hp 500 graphite electrode

Production process of hp 500 graphite electrode

hp 500 graphite electrode raw materials: In carbon production, the commonly used raw materials can be divided into two categories: solid carbon raw materials, binders and impregnants. Solid carbonaceous materials include petroleum coke, pitch coke, metallurgical coke, anthracite, natural graphite and graphite crushing. Binders and impregnants include coal tar pitch, coal tar, anthracene oil and synthetic resins. In addition, auxiliary materials such as quartz sand, metallurgical coke powder, and coke powder are also used in the production. Other special raw materials are used to produce some special carbon and graphite products (such as carbon fiber, activated carbon, pyrolysis carbon and pyrolysis graphite, glassy carbon).

hp 500 graphite electrode calcination: The process of heat-treating carbon raw materials at high temperature (1200≤1500℃) in isolated air is called calcination. Calcining is the first heat treatment process in carbon production. Due to calcination, a series of changes have taken place in the structure and physical and chemical properties of various carbon-containing materials.

Both anthracite and petroleum coke contain a certain amount of volatiles and need to be calcined. The coking temperature of asphaltene coke and metallurgical coke is relatively high (above 1000°C), which is equivalent to the temperature of the calciner in a carbonization plant. Don’t burn it anymore, just dry the water. However, if pitch coke and petroleum coke are mixed before calcination, they should be sent to the calciner together with petroleum coke. Natural carbon black and graphite do not need to be calcined.

hp 500 graphite electrode screening:

The purpose of kneading is to obtain a uniform and plastic paste. However, due to changes in certain factors, the kneading quality will change significantly, resulting in unstable product quality. Tests have proved that when using hard pitch with a softening point of 80-90°C, the paste temperature should be increased to 168-174°C. In this temperature range, the best improvement in the wettability and cohesive properties of the dry material by asphalt is that the obtained paste has good plasticity and extrusion properties. Dry mixing for 30 minutes and wet mixing for 40 minutes. If the stirring time is too long, the large particles will be destroyed, and the original particle composition will be destroyed, so that the bulk density of the product will be reduced, the plasticity will be worse, the porosity will increase, and the mechanical strength will be reduced.

hp 500 graphite electrode molding: extrusion molding, vibration molding and molding. Our factory adopts 3500t extruder for molding. Before molding, the obtained paste was reduced from 168-174°C to 116°C in a cooler. The cooling time shall not be less than 8 minutes. After the heat preservation platform is kept warm for 20 minutes, put the heat preservation paste into the cylinder of the extruder, and the pressure is generally not lower than 25MPa. The product is extruded through a port installed in front of the extruder. The extruder is generally intermittently produced. The production is divided into three stages: In the first stage, when the plunger head starts to pressurize, the paste-like particles move quickly and become a big paste. The voids between the particles are filled by small paste-like particles, and the contact between the particles tends to be close. In the second stage, when the indenter continues to apply pressure, the electrode density gradually increases. When the density reaches a certain value, the pressure continues to increase and the density slowly increases. In the third stage, the pressure reaches the limit value and the density tends to be uniform. Then extrude the electrode from the nozzle

hp 500 graphite electrode roasting: roasting is a heat treatment process in which the pressed product is heated at a certain heating rate in the protective medium in the heating furnace under the condition of isolating the air.

The purpose of hp 500 graphite electrode firing is:

The main research results are as follows: (1) The volatile content of the product with coal tar pitch as the binder is about 10% after calcination. Therefore, the roasting yield is generally less than 90%.

The coking raw materials are roasted according to certain technological conditions, the binder is coked, and a coke network is formed between the aggregate particles, so that the aggregates of different particle diameters are firmly connected together, and the product has certain physical and chemical properties. Under the same conditions, the higher the scorch rate, the better the product quality. The residual carbon content of the medium temperature asphalt is about 50%

(3) During the firing process, the product of the fixed geometry softens and the binder migrates. As the temperature rises, a coking network is formed, making the product harder. Therefore, the shape does not change with increasing temperature.