CN113969351B - A method for preparing silicon-manganese alloy by synergistic reduction and electrolysis by multi-circuit DC electrode arc heating - Google Patents

Abstract

The invention belongs to the technical field of alloy preparation, and particularly relates to a method for preparing a silicon-manganese alloy by using the cooperation of reduction and electrolysis through multi-loop direct-current electrode arc heating. The technical scheme of the invention is as follows: a method for preparing silicon-manganese alloy by using the cooperation of reduction and electrolysis through multi-loop direct-current electrode arc heating is characterized in that a furnace body of a direct-current submerged arc furnace adopts a square groove type structure, two rows of multi-loop metal electrodes arranged in parallel are adopted in the direct-current submerged arc furnace, carbon-free distribution is carried out between the metal electrodes, and carbon distribution is carried out at other parts of the furnace body; and preparing the silicon-manganese alloy between the metal electrodes by utilizing an electrochemical reaction, and preparing the silicon-manganese alloy at other parts of the furnace body by utilizing a reduction reaction. The method for preparing the silicon-manganese alloy by the cooperation of reduction and electrolysis through the multi-loop direct-current electrode arc heating can save energy and reduce carbon consumption when producing the silicon-manganese alloy.

Description

A method for preparing silicon-manganese alloy by using reduction and electrolysis synergistically by multi-circuit DC electrode arc heating

technical field

The invention belongs to the technical field of alloy preparation, and in particular relates to a method for preparing a silicon-manganese alloy by means of reduction and electrolysis synergistically heated by a multi-circuit DC electrode arc.

Background technique

Both manganese and silicon are the main alloying elements used in carbon steel. Manganese is one of the most important deoxidizers in the steelmaking process, and almost all steel grades require manganese to deoxidize. Silicon is the most important alloying element after manganese in pig iron and carbon steel. There are two methods for the preparation of silicon-manganese alloy, carbothermic reduction method and electrolytic method.

The traditional process of smelting silicon-manganese alloy is reduction method, that is, submerged arc furnace smelting, which is an industrial electric furnace with huge power consumption and carbon consumption. Submerged arc furnaces are divided into alternating current submerged arc furnaces and direct current submerged arc furnaces. At present, the AC submerged arc furnace is widely used, which uses three electrodes, and arc transfer occurs during the smelting process, that is, the energy efficiency is reduced due to the side current problem. In addition, the arc combustion of the AC submerged arc furnace is intermittent, and the arc has to go through two arc-extinguishing-ignition processes for each cycle of voltage alternating, causing noise. The AC submerged arc furnace has short-circuit inductive reactance and excessive impedance, resulting in a low effective power of the AC submerged arc furnace. Generally, the power factor of the AC submerged arc furnace is about 0.85. At the same time, the consumption of the three electrodes is uneven, and the heating efficiency is low. In recent years, due to the development and application of high-power thyristor technology, the manufacturing technical difficulties of high-power DC power supply equipment have been solved, so DC arc technology has received attention. The DC submerged arc furnace technology avoids the disadvantages of eddy current, skin effect, noise and dust that cannot be solved by traditional AC furnace production. The power factor is as high as 0.93, and the effect of energy saving and consumption reduction is remarkable. However, due to the immaturity of the technology, many problems have arisen in actual production, such as poor electrode baking effect, high secondary voltage, and insufficient temperature resistance and processing capacity of some equipment.

The preparation of silicon-manganese alloy by electrolysis requires steps such as cathode preparation, molten salt pretreatment, pre-electrolysis, electrolysis, etc., which consumes a lot of electricity and has low efficiency.

SUMMARY OF THE INVENTION

The invention provides a method for preparing a silicon-manganese alloy by means of reduction and electrolysis synergistically heated by a multi-circuit DC electrode arc, which can save energy and reduce carbon consumption when producing the silicon-manganese alloy.

The technical scheme of the present invention is as follows:

A multi-circuit direct current electrode arc heating method for preparing silicon-manganese alloy by synergistic reduction and electrolysis. Carbon-free cloth is carried out between the metal electrodes, and carbon cloth is carried out in other parts of the furnace body; silicon-manganese alloy is prepared by electrochemical reaction between the metal electrodes, and is used in other parts of the furnace body. Reduction reaction to prepare silicon manganese alloy.

Further, the method for preparing a silicon-manganese alloy by means of reduction and electrolysis synergistically heated by multi-circuit DC electrode arc heating specifically includes the following steps:

(1) A carbon-free distribution port and a carbon distribution port are respectively provided on the furnace cover of the DC submerged arc furnace, and the carbon-free distribution port is located at the center position between the two metal electrodes or between the four metal electrodes. the center of the space; the carbon distribution port is located at the periphery of the metal electrode;

(2) immersing the metal electrode in the silicon-manganese oxide ore material at the bottom of the furnace, and using arc heating to make the silicon-manganese oxide ore material form a melt;

(3) adding a mixed mineral material of small particle size and not adding coke through the carbon-free cloth opening, forming an electrochemical reaction system between the metal electrodes, and using an electrolytic method to prepare a silicon-manganese alloy;

(4) After the temperature in the furnace is heated up, the mixed ore with normal particle size and coke is added through the carbon distribution port, and a reduction reaction system is formed around the metal electrode, and the silicon-manganese alloy is prepared by the reduction method.

Further, in the method for preparing a silicon-manganese alloy by means of reduction and electrolysis synergistically heated by a multi-circuit DC electrode arc, the metal electrode is a nickel rod.

Further, in the multi-circuit DC electrode arc heating method for preparing silicon-manganese alloy by synergistic reduction and electrolysis, the particle size of the mixed ore with small particle size and without adding coke is 15-25 mm.

Further, in the multi-circuit DC electrode arc heating method for preparing silicon-manganese alloy by synergistic reduction and electrolysis, the particle size of the mixed ore with normal particle size and mixed with coke is 75-85mm.

The beneficial effects of the present invention are as follows: the present invention utilizes reduction and electrolysis to synergistically prepare silicon-manganese alloy, which can improve electrical efficiency, prolong the service life of electrodes, reduce short-circuit inductance, improve power factor, and reduce power consumption; at the same time, reduce coke Equal the amount of reducing agent to reduce costs; DC arc heating has fast melting speed, high heating efficiency and good heating effect.

Description of drawings

Fig. 1 is the schematic diagram of utilizing reduction and electrolysis synergistic method to prepare silicon-manganese alloy in DC submerged arc furnace;

Figure 2 is a top view of the DC submerged arc furnace.

In the figure: 1 is the furnace body; 2 is the furnace cover; 3 is the metal electrode; 4 is the carbon-free distribution port; 5 is the carbon distribution port; 6 is the electrochemical reaction system; 7 is the reduction reaction system.

Detailed ways

The composition requirements of silicon-manganese alloy: the content of manganese is 60-63%, and the content of silicon is 20-23%. The silicomanganese minerals include Australian ore, carbonate ore, Myanmar primary ore, Guangxi ore, Myanmar ore, sinter, placer and dry slag in a ratio of 21:15:20:12:8:10:8:6. The chemical compositions of different types of minerals are shown in Table 1.

Table 1 Chemical composition of mineral material (mass fraction wt%)

A part of the mixed ore is processed into a mixed ore with a small particle size of 20 mm and no coke is added.

Another part of the mixed ore material is added with a certain amount of coke as a reducing agent according to the proportion, and the mixed ore material is processed into a normal particle size with a particle size of 80mm and mixed with coke.

The furnace body 1 of the DC submerged arc furnace adopts a square trough structure, and two rows of multi-circuit metal electrodes 3 arranged in parallel are used in the DC submerged arc furnace; the yin and yang metal electrodes 3 are nickel rods, which are hung on the DC submerged arc furnace through the electrode holder. Among them, the distance between the metal electrode 3 and the furnace bottom is 1.1m, and the metal electrode 3 is connected to the DC power supply. The furnace cover 2 of the DC submerged arc furnace is respectively provided with a carbon-free distribution port 4 and a carbon distribution port 5, and the carbon-free distribution port 4 is located at the center position between the two metal electrodes 3 or four of the metal electrodes. At the center between the electrodes 3 ; the carbon distribution port 5 is located on the periphery of the metal electrode 3 .

A cylindrical iron bucket with the same diameter as the metal electrode is placed directly under the metal electrode 3, and coke lumps are loaded into the iron bucket. After energizing, the metal electrode 3 and the coke block are in contact for a short time, and then separated and kept at a certain distance, an arc will appear between the metal electrode 3 and the coke block. The secondary rated voltage of the transformer is 125V.

In the DC submerged arc furnace, the ore material is heated up by the combined action of arc heat and Joule heat, and a molten body is formed around the metal electrode 3, and the melting temperature of the mixed ore material ranges from 1150 to 1440 °C. Judging the range and depth of the melt by observing the values of the ammeter and voltmeter to form an electrochemical system.

In the melt area, a mixed ore with small particle size and no coke is added through the carbon-free distribution port 4, an electrochemical reaction system 6 is formed between the metal electrodes 3, and a silicon-manganese alloy is prepared by electrolysis.

Mixed minerals with normal particle size and coke are added through the carbon distribution port 5, and a reduction reaction system 7 is formed around the metal electrode 3, and a silicon-manganese alloy is prepared by a reduction method.

The silicon-manganese alloy is prepared by the synergistic method of reduction and electrolysis. The energy saving effect of the DC submerged arc furnace reaches 10%, and the carbon reduction effect reaches 3% to 5%.

Claims (4)

1. A method for preparing silicon-manganese alloy by using the cooperation of reduction and electrolysis through multi-loop direct-current electrode arc heating is characterized in that a furnace body of a direct-current submerged arc furnace adopts a square groove type structure, two rows of multi-loop metal electrodes arranged in parallel are adopted in the direct-current submerged arc furnace, carbon-free distribution is carried out between the metal electrodes, and carbon distribution is carried out at other parts of the furnace body; preparing silicon-manganese alloy between the metal electrodes by utilizing an electrochemical reaction, and preparing the silicon-manganese alloy at other parts of the furnace body by utilizing a reduction reaction;

the method specifically comprises the following steps:

(1) a carbon-free material distribution port and a carbon distribution port are respectively arranged on a furnace cover of the direct-current submerged arc furnace, and the carbon-free material distribution port is positioned at the center between two metal electrodes or at the center between four metal electrodes; the carbon preparation and distribution port is positioned at the periphery of the metal electrode;

(2) immersing the metal electrode into a silicomanganese oxide mineral aggregate positioned at the bottom of the furnace, and forming the silicomanganese oxide mineral aggregate into a molten mass by adopting an electric arc heating mode;

(3) adding a small-granularity mixed mineral aggregate without adding coke through the carbon-free material distribution port, forming an electrochemical reaction system between the metal electrodes, and preparing the silicomanganese alloy by using an electrolysis method;

(4) after the temperature in the furnace is raised, adding mixed mineral aggregate with normal granularity and coke through the carbon-blending material-distributing port, forming a reduction reaction system at the periphery of the metal electrode, and preparing the silicon-manganese alloy by using a reduction method.

2. The method for preparing silicon-manganese alloy by using the cooperation of reduction and electrolysis through multi-loop direct current electrode arc heating according to claim 1, wherein the metal electrode is a nickel rod.

3. The method for preparing Si-Mn alloy by using the cooperation of reduction and electrolysis through multi-loop direct current electrode arc heating according to claim 1, wherein the mixed mineral aggregate with small particle size and no coke has a particle size of 15-25 mm.

4. The method for preparing Si-Mn alloy by using the cooperation of reduction and electrolysis through multi-loop direct current electrode arc heating according to claim 1, wherein the mixed mineral aggregate with normal particle size and added with coke has a particle size of 75-85 mm.

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