DE102013016366A1 - Production of high quality manganese from ferromanganese by evaporation in a vacuum induction plant - Google Patents

Abstract

A process for producing engineered manganese by evaporating carbonaceous ferromanganese in an induction vacuum vessel, the process being carried out under vacuum and at temperatures above the liquidus temperature of the manganese, and inserting a ladle of liquid carbonaceous ferromanganese into an induction vaporizer (1) Metal under vacuum, and by a vacuum pump (3) and filter system (10) in the range of 10-900 mbar and a temperature in the range of> 1248 ° C stirring with argon evaporated and later in the system by a primary cooler ( 4) is cooled with water, wherein the Mn vapors liquefied in a mobile condensation chamber (2) at temperatures in the range of 1350-1400 ° C by a secondary cooler (5) and continuously through a siphon-like heated tap hole in a casting machine (8) tapped and the final product (11) shed. Apparatus for carrying out the method.

Description

The present invention relates to a process for the production of technically pure manganese by evaporation of carbonaceous ferromanganese in an induction vacuum vessel.

Manganese is one of the most important alloying elements in steelmaking. It is characterized by high strength and elongation. The production of steel grades with manganese takes place by adding manganese-containing alloying agents during the steelmaking process. These include Mn alloys produced in blast furnaces or high carbon reduction furnaces such as FeMnHC (HCFeMn) and FeMnLC (LCFeMn) alloys with medium FeMnMC (MCFeMn) and low carbon content. produced in secondary metallurgical plants.

The manganese alloys are loaded in addition to the carbon contents mentioned also with other elements such as phosphorus and sulfur, so that the application of materials can not be used indefinitely.

Typical composition of manganese alloys in wt .-% are: C Si P S Mn FeMnHC 7-8 1.5-4.5 0.2-0.4 12:03 65-82 FeMnMC 1.0 1.5-2.5 0.2-0.4 12:02 75-85 FeMnLC 0.2-0.7 1-2 0.1-0.3 12:02 78-92

However, there is an increasing demand for technically pure manganese in order to meet the constantly growing demands of high-quality steel production. At present, technically pure manganese is only produced in an electrolytic manner, since pure manganese can not be obtained technically by reduction with carbon, since in addition to manganese there are also stable carbides, in particular Mn ₇ C ₃ .

For this purpose, as pure a manganese sulfate solution is used, which is electrolysed with stainless steel electrodes at 5-7 V. Pure manganese is produced at the cathode and oxygen at the anode, which reacts with manganese ions to form brownstone. 2MnSO ₄ + 2H ₂ O → 2Mn + 2H ₂ SO ₄ + O ₂

In addition, the extraction of manganese by the reduction of manganese oxides with aluminum (aluminothermy) or silicon are known.

Another way of Mangangewinnung is to heat the above manganese compounds so far, so that the manganese evaporates.

However, pure manganese is formed only at temperatures above 1600 ° C, since only at this temperature, a portion of the manganese begins to evaporate, so that this production route has not been economically applicable.

An object of the present invention is to provide a process for the continuous production of manganese by evaporation of the starting raw materials, which is inexpensive and thus economical.

This object is achieved by the features specified in claim 1, in particular by the fact that the process is carried out under vacuum and temperatures above the liquidus temperature of manganese, wherein a pan is used with liquid carbonaceous ferromanganese in an induction evaporator, the metal under vacuum, is generated by a vacuum pump and filter system in the range of 10-900 mbar and a temperature in the range of> 1248 ° C stirring with an inert gas and cooled in the course of the system with water, the Mn vapors in a mobile condensation chamber liquefied at temperatures in the range 1350-1400 ° C and tapped by a siphon-like heated tap hole continuously in a Vergießmaschine.

The plant presented in the invention and the process represents an innovative technique not only in terms of continuous manganese production but also their potting.

In the following, the metallurgical properties of manganese are described.

The two-component system Mn-Fe represents various phases of the manganese-iron solution. As shown in the diagram below, the liquidus temperature of pure manganese is 1246 ° C.

Fe-Mn Phasengleichgewichtsystem Mn-Fe

Fe-Mn phase balance system Mn-Fe

At the manganese content of 65-92%, typical content of the ferroalloys, the liquidus temperature is in the range 1246-1280 ° C. It defines the lowest temperature at which the liquid material starts to evaporate. The vapor pressure as a function of the temperature has an exponentially increasing course.

Mn-Dampfdruck

Mn-vapor pressure

In order to illustrate the physical conditions of the process according to the invention, the evaporation kinetics of manganese will be described below.

(–dMn/dt):

Verdampfungsrate in %/min

τ:

Phasenumwandlungskonstante in Minuten

[Mn]:

aktuelle Mangan-Konzentration

[Mn*]:

Mn-Gleichgewichtskonzentration bei aktuellem Prozesszustand (p, T, Inertgas) ist.

The evaporation kinetics of manganese is a function of pressure, temperature and inert gas rate. The evaporation process itself is carried out by phase change liquid / gas (steam) at a given temperature and the pressure according to the law of the first order, as shown in equation (1), (- dMn / dt) = 1 / τ ([Mn] - [Mn *]) (1) wherein

(-DMn / dt):

Evaporation rate in% / min

τ:

Phase conversion constant in minutes

[Mn]:

current manganese concentration

[Mn *]:

Mn equilibrium concentration at the current process state (p, T, inert gas).

den Verdampfungsdruck pMn als auch durch den Aktivitätskoeefizient fMn als Funktion der Metallzusammensetzung wird das Mangangleichgewicht [Mn*] folgend dargestellt:

worin

At a phase equilibrium (liquid-gas) [Mn *] = {Mn *} (2) expressed by a temperature-dependent constant K (T),

the vaporization pressure pMn as well as the activity coefficient fMn as a function of the metal composition, the manganese balance [Mn *] is represented as follows:

wherein

• 1. NMn: Mn-Volumenstrom im Vakuumgefäß in Nm3/min, direkt proportional zur Verdampfungsrate ausgedrückt durch k(–dMn/dt),
• 2. uAr: eingeblasener Ar-Volumenstrom in das Vakuumgefäß in Nm3/min,
• 3. p: Druck innerhalb des Verdampfungsgefässes

It applies

• 1. NMn: Mn volume flow in the vacuum vessel in Nm3 / min, directly proportional to the evaporation rate expressed by k (-dMn / dt),
• 2. uAr: blown Ar volumetric flow into the vacuum vessel in Nm3 / min,
• 3. p: pressure inside the evaporation vessel

Equations (4) and (5) in conjunction with equation (1) give the following relation:

• – Metalltemperatur T, geregelt im Temperaturbereich größer als 1246°C mit einer induktiven Heizung
• – Gefäßdruck p, geregelt im Bereich 10 bis 900 mbar mittels eines Vakuumpumpensystems
• – Ar-Inertgasdurchflussrate uAr, geregelt im Bereich 0.05 bis 0.5 Nm3/(tMetall min) mittels eines Einblassystems.

Equation (6) represents the control principle based on the following quantities:

• - Metal temperature T, regulated in the temperature range greater than 1246 ° C with an inductive heating
• - Vessel pressure p, regulated in the range 10 to 900 mbar by means of a vacuum pump system
• - Ar-Inertgasdurchflußrate uAr, regulated in the range 0.05 to 0.5 Nm3 / (tMetall min) by means of an injection system.

This results in all relevant parameters for carrying out the method according to the invention with the device according to the invention.

The method provides that the liquefaction of the Mn vapors takes place continuously by means of the secondary cooler, which is arranged in the vapor stream within a vapor line and is formed in a conical shape for the purpose of improving the drop outflow.

The vacuum pump system is additionally equipped with a secondary water cooling system, a condenser and a filter. The evaporation process is additionally supported with argon as an inert gas and forms a kind of inert gas atmosphere.

The technically pure manganese is continuously cooled with water, tapped and placed under the Argon protective gas atmosphere in a casting machine, where it can be poured into the desired formats.

During the process, it is intended to control the rate of evaporation, temperature, vacuum pressure and inert gas flow rate. The evaporation material to be evaporated may consist of various Mn concentrations, which in turn may then influence the rate of evaporation, temperature and inert gas flow rate.

It should also be possible that the evaporation material is charged continuously or discontinuously in the induction evaporator.

Another object of the present invention is to provide an apparatus for carrying out the method according to the invention.

This further object is achieved by a device according to the features specified in claim 9, in particular an evaporator in which the manganese alloy is used, the metal under vacuum, and generated by a vacuum pump and filter system in the range of 10-900 mbar and a temperature In the range of> 1248 ° C stirring with argon is inert as a protective gas and is cooled by a primary water cooling and a secondary water cooling, the Mn vapors are collected in a mobile condensation chamber at temperatures in the range 1350-1400 ° C in the liquid state and is continuously abstechbar by a siphon-like heated tap hole in a Vergießschieb.

In a further embodiment, the evaporator is an induction evaporator, which is arranged on a hydraulic platform and designed to be vertically movable over it.

According to an advantageous embodiment of the device according to the invention, the mobile condensation chamber is designed to be horizontally movable.

In a further embodiment, the induction evaporator and the condensation chamber are gas-tightly connected to one another via a steam line operatively connected to the primary water cooling and the secondary water cooling.

In a particularly advantageous embodiment of the device according to the invention, the secondary water cooling within the steam line is arranged in the vapor stream above the condensation chamber.

It is envisaged that the steam line is connected to a supply line for the protective gas (inert gas) and the protective gas (inert gas) is circulated in the steam line and the supply line, wherein manganese manganese can be separated by a secondary condenser assigned to the feed line and the protective gas (inert gas) via the feed line to the induction evaporator and thus the steam flow is fed back. It is envisaged that additional inert gas can be supplied via the feed to the circuit in order to compensate for the process-related losses and so to be able to regulate the concentration in the circulatory system.

In order to keep the concentration of the protective gas (inert gas) in the circulation as constant as possible, additional protective gas can be introduced via a feed into the supply line, where it can be flushed back into the induction evaporator via a secondary filter.

The device according to the invention for carrying out the method according to the invention is explained in more detail below with reference to an exemplary embodiment with reference to the accompanying drawings.

The only figure shows:

1 a schematic view of the apparatus for performing the method as a process flow model.

As shown in the single figure, the device consists 18 essentially from an induction evaporator 1 in which the FeMn introduced at a temperature of 1600-1700 ° C in the liquid Physical state is maintained. The induction evaporator 1 is in this embodiment on a hydraulic platform 9 arranged, which allows it to raise and lower.

In the bottom area of the induction evaporator 1 is at least one flush pipe connection 19 provided with a supply line 15 connected via the a protective gas, in this case argon, in the induction evaporator 1 is initiated. The inert gas rises through the FeMn melt, where it is with the vaporized portion of manganese at a pressure of 100 to 200 mbar in a steam line 14 collects and in a steam stream 17 , shown here as arrows, is discharged. The steam line 14 is gas-tight with the induction evaporator 1 connected.

Located in the steam line 14 located vapor stream 17 is at a primary water cooling 4 , which surrounds the steam line from the outside, passed by and cooled down. In a secondary water cooling 5 becomes the vapor stream 17 so far cooled down, that an aggregate state change of manganese from gaseous to liquid occurs. In order to do this as efficiently and quickly as possible, it is provided, the secondary water cooling 5 inside the steam pipe 14 and in the vapor stream 17 to arrange.

The secondary water cooling 5 is conical and lies with the tapered side in the direction of the incoming vapor stream 17 , In the figure, this is shown as an isosceles triangle.

Below the secondary water cooling 5 is a horizontally movable condensation chamber 2 arranged. Also the condensation chamber 2 can be gas-tight with the steam pipe 14 get connected.

In the horizontally movable condensation chamber 2 The liquefied high-purity manganese accumulates and is kept in a liquid state at a temperature of 1350 to 1400 ° C.

The movable condensation chamber 2 is a siphon-like tap hole 13 assigned. About the tap hole 13 The manganese is tapped and put into a casting machine 8th given up. The casting machine 8th is chambered and is also under a protective gas atmosphere 7 (Argon) and is equipped with appropriate device means for applying and maintaining the inert gas atmosphere. In the casting machine, the manganese becomes a final product 11 cast in the appropriate formats. The final product 11 has a purity of 99.9% manganese.

While the manganese-containing vapors in the vapor stream 17 at the secondary water cooling 5 condense is via a connection 20 the protective gas atmosphere by means of a vacuum pump 3 sucked off and back into the supply line 15 fed. The vaporized manganese still present in the shielding gas becomes a secondary condenser 12 cooled down and separated from the protective gas atmosphere. The secondary capacitor 12 stands for this a vacuum pump with water cooling 6 to disposal.

The inert gas cleaned by the manganese vapor is in the supply line 15 circulated and via an infeed 16 and a secondary filter 10 returned to the induction evaporator. About the feed 16 the circuit is returned through the course of the process lost inert gas, so that a stable argon inert gas atmosphere is ensured at any time.

LIST OF REFERENCE NUMBERS

1

induction evaporator

2

condensation chamber

3

vacuum pump

4

primary water cooling

5

secondary water cooling

6

Vacuum pump with water cooling system

7

Argon protective atmosphere

8th

casting machine

9

hydraulic platform

10

secondary filter

11

end product

12

secondary capacitor

13

tap hole

14

steam line

15

supply

16

feed

17

steam power

18

contraption

19

flush pipe connection

20

connection

Claims (15)

Process for the preparation of technically pure manganese by evaporation of carbonaceous ferromanganese in an induction vacuum vessel, characterized in that the process is carried out under vacuum and at temperatures above the liquidus temperature of the manganese, with a ladle of liquid carbonaceous ferromanganese in an induction evaporator ( 1 ), the metal is generated under vacuum, and by a vacuum pump ( 3 ) and filter system ( 10 ) is in the range of 10-900 mbar and a temperature in the range of> 1248 ° C stirring with an inert gas evaporated and later in the system by a primary cooler ( 4 ) is cooled with water, the Mn vapors in a mobile condensation chamber ( 2 ) at temperatures in the range 1350-1400 ° C by a secondary cooler ( 5 ) and continuously through a siphon-like heated tap hole in a casting machine ( 8th ) and the final product ( 11 ) are shed. Process according to Claim 1, characterized in that the liquefaction of the Mn vapors is carried out continuously by means of the secondary cooler ( 5 ) suspended in the vapor stream ( 17 ) within a steam line ( 14 ) is arranged and formed for the purpose of improving the drop flow in a conical shape takes place. Method according to claim 1, characterized in that the vacuum pump system is additionally provided with a secondary water cooling system ( 6 ), a capacitor ( 12 ) and a filter ( 13 ). A method according to claim 1, characterized in that the evaporation process is additionally supported with argon as an inert gas. A method according to claim 1, characterized in that the technical pure manganese is continuously cooled with water, tapped and under an argon protective gas atmosphere in a casting machine ( 8th ) is abandoned. A method according to claim 1, characterized in that the evaporation rate of temperature, vacuum pressure and inert gas flow rate is controlled. A method according to claim 1, characterized in that the evaporation material consists of different Mn concentrations. A method according to claim 7, characterized in that the evaporation material continuously or discontinuously in the induction evaporator ( 1 ) is charged. Device for carrying out the method according to claims 1 to 8, characterized by an evaporator ( 1 ) in which the manganese alloy is used, the metal under vacuum, generated and by a vacuum pump ( 3 ) and filter system ( 13 ) is in the range of 10-900 mbar and a temperature in the range of> 1248 ° C stirring with argon as an inert gas and over a primary water cooling ( 4 ) and via a secondary water cooling ( 5 ) is cooled, the Mn vapors in a mobile condensation chamber ( 2 ) are collected at temperatures in the range 1350-1400 ° C in the liquid state and by a siphon-like heated taphole ( 13 ) continuously into a casting machine ( 8th ) is abstechbar. Apparatus according to claim 9, characterized in that the evaporator ( 1 ) is an induction evaporator mounted on a hydraulic platform ( 9 ) is arranged and is formed vertically movable over this. Device according to claim 9, characterized in that the mobile condensation chamber ( 2 ) is formed horizontally movable. Device according to claim 10 and 11, characterized in that the induction evaporator ( 1 ) and the condensation chamber ( 2 ) with one another, with the primary water cooling ( 4 ) and secondary water cooling ( 5 ) Actively connected steam line ( 14 ), are connected gas-tight. Device according to claim 12, characterized in that the secondary water cooling ( 5 ) within the steam line ( 14 ) in the vapor stream ( 17 ) above the condensation chamber ( 2 ) is arranged. Device according to claim 13, characterized in that the steam line ( 14 ) with a supply line ( 15 ) is connected to the protective gas, and the protective gas in the steam line ( 14 ) and the supply line ( 15 ) is circulated, wherein vaporous manganese by one, the supply line ( 15 ), secondary capacitor ( 12 ) is separable and the protective gas via the supply line ( 15 ) the induction evaporator ( 1 ) is returned to the circulation. Apparatus according to claim 14, characterized in that the protective gas from the condensation chamber ( 2 ) via an infeed ( 16 ) again in the supply line ( 15 ) and via a secondary filter ( 10 ) in the induction evaporator ( 1 ) einspülbar and additional inert gas also via the feed ( 16 ) the vapor stream ( 17 ) is zuluhrbar.

Images