CN110004300A - The method for producing Antaciron as raw material plasma jet feeding using aluminium ash - Google Patents

Abstract

The invention provides a method for preparing ferrosilicon alloy by using aluminum ash as raw material by plasma jet feeding, using secondary aluminum ash as raw material, using waste cathode carbon block of aluminum electrolysis cell as reducing agent, and using fly ash as additive to adjust the content of the raw material. The content of aluminum in the raw material is adjusted by using diatomite waste residue as an additive, and the material mainly composed of alumina and silicon oxide is reduced at high temperature in an electric arc furnace to prepare a certain composition of aluminum-silicon-ferroalloy; plasma flame flow is used to transport powder It can increase the reaction temperature by heating the material, accelerate the reduction of oxides and the volatilization of fluorides, especially in the high-temperature reduction process to achieve the decomposition of aluminum nitride in aluminum ash and the decomposition of cyanide in waste cathode carbon blocks, and The volatilization and recovery of fluoride, chloride and alkali metal in the material strengthens the high temperature reaction process of the whole electric arc furnace smelting and improves the production efficiency. The comprehensive utilization of various hazardous wastes and solid wastes can be realized in the same process.

Description

Method for preparing ferrosilicon alloy by using aluminum ash as raw material by plasma jet feeding

technical field

The invention relates to the field of electrometallurgy, in particular to a method for preparing ferrosilicon alloy by using aluminum ash as raw material by plasma jet feeding.

Background technique

The production methods of ferrosilicon are mainly divided into metal fusion method and electrothermal reduction method. The metal fusion method is to use pure metal aluminum, silicon and iron in a certain proportion to form an alloy in a molten state; the electrothermal reduction method uses oxides containing aluminum, silicon and iron as raw materials, and carbonaceous materials as raw materials. Reducing agent, the alloy is prepared by reduction and smelting in an electric arc furnace. Among them, the metal fusion method has the problems of reheating of pure metal, secondary burning loss and high production cost. The electrothermal reduction method also has problems such as shortage of pure mineral raw materials and poor economical production process.

A large amount of aluminum ash is produced in the process of aluminum electrolysis, aluminum processing, and scrap aluminum remelting and recycling. At present, the main methods of processing these aluminum ash are: after the aluminum ash is sieved, remelting the large pieces of aluminum ash to obtain metal aluminum; The remaining aluminum ash after the ash-frying machine is usually called secondary aluminum ash. At present, the secondary aluminum ash is mainly treated by landfill or storage. The aluminum ash produced in the process of aluminum smelting and processing usually contains 50-80% of metal aluminum. After conventional recycling, the main components of the remaining secondary aluminum ash are metal aluminum, alumina and aluminum nitride, which contain 5- 10% metal aluminum, more than 40% aluminum oxide and 10-25% aluminum nitride. According to the different refining methods used by various manufacturers, aluminum ash also contains 5-10% of fluoride and chloride. Since aluminum ash contains a large amount of aluminum nitride, it will generate ammonia gas when it encounters water, and the chloride and fluoride contained in aluminum ash will also dissolve in water. In 2016, aluminum ash has been included in the list of hazardous wastes by the Ministry of Environmental Protection. . The current treatment methods for secondary aluminum ash not only fail to utilize the valuable resources, but also have huge ecological risks.

Aluminum electrolysis cell is the main equipment for producing metal aluminum. After the aluminum electrolytic cell is damaged and overhauled, a large amount of electrolytic cell overhaul slag will be produced. The overhaul slag is composed of cathode carbon block, cathode paste, refractory brick, thermal insulation brick, anti-seepage material and thermal insulation board. Further, the overhaul slag can be divided into two main parts: waste cathode carbon block (cathode carbon block, cathode paste) and waste refractory lining (refractory brick, thermal insulation brick, anti-seepage material) eroded by fluoride salt electrolyte, while waste cathode The mass ratio of carbon block and waste refractory material is about 50%. At present, 5-10kg of waste cathode carbon blocks and 5-10kg of waste refractory materials are produced for every ton of metal aluminum produced. The main component of the waste cathode carbon block is carbonaceous material, except for the carbonaceous material, the most component is the electrolyte. The electrolyte components in the waste cathode carbon block mainly include NaF, Na ₃ AlF ₆ , Na ₅ Al ₃ F ₁₄ and CaF ₂ . The carbon content in the aluminum electrolysis waste cathode carbon block is generally 60%-70%, and the electrolyte component content is 15-25%. In addition, 4%-8% of alkali metals, mainly sodium metal, are present in aluminum electrolysis waste cathodes. When potassium salt is present in the electrolyte composition, metallic potassium is also present in the spent cathode carbon block. In addition to the above three main components, the waste cathode carbon block also contains a small amount of carbides, nitrides, oxides and cyanide, wherein the cyanide content accounts for about 0.1%-0.2% of the total mass of the waste cathode carbon. NaCN, complex cyanides and fluorides in spent cathode carbon blocks are the main factors that harm the environment. Cyanide and most fluorides are soluble in water, and the long-term accumulation of waste cathode carbon blocks will pollute groundwater and surface water, causing serious pollution to the environment. The treatment of waste cathode carbon blocks in aluminum electrolysis cells is divided into two categories. One is treatment technology. Even if the waste cathode carbon block materials are harmless and then landfilled or used by other industries, such as high-temperature hydrolysis technology, combustion power generation technology, The production of slagging agent for high-speed rail industry, used as fuel and mineral raw materials in the cement industry, converted into inert materials that can be landfilled, etc.; the other type is recycling technology, mainly to recover fluoride and carbon in waste cathode carbon blocks, For example, fluoride is recovered by wet leaching, used as an additive for cathode and anode carbon blocks, and flotation is used to separate fluoride electrolyte and carbon blocks, but the current treatment of waste cathode carbon blocks has not yet reached the industrialized level.

Every ton of coal burned will produce 0.15-0.3 tons of fly ash, and coal with high ash content will produce up to 0.4-0.5 tons of fly ash. At present, my country's annual production of fly ash reaches more than 600 million tons. A small amount of high-alumina fly ash can be used to extract alumina, while a large amount of low-aluminum fly ash is mainly used in the production of various building materials, such as cement admixtures, concrete additives and building materials deep-processing products, as well as extraction from fly ash Floating beads are used to produce refractory and thermal insulation materials, but these methods cannot fundamentally solve the problem of fly ash utilization. In addition, the added value of producing building materials is low, and the enterprises that use them must be close to large cities with large populations. Therefore, this method of utilization is mainly used in the eastern provinces of my country. However, the fly ash distributed in Shanxi, Inner Mongolia, Ningxia, Shaanxi, Gansu and Xinjiang has not been effectively utilized, and most of them are still disposed of by stacking and landfilling.

The rolls of aluminum processing enterprises need to be cooled and lubricated with rolling oil during the production process. The rolling oil needs to be filtered after a period of use, and the filter medium is made of diatomite. In the process of aluminum rolling, because the aluminum is soft, the wear of the roll is less, so the impurities in the rolling oil mainly come from the wear powder of the aluminum. When the diatomite has been used for a certain period of time, when the filtration accuracy cannot reach the standard of rolling oil, it needs to be replaced regularly. The replaced oily waste diatomite is regarded as hazardous waste, which not only poses the risk of environmental pollution, but also causes a great waste of resources. The main components of diatomite in my country are silica, alumina and iron oxide. At present, the diatomite waste residue produced by filtering rolling oil in aluminum processing plants mainly contains rolling oil and aluminum powder. The rolling oil can be deoiled with a degreaser, and the removed oil can be used to produce kerosene, while the diatomite waste residue is still No effective treatment was given.

It can be seen from the above analysis that the hazardous waste and solid waste generated by the current electrolytic aluminum, aluminum processing and power industries are treated separately, most of which are in the stage of harmless treatment, and the effective resource utilization is still in the research stage. As a result, the environmental pollution problem of these solid wastes has not been fundamentally solved.

SUMMARY OF THE INVENTION

In order to overcome the problems existing in the prior art, the present invention provides a method for preparing aluminum-silicon-iron alloy by using aluminum ash as raw material plasma jet feeding, using secondary aluminum ash as raw material, and using aluminum electrolytic cell waste cathode carbon block as The reducing agent uses fly ash as the additive to adjust the aluminum content in the raw material, and the diatomite waste residue as the additive to adjust the silicon content in the raw material. A certain composition of aluminum-silicon-iron alloy; in the high-temperature reduction process, the decomposition of aluminum nitride in aluminum ash and the decomposition of cyanide in waste cathode carbon blocks, as well as the volatilization and recovery of fluoride, chloride and alkali metal in the material, are realized in the same The comprehensive utilization of various hazardous wastes and solid wastes is realized in the process. In order to achieve the above object, the present invention adopts the following technical solutions:

The method for preparing Al-Si-Fe alloy by using aluminum ash as raw material plasma jet feeding comprises the following steps:

Step 1, the waste cathode carbon block, fly ash and diatomite waste residue in aluminum ash, aluminum electrolytic cell overhaul slag are respectively made into powder;

Step 2, determine the consumption of aluminum ash, waste cathode carbon block, fly ash and diatomite waste slag according to the composition of the target Al-Si-Fe alloy, and use the fixed carbon contained in the waste cathode carbon block as the reducing agent to calculate the reduction of two by stoichiometric ratio. The amount of metal aluminum and silicon produced by Al ₂ O ₃ and SiO ₂ oxides in the secondary aluminum ash, and then calculate the Al ₂ O ₃ and SiO ₂ oxides of fly ash and diatomite waste residue by reducing the waste cathode carbon block. The amount of metal aluminum and silicon obtained by reducing fly ash and diatomite waste residue is used to allocate the amount of metal aluminum and silicon obtained by reducing secondary aluminum ash, that is, to obtain the aluminum, aluminum and silicon in the prepared aluminum-silicon-ferroalloy. The composition of silicon, and the amount of aluminum ash, fly ash, diatomite waste residue and waste cathode carbon block; put secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue powder together into the mixture Mix evenly in the device;

Step 3, start the electric arc furnace and gradually increase the temperature in the furnace, the electrode used in the electric arc furnace is a hollow electrode, and the hollow channel in the middle of the electrode is connected to the flame outlet of the plasma generator; when the temperature of the bottom arc zone is 1900-2300 ℃, Using the generated plasma flame as the carrier, the powdery material is sent to the arc reaction zone through the hollow channel. When the smelting process reaches 1-3 hours, the formed Al-Si-Fe alloy melt is released from the bottom of the electric arc furnace and refined outside the furnace, that is, Al-Si-Fe alloy can be obtained; the alloy can be used as deoxidizer for steelmaking and reducing agent for magnesium-smelting, and the refining slag is returned to the batching process for continued use;

In step 4, the soot collected from the top of the electric arc furnace is immersed and filtered, the leaching temperature is 20-100°C, the liquid-solid ratio in the leaching process is (2-10):1, the leaching time is 0.5-3h, and the leaching is filtered after , the leaching solution is evaporated to recover sodium carbonate and sodium chloride, and the leaching slag is melted at high temperature after drying, and the melting temperature is higher than 1000 ℃, so that the fluoride and oxide are separated, and the recovered fluoride electrolyte is returned to the electrolyzer for use, and the slag phase is oxidized The material is returned to the raw material batching workshop of the electric arc furnace as the raw material for the smelting of ferrosilicon in the electric arc furnace.

The composition of the above aluminum ash is: Al ₂ O ₃ 40-80%, AlN≤20%, Al≤10%, SiO ₂ ≤ 5%, Na ₂ O ≤ 5%, Fe ₂ O ₃ ≤ 5%, Chloride≤10%, Fluoride≤10%.

The composition of the above-mentioned waste cathode carbon block is: C 60-80%, Al ₂ O ₃ ≤ 3%, Na 4-10%, fluoride electrolyte 10-20%, fluoride electrolyte is mainly cryolite, fluoride Sodium and calcium fluoride, or with lithium and potassium fluoride.

The composition of the above fly ash by mass ratio is: Al ₂ O ₃ 15-50%, SiO ₂ 30-50%, Fe ₂ O ₃ ≤ 10%, CaO ≤ 5%, MgO ≤ 5%, Na ₂ O ≤ 3 %, K ₂ O ≤ 3%, TiO ₂ ≤ 3%, other single metal oxide content < 1%.

The components of the above-mentioned diatomite waste residue are as follows: Al ₂ O ₃ ≤5%, SiO ₂ 80-99%, and Fe ₂ O ₃ ≤ 10%.

In the above step 1, the particle sizes of the aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue powder are all less than 100 mesh.

In the above step 3, the diameter of the hollow channel in the middle of the electrode is 20mm-200mm.

In the above step 3, the flow rate and flow rate of the plasma flame are controllable, and the temperature of the plasma flame is between 300-3000°C.

In the above step 3, the working gas of the plasma generator is one of argon, air and carbon monoxide.

In the above step 3, the refining agent used in the out-of-furnace refining contains sodium chloride, potassium chloride and cryolite. ~1500℃.

Compared with the prior art, the beneficial effects of the present invention are:

1. The current aluminum ash, waste cathode carbon block, diatomite waste residue and fly ash are all processed separately, that is to say, a variety of processes and multiple sets of treatment systems are used. Among them, most of the aluminum ash is treated by wet process. Through the wet process, the aluminum nitride in the aluminum ash reacts with water to generate ammonia gas. The waste residue is used to produce refractory materials. Ammonia wastewater, and the decomposition of aluminum nitride in the waste residue is incomplete. The treatment process of waste cathode carbon block is also divided into wet method and fire method, and the wet method is the main method. Both use strong acid or strong alkali for leaching, so that fluoride is converted into soluble hydrogen fluoride or sodium fluoride and separated from carbonaceous materials , the treatment process also produces a large amount of acid or alkali-containing wastewater, which is likely to cause secondary pollution. Oil-bearing diatomite is currently mainly extracted from oil, and the diatomite residue formed after oil extraction is mainly stored. The invention is an integrated treatment technology developed for various hazardous wastes and solid wastes. Aluminum ash, waste cathode carbon block, diatomite waste residue and fly ash are all processed and recovered in an electrothermal carbon reduction process. In the carbothermic reduction process, not only the high-temperature decomposition of the main toxic substances aluminum nitride and cyanide is achieved, but also the high-temperature volatilization and separation of the fluoride in the aluminum ash and the waste cathode carbon block is realized. The metal oxides are reduced into Al-Si-Fe alloys, and there is no waste residue and waste water in the whole process, which is a green and environmentally friendly treatment process.

2. The prior art is mainly based on innocence and reduction in the treatment of hazardous wastes such as aluminum ash, waste cathode carbon block, diatomite waste residue, etc. The treatment process of the present invention is innocuous and reduced at the same time , to realize the resource utilization of waste, that is, the fixed carbon in the waste cathode carbon block is used as a reducing agent to convert aluminum ash, diatomite waste residue and fly ash alumina, silicon oxide, iron oxide, etc. in the form of metal At the same time, the fluoride and alkali metal are also recycled, and the waste treatment is realized, and the whole process is a closed loop.

3. Using secondary aluminum ash as raw material, using fly ash as additive to adjust the aluminum content in the raw material, and using diatomite waste residue as the additive to adjust the silicon content in the raw material, this batching method not only utilizes a variety of wastes , and it is easy to prepare aluminum-silicon-ferroalloy of various components, and then adapt to the smelting process of the electric arc furnace, so that the smelting process and alloy composition are easy to control, which is conducive to reducing production costs and creating conditions for subsequent processing.

4. The use of plasma flame to transport powder materials can increase the reaction temperature by heating the materials, accelerate the reduction of oxides and the volatilization of fluorides, especially the complete decomposition of toxic substances such as aluminum nitride and cyanide, and strengthen the entire arc The high temperature reaction process of furnace smelting improves production efficiency.

Description of drawings

Fig. 1 is the process flow chart of the method for preparing Al-Si-Fe alloy by using aluminum ash as raw material plasma jet feeding according to the present invention.

Detailed ways

Taking the following wastes as an example, the technical solution of the present invention is explained in detail.

Table 1 shows the phase composition of a treated secondary aluminum ash. Due to different casting and refining processes, the phase composition and content of aluminum ash produced by different enterprises are different.

The phase composition of a kind of treated secondary aluminum ash in Table 1

Table 2 shows the main components of a waste cathode carbon block. Due to the difference in electrolysis process and electrolyte composition, as well as the life of the electrolytic cell, the composition and content of waste cathode carbon blocks from different enterprises are different.

Table 2 Main components of a kind of waste cathode carbon block

Table 3 shows the main components of a low-aluminum fly ash.

Table 3 Main components of a kind of low-aluminum fly ash

Table 4 is the main component of a diatomite waste residue.

The main component of a kind of diatomite waste residue of table 4

Example 1

The method for preparing Al-Si-Fe alloy by using aluminum ash as raw material plasma jet feeding comprises the following steps:

Step 1, the waste cathode carbon block, fly ash and diatomite waste slag in the aluminum ash, aluminum electrolytic cell overhaul slag are respectively made into powder, and the particle size is all less than 100 mesh;

Step 2, according to the composition of the target Al-Si-Fe alloy, the content of aluminum is 28%, the content of silicon is 61%, and the rest are iron, calcium, titanium and other trace metals, and the fixed carbon contained in the waste cathode carbon block is used as the reducing agent. Calculate the mass of secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue required for the reduction of metal oxides by metering ratio, in which the metal aluminum in the secondary aluminum ash is calculated as all of the aluminum-silicon-ferroalloy, and the nitrided All aluminum is decomposed into metal aluminum and nitrogen, and the obtained metal aluminum is also calculated as all the aluminum-silicon-iron alloys. Finally, the mass ratio of aluminum ash, fly ash, diatomite waste residue and waste cathode carbon block is 1:10:1:6 ; Put the secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue powder into the mixer to mix evenly;

Step 3, start the electric arc furnace and gradually increase the temperature in the furnace. The electrodes used in the electric arc furnace are hollow electrodes, and the hollow channel in the middle of the electrode is connected to the flame outlet of the plasma generator; the diameter of the hollow channel in the middle of the electrode is 200mm. When the temperature of the arc zone at the bottom is 2300°C, the powdered material is sent to the arc reaction zone through the hollow channel with the generated plasma flame as the carrier. The temperature of the plasma flame is 300°C, and the working gas of the plasma generator is Air; when the smelting process reaches 3 hours, the aluminum-silicon-ferroalloy melt formed from the bottom of the electric arc furnace is released and refined outside the furnace. The refining agent used contains sodium chloride, potassium chloride and cryolite, and the proportion of each component is sodium chloride. 50% of potassium chloride, 40% of potassium chloride, 10% of cryolite; the refining temperature is 900 ℃, and the aluminum-silicon-ferroalloy can be obtained; the alloy can be used as a deoxidizer for steelmaking and a reducing agent for magnesium-smelting, and the refining slag is returned to the batching process for continued use;

In step 4, the soot collected from the top of the electric arc furnace is subjected to water leaching and filtration, the leaching temperature is 95°C, the liquid-solid ratio of the leaching process is 10:1, the leaching time is 0.5h, and the leaching solution is filtered after leaching, and the leaching solution is evaporated to recover sodium carbonate and sodium chloride; the leaching slag is melted at high temperature after drying, the melting temperature is 1200 ℃, so that the fluoride and oxide are separated, the recovered fluoride electrolyte is returned to the electrolyzer for use, and the slag phase oxide is returned to the electric arc furnace raw material batching workshop as Raw material for electric arc furnace smelting of Al-Si-Fe.

Example 2

The method for preparing Al-Si-Fe alloy by using aluminum ash as raw material plasma jet feeding comprises the following steps:

Step 1, the waste cathode carbon block, fly ash and diatomite waste slag in the aluminum ash, aluminum electrolytic cell overhaul slag are respectively made into powder, and the particle size is all less than 100 mesh;

Step 2, according to the composition of the target Al-Si-Fe alloy: the content of aluminum is 35%, the content of silicon is 54%, and the rest are iron, calcium, titanium and other trace metals; the fixed carbon contained in the waste cathode carbon block is used as the reducing agent according to the chemical method. Calculate the mass of secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue required for the reduction of metal oxides by metering ratio, in which the metal aluminum in the secondary aluminum ash is calculated as all of the aluminum-silicon-ferroalloy, and the nitrided All aluminum is decomposed into metal aluminum and nitrogen, and the obtained metal aluminum is also calculated as all the aluminum silicon ferroalloy enters. Finally, the mass ratio of aluminum ash, fly ash, diatomite waste residue and waste cathode carbon block is 2:8:1:6 ; Put the secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue powder into the mixer to mix evenly;

Step 3, start the electric arc furnace and gradually increase the temperature in the furnace. The electrodes used in the electric arc furnace are hollow electrodes, and the hollow channel in the middle of the electrode is connected to the flame outlet of the plasma generator; the diameter of the hollow channel in the middle of the electrode is 100mm. When the temperature of the arc zone at the bottom is 2100°C, the powdered material is sent to the arc reaction zone through the hollow channel with the generated plasma flame as the carrier. The temperature of the plasma flame is 1700°C, and the working gas of the plasma generator is Carbon monoxide, when the smelting process reaches 2 hours, the aluminum-silicon-ferroalloy melt formed from the bottom of the electric arc furnace is released and refined outside the furnace. The refining agent used contains sodium chloride, potassium chloride and cryolite, and the proportion of each component is sodium chloride. 40% of potassium chloride, 40% of potassium chloride, 20% of cryolite; the refining temperature is 1200 ℃, and an aluminum-silicon ferroalloy can be obtained; the alloy can be used as a deoxidizer for steelmaking and a reducing agent for magnesium-smelting, and the refining slag is returned to the batching process for continued use;

In step 4, the soot collected from the top of the electric arc furnace is subjected to water leaching and filtration, the leaching temperature is 60°C, the liquid-solid ratio of the leaching process is 6:1, the leaching time is 1.5h, and the leaching solution is filtered after leaching, and the leaching solution is evaporated to recover sodium carbonate With sodium chloride, the leaching slag is melted at high temperature after drying, and the melting temperature is 1100 ° C, so that the fluoride and oxide are separated, the recovered fluoride electrolyte is returned to the electrolytic cell, and the slag phase oxide is returned to the electric arc furnace raw material batching workshop as an electric arc Furnace smelting raw material for ferrosilicon.

Example 3

The method for preparing Al-Si-Fe alloy by using aluminum ash as raw material plasma jet feeding comprises the following steps:

Step 1, the waste cathode carbon block, fly ash and diatomite waste slag in the aluminum ash, aluminum electrolytic cell overhaul slag are respectively made into powder, and the particle size is all less than 100 mesh;

Step 2, according to the composition of the target Al-Si-Fe alloy: the content of aluminum is 43%, the content of silicon is 47%, and the rest are iron, calcium, titanium and other trace metals; the fixed carbon contained in the waste cathode carbon block is used as the reducing agent according to the chemical method. Calculate the mass of secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue required for the reduction of metal oxides by metering ratio, in which the metal aluminum in the secondary aluminum ash is calculated as all of the aluminum-silicon-ferroalloy, and the nitrided All aluminum is decomposed into metal aluminum and nitrogen, and the obtained metal aluminum is also calculated as all the aluminum-silicon-iron alloys. Finally, the mass ratio of aluminum ash, fly ash, diatomite waste residue and waste cathode carbon block is 2:2:2:3 ; Put the secondary aluminum ash, waste cathode carbon block, fly ash and diatomite waste residue powder into the mixer to mix evenly;

Step 3, start the electric arc furnace and gradually increase the temperature in the furnace. The electrodes used in the electric arc furnace are hollow electrodes, and the hollow channel in the middle of the electrode is connected to the flame outlet of the plasma generator; the diameter of the hollow channel in the middle of the electrode is 20mm. When the temperature of the arc zone at the bottom is 1900°C, the powder material is sent to the arc reaction zone through the hollow channel with the generated plasma flame as the carrier. The temperature of the plasma flame is between 3000°C and the plasma generator works The gas is argon; when the smelting process reaches 1 hour, the aluminum-silicon-ferroalloy melt formed from the bottom of the electric arc furnace is released and refined outside the furnace. The refining agent used contains sodium chloride, potassium chloride and cryolite, and the proportions of each component are in the range of Sodium chloride 60%, potassium chloride 10%, cryolite 30%; the refining temperature is 1500 ℃, and the aluminum-silicon ferroalloy can be obtained; the alloy can be used as a deoxidizer for steelmaking and a reducing agent for magnesium smelting, and the refining slag is returned to the batching process to continue use;

In step 4, the soot collected from the top of the electric arc furnace is subjected to water leaching and filtration, the leaching temperature is 20°C, the liquid-solid ratio of the leaching process is 2:1, the leaching time is 3h, and the leaching solution is filtered after leaching, and the leaching solution is evaporated to recover sodium carbonate and sodium carbonate. Sodium chloride and leaching slag are melted at high temperature after drying, and the melting temperature is 1000 ℃, so that the fluoride and oxide are separated, the recovered fluoride electrolyte is returned to the electrolyzer for use, and the slag phase oxide is returned to the electric arc furnace raw material batching workshop as an electric arc furnace Raw material for smelting aluminum ferrosilicon.

Claims (10)

1. the method for producing AL-Si-Fe alloy as raw material plasma jet feeding using aluminium ash, which is characterized in that including walking as follows It is rapid:

Step 1, powder is respectively prepared in waste cathode carbon block, flyash and the diatomite waste residue in aluminium ash, aluminium cell slag from delining；

Step 2, the use of aluminium ash, waste cathode carbon block, flyash and diatomite waste residue is determined according to the ingredient of target AL-Si-Fe alloy Amount stoichiometrically calculates Al in reduction Quadratic aluminum dust using fixed carbon contained in waste cathode carbon block as reducing agent₂O₃、SiO₂Oxygen The amount of metallic aluminium, silicon that compound generates, then calculate the Al with waste cathode carbon block reduction flyash, diatomite waste residue₂O₃、SiO₂Oxygen The amount of the obtained metallic aluminium of compound, silicon, the aluminium obtained with reduction flyash, diatomite waste residue, silicon amount allotment two secondary aluminiums of reduction The amount of metallic aluminium, silicon that ash obtains to get to the ingredient of aluminium, silicon in prepared AL-Si-Fe alloy and aluminium ash, flyash, The dosage of diatomite waste residue and waste cathode carbon block；Together by Quadratic aluminum dust, waste cathode carbon block, flyash and diatomite waste residue powder It is put into blender and is uniformly mixed；

Step 3, start electric arc furnaces and in-furnace temperature is gradually increased, the electrode that electric arc furnaces uses is coreless armature, among electrode Hollow passageway is connected with the flame outflux of plasma generator；When bottom arc area temperature is 1900-2300 DEG C, with generation Plasma flame stream is that granular material is sent to electric arc reaction area through hollow passageway by carrier, when fusion process reach 1-3 it is small when after The AL-Si-Fe alloy melt to be formed is released from electric arc furnace bottom and carries out external refining, and AL-Si-Fe alloy can be obtained；The alloy It can be used as deoxidizer in steel production and magnesium smelting reducing agent, refining slag returns to burden process and continues to use；

Step 4, by from electric arc furnaces collected overhead to cigarette ash water logging and filter, extraction temperature is 20~100 DEG C, is leached Journey liquid-solid ratio is 2~10:1, and extraction time is 0.5~3h, is filtered after leaching, and leachate passes through evaporation recycling sodium carbonate and chlorination Sodium, leached mud carry out high temperature melting after the drying, and fusion temperature is higher than 1000 DEG C, so that fluoride is separated with oxide, recycling Electrolysis of fluorides matter return electrolytic cell use, slag phase oxide return electric arc furnaces feed proportioning workshop as electric arc furnace smelting aluminium The raw material of ferrosilicon.

2. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, aluminium ash composition is in mass ratio are as follows: Al₂O₃40~80%, AlN≤20%, Al≤10%, SiO₂≤ 5%, Na₂O ≤ 5%, Fe₂O₃≤ 5%, chloride≤10%, fluoride≤10%.

3. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, the ingredient of waste cathode carbon block is in mass ratio are as follows: C60~80%, Al₂O₃≤ 3%, Na4~10%, electrolysis of fluorides Matter 10~20%.

4. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, fine coal ash composition is in mass ratio are as follows: Al₂O₃15~50%, SiO₂30~50%, Fe₂O₃≤ 10%, CaO≤ 5%, MgO≤5%, Na₂O≤3%, K₂O≤3%, TiO₂≤ 3%, other single metal oxide content < 1%.

5. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, the ingredient of diatomite waste residue is in mass ratio are as follows: Al₂O₃≤ 5%, SiO₂80~99%, Fe₂O₃≤ 10%.

6. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, step 1, the aluminium ash, waste cathode carbon block, flyash and diatomite waste residue powder granularity are respectively less than 100 mesh.

7. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, step 3, the diameter in the electrode central hollow channel is 20mm-200mm.

8. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, step 3, the flow and flow rate of the plasma flame stream is controllable, and the temperature of plasma flame stream is in 300- Between 3000 DEG C.

9. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, step 3, the working gas of plasma generator is one of argon gas, air, carbon monoxide.

10. the method according to claim 1 that AL-Si-Fe alloy is produced as raw material plasma jet feeding using aluminium ash, It is characterized in that, step 3, refining agent used in external refining contains sodium chloride, potassium chloride and ice crystal, each component ratio range chlorination Sodium 30~60%, potassium chloride≤30%, ice crystal≤30%；900~1500 DEG C of refining temperature.