GB2077768A - Recovering Non-volatile Metals from Dust Containing Metal Oxides - Google Patents
Recovering Non-volatile Metals from Dust Containing Metal Oxides Download PDFInfo
- Publication number
- GB2077768A GB2077768A GB8034807A GB8034807A GB2077768A GB 2077768 A GB2077768 A GB 2077768A GB 8034807 A GB8034807 A GB 8034807A GB 8034807 A GB8034807 A GB 8034807A GB 2077768 A GB2077768 A GB 2077768A
- Authority
- GB
- United Kingdom
- Prior art keywords
- reactor
- gas
- dust
- starting material
- metal oxides
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
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
- C22B34/00—Obtaining refractory metals
- C22B34/30—Obtaining chromium, molybdenum or tungsten
- C22B34/32—Obtaining chromium
-
- 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
- C22B4/00—Electrothermal treatment of ores or metallurgical products for obtaining metals or alloys
- C22B4/005—Electrothermal treatment of ores or metallurgical products for obtaining metals or alloys using plasma jets
-
- 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
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/10—Dry methods smelting of sulfides or formation of mattes by solid carbonaceous reducing agents
-
- 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
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/12—Dry methods smelting of sulfides or formation of mattes by gases
-
- 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
- C22B7/02—Working-up flue dust
-
- 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
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/16—Remelting metals
- C22B9/22—Remelting metals with heating by wave energy or particle radiation
- C22B9/226—Remelting metals with heating by wave energy or particle radiation by electric discharge, e.g. plasma
-
- 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
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
- C21C5/5205—Manufacture of steel in electric furnaces in a plasma heated furnace
-
- 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
Abstract
A method of recovering non- volatile metals from dust containing metal oxides, e.g. flue dust comprises blowing the material into the lower portion of a reactor 1 containing a solid reducing agent, passing said starting material into a reduction zone within said lower portion, said reduction zone being maintained by the use of a plasma generator 3 adjacent thereto, substantially instantaneously reducing and melting said starting material in said reduction zone, and removing the melted and reduced metal product from the bottom of the reactor. A portion of furnace off-gas may be used as feed gas to convey the dust to the reactor and as plasma gas. The remaining off- gas may be used for electricity generation. Carbon powder and flux may be added with the feedstock. <IMAGE>
Description
SPECIFICATION
Recovering Non-volative Metals From Dust
Containing Metal Oxides
The present invention relates to a method of recovering non-volative metals from material in dust form containing metal oxides. More particularly, the invention may be employed in the manufacturing of chromium from chromiferous metal oxides in dust form.
When refining metal melts according to conventional methods considerable quantities of metal oxide dust are obtained. This dust is normally recovered from the exhaust gases by means of flue gas filters or the like. In the Nordic countries alone about 50-60,000 tons per year of such metal oxide dust is obtained.
Even after being recovered, the dust has for a long tine constituted a major problem from the environmental point of view, since it contains considerable quantities of heavy metals and also toxic chromium compounds. Heretofore, the dust has been stored as waste and dumped since no technically or economically feasible processing methods have been discovered. In this regard, U.S Patent No. 4,072,504 discloses a method of reducing metal oxides including the step of prereducing the oxides with the reducing gases released during final reduction. The present invention represents an improvement over the method disclosed in said U.S. Patent No.
4,072,504 in that the pre-reduction step disclosed therein is neither necessary nor desirable and also because the present invention is particularly suited for the treatment of waste dust (which treatment is not mentioned in the 4,072,504 Patent).
It has now been found according to the invention that such dust can be processed for the first time under economically acceptable conditions. The invention thus not only solves the environmental problem posed by the storage of toxic wastes, but at the same time makes use of metals, particularly chromium, nickel and molybdenum, present in the waste dust.
In the method according to the invention, the dust containing the metal oxides is blown into the bottom of a reactor filled with solid reducing agent and brought to pass a reduction zone generated by means of a plasma generator, so that the oxides of non-volatile metals contained in the dust are brought to substantially instantaneous final reduction and melting. By balancing the energy supplied and the material containing metal oxide, the temperature of the metal obtained is regulated to between 1 500 and 16500C.
According to a preferred embodiment of the invention described below, the dust containing metal oxide is blown into the reactor by means of a carrier gas, and the reaction gas generated in the reaction may suitably at least partially be recycled as the carrier gas. Furthermore, slagformers and possibly a fuel such as carbon and/or hydrocarbon.may also be added to this carrier gas. Some of the reaction gas generated in the
reactor may also be used as a transport medium for thermal energy and thus as plasma gas if a plasma generator is used. In the preferred embodiment of the invention the energy supply is
provided by electric energy, for instance by means of conventional electrodes or plasma burners.
Any excess reaction gas generated in the
reaction, which contains primarily carbon
monoxide and hydrogen gas, may then be used for other purposes, e.g. such as to generate electricity.
Four a better understanding of the invention,
reference may be made to the following
description of an exemplary embodiment taken in conjunction with the single figure of the accompanying Drawing which illustrates diagrammatically a mode of carrying out the invention.
In the drawing a shaft-like reactor 1 is provided in its upper part with a gastight supply sluice 2 for solid reducing agent, such as coke. The reactor temperature is regulated by means of one or more plasma burners 3.
The dust to be processed is blown into the lower part of the reactor 1 immediateiy before the plasma burner, with the help of a feed gas, through pipe 4. The plasma burner is also connected to a supply pipe 5 for a transport medium (plasma gas) for the thermal energy.
A portion of reduction gas generated in the reactor 1 is recovered and used as feed gas and plasma gas, respectively. Said reduction gas leaves the reactor 1 through an outlet 6 and the temperature can then suitably be regulated by passage through a heat-exchanger 7. In the
Example shown, about 20% of the reduction gas passing the heat-exchanger 7 is returned as feed gas and plasma gas via gas-cleaning equipment 8, a subsequent fan and possibly a compressor 9.
The remaining 80% of the reduction gas leaving the heat exchanger, which contains carbon monoxide and hydrogen, may be used for other purposes, for example the generation of electricity.
The feed gas pipe 4 is arranged to cooperate with a feed means 10, such as a pneumatically operated feeder, which is connected to a feed channel 11 which in turn cooperates with three storage vessels 12, 13, 14 containing the dust to be processed, carbon powder and slag-former, respectively.
In operation, as the dust is injected into the reactor, it is substantially instantaneously reduced and melting occurs in the lower part of the reactor. The molten metal runs down to the bottom of the reactor and is withdrawn via a tapping channel 15, while the slag is continuously or intermittently tapped through a tapping channel 16.
According to the invention, the desired temperature (e.g.) between 1 5000 and 1 6500C) in the reduction zone of the reactor can easily be regulated by means of a plasma burner. The reactor and coke bed may in this case be
dimensioned so that the dust containing metal
oxides is collected in the lower part of the hot
coke bed 1 7 and the gas leaving the reactor
consists of a mixture of carbon monoxide and
hydrogen gas.
Reference is made to the following Example in
order to further explain the invention.
Example
One ton of material in dust form containing
metal oxides, namely chromiferous dust, was taken from the walls of the flue gas filters in the
manufacture of stainless steel. The dust had an original particle size of 2-6,um and the following composition: 13% Cr203
38% Fe203
6% Ni
1.2% MoO3 and the remainder slag, such as CaO, SiO2, etc.
The dust was blown continuously into the reduction zone of the reactor after mixing with 320 Kg carbon powder and 12kg SiO2 (slagformer). The energy requirement for maintaining a temperature of about 1 5500C in the reduction zone was about 2600 kWh, said temperature being generated with the help of a plasma burner.
The following was obtained:
475 kg crude iron with a chromium content of
21%, as well as 11% Ni and 2.3% Mo 620
Nm3 reaction gas consisting of
70% CO
20% H2 and 10% of a mixture of nitrogen, carbon dioxide and water.
The reaction gas had a thermal value of about 2700 kilo calories/Nm3.
Claims (11)
1. A method of recovering non-volatile metal from material in dust form containing metal oxides, which comprises blowing the material into the lower portion of a reactor, said reactor containing a solid reducing agent, passing said starting material into a reduction zone within said lower portion, said reduction zone being maintained by a plasma generator adjacent thereto, substantially instantaneously reducing and melting said starting material in said reducton zone, and removing the melted and reduced metal product from the bottom of the reactor.
2. A method according to claim 1 wherein the temperature of the melted product in the reactor is maintained at 1 5000C. to 1 6500C.
3. A method according to claim 1 or 2 wherein the starting material also includes carbon or hydrocarbons.
4. A method according to claim 3 wherein the starting material also includes a slag former.
5. A method according to any one of the preceding claims, wherein the starting material is blown into the reactor together with a carrier gas.
6. A method according to claim 5 wherein a portion of the reaction gas generated in the reactor is used as the carrier gas.
7. A method according to any one of the preceding claims wherein a portion of the reaction gas generated in the reactor is used as a plasma gas.
8. A method according to any one of the preceding claims wherein the non-volatile metal includes chromium.
9. A method according to claim 1 substantially as hereinbefore described with reference to the
Example.
10. A method according to claim 1 substantially as hereinbefore described with reference to the Figure of the accompanying
Drawing.
11. A non-volatile metal when recovered from its oxide by a method as claimed in any one of the preceding claims.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8034807A GB2077768B (en) | 1980-10-29 | 1980-10-29 | Recovering non-volatile metals from dust containing metal oxides |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8034807A GB2077768B (en) | 1980-10-29 | 1980-10-29 | Recovering non-volatile metals from dust containing metal oxides |
Publications (2)
Publication Number | Publication Date |
---|---|
GB2077768A true GB2077768A (en) | 1981-12-23 |
GB2077768B GB2077768B (en) | 1984-08-15 |
Family
ID=10516960
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8034807A Expired GB2077768B (en) | 1980-10-29 | 1980-10-29 | Recovering non-volatile metals from dust containing metal oxides |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2077768B (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2118578A (en) * | 1982-04-07 | 1983-11-02 | Skf Steel Eng Ab | Method of recovering metals from liquid slag |
GB2126606A (en) * | 1982-09-08 | 1984-03-28 | Skf Steel Eng Ab | Method of manufacturing ferrosilicon |
GB2165861A (en) * | 1984-10-19 | 1986-04-23 | Skf Steel Eng Ab | A method of manufacturing metals and/or generating slag |
EP0290974A1 (en) * | 1987-05-14 | 1988-11-17 | Fried. Krupp Gesellschaft mit beschränkter Haftung | Thermal treatment of solid scrap containing heavy metal compounds and/or toxic hydrocarbons |
EP0504700A1 (en) * | 1991-03-21 | 1992-09-23 | Linde Aktiengesellschaft | Process for operating a cupola |
GB2262104A (en) * | 1990-06-10 | 1993-06-09 | Antonio M Celi | Method and apparatus for the treatment of metal-laminated plastics scrap |
EP0551992A1 (en) * | 1992-01-17 | 1993-07-21 | Kaneko, Misa | Process for recovering valuable metals from an iron dust |
US5279643A (en) * | 1992-01-17 | 1994-01-18 | Yasuo Kaneko | Process for recovering valuable metals from an iron dust |
-
1980
- 1980-10-29 GB GB8034807A patent/GB2077768B/en not_active Expired
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2118578A (en) * | 1982-04-07 | 1983-11-02 | Skf Steel Eng Ab | Method of recovering metals from liquid slag |
GB2126606A (en) * | 1982-09-08 | 1984-03-28 | Skf Steel Eng Ab | Method of manufacturing ferrosilicon |
GB2165861A (en) * | 1984-10-19 | 1986-04-23 | Skf Steel Eng Ab | A method of manufacturing metals and/or generating slag |
FR2572097A1 (en) * | 1984-10-19 | 1986-04-25 | Skf Steel Eng Ab | PROCESS FOR PRODUCING METALS AND / OR DAIRY |
EP0290974A1 (en) * | 1987-05-14 | 1988-11-17 | Fried. Krupp Gesellschaft mit beschränkter Haftung | Thermal treatment of solid scrap containing heavy metal compounds and/or toxic hydrocarbons |
GB2262104A (en) * | 1990-06-10 | 1993-06-09 | Antonio M Celi | Method and apparatus for the treatment of metal-laminated plastics scrap |
EP0504700A1 (en) * | 1991-03-21 | 1992-09-23 | Linde Aktiengesellschaft | Process for operating a cupola |
EP0551992A1 (en) * | 1992-01-17 | 1993-07-21 | Kaneko, Misa | Process for recovering valuable metals from an iron dust |
US5279643A (en) * | 1992-01-17 | 1994-01-18 | Yasuo Kaneko | Process for recovering valuable metals from an iron dust |
Also Published As
Publication number | Publication date |
---|---|
GB2077768B (en) | 1984-08-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4310350A (en) | Recovering non-volatile metals from dust containing metal oxides | |
NZ211817A (en) | Method of reducing oxide ores in multizone reactor | |
US6001148A (en) | Process for obtaining metal from metal oxide | |
US4340420A (en) | Method of manufacturing stainless steel | |
US4244732A (en) | Manufacture of steel from ores containing high phosphorous and other undesirable constituents | |
Jones et al. | Plasma developments in Africa | |
US4526612A (en) | Method of manufacturing ferrosilicon | |
GB2077768A (en) | Recovering Non-volatile Metals from Dust Containing Metal Oxides | |
US4071355A (en) | Recovery of vanadium from pig iron | |
US4756748A (en) | Processes for the smelting reduction of smeltable materials | |
KR101189182B1 (en) | Method for separating vanadium from vanadium-containing melt | |
KR19980041966A (en) | Electric steelworks dust reduction method and apparatus | |
JP2938535B2 (en) | Manufacturing process of chromium-containing molten steel | |
WO2015041834A2 (en) | Steel production in a coke dry quenching system | |
US4654077A (en) | Method for the pyrometallurgical treatment of finely divided materials | |
US3420659A (en) | Method for the production of vanadium alloys | |
KR910008141B1 (en) | Method of smetting reduction of ores containing metal oxides | |
US4732368A (en) | Apparatus for the pyrometallurgical treatment of finely divided materials | |
GB2234528A (en) | Zinc recovery process | |
AU5720199A (en) | Method for reprocessing steel slags and ferriferous materials | |
Herlitz | The plasmadust process for recovery of metals from waste oxides | |
WO1985001750A1 (en) | Smelting nickel ores or concentrates | |
WO2023100707A1 (en) | Production method for metal iron | |
RU2217505C1 (en) | Method of processing nickel-bearing iron ore raw material | |
CA1195509A (en) | Method of producing metallic nickel |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19921029 |