The graphite which are in different properties should use different processing methods, we will give you a brief introduction:

　　Purification processing of the graphite products : the requirements of graphite products in modern industrial focus on the development of two aspects: the first, the requirements of large crystal scales to achieve high purity, and the second is required to achieve ultra fine graphite particles (such as less than 1 m or 0.5 m). Our company has established the production lines of graphite purification and fine powder processing , the purification method is mainly chemical purification. The most mature technology of graphite chemical purification is melting the caustic alkali and graphite at 700 DEG C, and then washing them to neutral, and then adding hydrochloric acid to treat and wash it so that the carbon content of the graphite can reaches 98% ~ 99%. There are also some manufacturers produce the high purity graphite with the hydrofluoric acid treatment.

　　Processing method for natural crystalline graphite: the natural crystalline graphite has good native floatability. in China , we are basically using the flotation method for processing. the method of multi - stage grinding and multi - selection is adopted to select large scale graphite as soon as possible because of the size of graphite flake is one of the most important quality indicators, The common collector for flotation is kerosene, diesel oil, etc., and the foaming agent is two oil, No. four oil, and the adjusting agent is lime and sodium carbonate.

　　Aphanitic graphite processing methods: the aphanitic graphite crystal is extremely small, so it’s also called microcrystalline graphite, the graphite particles are often embedded in clay, the separation is very difficult. Many graphite mines will crush and process the ore directly and then sell the graphite powder products because of the high grade ore (carbon containing is 60% ~ 80%). At present, some units are still in the process research of microcrystalline graphite flotation (such as oil agglomeration flotation, etc.).

　　In graphite field, impregnation is a kind of technology ,via dipping graphite product into certain kind of melted material, which can change physical or chemical condition of graphite product.

　　In general, increasing in porosity of graphite product can not only lead to decling in gravity (density),rising in resistance, decreacing in mechanical strength, but also make product become more easier to be oxidated, to be corrosion and to be immersed. To avoid those circumstance, you can use impregnation technology to control porosity of graphite product.

　　Usually, when you face following condition, you should apply impregnation .

　　1. Producing little scale graphitized electrode and Joint stock.

　　Those product are required high strength, low density and resistivity, so semi-finished products should be impregnated by coal tar pitch previously.

　　2. Producing high quality graphite anode used in diaphragm electrolyzer.

　　Normal graphite anode can only work for 5-6 months,but impregrated graphite anode can work 8-9 months, because ,after impregration,there is less porosity existing in graphite anode. Less porosity means less corrosion and less immersion. In order to improve service life of graphite anodes , drying oils (such as Tung oil, linseed oil, etc) should be used during the curse of producing, which can prolong 1/3 service life.

　　3. Producing impermeable graphite chemical .

　　Graphite products are porous materials, whose porosity can reduce by impregnating into organic resins (such as phenolic resins, Furfuryl ketone resin). At the same time,while mechanical trength was improved by this technology, thermal condition can also stay at it’s good condition.

　　4. Producing wear-resistant carbon and graphite products.

　　When the working temperature and the working media don’t allow to use lubricating oil and other liquid lubricants, using graphite and carbon materials,such as sealing rings, bearings or redirect loop is the only way to ensure the machine runs at high temperatures for long periods. This graphite or carbon wear-resisting material needs high density and hardness and wear-resistance, so this product usually impregnated by synthetic resins or low melting point metals (such as aluminum, Tin alloy, lead-bronze and babbit).

　　That is all what I want to introduce.After reading this article, you must have a superficial impression on impregnation technology.If want to learn more knowledge about graphite product, welcome to our web site:www.bjgreatwall.com. If you have any question, don’t hesitate to contact me:This email address is being protected from spambots. You need JavaScript enabled to view it..

　　The glassy carbon (GC) is a new type of carbon material ,it’s similar to glass and in the carbon structure, and it is also a new type of amorphous carbon structure material. The GC is made of biological resin carbon through high temperature pyrolyzation and carbonization . It does not contain harmful substances on the human body, high purity carbon. Glassy carbon is characterized by its high hardness and permeability due to its port morphology and structural characteristics similar to that of glass.

　　Glass carbon has high strength, hardness and elastic modulus. It can be used to make high speed typewriter wheel and record. Glass carbon has many superior properties: density is small, about 1.3g/cm3; 3800℃high temperature resistance; anti penetration; corrosion resistance. It’s widely used in chemical industry, metallurgical industry, electronic industry, biological engineering and many other fields.

　　Glass carbon can withstand 1 million 300 thousand times the atmospheric pressure, in other directions it can withstand the atmospheric pressure of 600 thousand times. It’s used in the manufacture of ultra high temperature micro electrode used as stoichiometric electrode, its diameter is below 1mm, a disc type, cylindrical, conical, used as a chemical measurement electrode used in analysis of trace components and measurement of various compounds coexisting clinical specimens, samples and raw thick liquid etc.. It can be used in medical equipment production such as tooth material and cardiac pacemaker. Glass carbon can be used for 3800 degrees heat insulation material and high heat resistant protective clothing. special glass carbon ultra high temperature crucible, ultra high temperature beaker, ultra high temperature pipe, ultra high temperature casting mold, carbon crystal wall heating, the carbon crystal heating plate, ultra high temperature electric heater, glass carbon fiber composite panel for the touch screen of computer and mobile phone , it’s also used in the manufacture of high-speed wheel typewriter and recording.

　　In order to enhance the oxidation resistance of graphite mould and prolong its service life, it is necessary to reduce the gasification reaction rate of graphite material at high temperature. Under normal circumstances, there are three factors affecting the gasification reaction of graphite materials:

　　(1) graphitization degree of carbon graphite material increased, the activity of gas decreased, gasification reaction rate was slow. The higher the heat treatment temperature of carbon materials, the higher the temperature of the starting oxidation.

　　(2) the state of the surface of the structure is loose and porous carbon graphite material, easy to react with the gas, and the surface of carbon graphite material, not easy to react with gas. For example, after 3200 degrees of heat treatment of the surface of the dense pyrolytic graphite, starting in the air temperature of up to 850 degrees C.

　　(3) the impurities impurities in the catalysis of carbon materials have great influence on the gasification reaction, such as oxidation of iron, lead, manganese, copper and other elements of carbon materials have a catalytic effect to reduce the impurity content of carbon graphite materials, can improve its antioxidant properties.

　　Therefore, to make use of carbon graphite products raw material of ultrafine particle size, and try to improve the graphitization temperature, can greatly reduce the porosity of carbon graphite products rate, stomatal aperture and impurity content, improve the graphitization degree, so as to improve the anti oxidative properties of carbon graphite products, reduce the oxidation speed.

　　The bipolar plate used therein are required to achieve higher electrical conductivity due to the requirements for redox flow batteries have become more and more stringent in recent years.and thus A bipolar plate composed of an electrically conductive composite achieves a higher electrical conductivity by increasing the conductive filler content in the material.

　　Graphite was used as one of the main bipolar plate material in redox flow batteries due to its high electrical conductivity ,low weight and good chemical stability in the past.Graphite blocks were produced by sintering process and plates were machined to desired sizes.The main limitation of this method was the porosity of produced graphite plates.

　　At present, our company provides a bipolar plate for a redox flow battery , the bipolar late including an electrically conductive composite prepared by mixing a thermoplastic resin ,a carbonaceous material selected from graphite and carbon black ,and a carbon nano-tube.

　　Our current business is extended from the overall solution of the material to the manufacture of bipolar plates, and thus provides the following three VRB assembly services:

　　1).The bipolar plate (we can provide punch service. The thickness of the bipolar plate now can be processed are 0.6/0.8/1.0 /1.2/1.3mm.

　　2).The composite of the bipolar plate and the electrode, the advantage is that the electrode felt is fully combined with the felt in the plate, it greatly reduces the theoretical value of the contact resistance to the felt.

　　3).The bipolar plate ,the electrode and outline border. Three in one frame after embedding flow

　　box (precision injection), it’s the way which improve the reliability greatly compared with the above 1 and 2.

　　Graphite has high temperature strength, low thermal expansion coefficient, good mach inability and good heat and conductivity, so graphite electrode is widely used in metallurgy, electric furnace, EDM and other fields. In the field of EDM, the development of new graphite electrode material and its processing technology expands the application range of EDM and improves its performance. Compared with the graphite electrode and the copper electrode has the advantages of electrode consumption, fast processing speed, good machining performance, high processing precision, small thermal deformation, light weight, high temperature resistance, easy processing, surface processing of high temperature, electrode bonding etc.. Although graphite is a very easy cutting material, but because the graphite materials used for EDM electrode must have sufficient strength to avoid damage during operation and EDM process, at the same time, electrode shape (thin, rounded, sharp change) and also put forward higher requirements on the graphite electrode and the grain size and strength, which leads to in the process of graphite work piece easily broken, the tool is easy to wear. So how to prevent the work piece from crushing, improve the surface processing quality and reduce the cost of processing tools become an important problem of graphite electrode processing. Conventional turning, milling and grinding methods can meet the demand of machining simple shape electrodes, but the requirement of electrode geometry complexity has been increasing in recent years. High speed machining high surface quality and high processing precision make graphite electrode high speed machining has become a hot spot in mold EDM processing,

　　Finishing should make the processing stable, have smaller shape error and good surface quality, at the same time the tool wear is small. Tool wear and machining costs are major considerations. In finishing machining, the influence of milling direction on machining precision and surface quality should be taken into account. In the feed milling along the surface will appear pull milling (upward knife) or drilling and milling (down knife) phenomenon, tool deformation will lead to work piece contour deviation. The contour deviation of drilling and milling is less than that of drawing and milling, and the contour deviation of reverse milling is better than that of forward milling. Therefore, considering the critical condition of tool quality and the stability and reliability of machining process, the best method of milling along the contour should be the combination of reverse milling and plane contour milling. In addition, when the milling, the envelope contour milling tool life is greater than drilling milling, reverse milling when the two almost.

　　Graphite is an important strategic resource，and China’s graphite resource reserves and production rank the first in the world. High purity graphite has excellent performance and graphite products are widely used. Purification of graphite is the premise and basis of graphite products application，therefore the performance and application of graphite products are directly affected by the purity of graphite. Graphite resource and production and consumption in China and the rest of the world are presented. The main methods for purification of graphite are discussed，and the research progress of graphite purification are reviewed from several aspects，including flotation method， alkali-acid processing method，hydrofluoric acid washing，chloridizing roasting and high temperature purification. After comparing the advantages and disadvantages of each method，the development direction and prospect of graphite purification is put forward. Grinding and flotation technology for protection of larger graphite flake，less fluoride or fluoride-free graphite purification and cost-effective high temperature graphite purification will be the new technologies in the future.

　　As the purification of graphite is the prerequisite and basis for the development and application of graphite materials, the demand for high purity graphite will be increased with the improvement of the application level of graphite. The purification of graphite should be adapted to local conditions, and the development of resource saving and environment friendly.

　　Graphite as a kind of important strategic resource and our country's advantage resources, need to develop the deep processing and application of graphite industry. Graphite purification technology to floatation purification technology as the foundation, according to the graphite product application field and application way requirements, in order to deepen the alkali acid, hydrofluoric acid, high temperature method and purification technology. The development trend of the purification technology will be the development of high temperature purification technology with the protection of large scale integrated grinding flotation technology, the low fluorine and fluorine free purification of acid and alkali substitution technology and the realization of superior cost-effective.

　　Pure graphite rod has high density, high strength, high purity graphite made, than ordinary graphite rod is to wear a little, but also relative wear resistance, some graphite products need to in the rotating device, so this requires ultra high pure graphite abrasion resistance, because there will be dust in repeated rotation friction thus, high purity graphite product itself is not very wear-resistant.

　　Gao Chunshi said the high purity materials simple ink manufactured by high purity graphite of high purity graphite rods with the same specific, high purity graphite rod belongs to artificial graphite, graphite powder is called asphalt binder or coal oil coke after high pressure extrusion molding machine, and then after several high-temperature roasting and impregnation, the inside of the graphite the adhesive has evaporated, and fill the gap by impregnation evaporation, so stomatal production and processing of high pure graphite rods, chlamydia, has the advantages of high density, high hardness, wear resistance, high strength characteristics.

　　Ordinary graphite cudgels pure graphite rod difference density and porosity of graphite rods, graphite rods without impregnation and calcination, is the use of graphite powder and binder extrusion molding, strength and density are very soft, falling dust, easy to loose. Greatly reduce the graphite conductive and lubrication characteristics. There is the use of graphite powder particles of different sizes, the graphite materials are of high purity graphite as raw materials for processing the high pure graphite graphite rod is used mostly recycled graphite powder, graphite powder is recycled some recycled graphite products used in pulverizing with binder molding, graphite powder so this impure, graphite raw materials produced graphite particles of coarse, large pores, trachoma and more. Mainly used for carbon arc gouging carbon rod cutting foundry, appearance is coated with a layer of copper to moisture conductive around.

　　Application environment of high purity graphite rod:

　　High pure graphite rod electrothermal commonly used in high temperature vacuum furnace body, a graphite rod maximum temperature is 3000 degrees centigrade, the graphite rods are easily oxidized at high temperature in vacuum, the graphite rods only in the neutral atmosphere or reducing atmosphere in use. Its lower thermal expansion coefficient, high thermal conductivity, resistance coefficient (8~13) * 10-6 Omega - m, SiC, MoSi2 processing is good, high temperature resistance, resistance to extreme heat is good, the price is cheaper.

　　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.

　　Acid graphite rod as non metal products, as carbon arc gouging cutting process in an essential pre welding cutting supplies, is composed of carbon and graphite with appropriate adhesive, through the extrusion, the temperature of 2200 DEG C after baking rotary plating a layer made from copper, high temperature resistance, good electrical conductivity, not easy to fracture, suitable for metal cutting into required shape.

　　Due to the acid resistant graphite rod using the temperature of high conductivity and good chemical stability. It has been widely used in machinery, metallurgy, national defense, chemical, foundry, non-ferrous alloy, light and other fields, especially the black acid graphite rod, was also used for the field of ceramics, semiconductors, medicine, environmental protection, laboratory analysis, become non metallic materials widely used. When cutting steel, the use of flammable, explosive gas, such as oxygen acetylene flame cutting is not required, the cost is low, operation and use of safety. You can use the method of processing a variety of arc cutting can not use gas cutting processing of metals, such as iron, stainless steel, copper, aluminum, high efficiency, and can obtain the ideal effect.

　　Performance of acid resistant graphite rod:

　　The element is hard and brittle texture, low expansion coefficient, can quench heat, not easy to deformation, good chemical stability, acid resistance is extremely strong, does not react with acid, alkali resistant ability is poor, can decompose rod under high temperature corrosion.

　　The bending strength of the acid proof graphite rod is more and more larger with the increase of the temperature of the component. The resistance value, and is reflected by the resistance, according to the standards stipulated in the 25 meters by micro ohms. The surface load current density of the element is closely related to the raw material formula and the pressing density of the black acid proof graphite bar, and can be arbitrarily adjusted according to the requirement.

　　Acid proof graphite rod:

　　1, acid resistant graphite rod must be kept dry, damp must be dried before use.

　　2, used in the DC power supply of acid resistant graphite rod connected to the positive electrode, the work of the negative electrode.

　　3, compressed air pressure to maintain 0.5-1.6MPa.

　　4, acid resistant graphite rod and the arc distance between the workpiece is about 3mm, acid proof graphite stick out of the clamp is about 100mm.

　　5, acid resistant graphite rod and the workpiece into a 45 degree angle, and along the tangent (or straight line) direction planing.

　　6, acid resistant graphite rod must be well ventilated when used. Operating current operation.

　　Application domain:

　　Graphite and graphite products are widely used in various fields of machinery, electronics, semiconductor, silicon, metallurgy, petroleum, chemical, textile, electrical appliances, motor, electric, transportation, communications, aviation, atomic energy, medicine, food, biological engineering, etc..