 3 of a plurality of batches including two or more batches, the carbon iron composite is mixed into the ore layer of at least one batch among the plurality of batches but not into at least another batch. In operation during which an ore layer thickness ratio, i.e., ore layer thickness/(ore layer thickness + coke layer thickness), is varied in a furnace radius direction, the furnace radius direction position preferably varies among ore layers of the plurality of batches and the carbon iron composite is preferably mixed into an ore layer 2 of a batch at a furnace radius direction position where the ore layer thickness ratio is relatively large.