#magnesiabricks

The melting point of MgO is as high as 2800℃, and the refractoriness of magnesia bricks is generally high, reaching above 2000℃. Therefore, magnesia bricks have good high temperature resistance, high temperature vacuum stability is good, and strong resistance to alkaline slag , but magnesia bricks have poor resistance to sulfate erosion, poor thermal shock stability, and are easy to hydrate. In addition to traditional magnesia bricks, magnesia refractories also include forsterite refractories and magnesia alumina spinel high-quality refractories, magnesia-chrome refractories, white jade refractories, etc.

Magnesium chromium refractory material. It is a refractory material made of magnesia and chromite, and with magnesia as the main component. According to the chemical composition, magnesia-chrome refractory products include chrome bricks and chrome-magnesia bricks. Magnesium-chromium refractory products have high refractoriness, high-temperature strength, good thermal shock stability, strong corrosion resistance to alkaline slag, adaptability to acidic slag, and good kiln-hanging properties. Magnesium-chromium refractory products are mainly used in RH ovens, AOD furnaces, non-ferrous metal smelting furnaces and glass kiln regenerators, cement rotary kilns, mixing furnaces, lime kilns and high-temperature kiln linings, etc.

However, due to the environmental impact of hexavalent chromium ion harm to the human body. Magnesium aluminum spinel refractory material. It is a refractory composed of magnesia and spinel with a magnesium oxide content (mass fraction) of not less than 20%. However, due to the large variation range of A12O3 and MgO content, we will use A12O3 and MgO as the main chemical composition of the refractory. It is called magnesia-aluminum spinel refractory. Magnesium-aluminum spinel refractories are mainly used in large cement rotary kilns, glass kiln regenerators, electric furnace tops, refining furnaces outside the furnace, ladle and other thermal equipment for enhanced operations. Dolomite refractory material. The main component is white jade clinker. White jade clinker refers to calcining natural magnesium calcium salts or hydroxides to form a uniform and dense mixture of calcium oxide and magnesium oxide. According to the chemical mineral composition, it can be divided into the following two categories.

Article Source:The characteristics and classification of magnesia refractories Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd Email: [email protected] Website:http://www.cxrefractories.com

After feed in EAF bottom ramming mass, use a shovel or a nail rake to level it, and then use an aluminum alloy long ruler and a level to level it, taking the baseline released in advance as the standard, and then spread a canvas on the leveled ramming material, and the canvas will ramming the furnace bottom cover it all. Put two vibrators on the canvas and keep a certain distance between the two vibrators. At the beginning, the two vibrators are best placed on the two ends of the furnace diameter inside the furnace shell. This will not only avoid mutual interference, but also enable the operator to reduce dust damage. After the vibrator is activated, it starts to vibrate from the outer ring and ramming from the outside to the inside. The next circle should overlap the previous one by one third to prevent missed beating. Continuously vibrate from the inside of the brick wall until the center of the furnace is regarded as-times. After the ramming is completed, the ramming is repeated several times from the outside to the inside, and each layer of ramming material is simultaneously rammed multiple times with two vibrators. After each layer of ramming is finished, remove the dust-proof canvas, and use a homemade nail rake to pull the surface of the ramming material in the same direction and comb into grooves to help increase the contact area of the upper and lower adjacent layers to form a seamless overall ramming stove bottom. The density of the ramming material after compaction should reach 2.8g/cm2 or more. At this time, the vibrator jumps up and down, the amplitude is larger, and the vibration sound is louder than the previous few times. These phenomena indicate that the material layer is basically solid. Knotting quality inspection method: use a 4mm diameter iron rod, such as φ 4mm welding rod, the insertion depth does not exceed 20mm.

Article Source:Lining method of EAF bottom ramming mass Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd Email: [email protected] Website:http://www.cxrefractories.com

The electric arc furnace is a device that uses the arc generated between the electrode tip and the charge as heat energy to make steel. The development of electric arc furnace technology is the development of direct current electric arc furnace, furnace bottom gas agitation and furnace bottom tapping based on the use of high power. The electric arc furnace is composed of furnace roof, furnace wall, furnace bottom and tapping trough. 1.?Refractory materials for electric arc furnace? The roof of the electric arc furnace is generally built with high-alumina bricks, and the alumina content is between 75%-85%. Compared with silica bricks, high-alumina bricks are characterized by high refractoriness, good thermal shock resistance and high compressive strength. Due to the rich domestic bauxite resources, high alumina bricks have become the main refractory material for electric arc furnace roofs, with a life span of about 2-3 times that of silica brick roofs. 2. Refractory materials for furnace wall The furnace wall is divided into general furnace wall, slag line area and hot spots near the arc. Generally, the furnace walls are mainly built with magnesia bricks, dolomite bricks and periclase bricks, and some use unburned magnesia alkaline bricks and asphalt combined with magnesia and dolomite ramming materials. The furnace wall of ultra-high power or special steel smelting electric arc furnace uses magnesia chrome bricks and high-quality magnesia bricks. The slag line area and hot spots are the weak links of the furnace wall. Because the life of the furnace wall mainly depends on the damage degree of the hot spot, special attention should be paid to the furnace lining at this spot. Nowadays, magnesia carbon bricks are widely used for masonry, which can show excellent high temperature resistance and slag resistance. The service life is significantly improved, reaching more than 300 heats. In order to balance the damage of the furnace wall and prolong its life, the furnace wall is also equipped with a water-cooled box or water-cooled jacket. The inner surface is sprayed with a layer of refractory coating to form a protective layer of slag, which can effectively reduce the unit consumption of refractory materials. But the corresponding energy consumption has increased. 3. Refractory materials for furnace bottom Select good magnesia or fused magnesia for the knotted lining. Pay attention to the joints of each layer during construction. The thickness and density of each layer should be consistent. There are working layers and permanent linings under the ramming layer. The working layer is selected from tar pitch combined with magnesium for brick masonry, magnesia bricks are mostly used for permanent lining. At the slag line on the upper part of the embankment slope, due to the serious erosion of the slag, the same or similar lining bricks as the hot spots of the furnace wall are often used, such as cast magnesia chrome bricks or combined with magnesia chrome bricks. It is better to use magnesia carbon bricks. 4. Refractory materials for tapholes The currently used furnace bottom eccentric tapping method changes the furnace body from a tilting type to a fixed type, and sets a tap hole at the eccentric position of the furnace bottom to replace the tapping trough. The advantages are: cancel the tilting equipment, expand the area of the water wall, alleviate the damage of the furnace lining, appropriately reduce the tapping temperature and shorten the tapping time, thereby reducing the cost. The eccentric taphole bricks are pitch-impregnated and fired magnesia bricks, the pipe bricks are made of magnesia carbon bricks with a resin-bonded carbon content of 15%, and the end bricks are magnesia-carbon bricks with a resin-bonded carbon content of 10%-15%. For 15% ALO-C-SiC bricks, for smooth tapping, coarse sand with olivine as matrix is often used as drainage material.

Article Source:Main parts and refractories of electric arc furnace steelmaking Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd Email: [email protected] Website:http://www.cxrefractories.com