Elektwolitik aliminyòm
Aliminyòm elektwolitik se aliminyòm ki jwenn pa elektwoliz. Pwodiksyon endistriyèl aliminyòm elèktrolitik modèn adopte kriyolit -alumina fonn sèl metòd elektwoliz. Kriyolit fonn se sòlvan an, alumina yo itilize kòm solut la, kò kabòn yo itilize kòm anod la, epi likid aliminyòm yo itilize kòm katod la. Tou de elektwoliz.
Non Chinwa Elèktrolitik aliminyòm
Sibstansyèlman aliminyòm jwenn pa elektwoliz
Metòd Cryolite-alumina elèktroliz sèl fonn
Kondisyon tanperati 950degre-970degre
Endistri modèn
Alumina yo itilize kòm solute a, kò kabòn yo itilize kòm anod la, epi likid aliminyòm yo itilize kòm katod la. Apre yo fin aplike yon kouran dirèk fò, reyaksyon elektwochimik la fèt sou de poto yo nan selil elektwolitik la nan 950.degre-970degre, se sa ki, elektwoliz.
Pwodiksyon elèktroliz aliminyòm ka divize an twa kategori: bò-ansète anod baton pwòp tèt ou-tank boulanjri, tèt-ansète anod baton pwòp tèt ou-tank boulanjri ak pre{{4 }} tank anod kwit.
Teknoloji elèktrolitik aliminyòm pwodiksyon pwòp tèt ou -tank boulanjri a gen karakteristik ekipman senp, peryòd konstriksyon kout ak envestisman ki ba, men li difisil pou fè fas ak gaz lafimen, polisyon nan anviwònman an grav, mekanizasyon difisil, entansite travay segondè, pa fasil. nan gwo-echèl, pwodiksyon ki ba pou chak tank, elatriye. Enpèfeksyon yo ki te simonte yo te fondamantalman elimine kounye a.
Kounye a, pifò peyi ak antrepriz pwodiksyon nan mond lan ap itilize gwo-tank pre-echèl. Entansite aktyèl la nan tank la se gwo anpil, ki pa sèlman gen yon wo degre de automatisation, konsomasyon enèji ki ba, ak pwodiksyon segondè pou chak tank, men tou, satisfè kondisyon ki nan règleman pwoteksyon anviwònman an.
peyi mwen an te konplete tès endistriyèl ak endistriyalizasyon 180kA, 280kA ak 320kA modèn tank pre-cuit. Amelyorasyon teknolojik ak transfòmasyon ki santre sou konsèvasyon enèji, ogmantasyon pwodiksyon ak konfòmite pwoteksyon anviwònman an te ankouraje transfòmasyon teknoloji pwodiksyon tank pwòp tèt ou -nan pre-tank boulanjri, e li te reyalize gwo siksè.
Dapre pwosesis pwodiksyon an nan aliminyòm elektwolitik, pri pwodiksyon an nan aliminyòm elektwolitik apeprè konpoze de pati sa yo:
(1) Matyè premyè: alumina, kriyolit, fliyò aliminyòm, aditif (fliyò kalsyòm, fliyò mayezyòm, elatriye), materyèl anod;
(2) Depans enèji: elektrisite (kouran dirèk ak kouran altènatif), lwil gaz;
(3) Depans travay: salè ak lòt depans jesyon;
(4) Lòt depans: pèt ekipman ak depresyasyon, depans finansye, depans transpò, taks, elatriye.
Pwosesis koule
Pwosesis elektwoliz aliminyòm: pwodiksyon endistri modèn aliminyòm adopte kriyolit -alumina fonn sèl metòd elektwoliz. Kriyolit fonn se sòlvan an, alumina yo itilize kòm solut la, kò kabòn yo itilize kòm anod la, epi likid aliminyòm yo itilize kòm katod la. Sa se elektwoliz. Reyaksyon chimik la sitou fèt pa ekwasyon sa a: 2Al2O3 plis 3C==4Al plis 3CO2. Anòd: 2O2ˉplis C-4eˉ=CO2↑Katod: Al3 plis 3eˉ=Al. Pwodwi anod yo se sitou gaz kabonik ak gaz monoksid kabòn, ki gen yon sèten kantite gaz danjere tankou fliyò idwojèn ak pousyè solid. Yo nan lòd yo pwoteje anviwònman an ak sante moun, gaz la anod bezwen yo dwe pirifye ak egzeyate nan atmosfè a apre yo fin retire gaz danjere ak pousyè tè. Pwodwi katod la se aliminyòm fonn, ki se ekstrè nan tank la pa louch vakyòm epi li voye nan fondri a. Apre pirifikasyon ak klarifikasyon nan gwo fou a kenbe, li jete nan lengote aliminyòm oswa dirèkteman trete nan billets fil ak pwofil.
Koule pwosesis pwodiksyon li yo se jan sa a:
Alumina Fliyò Sèl Kabòn Anòd DC
↓ ↓ ↓ ↓↓
Echapman anod gaz------elektwolizè
↑ ↓ ↓
Gaz echapman←Aliminyòm likid pou pirifye gaz
↓ ↓
Rekiperasyon fliyò, pirifikasyon ak klarifikasyon
↓ ↓ ↓
Retounen nan elektwolizè a
Vide Rolling oswa Distribisyon
↓ ↓
Lengote aliminyòm Bikèt fil oswa pwofil
Ekwasyon:
Aliminyòm elektwolitik se aliminyòm ki jwenn pa elektwoliz.
Li enpòtan pou kontinye atravè ekwasyon sa a: 2Al2O3 plis 3C-enèji→4Al plis 3CO2.
Anòd: 2O2ˉplis C-4eˉ=CO2↑
Katod: Al3 plis plis 3eˉ=Al
The latest technology
Nouvo teknoloji ekonomize enèji - nan aliminyòm elektwolitik soti, ak endistri a ekonomize 27.5 milya kWh elektrisite chak ane.
On March 17, 2012, China's electrolytic aluminum industry made a new breakthrough in energy saving and emission reduction. "Low-temperature and low-voltage aluminum electrolysis new technology" successfully passed the acceptance of the Ministry of Science and Technology in China Aluminum and Power Company on the same day. It has dropped to 11819 degrees, a drop of 10.7 percent , and many technologies have reached the international leading level. If the whole industry is promoted, the annual electricity saving of my country's electrolytic aluminum industry will be 27.5 billion kwh.
After more than 30 years of development, the electrolytic aluminum industry has gradually become an important basic industry in China. However, due to the high power consumption in the production process, it has always been called a "high energy-consuming industry" and is also one of the key industries controlled by the state. The research and development of low-temperature and low-voltage new technologies is the development direction of energy saving and consumption reduction in the electrolytic aluminum industry, and it is also a major technical problem faced by the world aluminum industry.
In 2009, "low temperature and low voltage aluminum electrolysis new technology" was included in the national science and technology support plan project. Project leader Liang Xuemin and other experts in the project team made unremitting efforts to successfully develop electromagnetic and magnetic fluid stabilization technology, low-temperature and low-voltage electrolytic cell structure, and low-temperature and low-voltage process operation technology for the first time in the world. The world's leading 400KA "static flow" aluminum electrolytic cell has realized large-scale industrial production and a series of high-efficiency and stable operation at low temperature, low voltage and long cycle under high current density.
According to reports, according to the estimated domestic production of electrolytic aluminum in 2012 of 20 million tons, after the promotion of this technology in the whole industry, the annual electricity saving of my country's electrolytic aluminum industry can achieve 27.5 billion kWh, which is equivalent to 265.9 billion kWh of electricity consumption in Henan Province in 2011. More than 10 percent of the time, calculated at 0.53 yuan per kWh, directly creating economic benefits of 14.575 billion yuan, equivalent to 8.8 million tons of standard coal, and reducing carbon dioxide and other greenhouse gas emissions by 15.66 million tons, which will promote the aluminum industry and my country's energy saving and reduction. The platoon work has played a good exemplary and leading role.
Karakteristik endistri yo
Tout aliminyòm nan mond lan pwodui pa elektwoliz. Pwodiksyon endistriyèl elektwoliz aliminyòm adopte Hall-Elu kriyolit-alumina fonn sèl elèktroliz metòd, se sa ki, kriyolit-sèl fliyò ki baze sou yo itilize kòm flux, ak alumina a se itilize kòm fonn pou fòme yon sistèm elektwolit milti-faz. Pami yo, sistèm binè Na2AlF6-Al2O3 ak sistèm ternary Na3AlF6-AlF3-Al2O3 se baz elektwolit endistriyèl yo. Endistri aliminyòm elektwolitik la gen yon gwo enpak sou anviwònman an epi li se yon gwo konsomasyon enèji ak endistri polisyon segondè. Gaz dechè yo egzeyate nan pwodiksyon aliminyòm elektwolitik se sitou CO2, ak fliyò gaz-solid sitou ki konpoze de gaz HF. CO2 se yon gaz lakòz efè tèmik e li se kòz prensipal rechofman planèt la. Efè lakòz efè tèmik CF4 ak C2F6 nan fliyò se 6,500-10, 000 fwa sa ki nan gaz kabonik, epi li pral gen diferan degre enpak sou kouch ozòn lan. HF se yon gaz trè toksik ki antre nan kò imen an atravè po a oswa aparèy respiratwa, epi sèlman 1.5g ka fatal.
Gen yon pwoblèm
The actual operating index is poor. Due to the short development time, the in-depth development of China's large-scale aluminum electrolytic cells in the production field is obviously insufficient, resulting in a large gap between the production indicators of actual operation indicators and the international advanced level. Most of them operate in a large load and small grid environment, and there are many hidden dangers. The joint operation of aluminum and electricity is one of the development trends of electrolytic aluminum enterprises in China, but at the same time, there are corresponding problems in technology. Since large-capacity electrolyzers are generally large in scale (one series can produce more than 200,000 tons), and the huge electricity load is concentrated on one production series (generally more than 400,000 KW), any fluctuation in the production of electrolysis series will cause The power grid or self-provided power plants have a greater impact, and even threaten the security of power supply.
Lack of "fine design" technology and comprehensive technical measures to improve the life of the cell based on a thorough grasp of the mechanism and laws of cathode damage, it is difficult for the electrolytic cell to reach the design life and the early damage rate is high. Problems Affecting the Life of Large-scale Electric Cells in China In addition to the quality of cathode carbon materials generally considered in China, there are also some problems in the design of electrolytic cells, furnace construction materials, furnace construction quality, roasting start-up, normal production operations and production management. . The deep-seated reason for these problems is that China still lacks in-depth understanding of the mechanism and laws of aluminum electrolytic cell damage (often called cathode damage), as well as the "fine design" technology and comprehensive technical measures to improve the life of the cell based on this. With the continuous expansion of electrolytic cell capacity, the problem of cell life becomes more prominent.
Lack of advanced production operation technology, high operating costs. China's 300KA class super-large pre-baked aluminum electrolytic cells have been put into industrial application for a short time. And can not completely copy the previous experience in large pre-bake tanks (these experiences also have great limitations). The problem of uneven current distribution during the roasting start-up process is more prominent and the energy consumption during the roasting start-up process is large; the physical field (electric field, magnetic field, flow field) of the electrolytic cell after being put into operation is easy to fluctuate, and it is difficult to maintain thermal balance; It is easy to fluctuate due to external interference, and it is difficult to extinguish after the anode effect occurs, and due to the large inertia of the electrolytic cell, once the cell condition fluctuates or the cell condition is abnormal, it is difficult to quickly return to normal. As far as the overall production status of electrolytic aluminum in China is concerned, the comprehensive energy utilization efficiency is about 15 percent lower than the international advanced level, mainly as follows: the difference in current efficiency is 2-3 percentage points; The difference in energy consumption in the production process is about 3Gj/t; the difference in the consumption of electrolytic aluminum anode is 30-60Kg (equivalent to about 75-150Kg of standard coal); the difference in the life of the cell is about 1000 days; the international advanced anode effect coefficient is 0.1 times/day. Below the cell, The best level in China is around 0.3 times/day.
Surkapasite
Since 2002, China's electrolytic aluminum industry has had a surplus of electrolytic aluminum production. Affected by the decline in demand from downstream industries, China's electrolytic aluminum surplus in 2008 is expected to reach 500,000 tons. The growth rate of electrolytic aluminum demand has slowed down. Affected by the economic crisis, the growth rate of demand from the real estate and automobile industries has dropped sharply, while the demand from the power equipment industry has maintained rapid growth. The demand for electrolytic aluminum in the packaging industry has remained stable. In 2008 The growth rate of electrolytic aluminum demand is around 10 percent . China's bauxite resources are scarce, and the bauxite resources can only be maintained for another 10 years, and it is impossible to support the average annual expansion rate of the electrolytic aluminum industry by about 20 percent . The production cost of electrolytic aluminum is between 15,000 yuan / ton and 17,500 yuan / ton, while the price of electrolytic aluminum is only 13,400 yuan / ton, and the industry has suffered serious losses. Raw materials have fallen further, and the average production cost of Chinese electrolytic aluminum enterprises is also around 15,000 yuan, so the possibility of a sharp drop in aluminum prices is very small. Around June 2009, the aluminum price may return to 15,000 yuan/ton.
When energy prices continue to rise, the world's major aluminum companies began to reduce the cost of electrolytic aluminum production in all aspects to ensure the price competitiveness of aluminum production. From the perspective of domestic policies, the national industrial policy positions the aluminum industry to meet domestic demand, and there will be differences in policies for high-precision products and low-tech products. Therefore, grasping the development trends of transportation, electric power, packaging, household appliances and other industries, and actively introducing advanced equipment, improving technical capabilities and reducing production costs have become the main development direction of the current aluminum company.
Ki jan yo plis rezoud twòp kapasite nan aliminyòm elektwolitik
On the basis of the just promulgated "Guiding Opinions of the State Council on Resolving Serious Overcapacity Contradictions" hereinafter referred to as "Guiding Opinions", researchers from China Industry Insight Network believe that policy implementation and support should be strengthened to further suppress supply and expand demand, and improve both supply and demand. policy, and strive to resolve the overcapacity of electrolytic aluminum. Specific suggestions are as follows.
Sou bò rezèv la, li sijere ke plizyè estrateji yo ta dwe pran pou estrikteman redwi kapasite pwodiksyon aliminyòm elektwolitik. An patikilye, refòm nan pri elektrisite yo ta dwe akselere pou dissiper enpilsyon rapidman elaji kapasite pwodiksyon an.
First, the "Guiding Opinions" should be strictly implemented, "it is strictly forbidden to build new production capacity projects", "categorically and properly handle illegal projects under construction", "clean up and rectify the construction of illegal production capacity", "eliminate and withdraw outdated production capacity", and suggest that violations can be dealt with. Fines are charged for building production capacity to establish a fund for eliminating outdated production capacity, and specific support policies have been introduced for the elimination and withdrawal of production capacity in terms of financial subsidies, enterprise conversion, and employee placement.
Second, effectively eliminate policy obstacles, implement the "integration of a group", and promote the merger and reorganization of enterprises. On the basis of entering the fast exemption/fast review channel for key industries, further study and reduce the cost of mergers and acquisitions of listed companies in the same industry; it is recommended to adjust the power policy to allow leading enterprises to build or absorb existing power generation enterprises to provide cheap electricity for their electrolytic aluminum production Supply; it is recommended to increase support in finance, taxation and other aspects, encourage leading enterprises as the main body of integration, and effectively promote cross-regional, cross-industry, and cross-ownership corporate restructuring.
Twazyèmman, balans pri elektrisite rejyonal la, akselere refòm nan sistèm elektrisite a, epi elimine atant gwo pwofi yo. Malgre ke nan tèm long la, gwo enèji -konsome endistri tankou aliminyòm elektwolitik gen yon tandans epi yo bezwen transfere nan enèji yo-rejyon lwès rich tankou Xinjiang, men nan kout ak mwayen tèm, la transfè konplè nan kapasite pwodiksyon ant rejyon yo mande pou yon pwosesis gradyèl, ak konsidere An tèm de kapasite transpò ak resous ak faktè anviwònman an, ekspansyon kapasite pwodiksyon an nan Xinjiang ak lòt rejyon lwès jis paske nan pri elektrisite preferansyèl pa ta dwe fèt pa franchi ak limit. Se poutèt sa, li rekòmande pou pran mezi pou balanse pri elektrisite rejyonal la ak pi vit refòm nan sistèm griy nasyonal la. Pou egzanp, li kapab premye moun ki pilòt endistri aliminyòm elektwolitik nan peyi a, ak frè sèvis koneksyon gri ka inifye nan 1 santim a 3 santim nan tout peyi a, oswa pèmèt endistri konstriksyon nan divès kote. Rezo transmisyon pouvwa rejyonal la ka elimine inegalite pri elektrisite ki te koze pa rezon politik, epi dissiper ekspetasyon antrepwiz ki enpòtan pou jwenn pwofi depase nan rejyon lwès yo tankou Xinjiang, kidonk anpeche enpilsyon envesti nan kapasite pwodiksyon an, epi fè antrepriz yo sispann volontèman. bati nouvo kapasite pwodiksyon an.
On the demand side, based on the current situation of sluggish external demand and escalating trade frictions, it is suggested to increase domestic demand for aluminum by means of purchasing and storing, expanding the scope of application, etc., effectively "digesting a batch", and improving the processing level of aluminum materials through technological innovation , to obtain higher returns. One is to appropriately increase the country's reserves of aluminum. The country's expansion of the scale of purchase and storage when the current aluminum price has hit a new low in two years is not only conducive to digesting part of the production capacity, promoting the preservation and appreciation of assets, but also building market confidence. The second is to increase RD and financial and taxation support, and actively expand the application scope of aluminum. The third is to actively strive to improve the processing level of my country's aluminum materials and obtain higher profits through technical research and innovation.
Pwovizyon ak demann sitiyasyon
The global production of electrolytic aluminum has grown steadily, and the driving force for the increase in production still comes from China. In 2005, the world's electrolytic aluminum output was 31.91 million tons, an increase of 6.45 percent year-on-year, of which China's output was 7.67 million tons, a year-on-year increase of 15.07 percent . In 2006, the global production of electrolytic aluminum reached 33.8 million tons. In June 2006, the global average daily output (excluding China) was 82,200 tons, an increase of 700 tons compared with the average daily output in May, and a month-on-month increase of 0.09 percent . The domestic output of electrolytic aluminum in June was 780,300 tons, and the average daily output of electrolytic aluminum was 26,000 tons, an increase of 1,975 tons compared with the average daily output in May, a month-on-month increase of 7.59 percent . China is still the main driving force for the increase in global electrolytic aluminum production. Since China's production accounts for 24.9 percent of global production, the changing trend of China's production has played a decisive role in global electrolytic aluminum supply. The development of China's electrolytic aluminum industry has determined that China's domestic electrolytic aluminum supply has always been relatively abundant. In 2005, the average production capacity of electrolytic aluminum was 10.7 million tons, and the capacity utilization rate was 75 percent . From the domestic data in June, China's production capacity has been released to a certain extent. . China has built 11 electrolytic aluminum projects with a total construction capacity of 1.12 million tons, and there are still 10 proposed electrolytic aluminum projects with a total capacity of 1.4 million tons. The production capacity of electrolytic aluminum reached 11.6 million tons in 2006 and 12.5 million tons in 2007. The electrolytic aluminum construction process is simple, the technical content is low, the construction period is short, and there is sufficient capital investment. It only takes 9 months from the start of construction to the completion and production.
The alumina production capacity of the upstream industry of electrolytic aluminum has rapidly expanded, and the industrial chain has been extended to the electrolytic aluminum industry, which has become the main driving force for the growth of electrolytic aluminum production capacity. The growth and development stage of the electrolytic aluminum industry determines that production growth is the main keynote. The competition, restructuring and mergers and acquisitions of electrolytic aluminum enterprises, continuous expansion, and increased industry concentration will also promote the growth of production capacity. The buyers of the electrolytic aluminum industry are aluminum consumers. The rapid development of China's economy and the urbanization process of China's infrastructure, public utilities, housing and automobiles and other consumer goods have greatly boosted China's electrolytic aluminum consumption demand. The electrolytic aluminum industry is in the stage of rapid development and growth, the industry survives the fittest, and the industry concentration continues to increase. From 2003 to 2005, the total output of electrolytic aluminum increased from 5.54 million tons to 7.67 million tons, an increase of 2.13 million tons, of which only the top ten electrolytic aluminum plants in China achieved an increase of 910,000 tons. The number of manufacturers decreased from 141 to 95, and the average production scale of a single manufacturer increased from 39,000 tons in 2003 to 80,000 tons in 2005.
Analiz endistri
From January to November 2012, China's primary aluminum output was 18.15 million tons, showing a slight downward trend year-on-year. The serious overcapacity situation has eased. By the end of October, the industry's goal of eliminating outdated production capacity of 270,000 tons has been more than half completed.
Nan etap sa a, antrepwiz aliminyòm elektwolitik yo ta dwe evite avèg elaji kapasite pwodiksyon, transfòme avantaj endistriyèl orijinal yo nan rentabilité, epi sèvi ak resous ki egziste deja pou konbine pouvwa chabon, fusion, ak pwosesis an tèm de avantaj orijinal yo fòme yon chèn endistriyèl konplè epi elaji echèl la. nan antrepriz la. Li te vin tounen yon objektif enpòtan nan antrepriz aliminyòm elektwolitik yo vin pi gwo, ranfòse kapasite pwodiksyon, ak rafine teknoloji pwosesis.
Apre plis pase 70 ane nan devlopman, endistri a aliminyòm elektwolitik nan New Lachin te fè gwo reyalizasyon nan tout aspè, men li tou fè fas a anpil defi ak pwoblèm, ki dwe byen rezoud, otreman, li pral favorab pou devlopman kap vini an.
twòp kapasite
As of the end of 2013, China's primary aluminum production capacity has exceeded 32,000kt/a, and it is necessary to develop to foreign countries to mine bauxite, extract alumina and produce aluminum ingots for remelting in places with relatively rich resources and energy. Joint venture or sole proprietorship to ship the obtained products back to the country. The amount of aluminum and aluminum products to be exported by 2020 is processed with imported aluminum ingots for remelting, not equivalent to imported aluminum resources (bauxite, alumina, scrap aluminum). By 2030, about 50 percent of the remelting aluminum ingots for domestic apparent consumption will be imported. The ideas of Japan, South Korea and Taiwan region to develop the primary aluminum electrolysis industry are worth learning from, as well as the practices of the United States and some European countries.
Going out to develop aluminum resources is risky. In some places, the risk is still very high. It may be necessary to "pay a certain amount of tuition fees". Tuition fees may be unavoidable, and strive to pay less. At present, Japan and other countries have all shut down domestic primary aluminum production (Japan also retains a Urahara aluminum plant with a production capacity of 15kt/a, which uses the power of a small hydropower station on Mount Fuji. The power station was built by an aluminum plant. The aluminum plant will then use the segregation method to extract high-purity aluminum to reduce environmental pollution), and in the past 30 years, the production of primary aluminum in industrially developed countries such as the United States and Germany has decreased. The output of primary aluminum in China has declined somewhat, while the output of enterprises abroad has risen by more than 35 percent .
In 2021, the world's per capita aluminum consumption (calculated by 7 billion people, primary aluminum consumption of 51,400kt) is 7.34 kg/person, and China's per capita aluminum consumption (calculated by 1.35 billion people, primary aluminum consumption of 25,500kt) is 18.89 kg/person , has far exceeded the world average consumption, which is 2.57 times, and is close to 21.4 kg/person of industrially developed countries. Our main task now is to improve the quality of raw material consumption and to do as much as possible with as little raw material consumption as possible. The domestic scale should no longer be expanded, and the measures of "reducing the east and increasing the west, and reducing the fire and increasing the water" can be adopted.
Defi teknik
Although the tank capacity of some electrolytic aluminum plants in China has caught up with or exceeded the world's leading level, the technical and economic indicators of similar tank types still need to be improved compared with the advanced level abroad.
At present, the anode effect coefficient of electrolytic cells of electrolytic aluminum plants in my country is relatively high; the power consumption per ton of aluminum is higher than that of the European leading level; the average cell life is generally shorter; the current efficiency of the foreign leading level has reached 96 percent , while more than 75 percent of China's The current efficiency of the enterprise is only 92.5 percent -93.5 percent , and the calculation of the rectification efficiency of a considerable number of factories is low; under the same power consumption conditions, the anode current density of Chinese electrolyzers is designed to be only 0.7-0.735A/cm2. This means that the output per unit area of the same electrolytic cell is low. Therefore, in the future, one of the main tasks of China Aluminum Electrolysis is to maximize the output per unit area of the electrolytic cell.
China's current development of electrolytic aluminum industry also has many advantages, such as the low investment per unit product of electrolytic aluminum plants, which is about 1/3 of that of industrially developed countries; the low labor cost, which is 1/5-1/2 of the corresponding labor costs in the primary aluminum cost of industrially developed countries. 4. The environmental protection requirements are low, so the investment in environmental protection facilities is also low, which should not be the case. Now is the time to increase investment in environmental protection. Thousands of saving, environmental protection cannot be saved, environmental protection standards should be raised, and those that do not meet the standards should be shut down, and environmental protection standards should become high-voltage lines.
