DE1783003C3

DE1783003C3 - Process for the production of ferro-silicon

Info

Publication number: DE1783003C3
Application number: DE19681783003
Authority: DE
Inventors: James Herbert Clarence NY Downing (VStA)
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1967-09-25
Filing date: 1968-09-14
Publication date: 1977-07-14

Description

Bei der Herstellung der Agglomerate ist es zweckmäßig, daß das kohlenstoffhaltige Material, dasIn the production of the agglomerates, it is advantageous that the carbonaceous material that

Eisenerz und das Siliciumdioxid in feinverteiltem Zustand vorliegen, z. B. mit Teilchendurchmessern von 0,075 mm und weniger. Zur Herstellung der Aggregate in Form von Kügelchen oder Briketts kann ein geeignetes Bindemittet wie Lignin verwendet werden.Iron ore and the silica are in a finely divided state, e.g. B. with particle diameters of 0.075 mm and less. To produce the aggregates in the form of beads or briquettes, a suitable binding agent such as lignin can be used.

Die Agglomerate können Größen von 12 —25 mm haben. Nach ihrer Herstellung bringt man sie in einen üblichen, für die Herstellung von Eisenlegierungen verwendeten elektrischen Ofen. Das Erhitzen geschieht am besten durch Unterpulverelektroden. Dann sticht man in üblicher Weise ab.The agglomerates can have sizes of 12-25 mm. After they are made, you put them in you common electric furnace used for the production of ferrous alloys. The heating happens preferably with submerged powder electrodes. Then you tap off in the usual way.

Die nachstehenden Beispiele erläutern die Herstellung von 50%igem Ferrosilicium.The following examples illustrate the production of 50% ferro-silicon.

example 1

Eine Mischung wurde hergestellt aus 44,1% SiO₂ mit einem Teilchendurchmesser von etwa 8 Mikron, 30,9 Hämatit mit einem Teilchendurchmesser von 0,075 mm, 25% Kohle mit einem Teilchendurchmesser von 0,1 mm uno unter Verwendung eines Bindemittels aus zwei Dritteln Lignin und einem Drittel NatriumsilicaLA mixture was made of 44.1% SiO ₂ with a particle diameter of about 8 microns, 30.9% hematite with a particle diameter of 0.075 mm, 25% coal with a particle diameter of 0.1 mm uno using a binder of two thirds of lignin and one third sodium silicaL

Die Kohlenstoff menge betrug 113% der zur Reduktion des Siliciumdioxids unter Bildung von Kohlenmonoxid erforderlichen Menge.The amount of carbon was 113% of that for reduction of the silicon dioxide required to form carbon monoxide.

Der brasilianische Hämatit hatte die nachstehende Zusammensetzung: 70.2% Fe, 0,52% SiO₂,0,70% Al₂O₃. Die Kohle hatte folgende Zusammensetzung: 79,7% gebundene Kohle, 15,0% flüchtige Bestandteile, 4,5% Asche.The Brazilian hematite had the following composition: 70.2% Fe, 0.52% SiO ₂ , 0.70% Al ₂ O ₃ . The coal had the following composition: 79.7% bound coal, 15.0% volatile components, 4.5% ash.

Die Ausgangsstoffe v/urden gemischt und zu Kügelchen von etwa 12 mm Durchmesser geformt. Diese Kügelchen wurden in einem elektrischen Lichtbogenofen erhitzt, wobei beide Kohleelektroden sich innerhalb der Charge befanden.
Zum Schmelzen und Reduzieren wurden je KiIogramm Silicium 103 kWh gebraucht. Die Ausbeute an Silicium betrug 98,98%.The starting materials are mixed and formed into spheres approximately 12 mm in diameter. These beads were heated in an electric arc furnace with both carbon electrodes inside the batch.
For melting and reducing, 103 kWh were used per kilogram of silicon. The yield of silicon was 98.98%.

Verwendete man dieselben Ausgangsstoffe, gab aber Kohle in einer Menge von 119,5% des theoretisch Erforderlichen zu, so brauchte man zur Herstellung des Ferrosiliciums je Kilogramm Silicium 143 kWh, und die Ausbeute an Silicium betrug nurP ',53%.If you used the same starting materials, but gave coal in an amount of 119.5% of the theoretical To produce the ferrosilicon, one needed 143 kWh per kilogram of silicon, and the The yield of silicon was only P ', 53%.

Example 2

Gemäß dem Beispiel 1 wurde ein Ausgangsgemisch auf 50,2% Quarz mit Teilchengrößen von 5 χ 2,5 mm, 23,2% Eisenschrott in Form von Drehspänen, 13,25% Koks und 13,25% Kohle gemischt. Der Gehalt an Kohlenstoff betrug 105% des theoretisch Erforderlichen. According to Example 1, a starting mixture of 50.2% quartz with particle sizes of 5 χ 2.5 mm, 23.2% scrap iron in the form of turnings, 13.25% coke and 13.25% coal mixed. The content of Carbon was 105% of what is theoretically required.

Die Kohle hatte folgende Zusammensetzung: 72,5% gebundenen Kohlenstoff, 23,12% flüchtige Bestandteile, 4,54% Asche. Der Koks enthielt 9C% gebundene Kohle. Zum Erschmefzen des Ferrosiliciums wurden je Kilogramm Silicium 13,1 kWh benötigt. Die Ausbeute an Silicium betrug 93,33%.The coal had the following composition: 72.5% bound carbon, 23.12% volatile components, 4.54% ash. The coke contained 9C% bound coal. For smelting ferrosilicon were ever Kilogram of silicon requires 13.1 kWh. The silicon yield was 93.33%.

Ein Vergleich der Zahlen der Beispiele 1 und 2 zeigt, daß bei einem Kohlenstoffgehalt von 113% der Theorie die erforderliche Energie niedriger lag als. bei anderenA comparison of the numbers in Examples 1 and 2 shows that with a carbon content of 113% of theory the required energy was lower than. with others

Kohlenstoffgehalten. Ebenfa'ls war bei 113% Kohlenstoff die Ausbeute höher.Carbon content. It was also 113% carbon the yield is higher.

Example 3

Es wurden ähnliche Mischungen wie in dem Beispiel 1 hergestellt, wobei Kohle in verschiedenen Mengen verwendet wurde. Bei einer Kohlenstoffmenge von 105% der Theorie wurden 17,4 kWh je Kilogramm Silicium benötigt, und die Ausbeute betrug 82,1%. Bei einer Kohlenstoftmenge von 110% der Theorie wurden 16,1 kWh je Kilogramm Silicium benötigt, und die Ausbeute betrug 85,7%. Bei einer Kohlenstoffmenge von 115% der Theorie wurden 22,1 kWh je Kilogramm Silicium benötigt, und die Ausbeute betrug 64,4%.Mixtures similar to those in Example 1 were prepared, using different amounts of coal has been used. With an amount of carbon of 105% of theory, 17.4 kWh per kilogram would be Required silicon, and the yield was 82.1%. With a carbon amount of 110% of theory 16.1 kWh per kilogram of silicon was required, and the yield was 85.7%. With an amount of carbon of 115% of theory, 22.1 kWh per kilogram of silicon were required, and the yield was 64.4%.

Diese Beispiele zeigen, daß es hinsichtlich des Energiebedarfs und der Ausbeute optimale Mengen für den Kohlenstoff gibt.These examples show that there are optimal quantities for in terms of energy requirements and yield gives the carbon.

Claims

Patent claims:

1. Process for the production of Ferrosilieium with 45 to 50% silicon from agglomerates of Silicon dioxide, iron ore and carbonaceous reducing agents by means of a submerged arc in an arc furnace, characterized in that that the carbon content is 105 to 115% of the theoretically required amount Reduction of silicon dioxide to metallic silicon and binding of oxygen as carbon monoxide is equivalent to.

2. The method according to claim 1, characterized in that the carbon content is 110 to 113% amounts to.

Iron ore

Vo Fe % S1O2 % AIjOj Vo Fe% S1O2% AIjOj

The invention relates to a method of manufacture of ferrous silicon with 45 to 50% silicon from agglomerates of silicon dioxide, iron ore and carbonaceous Reducing agents by means of a submerged arc in an electric arc furnace.

The invention is based on the surprising observation that in the production of ferrosilicon with a silicon content of 45 to 50% by reducing silicon dioxide and iron ore with coal a minimum for the energy to be applied is passed through, which depends on the carbon content in the Starting mixture depends.

GB-PS 10 32 747 describes a process for the production of ferrosilicon in an electric arc furnace, where the required iron is in the form of iron ore is fed. However, this leads to a considerable increase in the consumption of electrical energy.

The US PS 11 71 719 describes the implementation of Fe2C> 3, ground sand and coke to 50% Ferrosilicon. There is a special design of the melting furnace with a corresponding process management proposed that the iron component is already reduced in a preheating zone, so that in the actual reduction of the silicon dioxide, metallic iron is already present.

The object of the invention is to produce ferrosilicon from cheap ferrous starting material with lower energy consumption and higher ferrosilicon yield.

This object is achieved in that the carbon content is 105 to 115% of the theoretical Amount required to reduce the silicon dioxide to metallic silicon and bind the Oxygen than carbon monoxide.

In a preferred embodiment, the carbon content is 110 to 113%.

To carry out the process, an electric arc furnace is preferably used in which at least one of the electrodes is located within the agglomerates to be heated.

When carrying out the process, the commercially available starting materials can be used; they are brought into the form of agglomerates by known methods. So z. B. the silica in in the form of quartz or sand. The carbonaceous material can be metallurgical coal or be coke. For example, the following ores can be used as iron ores:

Orinoco

Brazilian. Haematii
Lac Jeannine

65.0 1.05 70.2 0.5 65.9 5.5

1.25

0.7

0.6