Ferro silicon manganese is widely used in the steel industry. This article introduces a new production method for ferro silicon manganese.
Introduction of silicon manganese alloy production process
Both silicon and manganese are commonly used as alloying elements in the production of carbon steel.
Manganese is an important deoxidizer in the steelmaking process at this stage. Common steel types on the market need to use manganese as a deoxidizer in the production process. From the perspective of properties, manganese is used as a deoxidizer. During the chemical reaction of steelmaking, the oxides formed have a lower melting point and are easier to float on the molten steel. At the same time, the use of manganese as a deoxidizer can further improve the deoxidation performance of strong deoxidizers such as silicon and aluminum. Therefore, in most industrial steelmaking processes, a certain amount of manganese will be incorporated into it, so that the steel can maintain good toughness and will not break during hot rolling, forging and other links.
And in a variety of steel grades, manganese is an important alloying element. After practical research, it is found that in the process of producing alloy steel, incorporating manganese with a content of 15% or more into it can effectively improve the strength and hardness of the steel structure.
Silicon is an alloying element that is second only to manganese in the production of carbon steel and pig iron forging. Most steels use this element as a deoxidizer in the production process, and this element It can also effectively improve the strength of steel and optimize the performance of steel. At the same time, silicon element is also a graphitized medium with good utilization effect, which can transform the carbon element in pig iron into free graphitic carbon.
At present, in the process of producing silicon-manganese alloys in major industrial enterprises, the raw materials used mainly include fluorite, coke, manganese ore, silica, dolomite, manganese-rich slag, etc., and these mineral materials are mixed for processing and production. After the various raw materials are weighed, proportioned and fully mixed according to the requirements of the smelting process, they must enter the electric furnace through the feeding system, material distributing system and feeding pipe, and be smelted by means of electric power supply. The electric furnace adopts continuous reduction smelting, and iron and slag are intermittently tapped at a fixed time. It should be noted that the content of phosphorus and iron in the ore used is lower than that of carbon manganese iron ore. Therefore, in the process of smelting silicon-manganese alloys, the ratio of manganese to iron and manganese scale in manganese ore is relatively large. The production process is mainly to use submerged arc furnace to reduce manganese oxide and silicon dioxide in manganese ore and silica, and finally Smelting silicon manganese alloy.
Problems in the production of silicon manganese alloy
Since the production of silicon-manganese alloys in my country is relatively lagging behind, and the relevant research and industrial production construction are relatively late, there is a certain gap in the application of production technology compared with Western countries. Despite the continuous development of the social economy in the new stage, the market demand for silicomanganese alloys is gradually increasing, and the production process of silicomanganese alloys in my country has also achieved certain results. However, in the actual production and development process, there are some problems that need further research.
(1) Ratio of ingredients
The raw materials used in the production process of silicomanganese alloy are relatively complicated, and various materials need to be put in strictly according to the specified ratio of ingredients, so as to ensure the quality of the alloy produced by smelting.
However, in the actual production process, some technicians ignore the importance of ingredient ratio, lack quality management and control awareness, are not rigorous enough in the process of putting in various raw materials, and do not strictly follow the regulations to check and weigh raw materials. The consequences of this will lead to uneven quality of silicon-manganese alloys, material waste and other problems, and even lead to production safety, threatening the lives of relevant personnel in industrial production.
(2) The problem of slag alkalinity
In the production process of silicon-manganese alloy, whether the alkalinity of slag is too high or too low will affect the production. If the alkalinity is too high, the amount of slag will increase, and a large amount of manganese will be carried when the slag is discharged, and the melting speed of the furnace charge will be accelerated, making it difficult to carry out the silica reduction reaction, and the silicon content in the alloy will decrease.
If the alkalinity is too low, it will help the reduction of silicon, and the slag liquid will become viscous, affecting the reaction and slag discharge, which will increase the carbon content in the alloy and decrease the silicon content, affecting the production quality of silicon-manganese alloys.
(3) Manganese recovery problem
During the production of silicon-manganese alloys, about 70%-80% of manganese will be reduced to the alloy, and a small part will enter the slag and be discharged. Manganese recovery is to fully restore the wasted manganese to the alloy to avoid waste of resources. However, due to the influence of factors such as process technology and equipment operation, the problem of low manganese recovery rate will inevitably occur in the actual production process. While wasting resources, the emitted gas will also have an impact on the natural environment.
How to deal with problems in the production process of silicon-manganese alloy
In view of the problems existing in the production process of silicon-manganese alloys, relevant industrial enterprises should increase their attention, change the process methods, establish environmental protection awareness, modern production awareness and quality control awareness,
Actively explore and explore, and use scientific methods to deal with these problems as much as possible.
(1) Guarantee the scientific nature of the ingredient ratio
In the process of silicon-manganese alloy production, when the mass of reducing agent used in the raw materials in the furnace is large, the conductivity of the furnace material will increase, and the current will also increase at this time, and the crucible will become smaller. By observing the furnace fire, there should be an excess of reducing agent during the ferrosilicon reduction reaction. In this case, the silicon dioxide in the furnace is reduced more, the silicon content in the alloy will also increase, and the surface of the produced alloy will be smooth. And if the reducing agent is used less, then the depth of electrode insertion will be greater, and the furnace fire will be found to show uneven combustion from the appearance, and the current is not stable enough. This is because the input of reducing agent is less, the content of silicon dioxide in the slag increases, and the iron slag will not be separated during the iron tapping process. Therefore, it is necessary to scientifically calculate the proportion of ingredients, clarify the amount of carbon to be produced, and fully consider the actual situation. For example, in the case of high slag alkalinity, the amount of carbon can be appropriately increased. Specifically, the actual situation of the taphole should be observed. If the newly tapped taphole is relatively narrow and the content of coke brought out during the tapping process is not much, in this case the amount of carbon can be appropriately reduced; if the previously tapped taphole is relatively narrow Broadly, the content of coke brought out during the tapping process is relatively large. In this case, the amount of carbon can be appropriately increased.
(2) Ensure the rationality of slag basicity
For the properties of slag, it is generally expressed by binary basicity and ternary basicity. The former is B2=W (CaO)/W (SiO2), and the latter is B3=[W (CaO)+1.4W (MgO) ]/W (SiO2). After practical research, it is found that in order to ensure the rationality of the basicity of slag, B2 can be controlled at 0.6-0.75, and B3 can be controlled at 0.6-0.8.
(3) Increase the importance of manganese recovery
Aiming at the problem of manganese recovery in the production process of silicomanganese alloy, the slag ratio can be appropriately reduced to reduce heat loss and increase the recovery rate of manganese. Specifically, the following methods can be used:
Improve the reduction rate of manganese and silicon
It can improve the recovery rate of silicon, maintain the basicity of slag, reduce the slag ratio, and then increase the recovery rate of manganese.
Increase the temperature in the furnace
The temperature in the furnace is high, and the temperature of the slag will also rise, which is conducive to the reduction of manganese oxide and silicon dioxide, reduces the amount of slag, and realizes the effective recovery of manganese.
Improve the taste of manganese
In the process of silicon-manganese alloy production, increasing the grade of manganese entering the furnace can increase the recovery rate of manganese and reduce power consumption. After research, it is found that it is necessary to combine the actual types of different silicon-manganese alloys to determine the grade of manganese ore entering the furnace. Generally, it is controlled at 30%-34%, and silicon is controlled at 21%-25%.
In short, there will be certain problems in the production process of silicon-manganese alloy due to various factors, which will affect the production quality and cause environmental pollution. In this regard, relevant production enterprises should increase their attention, be aware of the problems of ingredient ratio, slag alkalinity and manganese recovery in production, and take targeted measures to deal with them to ensure production quality and efficiency.