How to check whether the wallet is decentralized
private keys and assets are transferred to the wallet for centralized management. Users don't need to worry about the loss of the private key of this kind of wallet procts, resulting in the loss of funds; However, the capital risk will be more concentrated in the wallet project side and server side. When the centralized wallet is conquered by hackers, users will suffer unnecessary losses
decentralized wallets, commonly known as onchain wallets, have private keys maintained by users and assets stored in blockchains
decentralized wallets are often referred to as onchain wallets. The private key is handed over to the user. If the private key is lost, the wallet will not be able to help the user recover, and the funds will be lost forever. But the decentralized wallet is difficult to be attacked by hackers, and users don't have to worry about the self stealing of the wallet service provider
centralized wallets are where assets are stored, while decentralized wallets are where private keys are stored
except for the exchange, it is not recommended to use the centralized wallet, although losing the private key may help you find it. But there is always a risk that the company will run
a decentralized wallet is equivalent to a channel, a channel where you can master mnemonics to control your assets on the blockchain. For a decentralized wallet, the most important thing is to protect the security of the [private key]
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.
private keys and assets are transferred to the wallet for centralized management. Users don't need to worry about the loss of the private key of this kind of wallet procts, resulting in the loss of funds; However, the capital risk will be more concentrated in the wallet project side and server side. When the centralized wallet is conquered by hackers, users will suffer unnecessary losses
decentralized wallets, commonly known as onchain wallets, have private keys maintained by users and assets stored in blockchains
decentralized wallets are often referred to as onchain wallets. The private key is handed over to the user. If the private key is lost, the wallet will not be able to help the user recover, and the funds will be lost forever. But the decentralized wallet is difficult to be attacked by hackers, and users don't have to worry about the self stealing of the wallet service provider
centralized wallets are where assets are stored, while decentralized wallets are where private keys are stored
except for the exchange, it is not recommended to use the centralized wallet, although losing the private key may help you find it. But there is always a risk that the company will run
a decentralized wallet is equivalent to a channel, a channel to control its own assets on the blockchain by mastering mnemonics. For a decentralized wallet, the most important thing is to protect the security of the [private key]
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.
@ block chaining
to make complaints about the center is code open source, you can check, ensure that they will not install viruses and upload your personal data. p>
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it doesn't matter if the wallet goes out of business, just export the private key and save it to other wallets
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the exchange transfer fee is about 30 yuan per time, and the transfer from your wallet is only a few cents per time
For users,
may be more convenient,
but it hasn't been realized yet
core wallet, which needs to synchronize all blockchain data and takes up a lot of memory, but it can be completely decentralized. Light wallet relies on other all nodes in bitcoin network, only synchronizes data related to itself, which can basically achieve decentralization. Centralized wallet does not rely on bitcoin network, all data are obtained from its own centralized server, but the transaction efficiency is very high, and it can be received in real time. The account you register in the transaction platform is the centralized wallet.
exchange Wallet: in order to access the currency, each exchange will also provide the wallet address corresponding to the currency. This kind of wallet will not provide the private key to the user, so once it is deposited, it can only be retrieved by the mechanism of the exchange. It's also an online wallet
the Xueshuo innovation blockchain Technology Workstation of Lianqiao ecation online is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system.
A large number of tailings, coal gangue, waste rock, waste soil and other solid wastes, mine wastewater and waste gas emissions formed in the process of different types of mineral development in Southwest China are the main factors causing mine geological environment pollution, mine geological disasters and mine resources damage, It is an important measure to restore and control the mine geological environment
(I) comprehensive utilization of mine tailings
mine tailings are solid wastes discharged in the process of mineral processing, which are stored in the mine tailings pond. Up to 2002, the accumulated amount of tailings in Southwest China has exceeded 6 × 10 < sup > 4 < / sup > t, mainly distributed in large state-owned mines, small and medium-sized mines generally do not build tailings pond, directly discharged into valleys, rivers and lakes and depressions, polluting the environment and occupying a large area of land resources. The tailings are rich in useful elements, which can be comprehensively utilized. Some elements are even more valuable than the main elements, such as the Yangliuping nickel mine in Danba County, Sichuan Province. The tailings contain a lot of platinum and palladium, which can be comprehensively utilized, and its value is far more than that of nickel. Now Yangliuping nickel mine has been renamed platinum nickel mine; The value of scandium associated with Panhua vanadic titanomagnetite in Sichuan Province is higher than that of other valuable elements. The associated components with high value often enter the tailings without being recovered ring beneficiation, so the tailings have great potential for comprehensive utilization, which can be used as resources for secondary development, and can also rece mine environmental pollution and land resources damage
The United States, which has better comprehensive utilization of tailings abroad, has set up a tailings concentrator in Minnesota iron mine with annual treatment of 1 million tons and annual recovery of 20 million tons of iron concentrate × 10 < sup > 4 < / sup > t, the concentrate grade reaches 60%; In the United States, leaching method is used to extract copper mine slag, and more than 20% copper is recovered every year × More than 10 < sup > 4 < / sup > t. In South Africa, an old tailings processing plant with a daily capacity of 4000 tons was built to extract gold and uranium (ren Yongyun, 1980) The typical mines with the most tailings in Southwest China are Gejiu tin deposit in Yunnan Province and Panhua vanadium titanium magnetite deposit in Sichuan Province × 10 < sup > 4 < / sup > t tailings, the latter has 11000 × 10 < sup > 4 < / sup > t tailings, both of which have high comprehensive utilization value, and the mining area has taken measures for development and utilization Gejiu tin mine tailings comprehensive utilization in Yunnan Province is the capital of tin instry in China. Founded in 1883, Gejiu Tin Company is an old instrial base in China. Its tin output accounts for about one third of the country and 10% of the world. Its annual ore dressing capacity is more than 4.3 million tons, and the average recovery of tin and copper is 62.56% and 71.04% respectively. Lead, zinc, bismuth, tungsten, molybdenum, iron and other useful components associated with the ore enter the tailings. Gejiu tin mine has 28 large and small concentrators with 13000 tailings × 104t See table 6-7 for chemical composition of tailings from main concentrators. The average contents of Sn, Pb, Cu, Zn and Fe are 0.15%, pb.30%, Cu 0.25%, Zn 0.54% and Fe 19.4%, respectively, which can be used comprehensively (Ding qiguang et al., 1995). Moreover, the resources are considerable, and the amount of tin is up to 20% × 10 < sup > 4 < / sup > t, which is equivalent to the scale of four large tin deposits; The amount of copper is 32.5% × 10 < sup > 4 < / sup > t, lead content 169 × 10 < sup > 4 < / sup > t, zinc content 70.2% × 10 < sup > 4 < / sup > t, iron content 2522 × 104t
Table 6-7 chemical composition of tailings from main concentrators of Gejiu Tin Mine unit:%
in 1983, the comprehensive utilization of tailings from Gejiu Tin Mine in Yunnan Province was attached great importance by the state and listed in the national key scientific and technological projects. In 1984, the research results were appraised and accepted by the State Science and Technology Commission. The comprehensive development and utilization of tailings have achieved good indicators: huangmaoshan tailings contain 0.15% ～ 0.176% Sn, the procts recovered by secondary beneficiation contain 2% ～ 2.2% Sn, and the beneficiation recovery is 57.42% ～ 69.72%; The content of Sn in Gushan tailings is 0.158% ～ 0.172%, and the recovery rate is 50.93% ～ 65.23%. The cost of mineral processing is 3.6 ~ 8.48 yuan / T, and good benefit is obtained. On this basis, the tailings instrial proction has been carried out step by step
Comprehensive utilization of Panhua vanadium titanium magnetite tailings in Sichuan Province is an important iron and steel base in China. The iron reserves of vanadium titanium magnetite mined in Panhua account for 9.4% of the national iron ore reserves, 52% of Southwest China and 74% of Sichuan Province; Vanadium reserves account for 60.14% of the total reserves in China; Titanium reserves account for 90.54% of the national reserves, and it is the second largest iron mine in China. 1350 tons of ore per year × 10 < sup > 4 < / sup > t, open pit mining. In addition to the above three elements, the ore is also associated with scandium, chromium, gallium, cobalt, nickel, copper, sulfur, phosphorus, manganese, selenium, tellurium, platinum group elements and other valuable elements, whose contents meet the requirements of instrial comprehensive utilization, but these components have not been recovered and entered the tailingsthe tailings of Panhua vanadium iron magnetite are all stored in Majiatian tailings pond, with a storage capacity of about 11000 tons × 10 < sup > 4 < / sup > t, which is the largest tailings pond in Southwest China. The chemical composition of tailings is shown in table 6-8
according to the current beneficiation conditions, the titanium in the tailings of Majiatian tailings reservoir can be used for secondary beneficiation. In particular, the tailings pond elevation below 1188m is about 5841 × 10 < sup > 4 < / sup > t, belonging to the early iron tailings, is a valuable resource of titanium. If the content of TiO < sub > 2 < / sub > in table 6-8 is 9.37%, 5841 × 10 < sup > 4 < / sup > t there are about 540% TiO < sub > 2 < / sub > in tailings × 10 < sup > 4 < / sup > t, the recovery rate of TiO < sub > 2 < / sub > 142.9% was 26% × 10 < sup > 4 < / sup > t, equivalent to 47.5% grade of titanium concentrate about 300 × 10 < sup > 4 < / sup > t, which is equivalent to the output of Panhua Titanium Concentrator in 12 years. And there are 5000 above the elevation of 1188m × The tailings above 10 < sup > 4 < / sup > t also have recovery value (Ding qiguang et al., 1995), indicating that the titanium resource in the tailings pond is considerable. The comprehensive utilization of these tailings can not only solve the urgent need of national resources, but also alleviate the problems of mine geological environment
Table 6-8 chemical composition of tailings in Majiatian tailings pond unit:%
(II) comprehensive utilization of coal gangue, waste resie and wastewater × 10 < sup > 4 < / sup > t, it accumulates mountains near the mine pit, occupying a large amount of land area. In rainstorm season, it is easy to form landslide and debris flow geological disasters, polluting the rivers and lakes around the mine. But coal gangue is an important resource, which can be used comprehensively. The main utilization measures are as follows:
1) directly used for construction, traffic engineering fill, cushion subgrade, etc
(2) it is used to fill the goaf subsidence area or valley for land reclamation and terrain reconstruction3) it is used to make building materials, such as gangue brick, cement or cement mixture
4) used as power generation fuel of gangue power plant
from the situation of Southwest China, e to the rapid development of construction and traffic engineering in recent years, especially the highway construction near coal mines, a large amount of coal gangue is used for Subgrade bedding. However, the development of building materials made of coal gangue, such as the proction of gangue brick, cement, gangue power generation, is relatively slow, and only some mining enterprises have better comprehensive utilization effect, such as Bayi Coal Mine in Longchi Town, Emei City, Sichuan Province, with an annual output of 15 × 10 < sup > 4 < / sup > t, with an annual output of 8 × 10 < sup > 4 < / sup > t, because of the convenient transportation, the mine has built a brick factory specially, which uses coal gangue and tailings powder to proce building bricks, with an annual utilization of 6 × 10 < sup > 4 < / sup > t, the comprehensive utilization rate reached 75%, greatly alleviating the environmental pressure. The large and medium-sized mines of Guizhou Panjiang Coal Power Group and shuikuang group use coal gangue to generate electricity, which solves 60% of their own power consumption. Using coal gangue to proce shale brick and fill goaf, the annual consumption of coal gangue is 40 × 10 < sup > 4 < / sup > t, resulting in good economic benefits. The coal gangue is piled up in the valley around the mine. After the valley is filled, it is covered with soil, replanted, and returned to the people, which improves the relationship between instry and agriculture and creates certain social benefits. In addition, with natural coal gangue as raw material, alumina in coal gangue is dissolved by one-step acid dissolution, and the process conditions with the highest dissolution amount are determined through experiments. After the adjustment of basicity (about 70%), basic polymeric chloride is formed. The polymer has good flocculation, thus becoming a new type of high-efficiency purification agent (Liu Hongyan et al., 2004). It can be used in the purification of instrial water and sewage, and has broad application prospects. Chongqing, one of the first six pilot cities of circular economy in China, has approved an investment of 3 billion yuan to build 7 power plants for comprehensive utilization of coal gangue, with a total installed capacity of 58 × 10 < sup > 4 < / sup > kW, and graally form an instrial chain
Songzao Coal Power Company, the largest thermal coal proction base in Chongqing, has an annual coal output of 400 tons × 10 < sup > 4 < / sup > t, the annual emission of coal gangue is 100 × 104t Six coal gangue piles have been accumulated, which not only occupy land but also pollute the environment. In order to turn coal gangue into treasure, Songzao Coal Power Company will invest 1.3 billion yuan to build the largest environmental protection power plant in Southwest China, Chongqing Songzao Coal Power Company's Anwen coal gangue thermal power plant. The building has an installed capacity of 30 × The coal gangue thermal power plant of 10 < sup > 4 < / sup > kW, using waste coal gangue as fuel, can eat 150 tons of coal every year × 10 < sup > 4 < / sup > t coal gangue, annual power generation can reach 16 × 108kW·hSanhui town of Hechuan City is rich in coal resources, with an annual output of 150 × 10 < sup > 4 < / sup > t. To this end, they introced new technologies and invested 260 million yuan to build 550 million yuan × The coal gangue power plant of 10 < sup > 4 < / sup > kW can use coal gangue to generate electricity and turn waste into treasure. Using coal gangue to generate electricity can proce more than 300000 tons of fly ash every year. So the power plant and Fufeng cement group joined hands to build a proction line using fly ash to proce cement through technical transformation. It is reported that Fufeng cement group also plans to invest 80 million yuan to build a 1.5 million square meter building × In order to eliminate the adverse impact of waste heat generated in cement proction on the environment, the waste heat of 10 < sup > 4 < / sup > kW thermal power plant is used for power generation
Comprehensive utilization of coal ash and slag the coal ash and slag stored in energy mines in Southwest China is an important mineral resource, so comprehensive utilization should be strengthened to rece environmental pollution. The main component of coal ash and slag is SiO < sub > 2 < / sub >, accounting for about 50%; Secondly, Al < sub > 2 < / sub > o < sub > 3 < / sub > and Fe < sub > 2 < / sub > o < sub > 3 < / sub >, accounting for about 40%; The others are Cao, MgO, so < sub > 3 < / sub > and other rare dispersed elements. Foreign countries attach great importance to the comprehensive utilization of coal ash. The highest comprehensive utilization rate is 70% in Britain, 65% - 70% in West Germany, 50% in France, 52% in Japan and about 50% in the United States. The amount of ash discharged in China ranks the first in the world, but the utilization rate is only 20% - 30%according to the characteristics of 1% titanium, 15% aluminum and 7.5% ～ 15% iron in American coal ash, aluminum and iron are extracted from them; Rare dispersed elements such as germanium, gallium, uranium and selenium are extracted from fly ash of coal. The grade of iron concentrate extracted from coal ash containing more than 10% iron by magnetic separation in China is 48% ～ 50%, and the pig iron is completely qualified; Polyaluminum, aluminum chloride, aluminum sulfate and other procts were proced from coal ash slag with high aluminum content and low iron content
the coal ash slag after refining metal aluminum, iron and rare dispersed elements can be used to make coal ash cement, which has the characteristics of large ash consumption, low cost, simple process, good impermeability, high late strength, high tensile strength and low hydration heat. The 442m high new Sears Tower in Chicago, USA, is made of coal ash cement from walls, floors to fire prevention facilities
the ash contains aluminum