CA3003784C - Method and device for cleaning slag - Google Patents
Method and device for cleaning slag Download PDFInfo
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- CA3003784C CA3003784C CA3003784A CA3003784A CA3003784C CA 3003784 C CA3003784 C CA 3003784C CA 3003784 A CA3003784 A CA 3003784A CA 3003784 A CA3003784 A CA 3003784A CA 3003784 C CA3003784 C CA 3003784C
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- residual slag
- slag
- ladle
- residual
- furnace
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- 239000002893 slag Substances 0.000 title claims abstract description 183
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000004140 cleaning Methods 0.000 title abstract description 3
- 229910001092 metal group alloy Inorganic materials 0.000 claims abstract description 29
- 239000000203 mixture Substances 0.000 claims abstract description 18
- 238000006243 chemical reaction Methods 0.000 claims abstract description 17
- 239000002184 metal Substances 0.000 claims abstract description 17
- 238000004519 manufacturing process Methods 0.000 claims abstract description 12
- 229910000640 Fe alloy Inorganic materials 0.000 claims abstract description 9
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 9
- 238000010079 rubber tapping Methods 0.000 claims description 7
- 238000009847 ladle furnace Methods 0.000 claims description 6
- 238000000354 decomposition reaction Methods 0.000 claims description 5
- 238000007670 refining Methods 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 229910021652 non-ferrous alloy Inorganic materials 0.000 claims description 4
- 239000000654 additive Substances 0.000 claims description 3
- 239000003638 chemical reducing agent Substances 0.000 claims description 3
- 238000005469 granulation Methods 0.000 claims description 3
- 230000003179 granulation Effects 0.000 claims description 3
- 230000000996 additive effect Effects 0.000 claims 2
- 230000007613 environmental effect Effects 0.000 abstract description 5
- 239000002923 metal particle Substances 0.000 abstract description 2
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 abstract 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 229910001385 heavy metal Inorganic materials 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 229910001201 Ne alloy Inorganic materials 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000010926 purge Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000000265 homogenisation Methods 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910001018 Cast iron Inorganic materials 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000004393 prognosis Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/04—Working-up slag
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B3/00—General features in the manufacture of pig-iron
- C21B3/04—Recovery of by-products, e.g. slag
- C21B3/06—Treatment of liquid slag
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B3/00—General features in the manufacture of pig-iron
- C21B3/04—Recovery of by-products, e.g. slag
- C21B3/06—Treatment of liquid slag
- C21B3/10—Slag pots; Slag cars
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2400/00—Treatment of slags originating from iron or steel processes
- C21B2400/02—Physical or chemical treatment of slags
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2400/00—Treatment of slags originating from iron or steel processes
- C21B2400/02—Physical or chemical treatment of slags
- C21B2400/022—Methods of cooling or quenching molten slag
- C21B2400/026—Methods of cooling or quenching molten slag using air, inert gases or removable conductive bodies
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Geology (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Furnace Details (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
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.
Description
Method and Device for Cleaning Slag The invention relates to a method and a device for purifying slag from a nonferrous metal (NE) or iron alloy production process.
Such methods and devices are fundamentally known in the prior art, also for said production processes. For this purpose ¨ as shown in Figure 2 ¨ the slag arising during said production processes is typically continuously conducted via a slag intake channel 112 into a settling furnace 110 and heated and metallurgically treated therein. The treatment is used for the purpose of reducing the metal component still contained in the slag. After the treatment and a corresponding dwell time of the slag in the settling furnace 110, a part of the metals contained in the slag settles as a metal alloy or as a mat, for example, as a copper mat, on the bottom of the settling furnace. The original slag thus decomposes into a metal alloy and a first residual slag.
The metal alloy is poured off via a metal outlet channel 111 of the settling furnace 110, while the first residual slag, which typically floats on the metal alloy, is tapped via a slag outlet channel 114 from the first settling furnace 110.
Document EP 0 627 012 Al discloses a method for desulfurization of iron melts, which is to be applied by means of a slag both for crude iron and also for cast iron.
Document US 4,720,837 A discloses a ladle furnace device for refining molten steel. In this case, liquid steel and a slag former are introduced into the ladle furnace device.
The slag former is slagged by electric arc heating in the ladle, whereby the liquid steel is purified by means of the slag.
The purification of slag from an NE or iron alloy production process traditionally ends at this point. The remaining first residual slag still has a metal component of? 0.5 wt.%, however. This still relatively high metal component no longer meets modem requirements for environmental protection, in particular if toxic heavy metal components are still contained in the first residual slag.
Such methods and devices are fundamentally known in the prior art, also for said production processes. For this purpose ¨ as shown in Figure 2 ¨ the slag arising during said production processes is typically continuously conducted via a slag intake channel 112 into a settling furnace 110 and heated and metallurgically treated therein. The treatment is used for the purpose of reducing the metal component still contained in the slag. After the treatment and a corresponding dwell time of the slag in the settling furnace 110, a part of the metals contained in the slag settles as a metal alloy or as a mat, for example, as a copper mat, on the bottom of the settling furnace. The original slag thus decomposes into a metal alloy and a first residual slag.
The metal alloy is poured off via a metal outlet channel 111 of the settling furnace 110, while the first residual slag, which typically floats on the metal alloy, is tapped via a slag outlet channel 114 from the first settling furnace 110.
Document EP 0 627 012 Al discloses a method for desulfurization of iron melts, which is to be applied by means of a slag both for crude iron and also for cast iron.
Document US 4,720,837 A discloses a ladle furnace device for refining molten steel. In this case, liquid steel and a slag former are introduced into the ladle furnace device.
The slag former is slagged by electric arc heating in the ladle, whereby the liquid steel is purified by means of the slag.
The purification of slag from an NE or iron alloy production process traditionally ends at this point. The remaining first residual slag still has a metal component of? 0.5 wt.%, however. This still relatively high metal component no longer meets modem requirements for environmental protection, in particular if toxic heavy metal components are still contained in the first residual slag.
2 The invention is based on the object of refining a known method and a known device for purifying slag from an NE or iron alloy production process such that the slag is less environmentally harmful, and in particular the metal component in the slag is reduced further.
This object is achieved by the method according to Claim 1. Accordingly, the first residual slag is tapped in a ladle, 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 the metallurgical-physical reaction to form a second residual slag in the ladle, wherein the gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, and the second residual slag is transported in the ladle to a second settling furnace; and pouring off the second residual slag from the ladle into the second settling furnace, and the second residual slag remains for a predetermined dwell time in the second settling furnace and becomes calmer therein, and the decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace and the third residual slag floats on the second metal alloy.
The term "analyze" typically means taking a sample from the slag and analyzing the respective present metallurgical/chemical composition of sample. The analysis can possibly occupy a longer period of time, and therefore the results of the analysis are only available at the end of this period of time. The composition of the sample ascertained on the basis of the analysis then possibly no longer accurately corresponds to the composition of the slag at the end of said period of time, because further material introductions into the slag can have taken place in the meantime. The term "analyzing" in the meaning of the invention therefore possibly furthermore also includes a prognosis, to what extent the composition of the slag will presumably change during the analysis period of time, for example, because of further introductions into the slag which have occurred during this period of time.
The term "ladle furnace" is used here in the meaning of a slag treatment station (STS).
This object is achieved by the method according to Claim 1. Accordingly, the first residual slag is tapped in a ladle, 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 the metallurgical-physical reaction to form a second residual slag in the ladle, wherein the gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, and the second residual slag is transported in the ladle to a second settling furnace; and pouring off the second residual slag from the ladle into the second settling furnace, and the second residual slag remains for a predetermined dwell time in the second settling furnace and becomes calmer therein, and the decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace and the third residual slag floats on the second metal alloy.
The term "analyze" typically means taking a sample from the slag and analyzing the respective present metallurgical/chemical composition of sample. The analysis can possibly occupy a longer period of time, and therefore the results of the analysis are only available at the end of this period of time. The composition of the sample ascertained on the basis of the analysis then possibly no longer accurately corresponds to the composition of the slag at the end of said period of time, because further material introductions into the slag can have taken place in the meantime. The term "analyzing" in the meaning of the invention therefore possibly furthermore also includes a prognosis, to what extent the composition of the slag will presumably change during the analysis period of time, for example, because of further introductions into the slag which have occurred during this period of time.
The term "ladle furnace" is used here in the meaning of a slag treatment station (STS).
3 The gaseous medium in the meaning of the invention is either a gas or a gaseous carrier medium in combination with dusty or fine-grained materials; keyword: carbon injection. The introduction of the gaseous medium is used to intensify an intended (chemical) reaction, for example, for homogenization or better mixing of the slag or for generating turbulence in the slag. The gas or the gaseous carrier medium can be an inert gas or carbon dioxide.
Depending on the individual composition of the first residual slag and according to the desired chemical and/or metallurgical-physical reaction, the at least one gaseous medium is selected such that it causes its agglomeration of metal particles in the slag, a reduction of the slag, and/or an oxidation of the slag.
Due to the claimed ladle treatment, the first residual slag originally supplied to the ladle is converted into a second residual slag. This second residual slag is already less harmful from an environmental aspect than the first residual slag, because a part of the undesired components still contained in the first residual slag was separated by said treatment, either by vaporization or by conversion/settling into a heavy metal phase, which settles later on the bottom of the second settling furnace.
In one aspect the present invention resides in a method for purifying slag, as arises in a non-ferrous or iron alloy production process, having the following steps: heating and treating the slag in a first settling furnace to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle; analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle, wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle to a second settling furnace; and pouring off the second residual slag from the ladle into the second settling furnace, wherein the second residual slag remains for a predetermined dwell time in the second settling furnace and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace and the Date Recue/Date Received 2021-07-08 3a third residual slag floats on the second metal alloy; wherein heat energy is supplied to the second residual slag in the second settling furnace via a plurality of electrodes, which protrude into the slag of the second settling furnace.
In one aspect the present invention resides in a method for purifying slag, as arises in a non-ferrous or iron alloy production process, having the following steps: heating and treating the slag in a first settling furnace to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle; analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle, wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle to a second settling furnace; and pouring off the second residual slag from the ladle into the second settling furnace, wherein the second residual slag remains for a predetermined dwell time in the second settling furnace and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace and the third residual slag floats on the second metal alloy; wherein the third residual slag only has a metal component of less than 0.5 wt.%.
Two figures are appended to the description, wherein Figure 1 shows the device according to the invention; and Figure 2 shows a device according to the prior art.
The invention will be described in greater detail hereafter with reference to Figure 1 in the form of exemplary embodiments.
Date Recue/Date Received 2021-07-08 3b The invention begins according to Figure 1 where the prior art described above with reference to Figure 2 stops, namely upon the tapping of the first residual slag from the first settling furnace 110 via the slag outlet channel 114 into the ladle 120.
Date Recue/Date Received 2021-07-08
Depending on the individual composition of the first residual slag and according to the desired chemical and/or metallurgical-physical reaction, the at least one gaseous medium is selected such that it causes its agglomeration of metal particles in the slag, a reduction of the slag, and/or an oxidation of the slag.
Due to the claimed ladle treatment, the first residual slag originally supplied to the ladle is converted into a second residual slag. This second residual slag is already less harmful from an environmental aspect than the first residual slag, because a part of the undesired components still contained in the first residual slag was separated by said treatment, either by vaporization or by conversion/settling into a heavy metal phase, which settles later on the bottom of the second settling furnace.
In one aspect the present invention resides in a method for purifying slag, as arises in a non-ferrous or iron alloy production process, having the following steps: heating and treating the slag in a first settling furnace to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle; analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle, wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle to a second settling furnace; and pouring off the second residual slag from the ladle into the second settling furnace, wherein the second residual slag remains for a predetermined dwell time in the second settling furnace and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace and the Date Recue/Date Received 2021-07-08 3a third residual slag floats on the second metal alloy; wherein heat energy is supplied to the second residual slag in the second settling furnace via a plurality of electrodes, which protrude into the slag of the second settling furnace.
In one aspect the present invention resides in a method for purifying slag, as arises in a non-ferrous or iron alloy production process, having the following steps: heating and treating the slag in a first settling furnace to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle; analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle, wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle to a second settling furnace; and pouring off the second residual slag from the ladle into the second settling furnace, wherein the second residual slag remains for a predetermined dwell time in the second settling furnace and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace and the third residual slag floats on the second metal alloy; wherein the third residual slag only has a metal component of less than 0.5 wt.%.
Two figures are appended to the description, wherein Figure 1 shows the device according to the invention; and Figure 2 shows a device according to the prior art.
The invention will be described in greater detail hereafter with reference to Figure 1 in the form of exemplary embodiments.
Date Recue/Date Received 2021-07-08 3b The invention begins according to Figure 1 where the prior art described above with reference to Figure 2 stops, namely upon the tapping of the first residual slag from the first settling furnace 110 via the slag outlet channel 114 into the ladle 120.
Date Recue/Date Received 2021-07-08
4 The tapping of the first residual slag from an NE or iron alloy production process into a ladle 120, which is fundamentally known from the iron and steel industry, firstly causes the inflow of slag, which still takes place continuously into the first settling furnace 110, to be interrupted, because the tapping of the first residual slag takes place discontinuously. A
transition into so-called "batch operation" thus takes place. The use of the ladle 120 to receive the first residual slag offers the advantage that the ladle is already innately best suitable as a transportation and treatment vessel for the further treatment of the first residual slag. It thus typically has lance accesses in the cover, lateral injection options, or bottom purging plugs, each for introducing gaseous media.
According to one advantageous exemplary embodiment, the ladle 120 can also be designed as a ladle furnace or as a copper refining furnace/heating furnace and is best suitable as such for heating the first residual slag, to improve the metallurgical-physical reaction of the first residual slag with the gaseous medium. The residual slag is preferably heated using electrodes 128, as shown in Figure 1.
Furthermore, introduction ducts, i.e., a type of charging pipes, can be provided in the ladle for supplying additives, for example, reducing agents or slag formers, into the first residual slag, also to assist the metallurgical-physical reaction. For better mixing and homogenization of the residual slag, the gaseous medium can be introduced into the residual slag via a purging lance immersed from above into the slag, via lateral purging lances, or via bottom plugs.
The first residual slag originally supplied into the ladle is converted by the described treatment, which preferably provides the generation of turbulence in the residual slag to accelerate the reaction, into a second residual slag. This second residual slag is already less harmful from an environmental aspect than the first residual slag, because due to said treatment, a part of the undesired components still contained in the first residual slag was separated, for example, by vaporization or by conversion/settling into a heavy metal phase.
To improve the second residual slag still further with respect to environmental protection aspects, however, in particular to enable settling of the heavy metal phase, the method according to the invention optionally furthermore provides that the ladle 120 having the second residual slag is transported, for example, with the aid of a carriage 130 or with the aid of a crane (not shown) to a second settling furnace 140, and the second residual slag is then poured off from the ladle 120 into the second settling furnace 140.
The pouring off is performed, for example, with the aid of a tipple 135 via a slag inlet channel 142. In the second settling furnace 140, which is typically a reduction furnace (submerged arc furnace, SAF), the second residual slag is to come to rest by dwelling therein for a predetermined dwell time. During the dwell time, at least a part of the metals still contained in the second residual slag settles as the second metal alloy on the bottom of the second settling furnace 140, while a remaining third residual slag typically floats on the top of the second metal alloy. After the dwell time, the third residual slag can be tapped via a slag outlet channel 144, for example, into a bucket 150 or into a granulation. The second metal alloy, in contrast, is tapped separately via an outlet 146 from the third residual slag.
During its dwell time in the second settling furnace 140, the second residual slag is preferably kept at a constant temperature. For this purpose, heat energy can be introduced into the second settling furnace 140. This introduction of the heat energy preferably takes place via a plurality of small electrodes 148 having a diameter less than 900 mm, which protrude into the slag of the second settling furnace. The electrodes 148 can either be arranged along a straight line or each offset in relation to the straight line in a zigzag shape. The straight line preferably extends along or parallel to the longitudinal side of a preferably rectangular vessel of the second settling furnace. The plurality of small electrodes offers the advantage that they mix or swirl the residual slag less strongly than a single large electrode, and therefore enable better heat conservation. The second settling furnace 140 can be operated using direct current or alternating current. In the case of smaller slag introductions and therefore smaller dimensions of the second settling furnace 140, however, equipping it with 3 larger electrodes can have a simpler design and be more cost-effective.
6 =
The third residual slag advantageously only still contains a metal component of less than 0.5 wt.%, in particular of heavy metals, and is thus substantially more environmentally friendly to dispose of than the first or the second residual slag.
List of reference numerals 100 device 110 first settling furnace 111 metal outlet channel of first settling furnace 112 slag inlet channel of first settling furnace 114 slag outlet channel of first settling furnace 120 ladle 128 electrodes of the ladle 130 crane or carriage 135 tipple 140 second settling furnace 142 slag inlet channel of second settling furnace 144 slag outlet channel of second settling furnace 146 metal outlet of second settling furnace 148 electrodes 150 bucket
transition into so-called "batch operation" thus takes place. The use of the ladle 120 to receive the first residual slag offers the advantage that the ladle is already innately best suitable as a transportation and treatment vessel for the further treatment of the first residual slag. It thus typically has lance accesses in the cover, lateral injection options, or bottom purging plugs, each for introducing gaseous media.
According to one advantageous exemplary embodiment, the ladle 120 can also be designed as a ladle furnace or as a copper refining furnace/heating furnace and is best suitable as such for heating the first residual slag, to improve the metallurgical-physical reaction of the first residual slag with the gaseous medium. The residual slag is preferably heated using electrodes 128, as shown in Figure 1.
Furthermore, introduction ducts, i.e., a type of charging pipes, can be provided in the ladle for supplying additives, for example, reducing agents or slag formers, into the first residual slag, also to assist the metallurgical-physical reaction. For better mixing and homogenization of the residual slag, the gaseous medium can be introduced into the residual slag via a purging lance immersed from above into the slag, via lateral purging lances, or via bottom plugs.
The first residual slag originally supplied into the ladle is converted by the described treatment, which preferably provides the generation of turbulence in the residual slag to accelerate the reaction, into a second residual slag. This second residual slag is already less harmful from an environmental aspect than the first residual slag, because due to said treatment, a part of the undesired components still contained in the first residual slag was separated, for example, by vaporization or by conversion/settling into a heavy metal phase.
To improve the second residual slag still further with respect to environmental protection aspects, however, in particular to enable settling of the heavy metal phase, the method according to the invention optionally furthermore provides that the ladle 120 having the second residual slag is transported, for example, with the aid of a carriage 130 or with the aid of a crane (not shown) to a second settling furnace 140, and the second residual slag is then poured off from the ladle 120 into the second settling furnace 140.
The pouring off is performed, for example, with the aid of a tipple 135 via a slag inlet channel 142. In the second settling furnace 140, which is typically a reduction furnace (submerged arc furnace, SAF), the second residual slag is to come to rest by dwelling therein for a predetermined dwell time. During the dwell time, at least a part of the metals still contained in the second residual slag settles as the second metal alloy on the bottom of the second settling furnace 140, while a remaining third residual slag typically floats on the top of the second metal alloy. After the dwell time, the third residual slag can be tapped via a slag outlet channel 144, for example, into a bucket 150 or into a granulation. The second metal alloy, in contrast, is tapped separately via an outlet 146 from the third residual slag.
During its dwell time in the second settling furnace 140, the second residual slag is preferably kept at a constant temperature. For this purpose, heat energy can be introduced into the second settling furnace 140. This introduction of the heat energy preferably takes place via a plurality of small electrodes 148 having a diameter less than 900 mm, which protrude into the slag of the second settling furnace. The electrodes 148 can either be arranged along a straight line or each offset in relation to the straight line in a zigzag shape. The straight line preferably extends along or parallel to the longitudinal side of a preferably rectangular vessel of the second settling furnace. The plurality of small electrodes offers the advantage that they mix or swirl the residual slag less strongly than a single large electrode, and therefore enable better heat conservation. The second settling furnace 140 can be operated using direct current or alternating current. In the case of smaller slag introductions and therefore smaller dimensions of the second settling furnace 140, however, equipping it with 3 larger electrodes can have a simpler design and be more cost-effective.
6 =
The third residual slag advantageously only still contains a metal component of less than 0.5 wt.%, in particular of heavy metals, and is thus substantially more environmentally friendly to dispose of than the first or the second residual slag.
List of reference numerals 100 device 110 first settling furnace 111 metal outlet channel of first settling furnace 112 slag inlet channel of first settling furnace 114 slag outlet channel of first settling furnace 120 ladle 128 electrodes of the ladle 130 crane or carriage 135 tipple 140 second settling furnace 142 slag inlet channel of second settling furnace 144 slag outlet channel of second settling furnace 146 metal outlet of second settling furnace 148 electrodes 150 bucket
Claims (18)
1. A method for purifying slag, as arises in a non-ferrous or iron alloy production process, having the following steps:
heating and treating the slag in a first settling furnace (110) to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle (120);
analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle (120), wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle (120) to a second settling furnace (140); and pouring off the second residual slag from the ladle (120) into the second settling furnace (140), wherein the second residual slag remains for a predetermined dwell time in the second settling furnace (140) and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace (140) and the third residual slag floats on the second metal alloy;
wherein heat energy is supplied to the second residual slag in the second settling furnace (140) via a plurality of electrodes (148), which protrude into the slag of the second settling furnace.
heating and treating the slag in a first settling furnace (110) to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle (120);
analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle (120), wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle (120) to a second settling furnace (140); and pouring off the second residual slag from the ladle (120) into the second settling furnace (140), wherein the second residual slag remains for a predetermined dwell time in the second settling furnace (140) and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace (140) and the third residual slag floats on the second metal alloy;
wherein heat energy is supplied to the second residual slag in the second settling furnace (140) via a plurality of electrodes (148), which protrude into the slag of the second settling furnace.
2. The method as claimed in claim 1, characterized in that the first residual slag contains a metal component of 0.5 wt.% or more.
3. The method as claimed in claim 1 or claim 2, characterized in that the at least one gaseous medium is applied from above onto the first residual slag or is injected in the interior of the ladle (120) into the first residual slag.
Date Recue/Date Received 2021-07-08
Date Recue/Date Received 2021-07-08
4. The method as claimed in any one of claims 1 to 3, characterized in that the ladle (120) is designed as a ladle furnace or copper refining/heating furnace.
5. The method as claimed in claim 4, wherein the first residual slag in the ladle (120) is chemically or electrically heated to assist the metallurgical-physical reaction.
6. The method as claimed in any one of claims 1 to 5, characterized in that an additive in the form of a reducing agent and/or a slag former is added to the first residual slag in the ladle (120) to assist the metallurgical-physical reaction.
7. The method as claimed in claim 1, characterized in that the third residual slag is tapped into a bucket (150) or into a granulation; and the second metal alloy is tapped separately therefrom.
8. The method as claimed in claim 1, characterized in that only sufficient heat energy is supplied to the second residual slag in the second settling furnace (140) that the temperature of the second residual slag remains essentially constant.
9. The method as claimed in claim 7, characterized in that the third residual slag only has a metal component of less than 0.5 wt.%.
10. A method for purifying slag, as arises in a non-ferrous or iron alloy production process, having the following steps:
heating and treating the slag in a first settling furnace (110) to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle (120);
Date Recue/Date Received 2021-07-08 analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle (120), wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle (120) to a second settling furnace (140); and pouring off the second residual slag from the ladle (120) into the second settling furnace (140), wherein the second residual slag remains for a predetermined dwell time in the second settling furnace (140) and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace (140) and the third residual slag floats on the second metal alloy;
wherein the third residual slag only has a metal component of less than 0.5 wt%.
heating and treating the slag in a first settling furnace (110) to obtain a first metal alloy and a first residual slag, tapping the first residual slag into a ladle (120);
Date Recue/Date Received 2021-07-08 analyzing the composition of the first residual slag; and introducing at least one gaseous medium onto or into the first residual slag for the metallurgical-physical reaction to form a second residual slag in the ladle (120), wherein the at least one gaseous medium is selected as a function of the analyzed individual composition of the first residual slag, transporting the second residual slag in the ladle (120) to a second settling furnace (140); and pouring off the second residual slag from the ladle (120) into the second settling furnace (140), wherein the second residual slag remains for a predetermined dwell time in the second settling furnace (140) and becomes calmer therein, and wherein decomposition of the second residual slag during the dwell time into a second metal alloy and a third residual slag, wherein the second metal alloy settles on the bottom of the second settling furnace (140) and the third residual slag floats on the second metal alloy;
wherein the third residual slag only has a metal component of less than 0.5 wt%.
11. The method as claimed in claim 10, characterized in that the first residual slag contains a metal component of 0.5 wt% or more.
12. The method as claimed in claim 10 or claim 11, characterized in that the at least one gaseous medium is applied from above onto the first residual slag or is injected in the interior of the ladle (120) into the first residual slag.
13. The method as claimed in any one of claims 10 to 12, characterized in that the ladle (120) is designed as a ladle furnace or copper refining/heating furnace.
14. The method as claimed in claim 13, wherein the first residual slag in the ladle (120) is chemically or electrically heated to assist the metallurgical-physical reaction.
Date Recue/Date Received 2021-07-08
Date Recue/Date Received 2021-07-08
15. The method as claimed in any one of claims 10 to 14, characterized in that an additive in the form of a reducing agent and/or a slag former is added to the first residual slag in the ladle (120) to assist the metallurgical-physical reaction.
16. The method as claimed in claim 10, characterized in that the third residual slag is tapped into a bucket (150) or into a granulation; and the second metal alloy is tapped separately therefrom.
17. The method as claimed in claim 10, characterized in that only sufficient heat energy is supplied to the second residual slag in the second settling furnace (140) that the temperature of the second residual slag remains essentially constant.
18. The method as claimed in claim 17, wherein the supply of the heat energy takes place via a plurality of electrodes (148), which protnide into the slag of the second settling furnace.
Date Recue/Date Received 2021-07-08
Date Recue/Date Received 2021-07-08
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102015222825 | 2015-11-19 | ||
| DE102015222825.8 | 2015-11-19 | ||
| DE102016002419.4A DE102016002419A1 (en) | 2015-11-19 | 2016-03-02 | Method and device for cleaning slag |
| DE102016002419.4 | 2016-03-02 | ||
| DE102016214207.0 | 2016-08-02 | ||
| DE102016214207.0A DE102016214207A1 (en) | 2015-11-19 | 2016-08-02 | Method and device for cleaning slag |
| PCT/EP2016/076953 WO2017084912A1 (en) | 2015-11-19 | 2016-11-08 | Method and device for cleaning slag |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA3003784A1 CA3003784A1 (en) | 2017-05-26 |
| CA3003784C true CA3003784C (en) | 2022-07-05 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA3003784A Active CA3003784C (en) | 2015-11-19 | 2016-11-08 | Method and device for cleaning slag |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP3377660B1 (en) |
| JP (1) | JP2018534429A (en) |
| CA (1) | CA3003784C (en) |
| DE (2) | DE102016002419A1 (en) |
| WO (1) | WO2017084912A1 (en) |
| ZA (1) | ZA201802499B (en) |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61186413A (en) * | 1985-02-12 | 1986-08-20 | Daido Steel Co Ltd | Ladle refining device |
| DE4206091C2 (en) * | 1992-02-27 | 1994-09-22 | Anton Dr More | Process for the desulfurization of molten iron with minimal slag accumulation and a suitable device |
| ZA963234B (en) * | 1995-05-02 | 1996-07-29 | Holderbank Financ Glarus | Process for the production of hydraulic binders and/or alloys such as e g ferrochromium of ferrovanadium |
| DE102004046727A1 (en) * | 2004-09-25 | 2006-04-06 | Sms Demag Ag | Method and device for producing liquid steel |
| DE102006052181A1 (en) * | 2006-11-02 | 2008-05-08 | Sms Demag Ag | A process for the continuous or discontinuous recovery of a metal or metals from a slag containing the metal or compound of the metal |
| JP5049311B2 (en) * | 2009-03-31 | 2012-10-17 | パンパシフィック・カッパー株式会社 | Method and system for dry treatment of converter slag in copper smelting |
| JP2012067375A (en) * | 2010-09-27 | 2012-04-05 | Pan Pacific Copper Co Ltd | Dry processing method and system for converter slag in copper smelting |
-
2016
- 2016-03-02 DE DE102016002419.4A patent/DE102016002419A1/en not_active Withdrawn
- 2016-08-02 DE DE102016214207.0A patent/DE102016214207A1/en not_active Withdrawn
- 2016-11-08 CA CA3003784A patent/CA3003784C/en active Active
- 2016-11-08 WO PCT/EP2016/076953 patent/WO2017084912A1/en active Application Filing
- 2016-11-08 EP EP16801720.0A patent/EP3377660B1/en active Active
- 2016-11-08 JP JP2018526122A patent/JP2018534429A/en active Pending
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2018
- 2018-04-16 ZA ZA2018/02499A patent/ZA201802499B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| WO2017084912A1 (en) | 2017-05-26 |
| DE102016002419A1 (en) | 2017-05-24 |
| JP2018534429A (en) | 2018-11-22 |
| ZA201802499B (en) | 2019-01-30 |
| EP3377660B1 (en) | 2020-06-24 |
| CA3003784A1 (en) | 2017-05-26 |
| EP3377660A1 (en) | 2018-09-26 |
| DE102016214207A1 (en) | 2017-05-24 |
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