Utilization status of discarded magnesia carbon bricks

 At this stage, the iron and steel industry has overcapacity. With the country's continuous strengthening of capacity reduction, the continuous deepening of supply-side reforms, and the increasing attention to environmental protection effects, energy conservation and consumption reduction have gradually become the key to the survival of iron and steel enterprises. The steel industry has a huge demand for refractory materials, and the annual output of waste refractory materials has reached 7 million tons. Among them, most of the refractory materials dismantled after use by steel mills are magnesia-carbon. Recycling it not only greatly saves production costs, but also achieves environmental protection and solid waste recycling. Therefore, the development and utilization of waste magnesia carbon bricks at home and abroad has been increasing. The current status of the utilization of waste magnesia-carbon bricks by domestic and foreign iron and steel enterprises is as follows.

1. Preparation of metallurgical auxiliary materials

As an important way of recycling economy for metallurgical enterprises, the recovery of waste refractory materials and the preparation of metallurgical auxiliary materials have developed rapidly. Domestic Company cooperates with Henan Company to combine waste magnesia-carbon bricks and some additives to make multifunctional magnesium balls, which can replace dolomite in full or part as slag-making auxiliary materials, which are the steelmaking, slag-making process and slag-splashing process of the converter creating condition.

2. Preparation of recycled magnesia carbon bricks

Baosteel uses waste magnesia-carbon bricks from the ladle slag line as raw materials, after sorting, removing surface inclusions, slag and oxide layer, hydration and other treatments, adding 3% to 4% thermosetting phenolic resin ingredients and mixing them at 200℃, 260MPa Recycled ladle magnesia carbon brick are made after hydraulic pressure and 5h curing treatment, the effect is similar to the use of new magnesia-carbon bricks.

3. Preparation of tundish dry materials

The main raw material of tundish magnesia dry vibrating material is fused magnesia. With the changes in market demand in recent years, its price has far exceeded the cost, making the production of magnesia dry vibrating material basically without economic benefits. This situation has promoted the development of the use of recycled magnesia-carbon materials to prepare tundish dry materials. Guangzhou Iron and Steel, Maanshan Iron and Steel, etc. have conducted related research.

Guangzhou Iron and Steel has carried out research on the partial replacement of mid-range magnesia with waste magnesia carbon bricks to prepare dry materials for recycled tundishes. The waste magnesia-carbon brick particles were used to partially replace the mid-grade sintered magnesia in the original composition for batching. After making the strip samples, the performance was tested. It was found that both the shaped and unshaped waste magnesia-carbon brick particles could be used for the dry material of the tundish, and the shaping was used. When granular, the overall performance is better.

4. Preparation of gunning material for ladle

The magnesia-carbon bricks disassembled from the steel ladle slag line of Shan Iron & Steel Co., Ltd. are treated as qualified raw materials after removing the surface slag and iron, crushing, removing iron, and sieving. Since Shan Iron & Steel's ladle gunning repairs the slag line of the red hot ladle, the water in the sprayed layer quickly evaporates due to the high gunning temperature, making Al4C3 too late to hydrate. Therefore, it is not necessary to hydrate the raw materials during the production process.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:Utilization status of discarded magnesia carbon bricks

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Brief introduction of LRF delta castable

 Ladle is the main thermal equipment for loading molten steel. In the process of loading and transporting molten steel, due to the heat loss at the mouth of the ladle, many steel plants have chosen to increase the ladle roof to reduce the heat loss in recent years. There are many types of unshaped refractory materials for ladle lids, but the refractory castables used for ladle lids that can improve the use effect of ladle lids need to choose suitable castables according to the actual use environment.

The castable for ladle roof can choose high-aluminum mullite castable or low-cement steel fiber castable. High-aluminum mullite castable is to choose high-quality high-alumina bauxite as refractory aggregate, and add appropriate refractory powder according to the formula. The low-cement steel fiber refractory castable is a kind of refractory castable added with steel fiber. Steel fiber can improve the wear resistance and flexural performance of the castable. The low cement content can effectively improve the overall high temperature resistance of the castable. As the lining of the ladle roof, it can effectively resist the corrosion of molten steel gas and molten slag.

The ladle delta castable can be directly poured into the ladle roof mold during use. The high-alumina mullite castable has excellent high temperature performance, high compressive and flexural strength, and good volume stability. Because high alumina bauxite has good heat vibration performance, as the main raw material of the refractory castable for the ladle roof, can increase the service life and use times of the ladle, reduce the maintenance frequency of the ladle roof, effectively increase the turnover speed of the ladle, speed up the steelmaking production rhythm, and ensure the quality of molten steel. And production anterograde played an important role.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality High Alumina Cement are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:Brief introduction of LRF delta castable
Company name: Henan Changxing Refractory Materials Co.,Ltd
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4 indicators that determine the high temperature performance of refractories

 Refractory materials are subject to physical, chemical, and mechanical effects at high temperatures (usually 1000~1800°C) during use, which are easy to melt and soften, or are corroded, corroded, or cracked and damaged, causing the operation to be interrupted, and Contaminated materials. Therefore, it is required that refractory materials must have properties that can adapt to various operating conditions.

(1) Refractoriness

Refractoriness refers to the temperature at which a material reaches a certain degree of softening under the action of high temperature, which characterizes the performance of the material against high temperature. Refractoriness is the basis for judging whether a material can be used as a refractory material. The International Organization for Standardization stipulates that inorganic non-metallic materials with a refractoriness above 1500°C are refractory materials. It is different from the melting point of the material, and it is a comprehensive performance of a mixture of multiphase solids composed of various minerals.

(2) High temperature load deformation temperature

Also known as the refractory softening point under load or the refractory deformation temperature under load, it means the resistance of the refractory to the combined action of high temperature and load under a constant load or the temperature range in which the refractory exhibits significant plastic deformation. The maximum use temperature can be inferred from the refractory material’s load softening temperature.

(3) High temperature volume stability of refractories

Refractory materials produce volume expansion under the action of high temperature for a long time, which is called residual expansion. The size of the residual expansion (deformation) of refractories reflects the quality of high-temperature volume stability. The smaller the residual deformation, the better the volume stability; on the contrary, the worse the volume stability, the easier it is to cause deformation or damage to the masonry.

(4) Thermal shock stability

The ability of refractory materials to resist sudden changes in temperature without being damaged is called thermal shock stability. This performance is also called thermal shock resistance or temperature sudden change resistance.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:4 indicators that determine the high temperature performance of refractories
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Essentials of refractory construction for RH refining furnace

 RH system equipment is a secondary refining process equipment for molten steel used to produce high-quality steel. The entire molten steel metallurgical reaction is carried out in a vacuum tank with refractory lining. The lower part of the vacuum tank is two dip pipes with refractory lining, and the upper part is equipped with hot elbows. The temperature during refining in RH furnace is as high as 1600~1700℃.

Therefore, the lining refractories are required to have high fire resistance, can withstand the impact of maximum temperature and local overheating, and have a small amount of liquid phase at high temperatures, and can resist the erosion of low-viscosity slag. Alkaline bricks with high purity and direct bonding rate should be selected. The intermittent operation of HR will cause temperature fluctuations, and the material is required to have excellent thermal shock resistance. It is better to use magnesia carbon bricks and magnesia chrome bricks with the best thermal shock resistance.

In addition to selecting suitable refractory materials, construction is also the key to the service life of RH refining furnaces.

Ramming material construction: The bottom of the lower trough, the refractory bricks and the circumference of the circulation pipe are constructed with ramming material. Due to the high pressure, the ramming material is required to be compact, especially for some irregular shapes. A special hammer head is used for construction to ensure that the compactness of the ramming material meets the requirements.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality ladle magnesia carbon bricks are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:Essentials of refractory construction for RH refining furnace
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Classification of steel converters and refractory materials required

 

1. Oxygen top blowing converter

Oxygen top-blowing converter is the most widely used one in steelmaking converters. It is to charge the main raw materials, namely molten iron and return to work, into the furnace, add limestone, fluorite and other auxiliary materials, and then pass the oxygen gun through the furnace mouth. A steelmaking method in which pure oxygen is blown into molten iron for smelting. The oxygen top-blowing converter has the advantages of not using foreign fuels, low equipment and production costs, high production efficiency, and fast construction speed. Therefore, it has been rapidly popularized and has become the main equipment for contemporary steelmaking.

2. Electric (arc) furnace

The steel-making electric (arc) furnace stone is first charged with scrap steel or reduced iron, and the furnace charge is melted by the electric arc generated between the charge and the electrode, and the refining operation is carried out under the condition that the electric arc continues to heat. The molten steel with the required composition and temperature is a kind of thermal equipment that converts electrical energy into heat to smelt metal. Electric (arc) furnace steelmaking has the advantages of using scrap steel as the main raw material, high temperature, capable of controlling the atmosphere in the furnace, and particularly suitable for smelting alloy steel.

3. Mixing furnace

The mixer is a thermal equipment for storing molten iron in the steelmaking workshop.

4. Mixed rail car

The iron mixer is also called a torpedo car because it resembles a fish. It is a kind of thermal equipment for storing and transporting molten iron from the blast furnace to the transfer workshop.

5.?Iron furnace

The cupola (cupola) is one of the main thermal equipment in the foundry. It is used to melt pig iron lumps and overheat molten iron in order to obtain good quality molten iron.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality changxing refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc. Shall any interests, welcome to contact us. Our team would make best to be your reliable partner!

Article Source:Classification of steel converters and refractory materials required
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Refractory castables and measures to increase their service life

 As we all know, refractory castable is a kind of amorphous refractory without calcining. It is made up of refractory aggregate, refractory powder and cement in a certain proportion; it has good fluidity after adding water and stirring during construction. Then it is formed and cured (to be baked according to a certain temperature system) to make it condense and harden. The use characteristics of refractory castables are as follows: First, the masonry structure has few joints, strong integrity, and good sealing. It can avoid the infiltration of clinker powder during application and operation; Second, it is easy to anchor and convenient to construct, which is beneficial to improve masonry. Efficiency and masonry quality; The third is that raw materials are widely used, which is convenient for comprehensive utilization of resources, and the delivery time is short, which can reduce inventory and related costs accordingly.

With the gradual expansion of the application of refractory castables, its life cycle has become the most concerned issue of all owners. In order to ensure the life cycle that meets the design requirements, the following aspects should be achieved: First, a strong manufacturer should be selected to ensure the quality of the refractory castable itself; Second, a reasonable selection and configuration should be carried out according to the use environment; It is necessary to have a reasonable construction plan and strict construction process control measures during construction, including proportioning control, molding quality control and reasonable maintenance, heating system control and so on.

Popularly speaking, refractory castable is a kind of high-temperature-resistant concrete, so it also conforms to the theory of concrete. For example, the amount of water added is the fundamental reason for controlling whether the refractory castable can achieve the design strength. However, driven by profits, some construction parties will add a lot of water to the castable in order to speed up the construction progress during the construction of refractory castables, resulting in the use of the kiln refractory lining after the construction is much lower than the design requirements , Even after half a year of use, serious problems have occurred and must be overhauled (and for well-constructed refractory castables, there is no need for overhaul after 3 to 5 years of use). We know that refractory investment accounts for a small proportion of the entire plant investment (about 2% to 4%), but its impact on the future operation of the entire system is very large. The loss due to a refractory lining accident for a day of stopping can be as little as hundreds of thousands or even millions. Therefore, ensuring the high operating rate of the firing system can achieve the high-quality, high-yield and low-consumption operation of the system. Therefore, the construction process control of refractory castables is particularly important. Usually we should strictly follow the following regulations.

First, the amount of water added to the castable should be strictly controlled in accordance with the instructions for use, and should not exceed the limit. On the premise of ensuring the construction performance, the amount of water added should be less than more.

Second, the mixing time of the castable is not less than 5min. When operating, use a compulsory mixer. When mixing, dry mix first, and then add 80% of the amount of water to stir. Then, depending on the degree of dryness and wetness, slowly add the remaining water and stir until Obtain a suitable working consistency.

Third, the pouring material poured into the mold frame should be immediately stratified with a vibrating rod. The height of each layer should not be greater than 300mm, and the vibration spacing should be 250mm. When vibrating, try to avoid touching the anchors and not damaging the heat insulation. Do not vibrate and re-vibrate on the same part for a long time. After seeing the reflow of the castable surface, the vibrating rod should be slowly withdrawn to avoid segregation and voids in the castable layer.

Fourth, when pouring a large area, the construction should be divided into blocks. The pouring area of each block should be about 1.5m2. The expansion joints should be set according to the design and should not be omitted. The expansion joints should be set in the middle of the anchor interval.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc.?

Article Source:Refractory castables and measures to increase their service life
Company name: Henan Changxing Refractory Materials Co.,Ltd
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The role and performance of the slag ball

 1. How to determine the time and location of the slag ball? 　

When tapping reaches 3/4, use a special device to drop the slag ball from the top of the tapping hole 500 mm away from the slag surface, and the slag retaining effect is the best.

2. How to evaluate the use effect of slag ball?

The use effect of the slag ball can be evaluated by observing the shape of the tapping molten steel. When the slag retaining effect is good, the tapping molten steel should flow down in an annular shape. In addition, it can be judged by the color of the slag.

3. What is the function of the groove on the slag ball? How to calculate?

The function of the groove on the slag stop ball is to facilitate the flow of molten steel during the slag stop process.

The formula for calculating the groove volume is: V1=slot area*slot length=πr2/2*L

4. How to evaluate the performance of the slag ball after use?

The effect of the slag ball after use can be evaluated by the thickness of the slag layer in the ladle and the alloy yield. The thickness of the slag layer is small, the alloy yield is high, and the slag blocking effect is good.

5. What data need to be recorded in the field test?

The data that needs to be recorded in the field test include: tapping temperature, use time of slag ball, thickness of slag layer, alloy yield, etc.

We Changxing Refractory Material Co.,LTD is professional manufacturer and supplier of refractory materials for more than 30 years. Our high quality refractory products are good sold to many countries say South Africa, Bangladesh, Indonesia, Malaysia, etc.

Article Source:The role and performance of the slag ball
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