EP0222452B1 - Process for reducing the oxidation level of metallic oxides - Google Patents

Process for reducing the oxidation level of metallic oxides Download PDF

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Publication number
EP0222452B1
EP0222452B1 EP86201942A EP86201942A EP0222452B1 EP 0222452 B1 EP0222452 B1 EP 0222452B1 EP 86201942 A EP86201942 A EP 86201942A EP 86201942 A EP86201942 A EP 86201942A EP 0222452 B1 EP0222452 B1 EP 0222452B1
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Prior art keywords
fluidized bed
supplied
metal oxides
solids
reduction
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German (de)
French (fr)
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EP0222452A1 (en
Inventor
Martin Hirsch
Hermann Lommert
Harry Dr. Serbent
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GEA Group AG
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Metallgesellschaft AG
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    • 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
    • C22B47/00—Obtaining manganese
    • 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
    • C22B23/00—Obtaining nickel or cobalt
    • C22B23/02—Obtaining nickel or cobalt by dry processes
    • C22B23/023—Obtaining nickel or cobalt by dry processes with formation of ferro-nickel or ferro-cobalt
    • 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
    • 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
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S423/00—Chemistry of inorganic compounds
    • Y10S423/09—Reaction techniques
    • Y10S423/16—Fluidization

Definitions

  • the invention relates to a method for reducing higher metal oxides to lower metal oxides by means of carbon-containing reducing agents.
  • ores that contain metals - such as Fe, Ni, Mn - in the form of higher oxides have to be subjected to a reducing treatment so that these metals are in the form of lower oxides.
  • ferroalloys While e.g. in the case of an ore with 30% Fe and 2% Ni, an Fe / Ni ratio of 15/1 is present, commercially available ferroalloys have such ratios of at most 4/1, i.e. their nickel content is at least 20%.
  • Such ores are processed in such a way that they are reduced as far as possible to the FeO stage by means of a pre-reduction and then only as much metallic iron is produced in a melting process by further reduction as is permissible for the desired ferroalloy.
  • the remaining iron oxide is slagged.
  • the pre-reduction is carried out on an industrial scale in rotary kilns using coal as a reducing agent.
  • the problem of the pre-reduction in the rotary kiln lies in the constant adherence to an exact pre-reduction of the iron oxides, the discharge material being allowed to contain only as much excess, solid carbon as is permissible for the further reduction in the melting process.
  • Another case of using the method according to the invention relates to the reduction of ores which contain higher manganese oxides and whose manganese content is to be reduced to low manganese oxides.
  • the object of the invention is to carry out the reduction of higher metal oxides to lower metal oxides as largely and constantly as possible to the desired oxidation state and to set either as little or a constant, small excess of carbon in the reduced discharge material.
  • the grain size of the solids is in the range of less than 3 mm.
  • the calcination can take place in a stationary fluidized bed, a circulating fluidized bed or another process in which the solids are suspended in a gas stream.
  • the raw materials can be dried in the calcination before use. Drying can take place with the waste heat from the calcination. As a result, the water is evaporated without the consumption of carbon, the water vapor does not have to be heated to the considerably higher temperature in the calcination, and the waste heat is used in a favorable manner. After drying, further heating can be carried out before charging into the calcination, a certain amount of precalculation being able to occur.
  • a stationary fluidized bed is to be understood as a fluidized bed in which a dense phase is separated from the dust space above by a clear density jump, and a defined boundary layer exists between these two distribution states.
  • the amount of the oxygen-containing gases passed as a fluidizing gas into the stationary fluidized bed is such that the carbon-containing reducing agent is either virtually completely gasified or gasified to a desired excess of carbon in the discharge material.
  • the oxygen-containing gases generally consist of air.
  • a preferred embodiment consists in that the calcination according to (a) takes place in a circulating fluidized bed, the suspension discharged from the fluidized bed reactor is passed into a separator, at least a partial stream of the separated solids is returned to the fluidized bed reactor, and the exhaust gas for drying and preheating the solids containing higher metal oxides are passed into suspension heat exchangers.
  • the circulating fluidized bed system consists of a fluidized bed reactor, a separator and a return line for solids from the separator to the fluidized bed reactor.
  • the fluidized bed in the fluidized bed reactor has - in contrast to the stationary fluidized bed, in which a dense phase is separated from the gas space above by a clear density jump - distribution states without a defined boundary layer.
  • the solids discharged from the fluidized bed reactor with the gases are returned to the fluidized bed reactor to form a circulating fluidized bed such that the hourly solids circulation is at least five times the solids weight in the reactor shaft matters.
  • a quantity of solids corresponding to the entry is withdrawn from the system of the circulating fluidized bed and passed into the stationary fluidized bed.
  • the circulating fluidized bed results in a high throughput during calcination, a high burnout of the fuel and, due to the multi-stage combustion, a low content of CO and NO x in the exhaust gas.
  • a preferred embodiment consists in that the exhaust gas from the stationary fluidized bed according to (d) is passed through a separator before being introduced into the calcination, and the separated solid is returned to the stationary fluidized bed.
  • the dust separator expediently consists of a cyclone. This largely avoids the circulation of solids between the reduction stage and the oxidation stage.
  • a preferred embodiment is that the reduction according to (b) is carried out with the addition of solid, carbon-containing reducing agents.
  • the addition of solid fuels results in a better distribution in the fluidized bed and the desired amount of excess carbon in the discharge material can be adjusted very precisely and evenly.
  • One embodiment consists of the use of iron-nickel ores and the addition of carbon-containing reducing agent in the stationary fluidized bed in accordance with (c) such that it is used to reduce the higher iron oxides, for example to the FeO stage, to reduce the nickel oxides, is sufficient to set the reduction temperature and there is a maximum of 2% by weight of excess carbon in the discharge material, and the discharge material is further processed in the melt flow to produce an amount of metallic iron corresponding to the desired iron-nickel alloy and slagging of the remaining iron content.
  • One embodiment consists in that materials containing manganese oxides are used, and the addition of carbon-containing reducing agent in the stationary fluidized bed is dimensioned in accordance with (c) such that it is sufficient to reduce the higher manganese oxides, for example to the MnO stage, to set the reduction temperature, and There is as little excess carbon as possible in the discharge material.
  • the ore 1 is charged via a screw 2 into a venturi-like suspension dryer 3. There it is suspended in the gas stream and passed via line 4 into a separator 5. The gas is cleaned in the electrostatic filter 6 and discharged as exhaust gas 7. The separated solids are fed into line 8 by screw 7a. A partial stream is fed into the calcination via line 9.
  • the calcination is designed as a circulating fluidized bed and consists of the fluidized bed reactor 10, the recycle cyclone 11 and the recycle line 12. A part of the solid is passed via line 13 into the preheater 14, suspended there in the gas stream and passed via line 15 into the separator 16. The separated solid is passed into the reactor 10 via line 17. The gas flows from the separator 16 into the suspension dryer 3.
  • Fluidizing air 18 is introduced into the lower region of the reactor 10. At a higher point, secondary air 19 and coal 20 are introduced.
  • a gas / solid suspension which fills the entire reactor 10 is formed within the fluidized bed reactor 10 and is passed at the top via line 21 into the recycling cyclone 11, where a separation of solid and gas takes place.
  • the gas flows into the preheater 14 and the solid enters the return line 12, in which a U-shaped closure 13 is arranged, in the bottom of which a small amount of fluidizing air (not shown) is passed.
  • Part of the calcined solid passes from the closure 13 via a controllable valve 22 and line 23 into the stationary fluidized bed 24, in which the reduction takes place. Fluidizing air is blown into the lower part via line 25 and coal is introduced via line 26.
  • the dust-containing exhaust gas is passed via line 27 into the separator 28.
  • the separated solids return to the stationary fluidized bed 24 via line 29, while the exhaust gas is introduced via line 30 into the fluidized bed reactor 10 at a higher point.
  • the reduced material is discharged via line 31.
  • Calcined solids can also be fed into the stationary fluidized bed 24 via line 32.
  • the fluidized bed reactor 10 has a diameter of 3.7 m and a height of 16 m.
  • the temperature in the reactor is 900 ° C.
  • the fluidized bed reactor 24 has a diameter of 3 m and a height of 2.5 m.
  • the temperature in the reactor is 900 ° C.
  • the advantages of the invention are that, on the one hand, the calcination can be carried out in a very economical manner with the generation of a largely burnt-out, low-pollutant exhaust gas and, on the other hand, a reduced product is obtained which has a precise and uniform degree of reduction and a precisely defined and uniform content of excess Contains carbon, which content can also be practically zero.
  • the iron oxides can be largely reduced to FeO and the formation of metallic iron can nevertheless be avoided.
  • the carbon content in the discharge can be kept very low or only as high and absolutely uniform as is necessary for the reduction of the small amounts of metallic iron in the melting process. This enables precise metering of the amount of carbon in the electric furnace.

Description

Die Erfindung betrifft ein Verfahren zur Reduktion von höheren Metalloxiden zu niedrigen Metalloxiden mittels kohlenstoffhaltiger Reduktionsmittel.The invention relates to a method for reducing higher metal oxides to lower metal oxides by means of carbon-containing reducing agents.

In manchen Fällen müssen Erze, die Metalle - wie Fe, Ni, Mn - in Form höherer Oxide enthalten, einer reduzierenden Behandlung unterworfen werden, damit diese Metalle in Form niedriger Oxide vorliegen.In some cases, ores that contain metals - such as Fe, Ni, Mn - in the form of higher oxides have to be subjected to a reducing treatment so that these metals are in the form of lower oxides.

Dies ist insbesondere der Fall bei Verfahren zur Herstellung von Eisen-Nickel-Legierungen aus Eisen-Nickel-Erzen.This is particularly the case with processes for the production of iron-nickel alloys from iron-nickel ores.

Zur Versorgung der Industrie mit Nickel, insbesondere in Form seiner Legierung mit Eisen, müssen in zunehmendem Maße ärmere, z.B. lateritische, Erze eingesetzt werden. Diese weisen jedoch meist ein Fe/Ni-Verhäftnis auf, das bei vollständiger Reduktion beider Metalle und schmelzflüssiger Abtrennung der Erzgangart als Schlacke zu einer nicht marktfähigen, weil zu Ni-armen Ferrolegierung führen würde.To supply the industry with nickel, especially in the form of its alloy with iron, increasingly poorer, e.g. lateritic, ores are used. However, these usually have an Fe / Ni ratio, which, if both metals were completely reduced and the molten metal was separated off as a slag, would lead to a non-marketable ferroalloy that was low in Ni.

Während z.B. bei einem Erz mit 30% Fe und 2% Ni ein Fe/Ni-Verhältnis von 15/1 vorliegt, weisen handelsübliche Ferrolegierungen solche Verhältnisse von höchstens 4/1 auf, d.h. ihr Nickelgehalt beträgt mindestens 20%.While e.g. in the case of an ore with 30% Fe and 2% Ni, an Fe / Ni ratio of 15/1 is present, commercially available ferroalloys have such ratios of at most 4/1, i.e. their nickel content is at least 20%.

Aus diesem Grunde werden solche Erze deshalb in der Weise verarbeitet, daß sie durch eine Vorreduktion möglichst bis zum FeO-Stadium vorreduziert werden und dann in einem Schmelzprozeß nur so viel metallisches Eisen durch weitere Reduktion erzeugt wird, wie für die gewünschte Ferrolegierung zulässig ist. Das restliche Eisenoxid wird verschlackt. Die Vorreduktion erfolgt großtechnisch in Drehrohröfen unter Einsatz von Kohle als Reduktionsmittel. Das Problem der Vorreduktion im Drehrohrofen liegt in der konstanten Einhaltung einer genauen Vorreduktion der Eisenoxide, wobei das Austragsmaterial nur so viel überschüssigen, festen Kohlenstoff enthalten darf, wie für die weitere Reduktion im Schmelzprozeß zulässig ist. Da im Drehrohrofen bei der Vorreduktion relativ starke Schwankungen im Reduktionsgrad auftreten, die Bildung von metallischem Eisen aber vermieden werden soll, wird die Vorreduktion nicht bis zum Fe0-Stadium durchgeführt. Aus Sicherheitsgründen erfolgt die Vorreduktion nur bis zu einem beträchtlich höheren Oxidationsgrad. Dadurch wird aber eine größere Reduktionsarbeit im Schmelzfluß, die meistens in Elektroöfen erfolgt, notwendig, wodurch das Gesamtverfahren teurer wird. Außerdem ist die Einstellung der weiteren Reduktion im Schmelzfluß schwierig, da der Oxidationsgrad und Kohlenstoffgehalt des Austrages des Drehrohrofens, selbst bei kleinen Öfen, oft schwankt.For this reason, such ores are processed in such a way that they are reduced as far as possible to the FeO stage by means of a pre-reduction and then only as much metallic iron is produced in a melting process by further reduction as is permissible for the desired ferroalloy. The remaining iron oxide is slagged. The pre-reduction is carried out on an industrial scale in rotary kilns using coal as a reducing agent. The problem of the pre-reduction in the rotary kiln lies in the constant adherence to an exact pre-reduction of the iron oxides, the discharge material being allowed to contain only as much excess, solid carbon as is permissible for the further reduction in the melting process. Since relatively large fluctuations in the degree of reduction occur during the pre-reduction in the rotary kiln, but the formation of metallic iron should be avoided, the pre-reduction is not carried out until the Fe0 stage. For safety reasons, the pre-reduction takes place only up to a considerably higher degree of oxidation. As a result, however, a larger reduction work in the melt flow, which mostly takes place in electric furnaces, is necessary, which makes the overall process more expensive. In addition, the adjustment of the further reduction in the melt flow is difficult since the degree of oxidation and carbon content of the discharge of the rotary kiln often fluctuate, even in the case of small furnaces.

Ein solches Verfahren ist beschrieben im TMS-AIME Paper Selection, Paper No. A 74-40, Seiten 1-23.Such a process is described in TMS-AIME Paper Selection, Paper No. A 74-40, pages 1-23.

Ein weiterer Fall der Anwendung des erfindungsgemäßen Verfahrens betrifft die Reduktion von Erzen, die höhere Manganoxide enthalten und deren Mangangehalt zu niedrigen Manganoxiden reduziert werden soll.Another case of using the method according to the invention relates to the reduction of ores which contain higher manganese oxides and whose manganese content is to be reduced to low manganese oxides.

Aus US-A 4 044 094 ist es bekannt, MnO2 in einem Manganerz in einem zweistufigen Fließbettverfahren zu MnO zu reduzieren, wobei der mittels Synthesegas als Fluidisierungs- und Reduktionsgas in einem Fließbettreaktor bei ca. 730°C erfolgenden Reduktion ein Kalzinieren in einem Fließbettreaktor bei etwa derselben Temperatur vorausgeht.From US-A 4 044 094 it is known to reduce MnO 2 in a manganese ore to MnO in a two-stage fluidized bed process, the reduction taking place using synthesis gas as fluidizing and reducing gas in a fluidized bed reactor at about 730 ° C. calcining in a fluidized bed reactor at about the same temperature.

Der Erfindung liegt die Aufgabe zugrunde, die Reduktion von höheren Metalloxiden zu niedrigen Metalloxiden möglichst weitgehend und konstant zur gewünschten Oxidationsstufe durchzuführen und entweder möglichst wenig oder einen konstanten, geringen Überschuß an Kohlenstoff im reduzierten Austragsmaterial einzustellen.The object of the invention is to carry out the reduction of higher metal oxides to lower metal oxides as largely and constantly as possible to the desired oxidation state and to set either as little or a constant, small excess of carbon in the reduced discharge material.

Die Lösung dieser Aufgabe erfolgt erfindungsgemäß dadurch, daß

  • a) in einem ersten Reaktor höhere Metalloxide enthaltende Feststoffe in feinkörniger Form mit heißen Gasen von 800 bis 1100°C kalziniert werden, wobei die Feststoffe in den heißen Gasen suspendiert werden,
  • b) die kalzinierten Feststoffe dann in einem weiteren Reaktor mit einer stationären Wirbelschicht unter Zugabe von kohlenstoffhaltigen Reduktionsmitteln und sauerstoffhaltigen Gasen bei einer Temperatur im Bereich von 800 bis 1100°C zu niedrigen Metalloxiden reduziert werden,
  • c) der Zusatz an kohlenstoffhaltigem Reduktionsmittel in (b) so bemessen wird, daß die Menge des zugegebenen Kohlenstoffs zur Reduktion der höheren Metalloxide zu niedrigen Metalloxiden, zur Erzeugung der Reduktionstemperatur und zur Einstellung des gewünschten Kohlenstoffgehaltes im Austragsmaterial ausreicht,
  • d) das Abgas aus der stationären Wirbelschicht gemäß (b) als Sekundärgas in die Kalzination gemäß (a) geleitet wird und
  • e) in die Kalzination gemäß (a) Brennstoff in einer solchen Menge eingeleitet wird, daß dessen Verbrennung und die durch das Abgas gemäß (d) eingebrachte Wärmemenge die für die Kalzination erforderliche Wärmemenge ergeben.
This object is achieved in that
  • a) in a first reactor, solids containing higher metal oxides are calcined in fine-grained form with hot gases of 800 to 1100 ° C., the solids being suspended in the hot gases,
  • b) the calcined solids are then reduced to low metal oxides in a further reactor with a stationary fluidized bed with the addition of carbon-containing reducing agents and oxygen-containing gases at a temperature in the range from 800 to 1100 ° C.,
  • c) the addition of carbon-containing reducing agent in (b) is such that the amount of carbon added is sufficient to reduce the higher metal oxides to lower metal oxides, to generate the reduction temperature and to set the desired carbon content in the discharge material,
  • d) the exhaust gas from the stationary fluidized bed according to (b) is passed as secondary gas into the calcination according to (a) and
  • e) fuel is introduced into the calcination according to (a) in such an amount that its combustion and the amount of heat introduced by the exhaust gas according to (d) result in the amount of heat required for the calcination.

Die Korngröße der Feststoffe liegt im Bereich kleiner 3 mm.The grain size of the solids is in the range of less than 3 mm.

In der Kalzination werden Kristallwasser ausgetrieben, Karbonate unter Entwicklung von C02 zerlegt und eventuell vorhandene Feuchtigkeit verdampft. Die Kalzination erfolgt unter oxidierenden Bedingungen. Die heißen Gase können durch Verbrennung von festen, flüssigen oder gasförmigen Brennstoffen erzeugt werden.In the calcination, water of crystallization is driven out, carbonates are decomposed with the development of C0 2 and any moisture present is evaporated. The calcination takes place under oxidizing conditions. The hot gases can be generated by burning solid, liquid or gaseous fuels.

Die Kalzination kann in einer stationären Wirbelschicht, einer zirkulierenden Wirbelschicht oder einem anderen Verfahren erfolgen, bei dem die Feststoffe in einem Gasstrom suspendiert sind. Die Rohstoffe können vor dem Einsatz in die Kalzination getrocknet werden. Die Trocknung kann mit der Abwärme der Kalzination erfolgen. Dadurch erfolgt die Wasserverdampfung ohne Verbrauch an Kohlenstoff, der Wasserdampf muß nicht auf die beträchtlich höhere Temperatur in der Kalzination erhitzt werden, und die Abwärme wird in günstiger Weise ausgenutzt. Nach der Trocknung kann eine weitere Aufheizung vor der Chargierung in die Kalzination erfolgen, wobei bereits eine gewisse Vorkalzination eintreten kann.The calcination can take place in a stationary fluidized bed, a circulating fluidized bed or another process in which the solids are suspended in a gas stream. The raw materials can be dried in the calcination before use. Drying can take place with the waste heat from the calcination. As a result, the water is evaporated without the consumption of carbon, the water vapor does not have to be heated to the considerably higher temperature in the calcination, and the waste heat is used in a favorable manner. After drying, further heating can be carried out before charging into the calcination, a certain amount of precalculation being able to occur.

Der aus der Kalzination abgezogene Feststoff wird in einer stationären (klassischen) Wirbelschicht vorreduziert. Unter einer stationären Wirbelschicht ist eine Wirbelschicht zu verstehen, bei der eine dichte Phase durch einen deutlichen Dichtesprung von dem darüber befindlichen Staubraum getrennt ist, und eine definierte Grenzschicht zwischen diesen beiden Verteilungszuständen vorliegt.The solid withdrawn from the calcination is pre-reduced in a stationary (classic) fluidized bed. A stationary fluidized bed is to be understood as a fluidized bed in which a dense phase is separated from the dust space above by a clear density jump, and a defined boundary layer exists between these two distribution states.

Die Menge der als Fluidisierungsgas in die stationäre Wirbelschicht geleiteten sauerstoffhaltigen Gase wird so bemessen, daß das kohlenstoffhaltige Reduktionsmittel entweder praktisch vollständig vergast wird oder bis auf einen gewünschten Überschuß an Kohlenstoff im Austragsmaterial vergast wird. Die sauerstoffhaltigen Gase bestehen im allgemeinen aus Luft.The amount of the oxygen-containing gases passed as a fluidizing gas into the stationary fluidized bed is such that the carbon-containing reducing agent is either virtually completely gasified or gasified to a desired excess of carbon in the discharge material. The oxygen-containing gases generally consist of air.

Eine vorzugsweise Ausgestaltung besteht darin, daß die Kalzination gemäß (a) in einer zirkulierenden Wirbelschicht erfolgt, die aus dem Wirbelschichtreaktor ausgetragene Suspension in einen Abscheider geleitet wird, mindestens ein Teilstrom der abgeschiedenen Feststoffe in den Wirbelschichtreaktor zurückgeleitet wird, und das Abgas zur Trocknung und Vorwärmung der höhere Metalloxide enthaltenden Feststoffe in Suspensions-Wärmeaustauscher geleitet wird. Das System der zirkulierenden Wirbelschicht besteht aus einem Wirbelschichtreaktor, einem Abscheider und einer Rückführleitung für Feststoffe vom Abscheider in den Wirbelschichtreaktor. Die Wirbelschicht im Wirbelschichtreaktor weist - im Gegensatz zur stationären Wirbelschicht, bei der eine dichte Phase durch einen deutlichen Dichtesprung von dem darüber befindlichen Gasraum getrennt ist - Verteilungszustände ohne definierte Grenzschicht auf. Ein Dichtesprung zwischen dichter Phase und darüber befindlichem Staubraum ist nicht existent; jedoch nimmt innerhalb des Reaktors die Feststoffkonzentration von unten nach oben ständig ab. Bei der Definition der Betriebsbedingungen über die Kennzahlen von Froude und Archimedes ergeben sich die Bereiche:

Figure imgb0001
bzw.
Figure imgb0002
wobei
Figure imgb0003
und
Figure imgb0004
sind.A preferred embodiment consists in that the calcination according to (a) takes place in a circulating fluidized bed, the suspension discharged from the fluidized bed reactor is passed into a separator, at least a partial stream of the separated solids is returned to the fluidized bed reactor, and the exhaust gas for drying and preheating the solids containing higher metal oxides are passed into suspension heat exchangers. The circulating fluidized bed system consists of a fluidized bed reactor, a separator and a return line for solids from the separator to the fluidized bed reactor. The fluidized bed in the fluidized bed reactor has - in contrast to the stationary fluidized bed, in which a dense phase is separated from the gas space above by a clear density jump - distribution states without a defined boundary layer. A leap in density between the dense phase and the dust space above it does not exist; however, the solids concentration within the reactor decreases continuously from bottom to top. When defining the operating conditions using the key figures from Froude and Archimedes, the following areas result:
Figure imgb0001
 respectively.
Figure imgb0002
 in which
Figure imgb0003
 and
Figure imgb0004
 are.

Es bedeuten:

  • u die relative Gasgeschwindigkeit in m/sec.
  • Ar die Archimedes-Zahl
  • Fr die Froude-Zahl
  • pg die Dichte des Gases in kg/m3
  • pk die Dichte des Feststoffteilchens in kg/m3
  • dk den Durchmesser des kugelförmigen Teilchens in m
  • v die kinematische Zähigkeit in m2/sec
  • g die Gravitationskonstante in m/sec2
It means:
  • u the relative gas velocity in m / sec.
  • Ar is the Archimedes number
  • For the Froude number
  • pg is the density of the gas in kg / m3
  • pk is the density of the solid particle in kg / m3
  • d k is the diameter of the spherical particle in m
  • v the kinematic toughness in m2 / sec
  • g is the gravitational constant in m / sec 2

Die mit den Gasen aus dem Wirbelschichtreaktor ausgetragenen Feststoffe werden derart zur Ausbildung einer zirkulierenden Wirbelschicht in den Wirbelschichtreaktor zurückgeleitet, daß der stündliche Feststoffumlauf mindestens das Fünffache des im Reaktorschacht befindlichen Feststoffgewichtes ausmacht. Eine dem Eintrag entsprechende Menge an Feststoffen wird aus dem System der zirkulierenden Wirbelschicht abgezogen und in die stationäre Wirbelschicht geleitet. Die zirkulierende Wirbelschicht ergibt eine hohe Durchsatzleistung bei der Kalzination, einen hohen Ausbrand des Brennstoffes und durch die mehrstufige Verbrennung einen geringen Gehalt an CO und NOx im Abgas.The solids discharged from the fluidized bed reactor with the gases are returned to the fluidized bed reactor to form a circulating fluidized bed such that the hourly solids circulation is at least five times the solids weight in the reactor shaft matters. A quantity of solids corresponding to the entry is withdrawn from the system of the circulating fluidized bed and passed into the stationary fluidized bed. The circulating fluidized bed results in a high throughput during calcination, a high burnout of the fuel and, due to the multi-stage combustion, a low content of CO and NO x in the exhaust gas.

Eine vorzugsweise Ausgestaltung besteht darin, daß das Abgas aus der stationären Wirbelschicht gemäß (d) vor der Einleitung in die Kalzination durch einen Abscheider geleitet wird, und der abgeschiedene Feststoff in die stationäre Wirbelschicht zurückgeleitet wird. Der Staubabscheider besteht zweckmäßigerweise aus einem Zyklon. Dadurch wird eine Kreislaufführung von Feststoffen zwischen der Reduktionsstufe und der Oxidationsstufe weitgehend vermieden.A preferred embodiment consists in that the exhaust gas from the stationary fluidized bed according to (d) is passed through a separator before being introduced into the calcination, and the separated solid is returned to the stationary fluidized bed. The dust separator expediently consists of a cyclone. This largely avoids the circulation of solids between the reduction stage and the oxidation stage.

Eine vorzugsweise Ausgestaltung besteht darin, daß die Reduktion gemäß (b) unter Zusatz von festen, kohlenstoffhaltigen Reduktionsmitteln erfolgt. Der Zusatz von festen Brennstoffen ergibt eine bessere Verteilung in der Wirbelschicht und die gewünschte Menge an überschüssigem Kohlenstoff im Austragsmaterial kann sehr genau und gleichmäßig eingestellt werden.A preferred embodiment is that the reduction according to (b) is carried out with the addition of solid, carbon-containing reducing agents. The addition of solid fuels results in a better distribution in the fluidized bed and the desired amount of excess carbon in the discharge material can be adjusted very precisely and evenly.

Eine Ausgestaltung besteht darin, daß Eisen-Nickel-Erze eingesetzt werden, und der Zusatz an kohlenstoffhaltigem Reduktionsmittel in die stationäre Wirbelschicht gemäß (c) so bemessen wird, daß er zur Reduktion der höheren Eisenoxide etwa zum FeO-Stadium, zur Reduktion der Nickeloxide, zur Einstellung der Reduktionstemperatur ausreicht und im Austragsmaterial ein Gehalt an überschüssigem Kohlenstoff von maximal 2 Gew.-% vorliegt, und das Austragsmaterial im Schmelzfluß unter Erzeugung einer der gewünschten Eisen-Nickel-Legierung entsprechenden Menge von metallischem Eisen und Verschlackung des restlichen Eisengehaltes weiterbehandelt wird.One embodiment consists of the use of iron-nickel ores and the addition of carbon-containing reducing agent in the stationary fluidized bed in accordance with (c) such that it is used to reduce the higher iron oxides, for example to the FeO stage, to reduce the nickel oxides, is sufficient to set the reduction temperature and there is a maximum of 2% by weight of excess carbon in the discharge material, and the discharge material is further processed in the melt flow to produce an amount of metallic iron corresponding to the desired iron-nickel alloy and slagging of the remaining iron content.

Eine Ausgestaltung besteht darin, daß Manganoxide enthaltende Materialien eingesetzt werden, und der Zusatz an kohlenstoffhaltigem Reduktionsmittel in die stationäre Wirbelschicht gemäß (c) so bemessen wird, daß er zur Reduktion der höheren Manganoxide etwa zum MnO-Stadium, zur Einstellung der Reduktionstemperatur ausreicht, und im Austragsmaterial möglichst wenig überschüssiger Kohlenstoff vorliegt.One embodiment consists in that materials containing manganese oxides are used, and the addition of carbon-containing reducing agent in the stationary fluidized bed is dimensioned in accordance with (c) such that it is sufficient to reduce the higher manganese oxides, for example to the MnO stage, to set the reduction temperature, and There is as little excess carbon as possible in the discharge material.

Die Erfindung wird anhand einer Figur und eines Beispiels näher erläutert.The invention is explained in more detail with reference to a figure and an example.

Das Erz 1 wird über eine Schnecke 2 in einen venturiartigen Suspensionstrockner 3 chargiert. Dort wird es im Gasstrom suspendiert und über Leitung 4 in einen Abscheider 5 geleitet. Das Gas wird im Elektrofilter 6 gereinigt und als Abgas 7 abgeleitet. Die abgeschiedenen Feststoffe werden von der Schnecke 7a in Leitung 8 eingespeist. Ein Teilstrom wird über Leitung 9 in die Kalzination geleitet. Die Kalzination ist als zirkulierende Wirbelschicht ausgebildet und besteht aus dem Wirbelschichtreaktor 10, dem Rückführzyklon 11 und der Rückführleitung 12. Ein Teil des Feststoffes wird über Leitung 13 in den Vorwärmer 14 geleitet, dort im Gasstrom suspendiert und über Leitung 15 in den Abscheider 16 geleitet. Der abgeschiedene Feststoff wird über Leitung 17 in den Reaktor 10 geleitet. Das Gas strömt aus dem Abscheider 16 in den Suspensionstrockner 3. In den unteren Bereich des Reaktors 10 wird Fluidisierungsluft 18 eingeleitet. An einer höheren Stelle werden Sekundärluft 19 und Kohle 20 eingeleitet. Innerhalb des Wirbelschichtreaktors 10 bildet sich eine den gesamten Reaktor 10 ausfüllende Gas/Feststoff-Suspension aus, die am Kopf über Leitung 21 in den Rückführzyklon 11 geleitet wird, wo eine Trennung von Feststoff und Gas erfolgt. Das Gas strömt in den Vorwärmer 14 und der Feststoff gelangt in die Rückführleitung 12, in der ein U-förmiger Verschluß 13 angeordnet ist, in dessen Boden eine kleine Menge Fluidisierungsluft (nicht dargestellt) geleitet wird. Ein Teil des kalzinierten Feststoffes gelangt aus dem Verschluß 13 über ein regelbares Ventil 22 und Leitung 23 in die stationäre Wirbelschicht 24, in der die Reduktion erfolgt. Über Leitung 25 wird Fluidisierungsluft in den unteren Teil eingeblasen, und über Leitung 26 wird Kohle eingeführt. Das staubhaltige Abgas wird über Leitung 27 in den Abscheider 28 geleitet. Die abgeschiedenen Feststoffe gelangen über Leitung 29 wieder in die stationäre Wirbelschicht 24, während das Abgas über Leitung 30 in den Wirbelschichtreaktor 10 an einer höheren Stelle eingeleitet wird. Das reduzierte Material wird über Leitung 31 abgeleitet. Über Leitung 32 kann ebenfalls kalzinierter Feststoff in die stationäre Wirbelschicht 24 geleitet werden.The ore 1 is charged via a screw 2 into a venturi-like suspension dryer 3. There it is suspended in the gas stream and passed via line 4 into a separator 5. The gas is cleaned in the electrostatic filter 6 and discharged as exhaust gas 7. The separated solids are fed into line 8 by screw 7a. A partial stream is fed into the calcination via line 9. The calcination is designed as a circulating fluidized bed and consists of the fluidized bed reactor 10, the recycle cyclone 11 and the recycle line 12. A part of the solid is passed via line 13 into the preheater 14, suspended there in the gas stream and passed via line 15 into the separator 16. The separated solid is passed into the reactor 10 via line 17. The gas flows from the separator 16 into the suspension dryer 3. Fluidizing air 18 is introduced into the lower region of the reactor 10. At a higher point, secondary air 19 and coal 20 are introduced. A gas / solid suspension which fills the entire reactor 10 is formed within the fluidized bed reactor 10 and is passed at the top via line 21 into the recycling cyclone 11, where a separation of solid and gas takes place. The gas flows into the preheater 14 and the solid enters the return line 12, in which a U-shaped closure 13 is arranged, in the bottom of which a small amount of fluidizing air (not shown) is passed. Part of the calcined solid passes from the closure 13 via a controllable valve 22 and line 23 into the stationary fluidized bed 24, in which the reduction takes place. Fluidizing air is blown into the lower part via line 25 and coal is introduced via line 26. The dust-containing exhaust gas is passed via line 27 into the separator 28. The separated solids return to the stationary fluidized bed 24 via line 29, while the exhaust gas is introduced via line 30 into the fluidized bed reactor 10 at a higher point. The reduced material is discharged via line 31. Calcined solids can also be fed into the stationary fluidized bed 24 via line 32.

Ausführungsbeispiel:Design example:

Die Positionen beziehen sich auf die Figur.The positions refer to the figure.

Es wurde ein lateritisches Ni-Erz folgender Zusammensetzung eingesetzt (bezogen auf trockenes Erz):

  • 20% Fe203
  • 2%NiO
  • 6,8% CaCOa
  • 9,9% Hydratwasser
  • Feuchtigkeit 13,7%
A lateritic Ni ore of the following composition was used (based on dry ore):
  • 20% Fe203
  • 2% NiO
  • 6.8% CaCOa
  • 9.9% hydrate water
  • Humidity 13.7%

Der Wirbelschichtreaktor 10 hat einen Durchmesser von 3,7 m und eine Höhe von 16 m. Die Temperatur im Reaktor beträgt 900°C.The fluidized bed reactor 10 has a diameter of 3.7 m and a height of 16 m. The temperature in the reactor is 900 ° C.

Der Wirbelschichtreaktor 24 hat einen Durchmesser von 3 m und eine Höhe von 2,5 m. Die Temperatur im Reaktor beträgt 900°C.The fluidized bed reactor 24 has a diameter of 3 m and a height of 2.5 m. The temperature in the reactor is 900 ° C.

Schnecke 2: 100 t/h Erz

  • Fluidisierungsluft 18: 20 000 Nm3/h
  • Sekundärluft 19: 22 600 Nm3/h
  • Kohle 20: 4,26 t/h
  • 81,8% C
  • 2,6% H
  • 5,6%0
  • 1,5% Asche
  • 6,7% Feuchte
  • Hu: 7 043 kcal/kg
  • Leitung 21: 58 600 Nm3/h
  • 900°C
  • Leitung 9: 60% des Feststoffes
  • Leitung 13: 40% des Feststoffes
  • Fluidisierungsluft 25: 6030 Nm3/h
  • Kohle 26: 3,43 t/h
  • Abgas 27: 9430 Nm3/h
  • 18,8% CO
  • 17,6% CO2
  • 6,3% H2
  • 7,4% H20
  • 50,5% N2
  • Austrag 31: 72,65 t/h
  • 21,4% Fe0
  • 1,9% Ni
  • 1,37% C
  • Abgas 7: 82 000 Nm3/h
  • 13,7% CO2
  • 37,8% H20
  • 46,7% N2
  • 1,8%02
  • 140°C
Auger 2: 100 t / h ore
  • Fluidizing air 18: 20,000 Nm 3 / h
  • Secondary air 19: 22 600 Nm3 / h
  • Coal 20: 4.26 t / h
  • 81.8% C
  • 2.6% H
  • 5.6% 0
  • 1.5% ash
  • 6.7% moisture
  • Hu: 7 043 kcal / kg
  • Line 21: 58 600 Nm3 / h
  • 900 ° C
  • Line 9: 60% of the solid
  • Line 13: 40% of the solid
  • Fluidizing air 25: 6030 Nm3 / h
  • Coal 26: 3.43 t / h
  • Exhaust gas 27: 9430 Nm3 / h
  • 18.8% CO
  • 17.6% CO 2
  • 6.3% H 2
  • 7.4% H 2 0
  • 50.5% N 2
  • Discharge 31: 72.65 t / h
  • 21.4% Fe0
  • 1.9% Ni
  • 1.37% C
  • Exhaust gas 7: 82,000 Nm3 / h
  • 13.7% CO 2
  • 37.8% H 2 0
  • 46.7% N 2
  • 1.8% 0 2
  • 140 ° C

Die Vorteile der Erfindung bestehen darin, daß einerseits die Kalzination in sehr wirtschaftlicher Weise unter Erzeugung eines weitgehend ausgebrannten, schadstoffarmen Abgases durchgeführt werden kann und andererseits ein reduziertes Produkt erhalten wird, das einen genauen und gleichmäßigen Reduktionsgrad aufweist und einen genau definierten und gleichmäßigen Gehalt an überschüssigem Kohlenstoff enthält, wobei dieser Gehalt auch praktisch Null sein kann.The advantages of the invention are that, on the one hand, the calcination can be carried out in a very economical manner with the generation of a largely burnt-out, low-pollutant exhaust gas and, on the other hand, a reduced product is obtained which has a precise and uniform degree of reduction and a precisely defined and uniform content of excess Contains carbon, which content can also be practically zero.

Bei der Reduktion von Eisen-Nickel-Erzen können die Eisenoxide weitgehend zu FeO reduziert werden und trotzdem die Bildung von metallischem Eisen vermieden werden. Der Kohlenstoffgehalt im Austrag kann sehr gering gehalten oder nur so hoch und absolut gleichmäßig gehalten werden, wie für die Reduktion der geringen Mengen an metallischem Eisen im Schmelzprozeß erforderlich ist. Dadurch ist eine genaue Dosierung der Kohlenstoffmenge im Elektroofen möglich.When iron-nickel ores are reduced, the iron oxides can be largely reduced to FeO and the formation of metallic iron can nevertheless be avoided. The carbon content in the discharge can be kept very low or only as high and absolutely uniform as is necessary for the reduction of the small amounts of metallic iron in the melting process. This enables precise metering of the amount of carbon in the electric furnace.

Claims (6)

1. A process of reducing higher metal oxides to lower metal oxides by a treatment with a carbonaceous reducing agent, whereby
a) fine-grained solids which contain higher metal oxides are calcined in a first reactor (10) by a treatment at 800 to to 1100°C with hot gases, in which the solids are suspended,
b) the calcined solids are then reduced at a temperature in the range from 800 to 1100°C in a further reactor with a stationary fluidized bed (24), which is supplied with carbonaceous reducing agents and oxygen-containing gases and in which the higher metal oxides are reduced to lower metal oxides,
c) carbonaceous reducing agent is supplied in step (b) at such a rate that the carbon which is supplied is effective to reduce the higher metal oxides to low metal oxides, to maintain the reduction temperature, and to maintain the desired carbon content in the matter discharged,
d) the exhaust gas from the stationary fluidized bed used in step (b) is used as a secondary gas in the calcining step (a),
e) fuel is supplied to the calcining step (a) at such a rate that the total of the heat generated by the combustion of such fuel and of the heat supplied to the calcining step by the exhaust gas used in step
(d) will be sufficient to effect the calcination.
2. A process according to claim 1, characterized in that the calcining step (a) is effected in a circulating fluidized bed, the suspension discharged from the fluidized bed reactor is supplied to a separator, at least one partial stream of the separated solids is recycled to said, reactor, and the exhaust gas is supplied to suspension heat exchangers for drying and preheating the solids which contain higher metal oxides.
3. A process according to claim 1 or 2, characterized in that the exhaust gas coming from the stationary fluidized bed and used in step (d) is passed through a separator before being supplied to the calcining step, and the separated solids are recycled to the stationary fluidized bed.
4. A process according to any of claims 1 to 3, characterized in that solid carbonaceous reducing agents are supplied to the reducing step (b).
5. A process according to any of claims 1 to 4, characterized in that iron-nickel ores are charged and carbonaceous reducing agent is supplied in step (c) to the stationary fluidized bed at such a rate as to effect a reduction of the higher iron oxides approximately to an FeO state, a reduction of the nickel oxides, and a maintenance of the reduction temperature in step (b) and of a content of surplus carbon not in excess of 2% by weight in the matter discharged, and the matter discharged is processed further in a molten state with formation of metallic iron in the amount required for the desired iron-nickel alloy, whereas the remaining iron content is slagged.
6. A process according to any of claims 1 to 4, characterized in that materials which contain manganese oxides are processed and carbonaceous reducing agent is supplied in step (c) to the stationary fluidized bed at such a rate as to effect a reduction of the higher manganese oxides, approximately to the MnO state and a maintenance of the reduction temperature in step (b) and to minimize the surplus carbon contained in the discharged matter.
EP86201942A 1985-11-15 1986-11-07 Process for reducing the oxidation level of metallic oxides Expired EP0222452B1 (en)

Applications Claiming Priority (2)

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DE3540541 1985-11-15
DE19853540541 DE3540541A1 (en) 1985-11-15 1985-11-15 METHOD FOR REDUCING HIGHER METAL OXIDS TO LOW METAL OXIDS

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Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI84841C (en) * 1988-03-30 1992-01-27 Ahlstroem Oy FOERFARANDE OCH ANORDNING FOER REDUKTION AV METALLOXIDHALTIGT MATERIAL.
ZA946071B (en) * 1993-08-30 1995-03-16 Mintek The production of ferronickel from nickel containing laterite
RU2044088C1 (en) * 1994-04-15 1995-09-20 Акционерное общество закрытого типа "ККИП" Method to extract manganese from manganese-containing ore
CH689633A5 (en) * 1995-01-10 1999-07-30 Von Roll Umwelttechnik Ag Process for cooling and cleaning of flue gases.
CU23070A3 (en) * 1999-01-12 2005-07-19 Falconbridge Ltd REDUCTION OF THE FLUDIZED LAYER OF LATERITE FINE WITH REDUCTION OF GASES GENERATED IN SITU.
DE10101157A1 (en) * 2001-01-12 2002-07-18 Mg Technologies Ag Process for producing a mixture of iron ore and smoldering coke
DE10260738A1 (en) * 2002-12-23 2004-07-15 Outokumpu Oyj Process and plant for conveying fine-grained solids
DE10260734B4 (en) * 2002-12-23 2005-05-04 Outokumpu Oyj Process and plant for the production of carbon coke
DE10260733B4 (en) * 2002-12-23 2010-08-12 Outokumpu Oyj Process and plant for the heat treatment of iron oxide-containing solids
DE10260741A1 (en) 2002-12-23 2004-07-08 Outokumpu Oyj Process and plant for the heat treatment of fine-grained solids
DE10260737B4 (en) * 2002-12-23 2005-06-30 Outokumpu Oyj Process and plant for the heat treatment of titanium-containing solids
DE10260731B4 (en) * 2002-12-23 2005-04-14 Outokumpu Oyj Process and plant for the heat treatment of iron oxide-containing solids
DE10260739B3 (en) * 2002-12-23 2004-09-16 Outokumpu Oy Process and plant for producing metal oxide from metal compounds
DE102004042430A1 (en) * 2004-08-31 2006-03-16 Outokumpu Oyj Fluidized bed reactor for the thermal treatment of vortex substances in a microwave-heated fluidized bed
CN101896581B (en) 2007-12-12 2014-08-27 奥图泰有限公司 Process and plant for producing char and fuel gas
CN102851490B (en) * 2012-08-30 2014-04-16 北京矿冶研究总院 Method for preparing high-quality calcine by fluidized reduction roasting of nickel oxide ore
CN104911332B (en) * 2015-05-07 2017-04-05 王立臣 A kind of Low grade manganese ore segmentation vertical roasting stove device and its using method
JP7147409B2 (en) * 2018-09-20 2022-10-05 住友金属鉱山株式会社 Method for smelting oxide ore
RU2721249C1 (en) * 2019-11-29 2020-05-18 Валентин Николаевич Терехов Composition of charge for melting of carbon-free iron

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR955384A (en) * 1950-01-14
GB191208400A (en) * 1911-04-07 1912-10-24 Isabellen Huette G M B H Improvements in the Treatment of Manganese Ores with a View to the Extraction of the Metal therein Contained.
US2310258A (en) * 1941-08-11 1943-02-09 Riveroll Elfego Process for recovering manganese from ore
FR996269A (en) * 1949-09-26 1951-12-17 Dorr Co Device for processing iron ores containing nickel
US2745730A (en) * 1952-01-29 1956-05-15 Pickands Mather & Co Process of reducing manganese ores
US2913331A (en) * 1958-04-15 1959-11-17 John G Dean Nickel ore reduction process using asphalt additive
US3375098A (en) * 1964-07-22 1968-03-26 Armco Steel Corp Gaseous reduction of iron ores
US3276858A (en) * 1964-12-07 1966-10-04 Pullman Inc Method for carrying out gas-solids reactions
FR1564579A (en) * 1968-01-25 1969-04-25
US3721548A (en) * 1968-12-23 1973-03-20 Republic Steel Corp Treatment of iron-containing particles
AU3565371A (en) * 1971-11-12 1973-06-28 Universe Tankship Inc Production of ferronickel by selective reduction of oxide ores
JPS5242552B2 (en) * 1974-08-01 1977-10-25
US4044094A (en) * 1974-08-26 1977-08-23 Kennecott Copper Corporation Two-stage fluid bed reduction of manganese nodules
SE387366C (en) * 1974-12-12 1980-03-27 Stora Kopparbergs Bergslags Ab SET FOR REDUCING FINALLY DISTRIBUTED METAL OXID CONTAINING MATERIAL
US4006010A (en) * 1975-05-30 1977-02-01 Amax Inc. Production of blister copper directly from dead roasted-copper-iron concentrates using a shallow bed reactor
DK288176A (en) * 1975-07-04 1977-01-05 Boliden Ab PROCEDURE FOR PREPARING A PARTLY PRE-REDUCED PRODUCT
US4010236A (en) * 1975-07-21 1977-03-01 Diamond Shamrock Corporation Manganese ore reduction
US4185996A (en) * 1978-02-13 1980-01-29 The Hanna Mining Company Arsenic and sulfur elimination from cobaltiferous ores
IN164687B (en) * 1984-08-16 1989-05-13 Voest Alpine Ag
DE3437686C2 (en) * 1984-10-15 1986-10-02 Hoechst Ag, 6230 Frankfurt Process for the reduction of metal ions in aqueous solutions

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NO169499C (en) 1992-07-01
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NO864490L (en) 1987-05-18
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US4789580A (en) 1988-12-06
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DE3662700D1 (en) 1989-05-11

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