2022年3月29日星期二

What Kind of Steel is Suitable for Smelting Ferrosilicon?

Smelting Ferrosilicon

What Kind of Steel is Suitable for Smelting Ferrosilicon?


The iron in the ferrosilicon comes from the steel chips in the charge. According to the requirements of ferrosilicon quality, only ordinary carbon steel chips are allowed to be used in smelting, and alloy steel chips are not allowed, such as stainless steel, high chromium, high manganese steel, high manganese, etc. Therefore, smelting ferrosilicon, such as alloy steel scrap, will cause waste products. Pig iron scrap can not be used because of its high phosphorus content. Smelting ferrosilicon can not use non-ferrous metal chips, such as copper, aluminum, and so on. Therefore, in order to ensure the quality of ferrosilicon, only the steel chips of ordinary carbon steel are allowed to be used in smelting.

The steel chips with serious rust cannot be used. Due to its large amount of impurities, it is difficult to control the iron content during smelting. At the same time, the steel chips with serious rust have poor strength and many powders, which will affect the air permeability of the charge surface when added into the furnace. Therefore, it is required that the iron content of steel chips used shall be greater than 95%, and the surface shall be clean without significant impurities.

The length of steel scraps should not be too long to prevent uneven mixing and blocking of blanking pipe. Too long steel scraps also lead to uneven charging and affect the imbalance of three-phase load. Therefore, the length of steel chips shall not be more than 100mm.


Hani Tech is a Hot Rolling Mill manufacturing company working mainly in the area of the bar and wire rod mills, high-speed wire rod mills, high-speed rebar rolling mills, TMT rolling mills, flying shear, cold strip rolling mill, reheating furnace, induction furnace, intermediate frequency furnace, electric arc furnace, ladle refining furnace, blast furnace, continuous casting machine.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com

Smelting Ferrosilicon


2022年3月28日星期一

Electric Arc Furnace VS Blast Furnace

Electric Arc Furnace

Electric Arc Furnace VS Blast Furnace


Introduction of Electric Arc Furnace VS Blast Furnace

Introduction of Electric Arc Furnace

Electric arc furnace is an electric furnace that uses the high temperature generated by electrode arc to smelt ore and metal. When gas discharge forms an arc, the energy is very concentrated, and the temperature of the arc area is above 3000 ℃. For smelting metal, the electric arc furnace has greater process flexibility than other steelmaking furnaces, can effectively remove impurities such as sulfur and phosphorus, the furnace temperature is easy to control, and the equipment covers a small area, which is suitable for smelting high-quality alloy steel.

The industrial furnace that generates electric arc heating through metal electrodes or non-metal electrodes is called an electric arc furnace. According to the form of electric arc, electric arc furnaces can be divided into three-phase electric arc furnaces, consumable electric arc furnace, single-phase electric arc furnaces, and resistance electric arc furnace. The furnace body of electric arc steelmaking furnace is composed of furnace cover, furnace door, tapping trough, and furnace body. The furnace bottom and furnace wall are built with alkaline refractory or acid refractory. Electric arc steelmaking furnace is divided into ordinary power electric arc furnace, high power electric arc furnace, and ultra-high power electric arc furnace according to the transformer capacity per ton of furnace capacity. Electric arc furnace steelmaking is to input electric energy into the electric arc steelmaking furnace through graphite electrode and make steelmaking with the electric arc between the electrode end and the charge as the heat source. The electric arc furnace takes electric energy as the heat source and can adjust the atmosphere in the furnace, which is very beneficial to smelting steel grades containing more easily oxidized elements. Shortly after the invention of electric arc furnace steelmaking, it was used to smelt alloy steel and developed greatly.

With the improvement of electric arc furnace equipment and smelting technology and the development of the electric power industry, the cost of electric arc furnace steelmaking continues to decline. Now electric arc furnace steelmaking is not only used to produce alloy steel, but also a large number of ordinary carbon steel. Its output accounts for an increasing proportion of the total steel output of major industrial countries.


Introduction of Blast Furnace

The blast furnace is made of steel plate with refractory brick lining inside. From top to bottom, the blast furnace body is divided into five parts: furnace throat, furnace body, furnace waist, bosh, and hearth. Due to the advantages of good technical and economic indicators, simple process, large production capacity, high labor production efficiency, and low energy consumption, the iron produced by this method accounts for the vast majority of the total iron output in the world.

During blast furnace production, iron ore, coke, and slag forming flux (limestone) are loaded from the top of the furnace, and preheated air is blown from the tuyere located at the lower part of the furnace along the periphery of the furnace. Under high temperature, the carbon in coke (some blast furnaces also inject pulverized coal, heavy oil, natural gas, and other auxiliary fuels) and the carbon monoxide and hydrogen generated by the combustion of oxygen blown into the air will remove the oxygen in iron ore during the rising process in the furnace, so as to obtain iron. The molten iron is discharged from the iron mouth. Unreduced impurities in iron ore combine with fluxes such as limestone to form slag, which is discharged from the slag mouth. The produced gas is discharged from the top of the furnace and used as fuel for hot blast stove, heating furnace, coke oven, boiler, etc. after dust removal.

The main products of blast furnace smelting are pig iron, as well as blast furnace slag and blast furnace gas.


Characteristics of Electric Arc Furnace VS Blast Furnace

Characteristics of Electric Arc Furnace

Electric arc steelmaking furnace takes electric energy as the main energy. The electric energy generates high temperature above 2000 ~ 6000 ℃ through the discharge arc between graphite electrode and furnace charge and melts the scrap raw material in the way of arc radiation, temperature convection, and heat conduction.

Electric arc furnace steelmaking process is short, the equipment is simple, the operation is convenient, the pollution is easy to control, the construction investment is small, the floor area is small, and there is no need to rely on the complex ironmaking system like converter steelmaking.

Electric arc furnace steelmaking has strong adaptability to furnace charge. It takes scrap steel as the main raw material, but it can also use solid and liquid iron-containing raw materials such as molten iron (molten iron of blast furnace or cupola), sponge iron (DRI), hot-pressed block (HBI), pig iron block and so on.

Electric arc furnace can not only smelt high-quality steel with low phosphorus, sulfur, and oxygen content but also use a variety of elements for alloying (including elements easy to be oxidized such as lead, boron, vanadium, titanium, and rare earth) to produce all kinds of high-quality steel and alloy steel, such as ball-bearing steel, stainless and acid-resistant steel, tool steel, electrical steel, heat-resistant steel, magnetic materials, and special alloys.


Characteristics of Blast Furnace

Characteristics of blast furnace ironmaking: large scale. Whether in other countries in the world or China, the volume of the blast furnace is expanding. For example, the blast furnace of Baosteel in China is 4063 cubic meters, with a daily output of pig iron of more than 10000 tons, slag of more than 4000 tons, and coke consumption of more than 4000 tons.


Blast furnace smelting is a continuous production process of reducing iron ore into pig iron. Solid raw materials such as iron ore, coke, and flux are fed into the blast furnace in batches by the furnace top charging device according to the specified batching ratio, and the material surface of the furnace throat is maintained at a certain height. Coke and ore form alternating layered structures in the furnace. The ore material is gradually reduced and melted into iron and slag in the descending process, gathered in the hearth, and discharged from the iron mouth and slag mouth regularly.

Under high temperature, the carbon in coke (some blast furnaces also inject pulverized coal, heavy oil, natural gas, and other auxiliary fuels) and the carbon monoxide and hydrogen generated by the combustion of oxygen blown into the air will remove the oxygen in iron ore during the rising process in the furnace, so as to obtain iron. The molten iron is discharged from the iron mouth. Unreduced impurities in iron ore combine with fluxes such as limestone to form slag, which is discharged from the slag mouth.


Electric Arc Furnace Smelting Finished Products VS Blast Furnace Smelting Finished Products


Electric Arc Furnace Smelting Finished Products

The raw materials of electric arc steelmaking furnaces are mainly solid scrap with alloy and pig iron for adjusting carbon content. It can also use direct reduced iron or some hot molten iron. The selection range of raw materials is wide; Therefore, except for some ultra-low carbon steel varieties, or varieties and special alloy materials that must adopt special means such as vacuum treatment, most steel varieties can be smelted.


Blast Furnace Smelting Finished Products

Pig iron is the product of the blast furnace (referring to the smelting of pig iron in the blast furnace), and the products of the blast furnace are not only pig iron, but also ferromanganese, belonging to ferroalloy products. A ferromanganese blast furnace does not participate in the calculation of various indexes of the ironmaking blast furnace. In the process of blast furnace ironmaking, by-products such as water slag, slag wool, and blast furnace gas are also produced.


Hani Tech is a Hot Rolling Mill manufacturing company working mainly in the area of the bar and wire rod mills, high-speed wire rod mills, high-speed rebar rolling mills, TMT rolling mills, flying shear, cold strip rolling mill, reheating furnace, induction furnace, intermediate frequency furnace, electric arc furnace, ladle refining furnace, blast furnace, continuous casting machine.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com


Blast Furnace


2022年3月25日星期五

Causes of Excessive Slag in Ferrosilicon Smelting Furnace

Ferrosilicon Smelting Furnace

Causes of Excessive Slag in the Ferrosilicon Smelting Furnace


1. In ferrosilicon smelting, sometimes the furnace is short of carbon for a long time, and a large amount of excess silica dissolves to form viscous slag, which is not easy to eliminate.

2. Due to the high charge level, the depth of electrode inserted into the charge becomes shallow, the furnace temperature is low, and the slag is not easy to be removed. In particular, the electric furnace with a small capacity is more likely to produce this phenomenon, resulting in too much slag in the furnace.

3. Although the amount of slag is small when smelting ferrosilicon, the slag shall be brought out as far as possible during tapping to make the electrode deeply inserted. If you don't pay attention to slag, it will cause too much slag in the furnace for a long time.

4. Poor quality of raw materials, such as too high ash content in coke or too much soil on the surface of silica, will also increase the amount of slag.


Hazards of Excessive Slag in the Smelting Furnace:

1. The bottom of the furnace rises, it is difficult to insert deeply after clicking, it shrinks after drying, the air permeability of the charge surface deteriorates, and the furnace condition deteriorates.

2. The furnace bottom temperature is low, the taphole is not easy to open, the furnace hole is not unblocked, the flow rate of molten iron is slow, and the amount of iron is less.


Hani Tech is a Hot Rolling Mill manufacturing company working mainly in the area of the bar and wire rod mills, high-speed wire rod mills, high-speed rebar rolling mills, TMT rolling mills, flying shear, cold strip rolling mill, reheating furnace, induction furnace, intermediate frequency furnace, electric arc furnace, ladle refining furnace, blast furnace, continuous casting machine.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com


Ferrosilicon Smelting Furnace

2022年3月23日星期三

How to Reduce the Unit Power Consumption of Smelting Ferrosilicon?

smelting ferrosilicon

How to Reduce the Unit Power Consumption of Smelting Ferrosilicon?


The unit power consumption of smelting 75 ferrosilicon accounts for 60-65% of the production cost. The unit power consumption of smelting 45 ferrosilicon accounts for 50-55% of the production cost. Therefore, reducing power consumption is one of the points to reducing the production cost of ferrosilicon.

According to the preliminary calculation, the theoretical power consumption for smelting 75 ferrosilicon is 6850-7050 degrees, but in actual production, the power consumption is 8200-9000 degrees and the heat loss is about 16-18% (including the electric loss), so the visible heat and electric energy losses are very large. This is closely related to the operation level, equipment maintenance, raw material conditions, power supply system, and the design of the submerged arc furnace. Now let's talk about some production-related issues:

1. Maintain the furnace condition carefully so that the electrode can be inserted into the furnace deeply and steadily, thus enlarging the crucible to raise the temperature of the furnace, maintaining good air permeability of the material surface, and striving to reduce the phenomenon of sparking and slumping and reduce the heat loss.

2. Strengthen the maintenance of equipment and electrodes to reduce the time of hot shutdown. Ferrosilicon smelting is continuous production. If the hot shutdown time is long or the number of times is large, the time to return to normal furnace condition will be longer. For example, the hot shutdown time is one hour or about two hours. Raise the temperature of the furnace to normal furnace condition, thus less iron will be produced. Two hours of the hot shutdown will result in two fewer irons. The unit power consumption of ferrosilicon is bound to increase.

3. Raw material condition. The concentrate is very important to reduce the unit power consumption of ferrosilicon.

For coke used in ferrosilicon smelting, proper grain size and high resistance at high temperatures are required to facilitate deep electrode insertion.

For silica, it is required to have good thermal stability to prevent premature fragmentation at high temperatures and even to destroy the permeability of the material surface. If conditions permit, silica should be washed in water.

The chemical composition of all raw materials shall be qualified.

4. Select the appropriate power supply system. Secondary voltage is too high and input power is high, but unit power consumption increases due to shallow electrode insertion and more heat loss. Low secondary voltage, although heat loss is small, low input power, low furnace temperature, and low output are not conducive to reducing unit power consumption. Therefore, a suitable secondary voltage should be selected for smelting.

5. Strengthen the recovery of returned iron, eliminate waste, increase productivity and reduce power consumption.


Hani Tech is a Hot Rolling Mill manufacturing company working mainly in the area of the bar and wire rod mills, high-speed wire rod mills, high-speed rebar rolling mills, TMT rolling mills, flying shear, cold strip rolling mill, reheating furnace, induction furnace, intermediate frequency furnace, electric arc furnace, ladle refining furnace, blast furnace, continuous casting machine.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com


Smelting Ferrosilicon

2022年3月21日星期一

Ferroalloy Electric Furnace Production Method

Ferroalloy Electric Furnace

Ferroalloy Electric Furnace Production Method


Electric furnace is the main method for smelting continuous cast steel | ferroalloys. The output of electric furnace ferroalloys accounts for more than 70% of the total output of ferroalloys.

Electric furnaces are mainly divided into ORE-HEATING furnaces and electric arc furnaces, also called refining furnaces. Ore reduction furnaces commonly used in electric furnaces for producing ferroalloys with carbon as the reducing agent are abbreviated as mineral heat furnaces.

Mixed raw materials are added to the furnace mouth during smelting, and the root electrode is buried in the charge, which is heated by electric arc and electric current through the charge. The production process is continuous by regularly discharging iron and slag at the tap.

According to the amount of slag produced by the product, the submerged arc furnace can be divided into two operations: Micro-slag method and slag method. Ferrosilicate, high-silicon ferrochromium used materials of high purity, with less impurity oxides, production without flux. Slag production during smelting is very small and is often called Micro-slag method. The main raw materials used in the production of Micro-slag method are silica, coke, and steel chips, and carbon ferrochromium used in the production of silicon chromium. Ferromanganese, ferrochromium, Silicon-manganese alloys, and other ores contain many impurity oxides and need to be slagged with flux. Therefore, the slag method is often called the slag method because the slag amount is large and exceeds the weight of the alloy. In addition to ores and reducing agents, fluxes are often added to the raw materials used in the slagging process.

High carbon alloys can only be obtained in the submerged arc furnaces due to the use of carbon-reducing agents (therefore, in addition to siliceous alloys). Ferrous alloys produced from silicon, mainly siliceous alloys (as reducing agents), are usually produced in electric arc furnaces, which are similar to steel-making electric arc furnaces.

Raw materials used in electric arc furnace production are mainly ores, including concentrates or purer oxides, (siliceous reducing agents and fluxes). The whole smelting process can be divided into arc striking, feeding, melting, refining, and iron tapping. The smelting process is completed by arc exothermy and silica oxidation reaction heat. The tapping time depends on the silicon content in the alloy and the production is intermittent.

At present, the main production varieties are medium and low carbon ferromanganese, medium and low carbon ferrochromium, micro-carbon ferrochromium, ferrovanadium, and some other alloys with low carbon content.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com


Ferroalloy Electric Furnace


2022年3月18日星期五

Ferro-Alloy Submerged Arc Furnace

Ferro-Alloy Submerged Arc Furnace

Ferro-Alloy Submerged Arc Furnace

Application

The Submerged Arc Furnace is mainly used for reducing and smelting ore, carbon-reducing agents, solvents, and other raw materials. It mainly produces ferrosilicon, ferromanganese, ferrochromium, ferrotungsten, Silicon-manganese alloy, silicon-chromium alloy, industrial silicon, carbide, high-titanium slag, and other ferroalloys. It is an important industrial raw material and chemical raw materials such as carbide in the metallurgical industry.

Equipment Features

It uses carbon or magnesium refractories as lining and self-culturing electrodes. Electrodes are inserted into the charge for submerged arc operation, which uses the energy and current of the arc to pass through the charge and generates energy due to the resistance of the charge to melt metal. Adding materials one after another and discharging slag intermittently is an industrial electric furnace for continuous operation.

Main Equipment for the Large Current System of Submerged Arc Furnaces

1. Combined electrode clamper

2. Clamper, pressure ring type with expansion pipe 

3. Pipe type short network

4. Furnace transformer

Combined Electrode Clamper

Combined electrode clamper is a new type of combination electrode holder technology including pressure relief device. It is completely different from the traditional method, which simplifies the holding device and adapts to different diameters of electrodes. 

Due to the corresponding change of the rib structure of the shell of the electrode, the current distribution on the cross-section of the electrode is more balanced, which is conducive to accelerating the sintering of the electrode and avoiding the occurrence of electrode accidents. 

At the same time, because the combination electrode holder is conductive to the rib, the current flows directly to the core of the electrode through the rib of the combination electrode holder, fundamentally changing the traditional surface conduction to the core of the electrode. 

It is because of the different conductive principles that the phenomenon of electrode skimming is solved, thus greatly improving the opening rate of the submerged electric furnaces and fundamentally solving the problem of electrode opening rate. 

At the same time, the combination holder has a long service life, can be repaired and reused, and reduces production costs. It can not be solved by conductive copper bush. It has the advantages of reliable operation and a high operation rate.

Clamper, Pressure Ring Type with Expansion Pipe 

The main structural features of clamper, pressure ring type with expansion pipe are: clamping copper shell part is bellows clamping ring. It consists of a water-cooled protective sleeve, water-cooled pressure ring, water-cooled pressure bellows, and hydraulic media. In the clamping ring, the bellows are pressed against the forged copper bushes one by one, which ensures that the clamping force of each copper bush to the electrode is balanced and the pressure of the copper bush to the electrode is easily adjusted. It has the advantages of stable pressure, good randomness, and easy automatic pressure relief and adjustment.

Pipe Type Short Network

Short network with pipe structure, consisting of copper pipe, flexible part is water-cooled cable. The whole system is cooled with soft water. This short network structure has the advantages of reliable technology, strong current carrying capacity, good electrical performance, lightweight and low investment, and is also an ideal match for the new type of holder system. It is a practical technology worth popularizing and using to realize the one-to-one connection between transformer outlet and conductive component.

Furnace Transformer

Ferry-Alloy Submerged Arc Furnace Transformers are optimized by computer. New technologies, new materials, and processes are applied to reduce loss and increase mechanical strength. High-quality cold-rolled silicon steel sheets with high magnetic conductivity and high-quality materials such as oxygen-free copper electromagnetic wire are carefully manufactured. Optimized magnetoelectric balance technology is used to ensure excellent dynamic and thermal stability, internal multi-point positioning, complete loosening-proof treatment of fasteners, and on-site core-free operation. Reliable anti-oil aging measures for fully sealed diaphragm oil storage tank, sealing structure to ensure no leakage

Mining furnace equipment is developing towards large-scale, automation, enclosed, environmental protection, and energy-saving. Our company has designed and manufactured ferromanganese, ferrosilicon, and ferrochromium electric arc furnaces with a capacity of 3300KVA. 3500KVA - 6300KVA refining electric arc furnace; 6300KVA DC arc furnace; 25000KVA industrial silicon electric arc furnace; 45000KVA Calcium Carbide Furnace; 36000KVA ferrosilicon aluminum arc furnace.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com

Ferro-Alloy Submerged Arc Furnace


2022年3月15日星期二

Advantages of Electric Arc Furnace Bottom Blowing Technology

Electric Arc Furnace

Advantages of Electric Arc Furnace Bottom Blowing Technology


What is the bottom blowing technology of the electric arc furnace? 

What are the advantages? 

With the expanding market and increasing demand, the bottom-blowing technology of electric arc furnaces comes into being. Many steel mills have introduced the bottom blowing technology of electric arc furnaces successively, because this technology can greatly shorten the smelting time, reduce the content of iron oxide in slag and improve the yield of metal, thus achieving a function of reducing the consumption of ferroalloys. Low arc furnace blowing technology can also uniform the composition and temperature of molten steel, so it is recognized by everyone!

The arc furnace bottom blowing technology has some points which can be roughly summarized as follows:

1: EAF bottom blowing technology reduces the soft melting in the cold zone, promotes the melting of waste steel, and plays an active role in eliminating the cold zone in EAF steelmaking.

2: EAF bottom blowing technology improves the reaction speed at the steel slag interface, promotes the adsorption and removal of impurities in EAF rough steelmaking, improves the reaction speed of dephosphorization and decarbonization, and plays an active role in shortening the smelting cycle.

3: Bottom blowing technology of electric arc furnace accelerates the running speed of molten steel in the molten pool and plays an important role in eliminating the phenomenon of uneven temperature in the molten pool. The key point is that the temperature of steel discharging can also be reduced.

4: Due to one stirring effect of bottom blowing, the reaction at the steel slag interface is particularly balanced, and the iron oxide content in the slag is greatly reduced, which is conducive to the reduction of iron consumption.

5: The bottom blowing technology of the electric arc furnace reduces the tapping temperature and iron oxide content of the electric arc furnace, so the life of the lining is also prolonged.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com

Electric Arc Furnace


2022年3月13日星期日

Reasons for Power Consumption in Electric Arc Furnace Steelmaking

Electric Arc Furnace Steelmaking

Reasons for Power Consumption in Electric Arc Furnace Steelmaking


1. Raw Material.

As we all know, the steel used for electric arc furnace steelmaking is scrap steel, because the raw materials required for electric arc furnace steelmaking are light and thin materials, pressing blocks, etc., which will result in high temperature and shutdown when feeding, so the heat loss will be very large. If one charge is insufficient, it will need to be fed again, or even three times, which will cause a lot of heat loss. A large amount of power consumption is required for each charging. It is also worth noting that C and P are higher after the raw material is cleaned up. When entering the oxidation period, C and P removal also takes a long time, which will greatly increase energy consumption.


2. Technology.

The technology referred to here is electric arc furnace steelmaking, which refers to the operator's skill. If the operator's skill is not good, it will waste a lot of lime and energy, which in turn will greatly increase power consumption.


3. Objective.

How do you understand that objective conditions can also lead to increased power consumption? For example, in the process of electric arc furnace steelmaking, we suddenly trip due to lack of electric energy. Over a long period of time, molten steel cooling and solidification need to be melted again. This process also wastes a lot of electric energy.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Email: stella@hanrm.com    stellarollingmill@gmail.com

Website:  https://www.hanrm.com

Electric Arc Furnace Steelmaking


Electric Arc Furnace VS Medium Frequency Induction Furnace

Electric Arc Furnace

Electric Arc Furnace VS Medium Frequency Induction Furnace


Nowadays, there are two kinds of equipment used for metal smelting in enterprises, namely electric arc furnace and medium frequency induction furnace. Because of the large volume of electric arc furnace and high investment in equipment, electric arc furnace is only used by enterprises with a certain scale. Medium frequency induction furnace is lower cost than electric arc furnace and suitable for small and medium-sized enterprises.

1. Field of Application

Electric arc furnaces are electric furnaces that use the high temperature produced by electrode arcs to melt ores and metals. For smelting metal, the electric arc furnace is more flexible than other steelmaking furnaces and can effectively remove impurities such as sulfur and phosphorus. The furnace temperature is easy to control and the equipment covers a small area. It is suitable for smelting high-quality alloy steel. Electric arc furnaces are large in size and have high investments. Generally, they are more than 3 tons. Therefore, only enterprises with a certain scale can use electric arc furnaces.

Medium frequency magnetic field has a magnetic stirring effect on molten metal, which is favorable for uniform composition and scum. Medium frequency induction furnace is easy to install and operate, and it is convenient to replace furnace bodies with different weights, materials, and starting modes to meet various smelting requirements. Medium frequency induction furnace is suitable for various metal smelting and casting processes. Medium frequency furnace steelmaking costs less than electric arc furnace and is suitable for small and medium-sized enterprises.

2. Ability to Remove Phosphorus, Sulfur, and Oxygen

Electric arc furnaces are better than induction furnaces in removing phosphorus, sulphur, and oxygen. The induction furnace is cold slag, slag temperature is maintained by heat supplied by molten steel. The electric arc furnace is hot slag, which is heated by electric arc. The dephosphorization and desulfurization can be accomplished by the slag and the diffusion deoxidization can be carried out fully by the slag. Therefore, the ability of removing phosphorus, sulphur, and oxygen in electric arc furnace is better than that in the induction furnace.

3. Nitrogen Content

Nitrogen content in EAF steels is higher than that in induction furnaces because nitrogen molecules are ionized into atoms in the air at high arc temperatures and then absorbed by the molten steel. The nitrogen content in alloy smelted in induction furnace is lower than that in electric arc furnace, while oxygen content is higher than that in electric arc furnace, and the rapid life value of alloy is higher than that in electric arc furnace.

4. Burn Rate

Alloy elements in the returned material can be effectively recovered during induction furnace smelting. Alloy elements in the return material of electric arc furnace are oxidized into the slag first and then returned to liquid steel from the slag. The volatilization and oxidation losses of elements at high arc temperatures increase significantly. The burning rate of alloy elements in induction furnace is lower than that in electric arc furnace, especially in the return material loaded with the furnace, and the electric arc furnace is much higher than that in induction furnace.

5. Carbon Increase

Induction furnace is based on the principle of induction heating to melt metal charge without carbon increase in molten steel. The electric arc furnace relies on the graphite electrode to heat the furnace charge by electric arc, and the molten steel will be carbon-enriched after melting. Under normal conditions, when smelting high alloy nickel-chromium steel, the carbon content is 0.06% in electric arc furnace and 0.020% in induction furnace. The carbon increment in electric arc furnace smelting process is 0.020% and that in induction furnace is 0.010%.

6. Data Regulation

Temperature control, refining time, stirring intensity and constant temperature in induction furnace are more convenient than electric arc furnace and can be carried out at any time. It plays an important role in the smelting of high alloy steels and alloys. It can produce products independently, and can also be produced in a tandem process with secondary refining such as electroslag remelting and vacuum self-consumption. Therefore, non-vacuum medium frequency induction furnace smelting has become an important smelting method for the production of special steels and alloys such as high-speed steel, heat-resistant steel, stainless steel, electrothermal alloys, precision alloys, and superalloys, and has been widely used.


Please contact stella@hanrm.com for a quotation.
And free send inquiry to us.
Email: stella@hanrm.com   stellarollingmill@gmail.com
Whatsapp/Wechat:+8615877652925

Medium Frequency Induction Furnace


2022年3月10日星期四

What is Electric Arc furnace?

Electric Arc furnace

What is Electric Arc furnace? 


An electric arc furnace is an electric furnace that melts metals and ores at high temperatures produced by electrode arcs. When gas discharge forms an arc, the energy is very concentrated and the temperature in the arc zone is above 3000 C. For smelting metal, the electric arc furnace is more flexible than other steelmaking furnaces and can effectively remove impurities such as sulfur and phosphorus. The furnace temperature is easy to control and the equipment covers a small area. It is suitable for smelting high-quality alloy steel.


Classification

Arc furnaces can be divided into indirect heating, direct heating, and submerged arc according to the heating mode.

1. The indirect heating electric arc furnace is that the electric arc is produced between the two electrodes, which does not touch the material and heats the material by heat radiation. This furnace is noisy, inefficient, and gradually eliminated.

2. The direct heating electric arc furnace is the electric arc generated between the electrode and the material, which directly heats the material. Three-phase electric arc furnaces for steelmaking are the most commonly used direct heating electric arc furnaces.

2. Submerged arc circuit is also called a reduction electric furnace or mineral heat furnace. One end of the electrode is embedded in the material layer, which forms an arc and heats the material by using the resistance of the material layer itself. It is commonly used for smelting ferroalloys, nickel matte, copper matte, and carbide production.


Composition

1. Power supply: electric furnace transformer (rectifier), high-voltage power supply, low-voltage electrical control cabinet, etc.

2. Electrode parts: electrode lifting device, conductive cross arm, electrodes, etc.

3. Furnace body parts: shell, cover, tilting mechanism, etc.

4. Short mesh parts: conductive copper bars, water-cooled cables, etc.

5. Cooling water system.


Working Principle

Electric arc furnace smelting uses the heat generated by the arc between the graphite electrode and the iron (liquid iron) to melt the iron and overheat the liquid iron. During the process of electric arc furnace smelting, the smelting operation to further increase the temperature and adjust the chemical composition after the iron is melted is carried out under the condition that the slag covers the molten iron. The electric arc furnace is divided into acidic and alkaline according to the properties of slag and lining refractories. Alkaline electric arc furnaces are capable of desulfurizing and dephosphorizing.


Advantages and Disadvantages

The advantage of electric arc furnace smelting is its strong ability to melt solid charge, the molten iron is superheated and the chemical composition is adjusted under the condition of slag covering, so it can avoid the aspiration of molten iron and the oxidation of elements to a certain extent. This creates good conditions for smelting low carbon and alloy cast iron.

The disadvantage of electric arc furnace is that it consumes much electric energy and is not as economical as the cupola from the point of view of melting. Therefore, the cupola-electric arc furnace duplex melting method is often used in the production of cast iron. Because the lining of alkaline electric arc furnace has poor resistance to rapid cooling and heat, and its service life is short under the condition of intermittent smelting, the smelting cost is high. Therefore, acid electric arc furnace is mostly used in combination with cupola furnace.


Application

1. Steel smelting and ferroalloy refining;

2. Melting of high titanium slag and welding slag flux;

3. Melting of high-temperature refractories such as alumina, magnesium oxide, and aluminum-calcium cement;

4. Melting of stainless steel grinding wheel ash and oxide scale.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Website:  https://www.hanrm.com

electric arc furnace


2022年3月9日星期三

Maintenance of Short Network of Submerged Arc Furnace

 Submerged Arc Furnace

Maintenance of Short Network of Submerged Arc Furnace


The short network of submerged arc furnaces is an important equipment for conveying low pressure and strong current. The power loss of the resistance of the short network of the submerged arc furnace makes the bus temperature rise. In addition, high-temperature radiation will be produced on the surface of the short network bus bar of the submerged arc furnace, and the bus bar contact point will be oxidized and even partially melted due to the high temperature.

In addition, the short network of the submerged arc furnace runs in a harsh environment. Coke particles, dust, and other substances often cause a short circuits between the positive and negative poles of the bus bar and cause the electric furnace failure.

Therefore, it is necessary to strengthen the maintenance of the short network of the submerged arc furnace, and the following points should be paid attention to in general:

(1) Avoid open-arc operation as far as possible, otherwise, the high-temperature radiant heat of open-arc will not only increase the temperature of short-net, but also destroy the electrode parts.

(2) Periodically remove the dust attached to each part of the short net with compressed air to ensure good heat dissipation of each part of the short net

(3) Always pay attention to whether the cooling water is unblocked and master the temperature change. The inlet temperature should not exceed 25 C and the outlet temperature should not exceed 50 C.

(4) Measure the temperature of each part of the short-mesh short-mesh of the submerged arc furnace regularly. Generally, the temperature of the contact point should not exceed more than 10 C than that of other parts.

(5) For submerged arc furnaces with elevated and lowered electrodes controlled by high voltage current, when operating at lower tap voltage levels, attention should be paid to operating at the same high voltage current value as the voltage at this level. The high voltage current value at the original voltage level should not be used, otherwise, the transformer will be under low voltage overload. Conductor temperature should not be too high or even damaged by overloading frequently.

(6) In conjunction with the regular overhaul of the electric furnace, each contact surface of the short-mesh system of the submerged arc furnace shall be dismantled to remove its oxide layer and replace the solid parts that must be replaced.

(7) Among several parallel branches of each polarity of the short network of the ore heating furnace, if one branch is repaired due to damage, the contact surface of the other branches must be repaired at the same time. Otherwise, a branch that is replaced or repaired will be damaged quickly and continuously because it bears too much current because its contact resistance is smaller than other branches. 


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Website:  https://www.hanrm.com

submerged arc furnace


More News You May Interesting:

What are the Advantages and Disadvantages of Blast Furnace?

Characteristics of Electric Arc Furnace Steelmaking

Walking Beam Reheating Furnace VS Push-steel Reheating Furnace

Why Intermediate Frequency Furnace cannot be Turned on Normally?

2022年3月3日星期四

Ladle Refining Furnace VS Ferroalloy Refining Furnace

Ladle Refining Furnace

Ladle Refining Furnace VS Ferroalloy Refining Furnace


Ladle Refining Furnace

Ladle refining furnace is important metallurgical equipment used to refine the molten steel melted in the primary smelting furnace (electric arc furnace, open-hearth furnace, and converter), and can adjust the molten steel temperature and buffer the process, so as to meet the requirements of continuous casting and continuous rolling. Ladle furnace is one of the main pieces of equipment for refining outside the furnace.

Main Functions of Ladle Refining Furnace

1. The temperature rise of molten steel and heat preservation function. 

Liquid steel is heated by an electric arc to obtain new heat energy, which can not only add alloy and adjust composition but also add slag during ladle refining, which is convenient for deep desulfurization and deoxidation of liquid steel. 

Moreover, the start pouring temperature of liquid steel required by continuous casting is guaranteed, which is conducive to the improvement of dry slab quality.

2. Argon stirring function. 

Argon is blown into the molten steel through the permeable brick installed at the bottom of the ladle, and the molten steel obtains a certain mixing function.

3. Vacuum degassing function. 

After the ladle is lifted into the vacuum tank, the steam jet pump is used for vacuum degassing, and argon is blown into the ladle bottom to stir the liquid steel, which can remove the hydrogen content and nitrogen content in the liquid steel, further reduce the oxygen content and sulfur content, and finally obtain the liquid steel with high purity and materials with superior performance. 

For the whole enterprise, the application of a ladle refining furnace can at least increase the following benefits: speed up the production rhythm and improve the efficiency of the whole metallurgical production.

Application: 

Ladle refining furnace is widely used in industry, steel, metallurgy, and other industries.


Ferroalloy Refining Furnace

Ferroalloy refining furnace is the main equipment for smelting ferroalloy. Ferroalloy electric furnaces are divided into reduction electric furnaces and refining electric furnaces. 

Reduction electric furnace, also known as submerged arc furnace or submerged arc furnace, adopts the submerged arc operation of inserting an electrode into furnace charge. The reduction electric furnace has open, closed (or semi-closed), and the furnace body has various forms such as fixation and rotation. 

Electric refining furnace is used to refine medium carbon, low carbon, and micro carbon ferroalloys. The capacity of an electric furnace is generally 1500 ~ 6000 KVA, which adopts the form of open fixing or tilting with cover. 

The former is similar to the reduction furnace and can be equipped with a continuous self baking electrode; The latter is similar to an electric arc steelmaking furnace, using graphite or carbon electrode.

Equipment Features

The capacity of an electric furnace is generally 1500 ~ 6000 KVA, and its structure is divided into two forms:. The utility model is similar to an electric arc furnace, which uses graphite or carbon electrodes and has the function of electricity. Arc heating, furnace tilting, tapping, slag raking, and matching process require that the furnace top can be fed.

The other is similar to the reduction electric furnace, which is equipped with continuous self baking electrodes. The furnace body has various forms such as fixed and rotating, and adopts the form of closed (or semi-closed) fixed furnace cover; The operation of an automatic feeding system for tapping, slag raking, and smelting process is consistent with that of reduction electric furnace.

Equipment Composition

Transformer, short net, conductive cross arm (holder), lifting column, furnace body, furnace cover (smoke hood), tilting mechanism (furnace rotating mechanism), cooling water system, hydraulic system, furnace top charging device, heat matching car, tapping device, batching system, electric furnace automatic control system, etc.

Application

It is mainly used for desilication refining of ore, high silicon, and low carbon ferroalloy remanufacturing products and flux, so as to obtain medium carbon, low carbon, and micro carbon ferroalloy products. 

At present, it is used for smelting ferroalloy products such as medium chromium, low chromium, low micro chromium, medium and low carbon ferromanganese, metal manganese, ferrotungsten, ferronickel, high titanium slag, rare earth alloy, and zirconium.


Free send inquiry to stella@hanrm.com if any needs.

Whatsapp/Wechat:+8615877652925

Website:  https://www.hanrm.com


Ferroalloy Refining Furnace


Featured Article

Minimizing Energy Cost in Electric Arc Furnace Steel Making by Optimal Control Designs

Minimizing Energy Cost in Electric Arc Furnace Steel Making by Optimal Control Designs The article is incomplete due to editor reasons, to d...

Popular Articles

About Me

Xian, Shaanxi, China
We are the manufacturer of Steel Rolling mills, Wire Rod Mills, TMT Rebar Mills, Electric Arc Furnaces, Flying shears, Continuous Casting machines, and spare parts. we can supply designing, manufacturing, installation and commissioning of the equipment with "turn-key" service. We can also design, manufacture and revamp other non-standard equipment according to the requirements of users. Free mail to Stella@hanrm.com for your rolling mill plant Solution  Whatsapp/Wechat:+8615877652925 https://www.hanrm.com/ https://www.electricarcfurnaces.com/ https://www.hanmetallurgy.com/ https://www.rollingmillmachine.com/ https://yfmetaltech.com/

Electric Arc Furnace

Contact Us

名称

电子邮件 *

消息 *