Graphite Industry and Environment

1. graphite

is a non-metallic element,The chemical composition of graphite is mainly carbon (C)It is a natural element mineral composed of carbon atoms in the hexagonal or trigonal crystal system. Has excellent electrical conductivity, thermal conductivity and lubrication properties,In graphite crystals, the carbon atoms in the same layer aresp2 hybridization forms covalent bonds, with each carbon atom being attached to three other atoms in three covalent bonds. The distance between each mesh layer is 3.40 Å, and the spacing between carbon atoms in the same mesh layer is 1.42 Å. It belongs to the hexagonal crystal system, with complete layered cleavage.The cleavage surface is dominated by molecular bonds, which is weakly attractive to molecules, so its natural floatability is very good.

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classification of 2. graphite:

Natural Graphite:This is a graphite single crystal exfoliated from a graphite ore. It is the most primitive form of graphite, with scale size and crystal orientation of different characteristics. Natural graphite can be divided into three categories according to its crystalline form, namely cryptocrystalline graphite, dense crystalline graphite and ribbon graphite.

artificial graphite: This is a graphite material obtained by organic carbonization and then graphitization high temperature treatment. For example, all graphite materials obtained by organic carbonization and then graphitization high temperature treatment, such as carbon fiber, pyrolytic carbon, foam graphite, etc., can be called artificial graphite.

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3,the production process of graphite:

 

Mechanical grinding method:The purpose of grinding is achieved by using the friction and impact force generated by the ball and graphite ore. This method is simple and low cost, but the quality of the prepared graphite powder is not stable enough and the grain size distribution is uneven.

chemical oxidation reduction method:Using graphite as raw material, artificial graphite was prepared by oxidation and reduction reaction. First, graphite is added into concentrated nitric acid to make it undergo oxidation reaction, and then it is put into a reducing agent containing iron ions for reduction reaction to make artificial graphite. The artificial graphite prepared by this method has good quality and good crystallization, but the preparation cost is high.

high temperature graphitization method:The natural graphite raw material is placed in a high-temperature reaction furnace and subjected to a graphitization treatment at a high temperature. The graphite prepared by this method has high purity, excellent quality and uniform grain size, but the production cycle is long and the preparation cost is high.

carbide pyrolysis method:Graphite materials are prepared by high temperature pyrolysis of carbide feedstocks such as coke, graphitized silicon, graphitized aluminum, etc. The graphite material prepared by this method has complete crystal structure, high density, good strength and electrical conductivity.

Compression forming method:The graphite powder is mixed with resin, glue and other adhesives, pressed and molded, and then dried, calcined and other processes to make graphite materials. The graphite material prepared by this method has good formability and is suitable for preparing graphite parts with complex shapes.

chemical vapor deposition method:Graphite precursor substances (such as methane, benzene, etc.) are decomposed and deposited on the substrate at high temperature, and graphite films with high purity and high crystallinity can be prepared by this method.

Hot pressing method:The graphite powder is mixed with other additives (such as titanium, boron, etc.), and then hot-pressed under high temperature and high pressure to prepare high-strength, high-density graphite materials.

graphite oxide reduction method:The graphite oxide is reduced to a graphite material. The graphite material prepared by this method has a high purity, but it is easy to leave oxide residues in the graphite due to the need to use an oxidant in the preparation process.

The above is the production process of graphite, different processes have different characteristics of application areas.

 

Test Method for Purity of 4. Graphite：

Thermal analysis method:The purity of graphite is judged by measuring the mass change of the sample at different temperatures. among them,TG-DTA (thermogravimetric analysis-differential thermal analysis) is a commonly used thermal analysis method, by heating the graphite sample, measuring the change of sample quality and temperature, the thermal stability of graphite, thermal decomposition temperature and other information can be obtained, so as to judge the quality and purity of graphite.

spectral analysis method: By using infrared spectroscopy, Raman spectroscopy and ultraviolet spectroscopy, graphite samples can be analyzed quickly and accurately. Infrared spectroscopy can determine the composition and structure of a sample by measuring the ability of a graphite sample to absorb infrared radiation. Raman spectroscopy can analyze molecular vibrational information of a sample by measuring the frequency and intensity of scattered light from the sample. Ultraviolet spectroscopy can determine the electronic structure of a sample by measuring the absorption of the sample under ultraviolet light. Through these spectral analysis methods, the content and purity of graphite can be accurately judged.

chemical analysis method:The chemical composition of graphite is determined by chemical experimental methods, such as the content of carbon, hydrogen, oxygen, nitrogen and other elements, so as to judge the purity of graphite.
Atomic absorption spectrometry: Determine the purity and content of a sample by measuring the atomic absorption spectrum of a specific element in a graphite sample.

X-ray diffraction method: By measuring the graphite sampleX-ray diffraction pattern, analysis of its crystal structure and defects, so as to judge the purity and quality of graphite.

scanning electron microscopy method:The purity and quality of graphite samples were judged by observing their surface morphology and particle size distribution.

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5. THE ORIGIN DISTRIBUTION OF GRAPHITE IN CHINA：

 

Qingdao, Shandong:The graphite industry in Qingdao, Shandong Province has always been at the center of national development and is the birthplace of China's graphite industry.The reputation of "the hometown of graphite in China. Qingdao is one of the three major natural graphite producing areas in China, mainly producing flake graphite with the largest industrial value. There are more than 100 graphite enterprises in Qingdao, and Qingdao's graphite products have always been the representative of high quality.

 

heilongjiang jixi:be called"China's graphite capital", production accounted for 38% of the country, is China's main graphite producing areas. Jixi graphite mainly produces large flake crystalline graphite, which has high industrial utilization value and good market development prospects. Jixi has 24 graphite deposits. Jixi Graphite Industrial Park has been built in Hengshan District and Mashan District, which are rich in graphite resources. In order to promote industrial transformation, China-Korea (Jixi) Graphene Industrial Park has been planned and built in Jiguan District.

Heilongjiang Luobei: Known as China Graphite City, it has the largest crystalline graphite mineral resources in Asia. Graphite resources are mainly concentrated in Yunshan Graphite Mining Area, which is the first mine in Asia. It is listed as an important graphite development base by the state. It has been built with graphite mining and processing. Mainly professional characteristic industrial park.

Inner MongoliaXinghe: The prospective reserves of graphite in Inner Mongolia are approximately3-0.5 billion tons, occupying the first place in the country. Among them, the graphite products produced in Xinghe County, Inner Mongolia, have very large scales and good flexibility. They are the three major graphite production bases in China. Xinghe County, Inner Mongolia, has integrated graphite resources, improved the strength of the main body of development, built an important domestic production base of graphite carbon new energy and new materials, guided enterprises to settle in Xinghe Xingmong Kok Industrial Park, and built Ruisheng Graphite Park in Xinghe County.

hunan chenzhou:Chenzhou City, Hunan Province is the main producing area of microcrystalline graphite in China. Its storage capacity of cryptocrystalline graphite ranks first in the country. Chenzhou Lutang is called"The capital of graphite" is a region with a very large storage of cryptic graphite ore in China.

jilin rock:Jilin Panshi graphite reserves10.6 million tons, is one of China's three major graphite producing areas. Panshi City is the main storage of cryptocrystalline graphite and the main producing area of microcrystalline graphite in China. Its storage capacity is second only to Chenzhou City, Hunan Province. Its graphite grade is high and can be directly produced and utilized.

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6. the relationship between graphite and graphene：

graphene is a single layer of graphite:GrapheneIt is an extremely thin two-dimensional material, which is formed by the peeling of graphite layers, andGraphiteIt is composed of multilayer graphene chromatography.

The structure of the two is similar:Both graphene and graphite are materials made of carbon atoms, and their structures are made up of hexagonal closely packed crystals of carbon atoms.

In general, graphite and graphene are structurally similar, but graphene is composed of a single layer of carbon atoms, which has a higher specific surface area and better electrical and thermal conductivity.

 

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7. graphite industry upstream and downstream industry chain:

 

UpstreamMainly graphite ore mining and processing. The mining of graphite ore mainly depends on geological exploration, mining, mineral processing and other links. The mined ore is processed by crushing, grinding, flotation and other processing techniques to obtain graphite products with different particle sizes and qualities. In this process, it is necessary to use professional mining equipment and processing equipment, such as excavators, conveyor belts, crushers, mills, flotation machines, etc.

midstreamMainly the production and supply of graphite. According to different application fields and uses, graphite products can be further subdivided into ordinary graphite, high purity graphite, high thermal conductivity graphite, spherical graphite, expanded graphite, etc. These graphite products are produced by different production processes and processing methods, such as chemical methods, physical methods, high temperature reduction methods, etc. The graphite products produced are further processed and processed, such as cutting, grinding, and purification, to meet the needs of the downstream market.

DownstreamIt is the application field of graphite, including battery, metallurgy, chemical industry, machinery, electronics, photovoltaic, new energy, aerospace, military industry, nuclear engineering and other industries. In the field of batteries, graphite is mainly used to manufacture lithium-ion battery anode materials; in the field of metallurgy, graphite as a refractory material and carburant is widely used in steel, casting and other fields; in the field of chemical industry, graphite can be used as a catalyst carrier, desiccant, adsorbent, etc.; in the field of machinery and electronics, graphite has high conductivity and wear resistance, and is widely used in the manufacture of mechanical parts and electronic components. In addition, graphite is also widely used in photovoltaic, new energy, aerospace, military industry and nuclear engineering.

Generally speaking, the upstream and downstream industrial chain of graphite industry involves many fields and links, including mining, processing, production, supply and application. These links are interdependent and jointly promote the development of graphite industry.

 

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The relationship between 8. graphite and lithium battery anode:

Graphite and lithium industry have a close relationship.In lithium batteries, graphite is the main negative electrode material, which is used to take up electrons and guide the flow of ions. During the discharge of a lithium battery, lithium ions flow through the electrolyte to transport charge from the negative electrode to the positive electrode, and graphite plays a vital role as a negative electrode material.

In addition, the high thermal conductivity, high corrosion resistance and low adhesion of graphite materials make them have unique advantages in the manufacture and production of lithium batteries, which helps to improve the energy density and safety of lithium batteries.

As the global demand for renewable energy and electric vehicles continues to grow, the lithium battery and graphite industries are also developing rapidly. Many portable devices such as mobile phones and laptops need to use lithium batteries, and graphite as one of its main materials, the demand is also growing.

In general, there is a close relationship between graphite and lithium battery industry. As one of the main materials of lithium battery, graphite plays an important role in promoting the global energy transition and achieving sustainable development.

 

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Introduction of 9. special graphite:

 

flake natural graphiteIt is a kind of natural crystal graphite, which is similar to fish phosphorus, belongs to the hexagonal crystal system, and has a layered structure. It has good high temperature resistance, electrical conductivity, thermal conductivity, lubrication, plasticity and acid and alkali resistance.

 

spheroidized graphiteIs a high-quality high-carbon natural flake graphite as raw materials, the use of advanced processing technology to modify the surface of graphite, the production of different fineness, shaped like ellipsoidal graphite products. It has high purity, high density, high specific surface area and other characteristics, widely used in batteries, electrodes, brushes and other manufacturing fields.

 

expanded graphiteIt is a loose and porous worm-like substance obtained by natural graphite after intercalation, washing, drying, high temperature expansion and other processes. Expanded graphite has many excellent characteristics, such as flexibility, resilience, self-adhesion, impermeability, adsorption, low density, etc., is widely used in petroleum, chemical, machinery, metallurgy, atomic energy and other industries.In addition, expanded graphite can also be used as a sealing material, with a wide available temperature range and a small thermal expansion coefficient. It has been widely used in petrochemical, machinery, metallurgy, atomic energy and other industries.

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purification process of 10. graphite:

Flotation method:The use of graphite and water contact is not easy to be water infiltration, as well as the characteristics of good suspension of graphite, graphite ore with flotation reagent treatment, so that graphite minerals selectively adhere to the bubble, so as to separate the useful minerals and gangue minerals. After contact with water, the surface of graphite is not easily infiltrated by water, and the suspensibility of graphite is very good, so graphite is easier to be separated. The application range of flotation method is particularly wide, almost all ores and mineral raw materials can be separated and enriched by flotation method.

Alkali-acid method:It is a common and mature process method in the chemical purification of graphite. The specific process flow is as follows: the impurities in graphite ore are acted on by strong acid, strong alkali or other compounds to convert them into water-soluble substances, and the final product is obtained by washing and drying. Commonly used methods include alkaline acid method, chlorination roasting method, hydrofluoric acid method, etc.

hydrofluoric acid method:The use of hydrofluoric acid in the role of impurities in graphite, so that it can be converted into water-soluble substances, the final product is washed and dried.

High temperature method:Using high temperature roasting to remove impurities in graphite, such as silicate minerals.

Different graphite purification processes are suitable for different graphite ores and impurity types. In actual operation, it is necessary to select the appropriate purification process according to the specific situation.

 

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Eleven, China's industrial level in the graphite industry:

Graphite Mining and Processing:China's graphite mining and processing industry has formed a relatively complete production and processing system. Today, China has become the world's largest producer of natural graphite. In Heilongjiang, Shandong, Inner Mongolia, Shanxi, Hebei, etc.Graphite deposits have been discovered in more than 20 provinces and cities, with more than 90% of the country's reserves concentrated. The primary processing products of graphite ore and low-grade graphite concentrate are exported to Japan, South Korea, India and other countries.

 

Graphite production:In recent years, China's natural graphite production has remained basically stable,In 2017, under the influence of environmental protection policies, China's natural graphite production declined, and then began to show a fluctuating upward trend. By 2021, China's natural graphite production will reach 735000 tons, up 13.1 percent year-on-year. In this process, the proportion of microcrystalline graphite production increased year by year, from 44% in 2015 to 44% in 2021.

graphite advanced processing products:Although my country's graphite production is large, the price of advanced processed products is far less than that of developed countries such as the United States, Britain, and Japan. On the contrary, the export price of graphite is low.

To sum up, China's industrial level in the graphite industry is in the forefront of the world, with high mining and processing capacity, and is one of the largest natural graphite producers in the world. At the same time, China is also making progress in the deep processing of graphite, but it still needs to be improved in the advanced processing products.

 

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XII. Impact of production in the graphite industry on the environment：

Environmental damage during mining and production:In the process of graphite mining, due to the lack of clear industry norms, the technical level and economic benefits are not high, resulting in a large amount of dust, smoke and tailings in the process of graphite mining and production, which not only pollutes the surrounding land, surface water system and the ecological environment of the mining area, but also affects the production and life of residents. At the same time, the waste water produced in the purification process of graphite contains metal salts, such as iron and aluminum and silicon compounds, which can be used to produce iron and aluminum compounds and white carbon black, but it also causes some pollution to the environment.

Waste emissions cause pollution to the environment:The waste quarry, waste rock, waste residue and waste water discharge produced in the process of graphite mining and production will pollute the surrounding environment. These wastes not only occupy a lot of land, but also pollute the land and water sources, affecting the production and life of the surrounding residents.

In order to reduce the environmental impact of graphite industry production, the following measures need to be taken:

Strengthen industry norms and supervision:Formulate more stringent industry norms and regulatory policies, strengthen environmental protection and management in the process of graphite mining and production, and ensure that enterprises carry out production in accordance with environmental protection requirements.
Improve the technical level: increase the technical research and development and investment in the process of graphite mining and production, improve the technical level, and reduce waste emissions and environmental damage.

Implementing a circular economy:Encourage enterprises to implement a circular economy, the use of waste resources, into useful products or materials, to reduce environmental pollution.
Strengthen public participation and publicity and education: strengthen environmental protection publicity and education to the public, improve public awareness and participation in environmental protection issues in the graphite industry, and form a good atmosphere for the whole society to pay attention to environmental protection issues in the graphite industry.

The impact of the production of graphite industry on the environment needs to be paid attention to. Strengthening industry norms and supervision, improving the level of technology, implementing circular economy and strengthening public participation and publicity and education can reduce its damage and pollution to the environment.

 

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Thirteen, graphite industry wastewater treatment process:

 

NeutralizationFilm Treatment Evaporation Crystallization.

 

Neutralization treatmentThe main method is to use lime and other neutralizers to neutralize wastewater and remove pollutants such as fluoride ions. In this process, calcium ions react with fluoride ions to form calcium fluoride precipitates, thereby reducing the content of dissolved substances in the water. An appropriate amount of flocculant can be added to make the calcium fluoride in the graphite purification wastewater to form alum flowers that are easy to separate, so as to realize the separation of fluoride ions in the wastewater.

Membrane treatment processes include multi-media filtration.Activated carbon filtration, ultrafiltration, reverse osmosis,Selective separation using these membranes enables the separation, purification, and concentration of different components of the feed solution. Ultrafiltration and reverse osmosis can separate the salt in wastewater into concentrated brine and fresh water through membrane treatment, so as to realize the reuse of fresh water and achieve the purpose of reducing discharge.

The final process of evaporation and crystallization is to use multi-effect evaporation of concentrated brine, which is a common treatment method,The heated brine is evaporated in a plurality of evaporators in series, and the steam evaporated from the previous evaporator is used as the heat source of the next evaporator and condensed into fresh water.

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XIV. Dust and solid waste treatment process generated by graphite industry：

Dust treatment:(1) Select the appropriate trap:According to the different graphite processing technology, select the appropriate trap, such as filter, impactor, wet dust filter, etc.

 

(2) Strengthen the operation of air purification equipment:While dealing with graphite dust, it is also necessary to strengthen the operation of air purification equipment to ensure clean air. Sometimes it is necessary to manually clean the dust by manual means. In the case of safety, mechanical cleaning can be carried out to reduce the pollution of graphite dust to the environment.

(3) Reasonable treatment of waste water and waste gas: In the graphite processing process, in addition to dust, a large amount of polluted waste water and waste gas will be produced. This pollution must also be dealt with properly. For the generated waste water, appropriate treatment methods should be adopted to reduce the impact on the environment; for waste gas, corresponding measures should also be formulated, and effective treatment must be obtained before collection and discharge to ensure that the national discharge standards are met.

(4) Perfect management system:People pay more and more attention to the treatment and management of graphite dust.

Solid waste treatment:(1) Resource: Recycling valuable graphite solid waste, such as for the production of composite materials, functional materials, etc.

 

(2) Harmless: harmless treatment of graphite solid waste that cannot be reused, such as incineration or sanitary landfill.

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Fifteen, graphite evaporator:

 

graphite evaporatorIs an important industrial equipment, with strong corrosion resistance, high heat transfer efficiency, is widely used in chemical, pharmaceutical, petrochemical and other fields. Its main function is to realize the concentration and separation of materials, and can be crushed at room temperature to achieve the same yield and fineness as the cryogenic crushing process.

The application range of graphite evaporator is very wide. For example, in the chemical production line, it can effectively absorb the waste liquid in the production, and produce high-quality chlorination reaction, ferrous chloride and other products, so as to turn waste into treasure. In addition, graphite evaporators can also be used for wastewater treatment and recovery of valuable substances, such as in the manufacture and production of lithium batteries. As one of the main anode materials, graphite has high thermal conductivity, high corrosion resistance and low adhesion. The characteristics of sex make it have unique advantages in the manufacture and production of lithium batteries.

Graphite evaporator is widely used in many fields and is an efficient and durable industrial equipment.

 

Tubular evaporator is mainly composed of graphite tube,Corrosive medium goes inside the pipe, and cooling medium goes outside the pipe. The evaporator has simple structure, high heat transfer efficiency and strong adaptability, and can be used to deal with corrosive media.

 

The block hole graphite evaporator equipment consists of a cylindrical non-permeable graphite heat exchange block,Drill the horizontal hole and the vertical hole, respectively, to go two kinds of medium, to reach the purpose of heat exchange. This evaporator is easy to deal with sealing problems and uses fluorine rubberO-ring sealing medium, the installation of pressure spring as the active compensation of thermal expansion and contraction, to seal the consequences of stalemate. At the same time, the use of short channel progress turbulence level makes the equipment structure high, temperature resistance and pressure resistance function is strong, thermal shock resistance function is good, volume use rate is high, heat transfer result is good and easy to assemble and disassemble maintenance. In addition, the block hole graphite evaporator equipment also uses a short channel design, so that the medium can produce higher turbulence when flowing through the equipment, and improve the heat transfer efficiency and thermal shock resistance of the equipment. At the same time, this design also makes the volume utilization rate of the equipment higher, which can save space.

 

Graphite Manufacture Graphite Evaporator,Graphite evaporators have falling film three-effect wastewater evaporators, multi-effect wastewater evaporators, graphite block coolers and other types. These evaporators are made of graphite materials and have the advantages of strong corrosion resistance and high heat transfer efficiency.

 

in addition,Graphite can also manufacture scraper falling film evaporator, titanium tube graphite polypropylene spray condenser and other equipment,These devices are widely used in chemical, pharmaceutical, petrochemical and other fields.

It should be noted that the types and specifications of evaporators manufactured in the graphite industry will vary depending on the specific purpose and process requirements, so in actual operation, it is necessary to select the appropriate evaporator type and specifications according to the specific situation.

 

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Sixteen, China's implementation of standards for the production of graphite industry:

Technical Conditions for Graphite Electrodes(YB/T 4088-2016)：This standard specifies the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificates of graphite electrodes.

General Technical Conditions for Medium and High Temperature Pyrolytic Graphite Products(YB/T 4089-2016)：This standard specifies the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificates of medium and high temperature pyrolytic graphite products.

"Flake Graphite"(GB/T 3518), Microcrystalline Graphite (GB/T 3519), Expandable Graphite (GB/T 10698), Technical Conditions for Flexible Graphite Sheet (JB/T 7758.2), Spherical Natural Graphite (JC/T 2315) and other relevant standards: these standards specify the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificates of graphite products.

In addition, China has also implemented a national standard industry classification for graphite production enterprises, which classifies graphite production as a carbon material product manufacturing industry, corresponding to the code.C3633. At the same time, the environmental protection requirements and energy consumption of graphite production enterprises have also formulated relevant standards.

In general, China's implementation standards for graphite production are strict, aiming to ensure that the quality and environmental performance of graphite products comply with national laws and regulations and related regulations. There are mainly the following:

 

Technical Conditions for Graphite Electrodes(YB/T 4088-2016)：This standard specifies the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificates of graphite electrodes.

General Technical Conditions for Medium and High Temperature Pyrolytic Graphite Products(YB/T 4089-2016)：This standard specifies the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificates of medium and high temperature pyrolytic graphite products.

"Flake Graphite"(GB/T 3518), Microcrystalline Graphite (GB/T 3519), Expandable Graphite (GB/T 10698), Technical Conditions for Flexible Graphite Sheet (JB/T 7758.2), Spheroidized Natural Graphite (JC/T 2315) and other relevant standardsThese standards specify the technical requirements, test methods, inspection rules, packaging, marking, transportation, storage and quality certificates for graphite products.

In addition, China has also implemented a national standard industry classification for graphite production enterprises, which classifies graphite production as a carbon material product manufacturing industry, corresponding to the code.C3633. At the same time, the environmental protection requirements and energy consumption of graphite production enterprises have also formulated relevant standards.

China's implementation standards for graphite production are strict, aiming to ensure that the quality and environmental performance of graphite products comply with national laws and regulations and related regulations.

 

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Seventeen, China has a clear policy on the export of graphite.

On the one handChina is the world's largest producer and exporter of graphite. For a long time, China has firmly fulfilled its international obligations such as non-proliferation. According to the needs of safeguarding national security and interests, China has implemented export control on specific graphite items and temporary control on some graphite items.On the other handChina has implemented export controls on specific types of graphite, especially for purity exceeding99.9%, flexural strength of more than 30Mpa, density of more than 1.73g/cm3 of artificial graphite, natural flake graphite and its products. These policies reflect integrated development and security considerations.

 

Specifically,the People's Republic of China Export Control ActIt also stipulates that export operators should apply to the national export control administration for licensing procedures. This is to safeguard national security and interests and to ensure that exported goods do not harm national security and interests.

In addition, China has also imposed temporary controls on some graphite items, which are temporary measures taken in response to specific circumstances. For example, under certain circumstances, China may impose temporary controls on certain graphite items to protect the security and interests of the country.

In general, China's graphite export policy is based onthe People's Republic of China Export Control Actand other relevant laws and regulations, aimed at safeguarding national security and interests, to ensure that the export of goods in line with national laws and regulations and relevant provisions.

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Hunan EnruiProfessional non-standard custom productiongraphitization furnace,high temperature graphitization furnace.