博文

目前显示的是 五月, 2021的博文

Construction spraying method of refractory spray coating

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  The spraying methods of refractory spray coatings are divided into three types: wet method, dry method and flame method. 1.Wet spraying refers to the spray surface of refractory spray coating after adding water or liquid binder. Wet spraying is divided into four types: mud method, wet method, semi-dry method and pseudo-dry method. The mud method is to mix the refractory mixture into a slurry before spraying, and is mainly used for thermal gunning of furnace lining ; the wet method is to stir the refractory mixture into pumping mud and then spray; the semi-dry method is to add the refractory mixture first A small amount of water is stirred evenly. When it is delivered to the nozzle, the remaining water is added and then sprayed; the false dry method is to stir the refractory mixture evenly through a mixer, and then send it to the nozzle to add water for spraying. 2. Dry spraying means to spray the mixed refractory spray coating directly to the sprayed surface through the

The opening and baking of the submerged electric furnace in the ferroalloy industry

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  (1)Oven After the furnace body of the electric furnace is built, the furnace needs to be baked before it is officially put into production. The so-called oven is an operation in which the furnace lining and electrodes are gradually adapted to the feeding and smelting by means of heating. The main purpose of the oven is to dry the lining and roast the electrode. The quality of the oven will not only affect the service life of the furnace lining, but also affect whether the electric furnace can be put into production smoothly. The oven of the electric furnace should be carried out in strict accordance with the oven schedule under normal circumstances. The length of the oven time depends mainly on the size of the oven, the type of lining, the type of ferroalloy and the oven method. The whole oven process is divided into two stages: the first stage is wood baking, oil baking or coke baking, the purpose of which is to bake the electrode, so that the electrode has a certain

The erosion phenomenon of the submerged entry nozzle steel

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  The erosion of the submerged entry nozzle by the casting powder is mainly the result of various physical and chemical interactions between the casting powder and the nozzle. The direct interaction between the casting powder and the nozzle mainly has the following phenomena: 1. When the casting powder has a large erosion and melting rate on the nozzle, and the casting powder component migrates into the nozzle at a low speed, the oxides in the refractory material melt in the casting powder and form on the nozzle wall. The contact layer slag film will reach a saturated state, at this time the dissolution of oxides in the nozzle will be inhibited and the erosion and dissolution of the nozzle by the mold flux will be reduced. 2. When the erosion and melting rate of the casting mold powder to the nozzle is very small, the mold powder will intrude into the nozzle along the pores of the nozzle itself and the channel formed by the oxidation of carbon in the nozzle , and combi

The classification of unshaped refractory castable

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  Refractory castable is a new type of refractory that does not need to be fired at high temperature and is directly used after construction and baking. Unshaped refractory castable has simple production process, saves energy and labor, can be mechanized construction, has good integrity, is easy to repair and has a long life. Unshaped r efractory castables are usually classified according to the size of the porosity, the selected bonding agent or bonding method, the type of aggregate and the construction method. According to the porosity, it can be divided into dense refractory castables and insulated refractory castables. 1.High alumina bauxite. The high-alumina bauxite clinker calcined at high temperature is mainly used for high-alumina refractory materials, and can also be used to make fused brown corundum and sub-white corundum. In recent years, the homogenized bauxite clinker produced in my country has achieved good results in the application of monolithic refrac

Precautions for building the bottom of industrial furnac

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  1) After the position of the lead-out rod hole is aligned, masonry shall be started from this end first, so as to avoid the hole being blocked by bricks and affecting the placement of electric heating elements. 2) The supporting bricks should be laid on the side, and the bricks laid on the side have large supporting capacity and long service life. The supporting bricks between the two rows of bottom bricks are vertically laid, while the supporting bricks at both ends of the oven door are horizontally laid. 3) When laying supporting bricks, it is necessary to find a good level, and all supporting bricks on the bottom of the furnace should be in the same horizontal plane, so that the bottom plate of the furnace can be placed stably with uniform stress. 4) When all supporting bricks are laid, try to squeeze each other tightly without loosening. 5) When laying supporting bricks, we should not only pay attention to levelness and straightness, but also master the dis

The function of the continuous casting tundish

  The continuous casting tundish was originally used for the heat preservation of molten steel, and its main purpose was to distribute and rectify molten steel. With the successful development of technologies such as slow cooling of molten steel, molten steel reheating technology, argon gas sealing technology, gas stirring technology and removal of non-metallic inclusions in molten steel, continuous casting tundish have become the most important part of the final stage of the steel smelting process. The main refining vessel is developing to a large scale. 1 Purification function To produce high-purity clean steel, install porous air-permeable bricks at the bottom of the tundish or embed porous tubular gas distributors between the working layer and permanent layer, or install porous bricks on the slag retaining wall to blow argon to make argon bubbles. Float evenly from the bottom to promote the removal of inclusions. These devices can eliminate

The purpose of Tundish Slag Wall

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  The retention time of molten steel obtained from the tundish capacity and the flow rate of the molten steel is called the theoretical retention time. However, in actual production, the molten steel flow in the tundish is uneven, fast in some places, and slow in some places, especially in the bottom area of the tundish where there is an inactive molten steel stagnation area, which makes it difficult for inclusions to float up. The actual average residence time of molten steel in the tundish is shorter than theoretical average residence time. In order to make full and effective use of the volume of the tundish and promote the floating of inclusions, the measures taken are to add tundish slag wall and slag dam in the tundish. The purpose is: 1.Eliminate the dead zone in the bottom area of the tundish ; 2.Improve the trajectory of molten steel flow, make the flow flowing along the steel slag interface, shorten the floating distance of inclusions, and fa

Cause analysis of abnormal melting loss in slag line of monoblock stopper

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  The monoblock stopper plays a very important role in continuous casting production. Sometimes, the abnormal melting loss and fracture of slag line of the stopper may occur, resulting in abnormal final casting. The research shows that the main reason for the abnormal melting loss of slag line of the monoblock stopper is that the Fe2O3 and MnO in the slag are abnormally high, which react with the C in the monoblock stopper below the steel-making temperature, and the C is gradually consumed, and the slag resistance of the stopper decreases obviously. On the one hand, the CO2 produced by the decomposition of CaCO3 in the covering agent will react with the C in the plug, resulting in the gradual consumption of C in the plug and accelerated corrosion.? On the other hand, the water bearing minerals in the covering agent decompose at high temperature to produce water vapor, which will react with the C in the plug rod to form water gas, which also causes the C in the plug ro

Selection and technological requirements of ladle purging plug

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 Argon blowing is usually to build one or several ladle purging plug at the bottom of the pouring ladle or brick ladle. After tapping, blow argon gas through the breathable bricks to cause agitation of the molten steel in the ladle. Argon blowing can promote the floating of emulsified slag droplets and inclusions in steel, and can partially remove the dissolved gas and uniform components in the steel. In the case of continuous casting, the ladle blowing of argon can play a role in adjusting the temperature of the molten steel. Ladle argon blowing is an important steelmaking process, and breathable bricks are an important functional element of this process. 1.Material and performance of ladle purging plug The materials of permeable bricks are mainly sintered magnesia, magnesia chromium, high aluminum and corundum. It is a better choice to use corundum as the main crystal phase of the breathable brick. To realize the argon blowing process, the air-permeable brick must ha

The application of corundum refractory castable

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  Usually the refractory castable with Al2O3 content (mass fraction) greater than 90% is called corundum refractory castable, and its main phase is corundum, because corundum has the characteristics of high melting point (2050℃) and strong resistance to slag erosion, which makes corundum high-quality castables have high refractoriness and good chemical stability. The refractory raw material combination of corundum refractories has many forms, such as: (1) Corundum refractory castable use white corundum as aggregate and powder. (2) Use plate-shaped alumina and dense (sintered) alumina as aggregates, and use dense (sintered) alumina as powder; (3) Sub-white corundum or brown corundum is used as aggregate, and dense (sintered) alumina is used as powder; (4) Use white corundum and super bauxite clinker as aggregate, white corundum as powder, etc. Wanhao is a manufacturer who is specialized in designing various kinds of furnace and making refractory products for electric furnac

Analysis of causes of transverse cracks in tundish working lining

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 The tundish is an important intermediate equipment that connects steelmaking and continuous casting in the steelmaking production process. It can store molten steel, distribute molten steel, ensure continuous pouring, reduce pressure and stabilize flow, promote the floating and removal of non-metallic inclusions, and uniform molten steel composition and temperature. And many other metallurgical functions. The normal operation of the tundish directly affects the antegrade of the continuous casting process and the final quality of the slab. However, due to the particularity of the working conditions of the tundish, not only the high-temperature molten metal is constantly eroded, but also experienced a sudden drop in temperature, which has a great impact on the life of the tundish. Cause Analysis 1.The difference in the composition of different dry ingredients The two dry aggregates use different grades of sintered magnesia or fused magnesia. When baking at low temperatur