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Q
What are the characteristics of graphite electrode?
Features Of Graphite Electrodes
1.They are currently the only products with high electrical conductivity and are capable of maintaining extremely high heat production in such a demanding environment. 
2.The production technology of graphite electrode is simple, high efficiency and low loss.
3.Our graphite electrodes are very durable and have a long service life.
4.The graphiterectangularelectrode produced by our factory has the advantages of low resistivity, good thermal conductivity, high density and good oxidation resistance.
Q
Main process of graphite electrode
The graphite electrode is made of petroleum coke and needle coke as an aggregate, and coal pitch is used as a binder, and kneading and molding are performed.
A high temperature resistant graphite conductive material produced by a series of processes such as molding, baking, dipping, graphitization and machining. Graphite electrodes are important high temperature conductive materials for electrical steel making. The graphite electrode is used to input electric energy to the electric furnace, and the high temperature generated by the arc between the electrode end and the electric charge is used as a heat source to melt the electric charge for steel making. Other ore furnaces that smelt materials such as yellow phosphorus, industrial silicon, and abrasives also use graphite electrodes as conductive materials. The excellent and special physical and chemical properties of graphite electrodes are also widely used in other industrial fields.
Q
Graphite electrode processing equipment
Graphite electrode processing equipment refers to special mechanical equipment used to process graphite electrodes. Includes graphite electrode body and joint processing equipment. The machining of graphite electrodes includes the steps of keyhole, scraping end face, outer circle, and thread milling. Domestic graphite electrode machining can be roughly divided into two types. The first category is the introduction of CNC wire processing automatic lines from the United States, Japan and other countries by leading enterprises such as Ji-Chong and Lan-Chong, which have greatly improved the processing quality of the electrodes and reached the international level. The other type is a domestically-made ordinary lathe that is still commonly used by other enterprises. The labor intensity of the workers is high, the production efficiency is low, the specifications are limited, and the processing precision and surface roughness are difficult to meet the requirements of the steelmaking industry. The competitiveness in the international market is not strong.
Q
Graphite electrode general processing lathe
Special equipment for graphite electrode processing, consisting of ordinary lathes.
(1) Working principle
Three sets of C630 ordinary lathe assembly line are used to realize the graphite electrode processing technology, so that the products meet the technical standards used by users.
3 C630 ordinary lathe division: the first C630 lathe realized the outer ring. The second C630 lathe achieves a flat end face. The third C630 lathe achieves internal threading of the graphite electrode. The tapered graphite electrode driven by the carriage relies on the main unit and a special milling device for taper internal thread machining.
(2) Equipment processing characteristics
The graphite electrode is processed by C630 lathe, which has the advantages of low equipment cost, simple operation, convenient maintenance, high processing yield and easy cutting. The disadvantages are high labor intensity, low processing precision of the system, large vibration during processing, and a large amount of dust generated during the processing, which causes machine wear and harms workers' health.
(3) Equipment composition
It consists of a headboard, a knife box, a trailer box, a bed and its accessories, just like the C630 regular lathe.

 
Q
Machining of graphite electrodes
With the continuous improvement of graphite electrode quality and technical requirements in the steelmaking industry, graphite electrodes are developing in the direction of large size, high precision and high power. This poses a new topic for the machining of graphite electrodes.
The machining of graphite electrodes includes the steps of keyhole, scraping end face, outer circle, and thread milling.
Domestic graphite electrode machining can be roughly divided into two types. The first category is Jijia, Lanjiao, etc. The introduction of CNC electrode processing automatic lines from the United States, Japan and other countries has greatly improved the processing quality of the electrodes and reached the international level. The other type is a domestically-made ordinary lathe that is still commonly used by other enterprises. The labor intensity of the workers is high, the production efficiency is low, the specifications are limited, and the processing precision and surface roughness are difficult to meet the requirements of the steelmaking industry. The competitiveness in the international market is not strong. For these enterprises, the fundamental way to quickly reverse this situation is to base on the domestic market and use advanced technology and equipment to transform the production line as soon as possible to improve the machining level of graphite electrodes.

 
Q
Thread processing of graphite electrodes
Thread processing of graphite electrodes is a key process in machining and the final machining process. Most of the domestic carbon industry uses C630 car sheet knives for milling. The disadvantages are serious tool wear, large pitch error, high tooth surface roughness, troublesome chamfer adjustment, and difficulty in uniformity. The manual comb processing of some enterprises has been or is being modified. Compared with the single-knife processing, the thread precision and the tooth surface quality have been greatly improved, but the axial and radial dimensions are difficult to precisely control, the chamfer is irregular, and the length of the electrode is not First, it is difficult to get the knife, and the labor intensity of the workers is also great.
Q
Advantages of POCO graphite compared to other graphite elect
POCO graphite electrode is recognized as the best EDM electrode material in the world. POCO graphite provides different grades of cost performance balance, which can provide high metal cutting rate and good wear resistance. The most popular grades are EDM-200 and EDM-3 for injection mold production.
Compared with other graphite electrodes, it is easier to machine, especially when processing high-difficult electrodes such as meshes and ribs, it is not easy to cause chipping, which can reduce the number of processing. The machining loss can be reduced during machining, and the machining efficiency will be increased accordingly. EDM has a high surface finish and low loss. POCO provides customers with surface finish gauges and EDM performance curve charts, allowing customers to choose the ideal processing speed and surface finish.
Q
What is the needle coke of the graphite electrode?
Needle coke is an appearance with a distinct fibrous texture, a particularly low coefficient of thermal expansion and easy to graphitize
A kind of high-quality coke, which can be split into slender strips according to texture when the coke is broken (the aspect ratio is generally above 1.75), and an anisotropic fibrous structure can be observed under a polarizing microscope. focal.
The anisotropy of physico-mechanical properties of needle coke is very obvious, parallel to the long axis direction of the particle
Good electrical and thermal conductivity, low coefficient of thermal expansion, the majority of the long axis of the particles are aligned in the extrusion direction during extrusion. Therefore, needle coke is the key raw material for manufacturing high-power or ultra-high-power graphite electrodes. The graphite electrode produced has low resistivity, small thermal expansion coefficient and good thermal shock resistance.
Needle coke is divided into oil needle needle coke produced from petroleum residue and refined coal bitumen raw material.
The coal produced is needle-like coke.
Q
What is the purpose of calcination?
The carbonaceous raw material is heat treated at a high temperature to discharge the moisture and volatile matter contained therein, and accordingly
The production process of the original cooking performance is called calcination. Generally, the carbonaceous raw material is calcined by using gas and its own volatiles as a heat source, and the maximum temperature is 1250-1350 °C.
Calcination makes profound changes in the structure and physicochemical properties of carbonaceous raw materials, mainly in improving the density, mechanical strength and electrical conductivity of coke, improving the chemical stability and oxidation resistance of coke, laying a foundation for the subsequent process. .
Calcined equipment mainly includes tank calciner, rotary kiln and electric calciner. The quality control index of calcination is that the true density of petroleum coke is not less than 2.07g/cm3, the resistivity is not more than 550μΩ.m, the true density of needle coke is not less than 2.12g/cm3, and the resistivity is not more than 500μΩ.m.

 
Q
Raw material crushing and ingredients
 
Before the batching, the bulk calcined petroleum coke and needle coke must be crushed, ground, and sieved. The medium crushing is usually carried out by crushing equipment of about 50 mm through a jaw crusher, a hammer crusher, a roll crusher and the like to further crush the 0.5-20 mm size material required for the batching. Milling is a process of grinding a carbonaceous material to a powdery small particle of 0.15 mm or less and a particle size of 0.075 mm or less by means of a suspension-type ring roll mill (Raymond mill), a ball mill, or the like.
Screening is a process in which a wide range of materials after a crushing is divided into several particle size ranges with a narrow range of sizes through a series of sieves with uniform openings. Current electrode production usually requires 4-5 pellets and 1-2 powder grades.
Ingredients are the production processes for calculating, weighing and focusing the various aggregates of aggregates and powders and binders according to the formulation requirements. The scientific suitability of the formulation and the stability of the batching operation are among the most important factors affecting the quality index and performance of the product.
The formula needs to determine 5 aspects:
1 select the type of raw materials; 2 determine the proportion of different types of raw materials; 3 determine the particle size composition of solid raw materials; 4 determine the amount of binder;
5 Determine the type and amount of additives.
 
Q
What is Kneading?
Kneading: Quantitative carbonaceous granules and powders with a certain amount of binder at a certain temperature
The process of kneading and mixing uniformly and kneading the plastic paste is called kneading.
The process of kneading: dry mixing (20-35 min) wet mixing (40-55 min)
1 When mixing dry, the various raw materials are uniformly mixed, and the solid carbonaceous materials of different particle sizes are uniformly mixed and filled to improve the compactness of the mixture;
2 After adding coal tar pitch, the dry material and the asphalt are uniformly mixed. The liquid asphalt uniformly coats and wets the surface of the granules to form a layer of asphalt bonding layer, and all the materials are bonded to each other to form a homogeneous plastic smear. Conducive to molding;
3 parts of coal tar pitch penetrates into the inner space of the carbonaceous material, further increasing the density and cohesiveness of the paste.
 Molding: The molding of carbon material refers to the external force exerted by the kneaded carbon paste in the molding equipment.
A process in which plastic deformation occurs to finally form a green body (or a green product) having a certain shape, size, density, and strength.
 
 
Q
The purpose and effect of graphitization
1 Improve the conductivity and thermal conductivity of the carbon material (reducing the resistivity by 4-5 times and increasing the thermal conductivity by about 10 times); 2 improving the thermal shock resistance and chemical stability of the carbon material (the linear expansion coefficient is reduced by 50-80%); 3 to make the carbon material lubricity and abrasion resistance;
4 Exhaust impurities, improve the purity of the carbon material (the ash content of the product is reduced from 0.5-0.8% to about 0.3%).
 Implementation of the graphitization process:
The graphitization of carbon material is carried out at a high temperature of 2300-3000 °C, so it can only be realized by electric heating in the industry, that is, the current directly passes through the heated calcined product, and the calcined product charged into the furnace is generated by the electric current at a high temperature. The conductor is again an object that is heated to a high temperature.
Q
Graphite electrode quality index
The indicators reflecting the quality and performance of the graphite electrode are mainly: bulk density db, electrical resistivity ρ, flexural strength σ, elastic modulus E, thermal expansion coefficient α and ash A%. According to the difference of these indicators and the difference of raw materials and manufacturing processes, the national standard (YB/T 4088/89/90-2000) divides the graphite electrode into ordinary power graphite electrode (RP) and high power graphite electrode (HP). There are three types of ultra high power graphite electrodes (UHP). The post-graphite electrode production plant has increased high-density graphite electrodes (HD) and quasi-ultra-high graphite electrodes (SHP) according to user needs.
On the basis of national standards, each company has its own corporate standards, and customers will also put forward their own quality standards when ordering.
Q
Five Reasons To Choose Zhengnai Industrial
1.We are passionate and professional about our work
What makes us different is that we are passionate and professional about our products and services and support our quality.Because of our professional attitude, we can give you professional answers and effectively solve your problems.
2.To serve our customers wholeheartedly
We have good cooperation with shipping companies, agents ,local customs and port authority. Make sure we deliver on time.No matter which link you have questions, we will provide service for you.
3.We welcome your Suggestions at any time
If there is any problem in the process of our cooperation, please contact us immediately, and we will try our best to solve it for you.
4.We have a better price for the same product
We can provide you a better price, and what you will get from us is our best effort in service and the hospitality that you are willing to become our Friend.
5.Product quality is our guarantee
Our products can pass all kinds of tests, and the quality is also our selling point. So you can rest assured that the purchase. If there is anything unclear, our professional staff will answer it for you
 
Q
About our packing and delivery
About Packing
Packing with wooden case and pallet,and enlace with baling band.
Standard export wooden case and pallet.
Customized shipping mark.
If you are interested in our products or have any questions, please contact us at any time. We will reply as soon as possible.
 
Q
What do you want to know about our company?
Company Introduction
Zhengzhou Zhengnai industrial co., LTD., is a joint-stock enterprise, is a collection of product research and development, production, furnace engineering design, construction, boiler anti-wear spraying, furnace and oven supporting services as one of the comprehensive refractory enterprises. The company has advantageous geographical position, fast and perfect communication, abundant domestic resources, fast logistics, convenient transportation, abundant raw materials, large reserves of refractory materials and excellent quality, which provide a unique condition for the development and production of our company. The company has successively established close technical cooperation relations with educational and scientific research institutions such as institute of refractory materials of Chinese academy of building materials science, Huazhong university of science and technology, etc., to jointly develop new products to meet the needs of various industries.
Q
Where are our strengths?
Our Advantages are follow point.
1.Stable product quality, all series products can meet the national standards;
2.A long service life in actual use and good reputation at home & abroad.
3.The slide plates have the advantages of high strength, good erosion resistance, thermal shock resistance and good stability etc..
 
Q
What are our services?
What are our services?
There are three aspects.
1.Zhengnai Industrial has established complete quality system and conducted quality control 
2.Our Products with excellent performance, to meet the needs of users, users have produced huge economic and social benefits, by the user's trust and praise, some products won the ministry of excellence, provincial excellence title. 
3.We have our own professional insulation construction team, construction guidance technical personnel, so that users use our products in the process of rest assured, at ease.
 
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