Let the converter lining prolong life and be environmentally friendly

In 2018, Beijing Union Rongda Engineering Materials Co., Ltd. (hereinafter referred to as Beijing Rongda) has developed and researched environmentally-friendly carbon-free “water-based” converters with large-scale self-flow materials for full-scale broadcast, and has been accepted by the majority of converter steel mills. Concerns have further promoted the promotion and adoption of this self-flow material.

The problem in production, the subject of R&D

According to Dr. Zhang Ronghui, Chairman of Beijing Rongda, the traditional converter lining repair has the following drawbacks:

First, the traditional large-surface repairing materials (also known as black materials) and their use methods are consumables, time-consuming and inefficient. In general, the industry uses magnesia or magnesia carbon brick crushing materials as the main raw materials, and uses organic materials such as asphalt and tar as binders to form black repair materials, which is the most common and most expensive material. When the material is added, the hopper is used. During the process of adding, the bitumen or tar is burned, the black smoke on the spot is large, the labor intensity of the worker is large, the environment is polluted, and the human health is endangered.

Second, the black material is seriously polluted during the sintering process and has a short life. The black smoke it takes is one of the main sources of pollution in the current steelmaking environment. The added materials must be sintered before they can be steel. The sintering process is actually the carbonization process of organic matter such as asphalt or tar. Many of the organic matter in the asphalt will volatilize, and finally carbon is formed to provide sufficient strength for the material to enter the smelting state. In the course of using this black material, the following problems still exist: the sintering time is too long, and it takes 60 minutes to 90 minutes to sinter using 1 ton to 2 tons of material, which affects the production rhythm. The sintering process releases a large amount of toxic and harmful fumes, and some are even very toxic and harmful carcinogens. In addition, after the tar and asphalt are sintered, eventually more than 45% of the carbon remains, and some sulfur is also mixed, which will cause pollution to the molten steel. The black material has a large amount of volatile matter, a loose material structure, is not washable, and has a short service life.

In summary, the converter steelmaking industry hopes to develop a new converter repair technology to solve the above problems.

To solve problems for users, Beijing Rongda is duty-bound. Its non-carbon water-based converter large-face self-flow repairing material is made of high-purity magnesium oxide as the main raw material, using inorganic solution as binder, using reasonable particle grading, innovative technology to produce dispersing agent containing ultrafine powder, low temperature and high temperature leveling agent. And bonding agents, etc. The material has the following advantages: the sintering process does not release toxic fumes, green and environmentally friendly; the material sintering time is shortened to about half of the black material; the structure is dense, the strength is high, and the erosion resistance; the ceramic combination, the bonding performance in the oxidizing environment is not affected; The life can reach more than three times that of black material.

In addition, the self-flowing repairing material can be stirred by a forced agitator on site, and the liquid binder can be quantitatively added according to the requirements, and the mixture can be discharged until it is flow-shaped. The material can be first placed in the scrap bucket and then poured into the converter at one time. There is no soot during the whole feeding process.

The actual use of the self-flowing material in a 130-ton converter in a factory shows that the cumulative service life is about 60 furnaces on average, and the longest time is more than 120 furnaces, which is several times the life of the black material under the same conditions, which is undoubtedly greatly reduced. The consumption of the refractory material is compensated.

The most direct advantage of the self-flowing material in the use process is that it is hygienic, can greatly reduce environmental pollution, and has a long service life, and the economic benefits are very significant. This is a great tool for converter steel mills with high environmental pressures.

Converter remote control wet spray repair technology icing on the cake

In the past, the dry spraying of the converter was carried out using a tube and compressed air, and the material was sprayed to the corresponding position by a spray gun. In the process, water was added behind the handle. This kind of operation is difficult to guarantee quality, and labor intensity is great. Therefore, it is not necessary to solve the series of problems such as how to reduce labor intensity, improve the working environment, improve work efficiency, and ensure the quality of spraying from a technical point of view.

Specifically, the dry spraying of the converter has the following problems: loose material structure, low strength, short service life; high rebound rate (20% to 30%), wasted material; construction dust is large. For example, a converter in a factory uses a dry spray roof. When the top spray test is performed, the amount of rebound is very large, and the material sprayed is powder. It is not the original designed product, and the compactness, wear resistance and strength of the material. It is difficult to meet the design requirements.

The converter remote-controlled wet-jet injection process developed by United Rongda combines the equipment technology of dry spray and concrete wet spray. The jet is sprayed by pneumatic conveying wet jet, plunger pumping wet jetting, screw pumping wet jetting. The self-flowing castables sprayed by the three injection processes are firmly bonded to the substrate, do not rebound, and do not flow. The results show that the technology can also improve the working environment, reduce the labor intensity of workers, improve the quality of spray repair, extend the service life of materials, and reduce the frequency of spray. At the same time, in addition to meeting the injection repair of the side wall of the converter, the technology can also be used for directional injection repair around the permeable brick.

Taking the user's 130t medium-sized converter as an example, the supply and demand sides have made the following economic benefits analysis for the self-flowing material and the injection technology: there are five 130-ton converters in a domestic factory, each of which has about 35 furnaces per day, and the furnace life is about 12,000. Furnace, compared with traditional large materials, the direct and indirect economic benefits brought by this self-flow material are as follows:

The single feeding amount was reduced from 2 tons to 1.5 tons; the sintering time was shortened from 80 minutes to 20 minutes; the average service life was increased from 12 times to 45 times; the number of furnaces was reduced from 500 times to 135 times; The time taken from 40,000 minutes was reduced to 2,700 minutes, and the production increased by 118,000 tons; the consumption of large fabrics was reduced from 1,000 tons to 200 tons; the cost of large fabrics was reduced from 3 million yuan to 1.8 million yuan. Poor and excellent, not to mention.

Taking a steelmaking workshop with a three-seat 30t converter as an example, the average steel output per furnace is 33.5t, the monthly steelmaking is about 180,000t, and the annual steelmaking is about 64476 heats. According to the above analogy: the life of the lining is increased by 21 times. Up to 84 times; the sintering time was shortened from 45 minutes to 17 minutes; the annual repair time was reduced from 138,150 minutes to 13,056 minutes, saving 125,094 minutes; and the production of converter steel was 168,000 tons.

At present, the output of crude steel is estimated at 800 million tons. The traditional large fabrics consume about 48-64 million tons. The new “water-based” large fabrics will be used. As the service life increases, the number of repairs will be reduced to about one-third. It can save resources of 3.2-42 million tons. At the same time, it will consume 6.2-96 million tons of toxic and harmful substances such as asphalt and tar. The time saved due to short sintering time and low number of repairs will increase steel production by 7-8% to about 60 million tons. Economic and social values are significant.

Practice has shown that in the modern converter lining repair, the promotion of environmentally friendly carbon-free water-based large-surface self-flow material does have a lot to offer!


    Xi'an Pengyuan Metallurgical Equipment Co., Ltd. was established on February 20, 2017. The company is located in Xi'an, Shaanxi, China. Its main business is the design and manufacture of metallurgical equipment (electric arc furnace, submerged arc furnace, ladle refining furnace, other refining furnaces and metallurgical auxiliary equipment). The company's vision is to become a service-oriented leading enterprise that can provide users with advanced and applicable complete smelting technology solutions. The company is determined to make “Pengyuan Metallurgy” into the electric furnace industry. Excellent brand. Pay attention to us, keep abreast of the latest developments in the industry, hotline: 13819831910.