Graphite crucible is a kind of refractory graphite crucible which is made of crystalline natural graphite as main material, plastic refractory clay as the binder, and with different types of clinker. It is mainly used for smelting special alloy steel, melting non-ferrous metals and their alloys. Graphite crucibles are an integral part of refractories materials according to its properties and application.

　　In graphite crucible, there are three kinds of common graphite crucible and special allotypic graphite crucible and high purity graphite crucible. Different types of graphite crucibles are different from raw materials, production methods, process technology and product type specifications due to their different performances, application and conditions.

　　The main raw material of graphite crucible is crystalline natural graphite. Therefore, it keeps all kinds of physical and chemical properties of the natural graphite. That is to say, it has good thermal conductivity and high temperature resistance, and the thermal expansion coefficient is small in the process of high temperature application, and it has a certain anti strain property to the rapid heating and rapid cooling. The corrosion resistance of acid and alkaline solution is strong, and it has excellent chemical stability.

　　The graphite crucible has many types and specifications, and it is not limited by the production scale, batch size and smelting material variety when we use them. It can be chosen arbitrarily, and it has strong applicability and can ensure the purity of the melted material.

　　Graphite crucible is widely used in smelting of alloy tool steel and the smelting of nonferrous metals and their alloys and it has better technical and economic effects because of their excellent properties.

　　The production materials of graphite crucible can be summarized into three types. The first is crystalline natural graphite, the second is plastic refractory clay, and the third is calcined hard kaolin skeleton clinker. In recent years, the high temperature resistant synthetic materials such as silicon carbide, alumina, carborundum and ferrosilicon have been used as the framework clinker. This kind of clinker has remarkable effect on improving the quality of crucible product, enhancing the density and mechanical strength of crucible.

　　There are three kinds of forming methods for graphite crucible which are hand molding,the rotary plastic forming method and the pressing forming method

　　The silicon carbide crucible is a bowl shaped container with a deep ceramic bottom. When solid is heated by fire, crucible must be used, because it can withstand high temperature more than glassware. This is also the reason why the silicon carbide crucible is used by the public. First of all, the use of the silicon carbide crucible is introduced, hoping to help everyone.

　　The crucible usually does not fill the melt too much to prevent the heat from jumping out and allowing the air to pass in and out freely to allow for possible oxidation. Because the bottom of the crucible is very small, it is usually needed to be heated directly by the fire on the mud triangle. The crucible can be placed on the iron tripod by either positive or oblique, and can be set up according to the requirements of the experiment. The crucible must not be placed on the cold metal table immediately after heating so as to avoid its rupture due to rapid cooling. You can't put it on the wooden table immediately to avoid burning the desk or causing fire. The correct method is to cool the holder on the iron tripod or to cool it on the asbestos net.

　　In some solid in high temperature processing, we need to use the crucible, because compared to ordinary glass crucible can withstand higher temperatures, here mainly recommended silicon carbide crucible, following on from the North carbon graphite products manufacturers to introduce the industrial value of silicon carbide crucible.

　　As the name suggests, the main raw material of silicon carbide crucible is silicon carbide, and the main characteristic of SiC crucible is due to silicon carbide. SiC is also called emery, chemical formula is SiC, it is made of quartz sand, petroleum coke (or coal tar), sawdust and other raw materials through the resistance furnace high temperature smelting materials. SiC content in silicon carbide is about 95% of the black silicon carbide has a strong toughness, high temperature characteristics, silicon carbide crucible is made of the black silicon carbide, silicon carbide crucible at high temperature in the process of using low thermal expansion coefficient, for rapid heating and cooling has good anti strain performance, good to have pH the corrosion resistance is a good chemical stability of the products. Silicon carbide crucible has good performance in metallurgical, mechanical, chemical and other industrial sectors depending on its good performance.

　　The performance of the silicon carbide crucible is good. It has good performance in metal smelting and alloy smelting, and has excellent technical and economic results in industry.

　　Beijing Great Wall Co., Ltd is dedicating on crucible over decade and hope to supply the best to our dear clients.

　　In general, the graphite crucible before using the inspection work, should do the following main points:

　　1. first of all, to check whether there is a crack in the graphite crucible before work, no cracks need to heat the graphite crucible to more than 600 degrees C and fully dry.

　　2. water around a stove and furnace before the pit, near the graphite crucible do not stack irrelevant articles.

　　3. strict inspection charge no explosives, add burden must be preheated and ensure drying, adding graphite crucible slower.

　　Graphite crucible before use, we must do the above points, otherwise it is likely to lead to the graphite crucible in use when the explosion risk.

　　The main purpose of the experimental material is graphite crucible heating heating, the general use of solid materials of graphite crucible heating experiments, graphite crucible with a variety of models, can choose the crucible type according to the number and type of material required for heating and heat expansion degree. In general, we should pay attention not to let the material to be heated with the crucible when using graphite crucible, that is very dangerous, not only easy to cause the accident and the experiment of graphite crucible, life will have a huge impact. In addition, attention should be paid to the fact that the crucible is normally heated to four or five Baidu. This time, it is very dangerous to not place graphite crucible or touch graphite crucible with hand.

　　1, the graphite crucible refractory requirements are very high, therefore, we must staple food graphite crucible raw material fire resistance, so that graphite crucible can make more safe use;

　　2, we often use graphite crucible and a variety of corrosive chemical smelting, therefore, the chemical stability of the graphite crucible is also very important, so that it can reduce corrosion;

　　3, graphite crucible hardness and toughness is also the factors we need to consider, to avoid brittle fracture of graphite crucible in use.

　　The above is when we make the graphite crucible, we should choose the material selection method, only in accordance with the above standards to select materials, can let graphite crucible can more fully play its performance.

　　Beijing great wall co., ltd is dedicating on graphite crucible over decade and it is our honor to provide quality products and effective service to our dear clients.

　　The Graphite crucible, which is divided into general type of graphite crucible, special type of graphite crucible, high purity graphite crucible.Graphite crucible, which is divided into general type of graphite crucible, special type of graphite crucible, high purity graphite crucible.The main raw materials of Graphite crucible is natural crystalline graphite. Therefore, it maintains the original natural graphite various physical and chemical properties.

　　Graphite crucible has good thermal conductivity and high temperature resistance;Uder the high temperature, the thermal expansion coefficient is small, rapid heating, quench with certain anti-strain properties. The strong corrosion resistance of acid, alkaline solution has excellent chemical stability. Graphite crucible, with their more excellent performance, in metallurgy, casting,mechanical, chemical and other industrial sectors, is widely used in smelting and alloy tool steel smelting of non-ferrous metals and their alloys . Besides,it has achieved a good technical and economic results.

　　Graphite crucible machined from high pure graphite and widely used in the gold,silver,platinum and other noble metal's melting.If it's used in oxygen atmosphere,it wil start to be oxygenized when the temperature is higher than 700-800°c. If it's used in the protective atmosphere, it can stand more than 2000°c.

　　Graphite crucible used for smelting gold is specialized in melting gold in headgear and jewelryindustry. That requests graphite material has high density and purity, ablation-resistance, and it can be used many times. We can machine various crucibles accordingto customer's requirement.Graphite crucible can be used for non-ferrous metal smelting and casting, dissolving gold or silver ornaments, analysis of special type steel, sintering hard metal.

　　The graphite crucibles are widely used in such fields as industrial furnaces, mono-crystalline silicon machinery, mono-crystalline silicon machinery, electron, semi-conductor, metallurgy, oil, chemistry, textile, electrical machinery, electrical equipment, electrical furnace, traffic, communication industry, medicine, etc.

　　Silicon carbide graphite crucible, isostatic molding technology, long life, is 4 times the ordinary crucible. Chemical resistance, strong oxidation resistance, thermal conductivity, thermal shock stability! bowl shaped container with a ceramic crucible. When a solid is heated by a fire, it is necessary to use a crucible. Because it is more able to withstand high temperatures than glassware.

　　When the crucible is used, it is usually not too full to prevent the heat from jumping out and allowing the air to move in and out for possible oxidation. Crucible because of its small bottom, generally need to stand on the mud triangle in order to direct heating fire. The crucible is placed on the iron tripod with a positive or oblique position, and the requirements of the experiment can be arranged on the self. The crucible should not be placed immediately on the cold metal table after heating, so as to prevent it from cracking due to sharp cooling. Do not immediately put on the wooden table, in order to avoid burning the desktop or cause a fire. The correct way is to keep the iron triangle on the natural cooling, or put on the asbestos network to make it cool.

　　The crucible can be divided into three categories: graphite crucible, clay crucible and metal crucible. In the graphite crucible, there are three kinds of common graphite crucible, special graphite crucible and high pure graphite crucible. Because of the surface treatment process, can be divided into ordinary graphite crucible, graphite crucible coatings (in graphite crucible with a layer of graphite crucible coating way), graphite crucible of various types, due to performance, and the use of different conditions, the raw material used, production method, technology and product specifications are the difference.

　　The main raw material of the graphite crucible is crystalline natural graphite. So it keeps the original physical and chemical properties of natural graphite.

　　That is, good thermal conductivity and high temperature resistance, high temperature in the use of the process, the coefficient of thermal expansion is small, for the heat, the cold has a certain strain resistance. The acid and alkaline solution has good corrosion resistance and excellent chemical stability.

　　The crucible has many types and specifications, and is not limited by the scale of production, the size of the batch and the variety of the smelting material in application, and the utility model has the advantages of arbitrary selection, strong applicability and high purity.

　　The graphite crucible has been widely used in metallurgy, casting, machinery, chemical industry and so on. It has been widely used in the smelting of alloy tool steel and smelting of nonferrous metals and alloys. And has a good technical and economic effect.

　　The graphite crucibles were prepared with flake graphite, silicon carbide, silica and kaolin. The influence factors on the properties of samples were investigated. The results show that, with the increase of the silicon carbide content, the volume density of samples increases, the porosity decreases, the weight loss rate of the sample reduces and the antioxidant activity improves. Elevating the oxidation temperature and prolonging the oxidation time increase the weight loss rate of the sample, decrease the antioxidant activity. The microstructure analysis show that the compactness of the samples rises when the silicon carbide content and the sintering temperature increase.

　　The numerical simulation results show that the electromagnetic force and the flow distribution induced by the melt surface are significantly different when the coil position is different. When the coil is located at the upper side of the melt side, the induced electromagnetic force and flow are mainly concentrated in the upper part of the melt, and in the actual production and experiment, it is easy to appear the splash of liquid droplets, and increase the risk. The top of the air and the side mold respectively the heat conduction rate of the melt during solidification process are different. Therefore, when the coil is located at the upper side of the melt side, the precipitation of the grains on the top and side of the melt will occur in time, and the effect of the magnetic oscillation will be affected. And the free grains will move to a long distance to form the solidification structure and increase the possibility of melting the high temperature melt. The coil is located in the side of the lower part of the melt, induction of electromagnetic force and flow distribution in the melt can lower precipitation oscillation impact melt grain side and the bottom of the mold and the heat conduction and the bottom side of the melt rate, grain precipitation at the same time will be better vibration shock effect, nucleation rate get increased significantly. In addition, with the flow of the grain can be directly deposited on the bottom of the melt solidification structure refinement, reduce the high temperature melt melted in free process, the grain refinement effect will be better than in the upper part of the side of the coil.

　　Graphite crucible materials selected for high pure graphite, high purity graphite is widely used in metallurgy, casting, mold and other industries, the production of high precision CNC machining equipment for horizontal continuous casting of high purity, high strength, high density graphite graphite mould mould; electronic industry; metallurgical industry by Shi Momo and other shapes, graphite processing products all kinds of parts can be realized, the machining precision and the roughness of the graphite demand.

　　Performance of graphite crucible:

　　1, thermal stability: the use of the graphite crucible for emergency cooling, special design to ensure the reliability of product quality.

　　2, erosion resistance matrix design fine uniform, delaying the crucible erosion degree.

　　3, impact resistance: graphite crucible can withstand high heat shock intensity, so any process can be assured.

　　4, acid resistance: special materials to join a significant improvement in the quality of the crucible, in terms of the performance of excellent acid resistance, and greatly extend the life of the graphite crucible.

　　5, high heat conductivity, high fixed carbon content: to ensure good thermal conductivity, shorten the solution time, and significantly reduce the fuel consumption or other energy consumption.

　　6, metal pollution control: strict control of material composition, to ensure that the dissolution of the graphite crucible on the metal without pollution.

　　7, quality stability: high pressure forming process and quality assurance system to more fully guarantee the stability of the quality. Welcome to map sample processing, and please inform us of the use of the products you need, we will choose the right material for you to provide satisfactory products and services.

　　Graphite crucible, because of its excellent performance, so in metallurgy, casting, mechanical, chemical and other industrial sectors, is widely used in the smelting of alloy tool steel and non-ferrous metals and alloys. And has a good technical and economic results.

　　Graphite crucible formation and types of graphite crucible is in crystalline form of natural graphite as the main raw material, plastic refractory clay as binder, with different kinds of clinker with and made the main application of anti flint graphite crucible smelting special alloy steel, molten non-ferrous metal and alloy. In terms of the performance and use of the product, the graphite crucible is a component of the refractory material.

　　Graphite crucible formation and types of graphite crucible is in crystalline form of natural graphite as the main raw material, plastic refractory clay as binder, with different kinds of clinker with and made the main application in smelting special alloy steel, molten non-ferrous metal and its alloy refractory graphite crucible. In terms of the performance and use of the product, the graphite crucible is a component of the refractory material.

　　The crucible can be divided into three categories: graphite crucible, clay crucible and metal crucible. In graphite crucible, there are three kinds of graphite crucible and special graphite crucible and high pure graphite crucible. Various types of graphite crucible, due to different properties, uses and conditions of use, the use of raw materials, production methods, process technology and product model specifications are also different.

　　Crucible type specifications are more, in the application is not limited by the size of the production, batch size and the variety of smelting materials, can be arbitrary choice, strong applicability, and can ensure the purity of the melting material.

　　1, after placing the dry place, avoids rain intrusion; use before the slow bake to 500 degrees Celsius can be used.

　　2, should be based on the crucible capacity feeding, avoid squeeze too tight, so as to avoid the metal thermal expansion of the crucible.

　　3, remove the molten metal, the best use spoon to scoop out, to minimize the use of calipers, if using calipers and other tools should and crucible shapes consistent, to avoid local stress and shorten the service life. 4. The service life of the crucible is related to the use of the method. It should avoid the strong oxidizing flame directly spray to the crucible, and make the crucible raw material oxidation. Graphite crucible, because of its excellent performance, so in metallurgy, casting, mechanical, chemical and other industrial sectors, is widely used in the smelting of alloy tool steel and non-ferrous metals and alloys. And has good technical and economic results.

　　Crucible are divided into three categories: the first class copper crucible, its specification "," and; the second category for copper alloy crucible, the super round a number 100, round number 100, the crucible with a third steelmaking, number 100.

　　Crucible size , usually expressed in the order of size, 1 crucible with a volume of molten 1000g brass, the weight of 180g. The calculation of melting amount of crucible in melting of different metals or alloys can be used to calculate the bulk density of the crucible and to multiply the corresponding metal and alloy coefficients.

　　Graphite crucible is widely used in casting but many customers don’t know how to use it correctly.

　　It is very significant for a new made graphite crucible to be conditioned before it is used. Using a graphite crucible correctly includes conditioning and storage. The crucible should be put in an oven at 500 degrees Fahrenheit (260 degrees Celsius) for two hours and then allowed to cool slowly in a dry situation. This keeps moisture from the crucible and prevents cracking. Crucibles should be kept away from moisture and should be re-conditioned if they get wet.

　　A graphite crucible should be cleaned completely when it is done being used. Metal should not be allowed to remain in the crucible to cool. Residual metal can expand and crack the crucible when it is reheated. Crucible tongs should be used that match the shape of the crucible. To prevent cracking, the tongs should hold the crucible without putting pressure on the sides.

　　Graphite crucibles can be damaged by improper use or handling. They should not be used for metals containing iron, because iron will react directly with the carbon in the crucible and will change the metal composition or destroy the crucible. Solid metals should be loosely packed in a crucible before it is heated. The metals might expand, and a tightly packed crucible can crack or fail. Water or damp metals should never be added to molten metal in a crucible, because that might cause a steam explosion or result in failure of the crucible.

　　The graphite crucible for melting silver has strong resistance to high temperature, small thermal expansion coefficient and small resistance performance, especially for acid and alkali corrosion resistance, it has a good chemical resistance to corrosion.

　　The graphite crucible for melting gold is dipped and coated with anti oxidation coating, the high temperature graphite will penetrate into the pores of the graphite crucible, and empty the space to form a protective film.This layer of protective film which can effectively cut off the oxidizing reaction after the contact of the air with the crucible, it won’t crack and shed in the high temperature can make graphite crucible in the construction of the delay and the oxidation, which prolongs the service life of the graphite crucible.

　　The graphite crucible has no any material produced in the high temperature and the room temperature by using this oxidation technology . It also can effectively protect the chemical reaction which the graphite crucible do at the high temperature .

　　The graphite crucible for melting silver , also named silicon carbide crucible is a kind of crucible with excellent performance which comes from the excellent properties of silicon carbide . The chemical formula of silicon carbide is SiC, the chemical six party crystal, stable structure. The silicon carbide is made from quartz sand, coal and sawdust, etc. as raw materials and smelted by resistance furnace in the high temperature ,it is a most widely used and economical raw material in the contemporary refractory materials.

　　The graphite crucible for melting gold is a silicon carbide crucible, the raw materials are quartz, coke and sawdust, etc., it’s forged in the high temperature electrical furnace, so the SiC also known as emery, its pure substance is a colorless and transparent crystal, it will show a pale yellow or gray and gray blue if it has a small amount of impurities . Due to the tight structure of silicon carbide, so hard, hardness second only to the natural diamond, it is visible to the hardness of the large. Not only that, the melting point of this material is as high as 2700 degrees celsius. The crucible made from this kind of material , the refractoriness is greatly improved, the density of unit volume increased, the heat transfer is fast, it has the characteristics of acid and alkali resistance and oxidation resistance and so on. Its life is 3 -5 times than graphite crucible.