Slag Cleaning via Composition-Adaptive Gas Injection
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Solution Overview
Problem
Existing methods for cleaning slag from non-ferrous or ferrous alloy manufacturing processes do not adequately reduce metal content to meet modern environmental protection standards, particularly when toxic heavy metals are present.
Innovation Solution
The method involves analyzing the composition of residual slag and introducing a selected gaseous medium to induce metallurgical-physical reactions, converting the slag into a second residual slag with reduced metal content, which is then treated in a second settling furnace to further separate metal components, resulting in a third residual slag with less than 0.5% metal content by weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional slag cleaning methods are used, then the process is simple and quick, but the metal content in the slag remains high (≥ 0.5 wt.%) and does not meet environmental protection requirements
Solution Approach 1:
The slag cleaning process is divided into multiple stages: first residual slag treatment in the settling furnace, then secondary treatment in the ladle with gaseous medium injection, and finally third residual slag production. This segmentation allows progressive metal content reduction from ≥0.5 wt.% to <0.5 wt.% while managing process complexity through modular steps.
Solution Approach 2:
A gaseous medium is introduced as an intermediary substance in the ladle to facilitate metallurgical-physical reactions with the first residual slag. This mediator enables the conversion of harmful metal-containing slag into cleaner third residual slag while separating recoverable metal alloys, thus reducing environmental harm without requiring direct complex treatment of the original slag.
2Manufacturing precision
If the slag is treated longer in the settling furnace, then more metal settles out, but the process time increases and productivity decreases
Solution Approach 1:
The gaseous medium is injected into the ladle before the slag enters the second settling furnace, performing preliminary metallurgical-physical reactions that pre-reduce metal content and prepare the slag for more efficient settling. This preliminary action reduces the residence time needed in subsequent settling stages, thereby increasing overall productivity while achieving precise metal content reduction.
Solution Approach 2:
The process changes physical parameters by introducing a gaseous medium that alters the chemical and physical state of the slag in the ladle. This parameter change accelerates metal separation kinetics, allowing faster settling times in the second furnace while achieving lower final metal content (<0.5 wt.%), thus resolving the trade-off between precision and productivity.
3Manufacturing precision
If a gaseous medium is introduced into the slag, then metal content is reduced through metallurgical-physical reactions, but the device complexity and operational complexity increase
Solution Approach 1:
The ladle serves multiple functions: it receives first residual slag from the settling furnace, acts as a reaction vessel for gaseous medium injection and metallurgical-physical reactions, and serves as a transport container to the second settling furnace. This multi-functionality consolidates several operations into one device, reducing operational complexity despite the added chemical treatment step.
Solution Approach 2:
The gaseous medium acts as a controllable intermediary that can be selectively introduced based on the analyzed composition of the first residual slag. This allows precise control over the metallurgical-physical reactions to achieve target metal content reduction, while the mediatory role of the gas simplifies the overall process compared to direct solid-liquid or liquid-liquid treatments.
4Adaptability or versatility
If the slag composition is analyzed before treatment, then the appropriate gaseous medium can be selected, but the process time increases due to analysis duration
Solution Approach 1:
The slag composition analysis is performed in advance, before the gaseous medium injection and settling processes. This preliminary action provides the necessary compositional data to select the appropriate gaseous medium, allowing subsequent treatment steps to proceed without interruption. The analysis time is effectively parallelized with material preparation and transport operations, minimizing its impact on overall process time.
Solution Approach 2:
The composition analysis results provide feedback that determines the selection and parameters of the gaseous medium to be introduced into the ladle. This feedback loop enables adaptive treatment tailored to the specific slag composition, ensuring optimal metal content reduction while the timing is managed by coordinating analysis completion with subsequent treatment initiation.
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 process significantly reduces the environmental harm of the slag by separating undesired components, making the final slag disposal more environmentally friendly and compliant with modern regulations.
Implementation Method 1
at least one gaseous medium is introduced onto or into the first residual slag for a metallurgical-physical reaction to form a second residual slag
Implementation Method 2
the second residual slag is poured from the ladle into the second settling furnace, where it remains for a predetermined residence time and settles, and during the residence time the second residual slag decomposes into a second metal alloy and a third residual slag, wherein the second metal alloy settles at the bottom of the second settling furnace
Data Source
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AI summary
The invention relates to a method and to a device for cleaning slag from a production process for non-ferrous (NE) metal or iron alloy. For this purpose, the slag arising in said production processes is typically continuously conducted into a settling furnace and is heated and metallurgically treated there. In order to improve the environmental friendliness of the first residual slag resulting from this treatment, the first residual slag, according to the invention, is tapped into a ladle (120), the composition of the first residual slag is analyzed, and finally, at least one gaseous medium is introduced onto or into the first residual slag for metallurgical-physical reaction to form a second residual slag in the ladle. The gaseous medium is selected in accordance with the analyzed individual composition of the first residual slag. In addition, the slag can optionally be heated. Thereafter, transport into a second settling furnace (140) and settling of the metal particles finely distributed in the slag in said second settling furnace are optionally performed.