Natural Graphite , as its name implies, is naturally formed by natural Graphite , which is generally found in graphite schist, graphite-gneiss, graphite-bearing schist and metamorphic shale.
Features
The chemical composition of graphite is carbon (C). Naturally produced graphite is rarely pure and often contains impurities, including SiO2, Al2O3, MgO, CaO, P2O5, CuO, V2O5, H2O, S, FeO and H, N, CO2, CH4, NH3, etc. Natural graphite minerals are black, steel gray, striated black; Metallic luster, crypto, dull, opaque; The hardness is isotropic, the vertical cleavage surface is 3 ~ 5, the parallel cleavage surface is 1 ~ 2; Qualitative soft, density is 2.09 ~ 2.23 g/cm3, have the feeling of greasy, easy to contaminate finger. Mineral chip under the transmitted light is generally not transparent, extremely thin can pervious to light, the light green gray, refractive index of 1.93 ~ 2.07, under the reflected light is light gray, reflective pleochroism, Ro gray with brown, Re dark blue gray, reflectivity Ro23 (red), Re5.5 (red), the reflected color, double reflection were significantly, strong heterogeneity, polarization color for straw yellow.
Graphite is a complex six-party double cone, assumes the six-party tabular crystal, common simplex are parallel double, six-party double cone, hexagonal prism, but in good condition with rare crystal forms, the generally show scaly or platy, aggregate density lump, earthy or globular.
Type
The process performance and usage of graphite is mainly depends on the degree of crystallization, in accordance with its natural Graphite Crystal morphology can be divided into crystalline graphite, Flake Graphite ) and aphanitic graphite (earthy graphite) two types of industry.
Crystalline graphite
In the crystalline (scale) graphite ore, the diameter of graphite crystals is greater than 1 mu m. Ore grade is low, but optional; The mineral associated with graphite is usually mica, feldspar, quartz, diopathic stone, diabase, garnet and a small amount of pyrite, calcite, etc., some of which have some useful components, such as rutile and vanadium. The ore is scales, grainy scales or granulocyte structures, flaky, flaky, or blocky structures.
Crystalline (scale) graphite is divided into High Purity Graphite, High Carbon Graphite, Medium Carbon Graphite and low Carbon Graphite according to the fixed carbon content.
The high purity graphite (fixed carbon content is greater than or equal to 99.9%) is mainly used for flexible graphite sealing material, nuclear graphite, instead of platinum crucible for chemical reagent melting and lubricant base material, etc.
High carbon graphite (fixed carbon content 94.0% ~ 99.9%) is mainly used for refractory materials, lubricant substrate, brush raw materials, carbon products, battery raw materials, pencil materials, filling materials and coatings, etc.
Carbon graphite (80% ~ 94% fixed carbon content) is mainly used for crucible, refractories, casting materials, foundry coatings, pencil raw materials, battery materials and dyes, etc.
Low carbon graphite (fixed carbon content 50.0% ~ 80.0%) is mainly used for foundry coatings.
Cryptocrystalline graphite
Cryptocrystalline graphite is also called soil graphite or amorphous graphite. In cryptocrystalline graphite ore, graphite crystals are less than 1 mu m in diameter, which are microcrystalline and can only be seen in the electron microscope. High grade of ore, but poor selectable; The mineral associated with graphite is often quartz and calcite; The ore is microscaly - cryptocrystalline structure, block or soil structure.
Cryptocrystalline graphite ore is mainly distributed in contact metamorphic deposits. Actually the diameter graphite flake graphite ore is uneven, the so-called crystalline graphite ore, may also contain the aphanitic graphite, are too many content is often referred to as the mixed type graphite ore, may also contain a small amount of aphanitic graphite quality mineral crystalline flake graphite piece diameter slightly larger than 1 microns.
Cryptocrystalline graphite ore is mainly used in pencil, battery, electrode, graphite emulsion, graphite bearing ingredients and the raw materials of battery carbon rod. The non-ferrous graphite is mainly used for casting materials, refractory materials, dyes and electrode paste.
Natural Graphite Natural Graphite,Expanded Graphite,Colloidal Graphite,Special Graphite Fengcheng Ruixing Carbon Products Co., Ltd , http://www.lnfcrxts.com
What are the application cases of RF cards?
[ Huaqiang Security Network News ]
RF card application case 1: RF access control
The access control system uses radio frequency identification technology to realize that the car with the valid electronic tag does not stop, facilitates the passage and saves time, improves the traffic efficiency of the intersection, and more importantly, can monitor the traffic of the community or the parking lot in real time, and accurately verify The identity of the vehicle and the owner of the vehicle is maintained, and the security of the area is maintained, so that the security management of the community or the parking lot is more humanized, informationized, intelligent and efficient.
RF card application case 2: electronic traceability
There are three kinds of traceability technologies: one is RFID radio frequency technology, which attaches a logo with a chip on the product packaging. The products can be automatically collected and read in and out of the warehouse and transported. The flow of products can be recorded on the chip. One is a two-dimensional code. Consumers only need to take a two-dimensional code through a mobile phone with a camera to query the relevant information of the product. The records of the inquiry will remain in the system. Once the product needs to be recalled, the message can be sent directly. To consumers, to achieve accurate recall; there is a bar code plus product batch information (such as production date, production time, batch number, etc.), in this way the production of the company does not increase production costs.
The electronic traceability system enables 100% bi-directional traceability of all batches from raw material to finished product and from finished product to raw material. The biggest feature of this system is the security of the data. Each manual input is backed up by the software in real time.
Application Case 3 of RF Card: Food Traceability
The use of rfid technology for traceability of food and medicine has been piloted in some cities, including Ningbo, Guangzhou, Shanghai, etc. The traceability of food and medicine mainly solves the problem of tracking food routes. If you find a problematic product, you can simply trace it. Until the root of the problem is found.
RF card application case 4: product anti-counterfeiting
RFID technology has experienced decades of development and application. The technology itself is very mature. It can be seen everywhere in our daily life. The application of anti-counterfeiting is actually adding an RFID electronic tag to ordinary goods. The tag itself is equivalent to the identity card of a product. With the various links of production, distribution and use of goods, all kinds of information on goods are recorded in each link. The tag itself has the following characteristics:
Uniqueness
Each label has unique identification information, and the label is bound to the product information during the production process, and the label uniquely represents the corresponding item in the subsequent circulation and use.
High security
Electronic tags have a reliable security encryption mechanism, which is why today's second-generation ID cards and subsequent bank cards in China use this technology.
Easy to verify
Whether it is pre-sale, in-sale, or after-sale, users can verify it in a very simple way whenever they want to verify. With the popularity of NFC mobile phones, users' own mobile phones will be the simplest and most reliable ones.
Long shelf life
The average label storage time can be several years, ten years, or even decades. Such a storage period is sufficient for most products.
In order to consider the security of information, the application of RFID in anti-counterfeiting generally adopts the 13.56M frequency band label, and the RFID label cooperates with a unified distributed platform, which constitutes a whole process of product anti-counterfeiting system.
Although there are many advantages in RFID anti-counterfeiting, there are obvious disadvantages. The most important one is the cost problem. The cost problem is mainly reflected in the cost of labeling and the construction cost of the whole anti-counterfeiting system. The cost of labeling is generally more than one piece of money. For ordinary cheap goods. It is not realistic to say that it is necessary to use RFID anti-counterfeiting. In addition, the construction cost of the whole anti-counterfeiting system is relatively high. It is not that the average enterprise can afford to realize and promote it. It is more suitable for enterprises with small scale. Third-party RFID anti-counterfeiting platform. museum
(USA) The California Technology Innovation Museum is using RFID technology to expand and enhance the visitor experience. They give each visitor an RFID tag that allows them to view information about the show on their personal web pages in the future; this tag can also be used to determine the language in the list of directories visited by visitors to the museum. category.
Perhaps one day in the future, the US Museum of Technology Innovation will develop a display to detect the impact of RFID technology on the world. However, the museum in California is using RFID technology to expand and enhance the visitor experience. The museum was founded in 1990. Since its inception, it has become a famous and popular place to visit in Silicon Valley, and has attracted many families and technology enthusiasts to visit. It can receive about 400,000 visitors every year. From the positive and good response made by the visitors, the use of RFID tags was successful.
The museum will be a permanent exhibition of science and technology that contributes to human science, life sciences and communication, and will showcase the achievements of Silicon Valley innovators and others. A life sciences exhibition called "Genetics: Technology With a Twist" was held in March 2004. At this meeting, the museum showed the use of RFID tags, which means that each visitor visits an RFID tag. To enable it to view relevant information about the exhibition on its personal webpage in the future.
Due to the influence of other visitors and the time limit, visitors are not able to understand and learn more about the display as expected. By using RFID tags to automatically create personalized information pages, visitors can choose to search for relevant information on a display topic at a convenient time, or find relevant documents in the museum.
After the visit, visitors can also access the website via the Internet at the school or at home and type in a 16-digit ID number on their label and log in. This way they can access their unique personal web page. Many museums in the United States and other countries plan to use RFID technology on the same end of a card or badge. At least one natural history museum in Denmark handed the reader to the visitors in the form of a PDA and combined the label with the display. But according to Greg Brown, deputy director of the Museum of Technology Innovation, the museum is the first museum to use RFID technology wristbands.
RF Card Application Case 5: Expo
The number of exhibitions held in Shanghai is increasing at a rate of 20% per year. The Shanghai Municipal Government has been actively exploring how to apply new technologies to enhance the ability of the group to better display the image of Shanghai. The application of RFID in large-scale exhibitions has been verified. In 2005, the ticket system of the Aichi Expo adopted RFID technology, which enabled a large number of visitors to enter the market quickly. The organizers of the 2006 World Cup also adopted tickets embedded in RFID chips, which played a role in anti-counterfeiting. This has attracted the attention of the organizers of large-scale exhibitions. At the 2008 Beijing Olympics, RFID technology has been widely used.
The 2010 World Expo will be held in Shanghai. There are a large number of information service needs for sponsors, exhibitors, visitors, volunteers, etc., including crowd flow, traffic management, information inquiry, etc. RFID systems are effective in meeting these needs. One of the means. The organizers of the Expo are concerned about the anti-counterfeiting of tickets. Participants are more concerned about which visitors have visited their booths, what they are about the content and products, and the personal information of the visitors. Visitors want to quickly get the information they want and find the content they care about.