[Chemical composition] There are few pure components, and often contain a large amount (10% to 20%) of various impurities such as clay , asphalt, and SiO 2 , Al 2 O 3 , FeO and other oxides. Figure Z-8 Crystal structure of graphite (2H polytype) (quoted from Pan Zhaoyu et al., 1993) [Crystal structure] hexagonal crystal system; Graphite has a typical layered structure (Fig. Z-8): C is arranged in layers, each C is connected equidistantly with three adjacent C, and C in each layer is arranged in a hexagonal ring shape, upper and lower phases. The C hexagonal rings of the adjacent layers are mutually displaced by the parallel mesh direction and then stacked to form a layered structure, and the different orientations and distances of the displacements result in different polytype structures. The distance between C in the upper and lower layers is much larger than the distance between C in the same layer (C-C spacing in the layer = 0.142 nm, interlayer C-C spacing = 0.340 nm). Graphite is a multiple bond-type crystal, the inner layer is primarily a covalent bond, there are some key metals, because each of the 3 C 3 outer electrons occupy 2 hybrid orbitals sp, and an sp 2 hybrid The orbital is symmetrically distributed in a plane, so that it can form three σ bonds (covalent bonds) with three Cs in the layer, and one outer electron occupies a p-orbit that does not participate in the hybrid. The p orbitals of different carbon atoms in the same layer are parallel and overlap each other to form a large π bond (metal bond). The layers are molecular bonds. This difference in chemical bonds causes the physical properties of graphite to be significantly anisotropic and electrically conductive. Graphite has two different types, in addition to the 2 H type common in Figure Z-8, there are 3 R type. [Form] Single crystal is in the form of a sheet or a plate, but it is rare but complete. Usually scaly, massive or earthy aggregates (Figure Z-9). Figure Z-9 Graphite aggregate [Physical properties] Colors and streaks are black; semi-metallic luster; cryptocrystalline is dim. Parallel {0001} cleavage is extremely complete. Hardness 1 to 2. The relative density is 2.21 to 2.26. The cleavage sheet is flexible. It has a slippery feel and is easy to dirty. Conductive. [genesis and production] graphite is the product of high temperature metamorphism. There are many graphite producing areas in China, among which Liumao in Jixi City, Heilongjiang Province is the largest producing area. [Identification features] Black, low hardness, low relative density, and slippery. If the copper sulfate solution on the wetting of the graphite particles of zinc, copper metal may be deposited spot, no such reaction in a similar graphite molybdenite. [Main use] Graphite is used for making high-temperature bismuth for smelting because of its high melting point, corrosion resistance, insoluble in acid, etc. It has a slippery feel and is used as a lubricant in the mechanical industry. It has good electrical conductivity and can be used for electrodes. The so-called high-carbon graphite with pure composition can be used as a neutron moderator in atomic energy reactors and for defense industry applications. 3 R -type graphite is used as a raw material for synthetic diamond because it is easily converted into diamond. Diamond and graphite are two kinds of simple crystals composed of carbon atoms. It was thought that before 1985, there were only two kinds of crystalline homogeneous polymorphic variants. In 1985, HWKroto of the United Kingdom and RESmalley and RFCarl of the United States conducted a collaborative study to bombard graphite targets with lasers in an attempt to artificially synthesize long-chain carbon molecules in the universe. In the resulting product, they unexpectedly discovered a novel arrangement of carbon atoms: 60 carbon atoms are arranged at 60 vertices of a truncated icosahedron, forming a hollow spherical molecule of the same shape as a modern football, called C. 60 molecules. C 60 crystals can be formed by the closest packing of C 60 molecules. This discovery earned Kroto, Smalley and Carl3 people the 1996 Nobel Prize in Chemistry. In addition to C 60 , such spherical (cage) molecules composed of carbon atoms are also C 70 , C 50 , C 36 , etc., which are collectively referred to as fullerenes, also known as footballenes. . Just as the work on fullerene such as C 60 quickly became a global craze or even formed a specialized discipline, a new member was discovered in the carbon crystal family. This is the carbon nanotube (Carbonnanotube), which was Japan in 1991. Iijima was found in carbon black deposited on cathode carbon rods after DC arc discharge in argon. The structure of the carbon nanotubes corresponds to a tubular shape formed by curling one layer (or layers) of the graphite layer structure. The discovery of fullerenes and carbon nanotubes has attracted widespread attention in the scientific community. This special cage and tubular structure opens up new fields of molecular bonding and molecular structure chemistry. Just as people found out when the earth was round, they were amazed! Although fullerenes and carbon nanotubes have not been found in the geological body, it is necessary to give a brief introduction here. 2.5 Ton Electric Counterbalance Forklift
Zowell 2500kg electric counterbalance forklift is a material handling for
both indoor and outdoor use. The
fork is set outside the center line of front wheel. With the counterbalance
installed at the tail, this forklift can easily offset the weight of goods. The
counter balanced forklift equipped with pneumatic tire to ensure operation
speed and gradeability. It is widely used in loading, unloading, stacking and
transporting finished goods in ports, stations and factory. Counterweight
forklift within 3 tons can also operate in cabins, train compartments and
containers.
Safe, efficiency, comfortable, no
pollution are key features and targets of Zowell counter balanced forklift as
well as other products. Ergonomical design on
rear-position multi-valve and bias layout of instrument panel, makes operation safer. The ultra-low torque steering system greatly
improves the reliability of steering. Besides, full range
of customized attachment choices such as side shift, fork positioner, bale
clamp, stabilizers, full closed cabin and heater can also be added into solid and
scalable body.
Basic information
electric lift truck,electric forklift,4 wheel electric forklift Hyster,Cat counterbalance forklift,Still electric forklift Suzhou Pioneer Material Handling Equipment & Technology Co., Ltd , https://www.xianfengforklift.com
a 0 = 0.246 nm, c 0 = 0.680 nm; Z = 4.
Type: FE25
Load: 2500kg
Max gradeability: 15%
Radius of turning circle: 2315mm
HS code: 8427109000
Certificate: CE/SGS/ISO9001
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