Ferroalloy furnace life extension measures

As the core equipment of production, the service life of the ferroalloy furnace body is directly related to the cost and benefit of the enterprise. In order to improve the service life of the furnace body, the company combined the experience summarized by the industry workers in the past, and carried out the summary and Explored, formulated a series of measures, and formed a set of internal furnace protection management system.

Ferroalloy smelting is a multi-phase physical and chemical process carried out at high temperatures, and the working conditions of refractories in the furnace are very harsh. The temperature in the crucible area of the slag-free smelting reaction can reach 2000~3000℃, and the high temperature area of the slag-free smelting process also has various erosion effects.

Our company's ferrosilicon and silicomanganese mainly use carbon bricks for masonry. Carbon bricks have the advantages of high melting point, good thermal shock resistance, high high-temperature strength, and no infiltration of alloys and slag. The disadvantage is that they are easy to oxidize and are exposed to Carbon bricks in the air can be oxidized, and carbon dioxide and water vapor will oxidize carbon products above 600°C. High-carbon ferrochrome is mainly used for masonry of magnesia bricks. Magnesium bricks have high strength and high temperature resistance, and are mainly used in alkaline slag smelting. The load softening temperature of magnesia bricks is 1550℃.

Up to now, the furnace age of Si-Mn 6# and chromium iron 8# furnaces are all over 7 years, and they have undergone several intermediate repairs. How to extend the furnace age is an important indicator to ensure the efficiency of the enterprise. The company has all implemented furnace protection system management since 2015. Since operation, the furnace body has basically been operating stably. It has summarized several experiences in furnace body damage and maintenance, and formulated a series of control measures.

Furnace protection measures

In response to the above problems, the company started with two aspects of "in-furnace maintenance and outside-furnace protection" and formulated the following measures:

Internal breeding

1. Reasonably control the pressure discharge amount, and the strong pressure electrode cannot be used as the job index. The reasonable electrode pressure discharge amount should be explored in combination with the furnace bottom temperature and the furnace wall temperature and various parameters. If the furnace bottom temperature is found to be abnormally increased, or the furnace wall For the phenomenon of red and rising, adjust the pressure release amount in time and perform cooling treatment.

2. Improve the technical operation standards. The silico-manganese alkalinity control and the control of the magnesium-aluminum ratio of ferrochrome are all included in the standards, and controlled in advance during the procurement and batching process. If the conditions cannot be met, some serpentine and magnesite can be appropriately mixed Avoid large deviations in ore and lime.

3. The addition of silicon slag above the ferrosilicon furnace eye has a certain effect from the depth of the later furnace eye plugging, but the total amount of silicon slag should be reasonably controlled.

4. Anhydrous carbonaceous furnace lining repair material is used for plugging and furnace body maintenance to maximize the service life of the furnace eye and surrounding furnace wall.

External protection

1. Using a combination of manual temperature measurement and electronic equipment. The company has established manual temperature measurement and tracking requirements for a hierarchical furnace protection system. The frequency and requirements of manual measurement are set for different temperature ranges. At the same time, furnace temperature measurement patches are installed in different areas of the furnace body, which can respectively monitor the temperature Carrying out tracking measurement and data recording, and forming a curve, can have a more accurate evaluation of the furnace operation through manual and electronic data.

2. Standardize the operating standards of the plugging machine for plugging holes. During the hole plugging operation of the furnace, it is necessary to plug deep and solid, and strictly control the use of oxygen during the process of opening.

3. Each furnace body is forced to cool the area with higher temperature by erecting axial flow fans and compressed air ducts to reduce the furnace bottom temperature, and control the heat balance to control the loss of the Thaiman temperature on the furnace wall.

4. The company tried the 8-2# furnace eye area fixed thermal imager in the early stage. From the use effect, the thermal imager regularly monitors the weaker area of the furnace body. The data image is more intuitive and the effect is better. If the conditions are better In case you can try the use of new equipment.

In the later stage of the submerged arc furnace campaign, internal maintenance and external protection are used to achieve a good furnace protection effect to maintain the stable operation of the furnace body. From the current point of view, the establishment of an effective furnace protection system and operation system, combined with the current mainstream advanced equipment, is a small investment, high output, and can create market and safety benefits.