After experiencing the shock of the vanadium- based market in 2010, the author believes that the market performance of vanadium-based products will not be particularly strong in the coming year. Although the “Twelfth Five-Year Plan†has proposed to expand special steel production, it will take a period of transition, and there are still many challenges in the 2011 market. On the technical level, the implementation of the “Vanadium Industry Pollutant Emission Standards†in 2012 has higher requirements for vanadium extraction technology, and the industry will undergo a new round of reshuffle for some time. The author has long been engaged in the technical work of the vanadium industry and has a certain understanding of the industry. Discussion of vanadium pyrometallurgical process of stone coal This article focuses on, some of the arguments set forth in the new era craft fire. In the spirit of sincere exchanges with the industry, the author hopes that the peers will correct and make progress together. 1 four questions stone coal to extract vanadium 1.1 What is the clean vanadium extraction process? The cleaning process is also called no waste process or less waste process. Refers to the use of advanced production processes and equipment, including the use of toxic and hazardous raw materials, to achieve recycling of waste, to improve the utilization of raw materials and energy and product yield, so that in the production process does not produce or as much as possible waste. In the actual production process, the realization of the clean vanadium extraction process also requires a corresponding industrial configuration to achieve clean production indicators. Such as wastewater recycling rate of more than 80%, industrial waste treatment and so on. According to the author's understanding, the clean vanadium extraction process should not be just the choice of the process route. The project is well designed and the process design process is done on the industrial three wastes. In the production, the advanced level of the domestic industry is actually made. The true embodiment of the vanadium extraction process. 1.2 What is the development direction of vanadium extraction by fire? At present, there are provinces in China that have stone and vanadium extraction industries. Most of the newly-built enterprises adopt industrial policies that prohibit the use of salt-adding (including low-salt) roasting and vanadium extraction technologies, such as Henan, Hubei, Chongqing, Shaanxi, Xinjiang, and Guizhou. Because it can not effectively solve the environmental pollution drawbacks of the salt-adding and vanadium extraction technology, the inorganic salt content in the wastewater is high, the wastewater recycling rate is low, and a large amount of discharged wastewater is generated in the production process, causing serious environmental disputes in the surrounding areas of the enterprise! The imminent implementation of the “Vanadium Industry Pollutant Emission Standard†and the vanadium extraction technology have encountered technically insurmountable problems. In the early 1990s, the Hunan Coal Research Institute and related enterprises researched and developed the vanadium-free vanadium extraction technology (without adding any additives). Currently, the technology is only used in individual enterprises in Huaihua City, Hunan Province. The total yield of vanadium in the ore is Between 38 and 45%, after technical improvement, the yield has increased. The technology has strong selectivity for ore, and the yield is low, and it does not have industrialized promotion value. The multi-component composite roasting additive used in the roasting process is only a modification of the process of the process, and has certain limitations, and is not in the scope of the new technology of the vanadium extraction process. Calcification roasting is a calcification additive. Since this technology does not need to add sodium salt, the problem of exhaust gas pollution containing hydrogen chloride and chlorine caused by sodium roasting is completely eliminated, and the wastewater recycling rate is over 90%, effectively solving the production wastewater. The problem of high inorganic salt content. The process was approved by the environmental protection department in Guizhou, Henan, Xinjiang, Chongqing and other provinces and cities, and was identified as a clean vanadium extraction technology. In the field of vanadium extraction by fire method, calcification roasting has presented a unique situation, which is considered to be the future development direction of the fire method. 1.3 What is calcification roasting? Calcification roasting and vanadium extraction process refers to the addition of lime or limestone to vanadium-bearing minerals. According to the high-temperature reaction study of minerals, vanadium in vanadium-bearing shale (stone coal) is calcined, and low-valent vanadium is oxidized to high-valence vanadium. Vanadium is mainly present in the form of calcium silicate vanadate and calcium titanium oxide. The mineral is chemically unstable and dissolves rapidly in weak acidic media. The calcium metavanadate compound is easily dissolved into the liquid in a weakly acidic environment, thereby achieving separation and extraction of vanadium in the mineral. Calcification roasting technology is to add a certain amount of calcium agent during roasting. When roasting, not only no toxic and harmful gases such as HCl and Cl2 are produced, but calcium can also fix sulfur in vanadium-bearing carbonaceous shale to further reduce the pollution of exhaust gas. 1.4 Why is calcification roasting a mature industrial technology? 1.4.1 Status of industrialization of calcification roasting Calcification roasting requires high process design and has certain requirements for equipment automation. The initial investment is higher than the traditional sodium roasting process. In the process of contacting the project consultation, many investors are eager for the traditional sodium roasting of vanadium in the fire method, indulging in the maturity of its technology, less investment, and quick results. Its economy has also been continuously enlarged. Here, Zheng reiterated that this road is unreasonable, ignoring environmental protection, and will suffer from self-discipline! The industry should be self-disciplined and resolutely resist and crack down on illegal vanadium plants. Today, with the increasing awareness of environmental protection, the cleanliness of calcification roasting has been fully demonstrated and the advantages are obvious. In recent years, the large-scale fire method vanadium plant has basically selected this process. 1.4.2 Research process and results of low-acid leaching and vanadium extraction technology for stone coal calcification roasting 1.4.2.1 Research process ◆ The author team began to work on the systematic research of vanadium extraction technology in stone coal in 1997. A lot of basic research has been done on the vanadium extraction technology of stone coal. The technical route of calcification roasting low acid leaching has been put forward, and good research results have been obtained. At the end of the 1990s, the average leaching rate was 70-75%. ◆ In 2000, a pilot test of calcification roasting was conducted at a factory in Xiangxi, and the roasting rate was 76%. ◆ After that, further research was carried out on the follow-up process, the technology was gradually improved, and industrialization was finally realized. ◆ Calcification roasting Low acid leaching ion exchange vanadium extraction technology has cost researchers more than ten years, and has repeatedly entered factory experiments and pilot tests. At present, it has been applied in large-scale industrial applications in several provinces, with mature technology and industrialization. condition. 1.4.2.2 Characteristics of vanadium calcification roasting low acid leaching vanadium extraction technology ◆Using calcium salt (lime, limestone) instead of salt, completely eliminates the problem of exhaust gas pollution of toxic and harmful gases such as HCl and Cl2 by sodium roasting technology. ◆ Significant technological innovations have been made in the selection and design of the roaster, the roasting process is mechanized, the temperature control accuracy is ±10 °C, the production efficiency is high, and the labor hygiene conditions are good. The step-type vanadium ore roaster, which was developed by the author's team, has been successfully operated in a factory in Henan for more than two years and has a daily processing capacity of 300 tons. It is the only environmentally friendly vanadium ore roaster in the same industrial scale in the same industry in the country; The one-day roasting furnace that processes 600 tons of ore is currently in trial operation. (Current roasting equipment mostly uses flat kiln. Although flat kiln has the advantage of less equipment investment, the shortcomings are obvious, mainly in the bed temperature is difficult to control, labor intensity is large, sanitary conditions are poor, and flue gas unorganized emissions are serious, due to The bed temperature is difficult to control, and the conversion rate of the roasting process is low. It has been banned in some provinces and cities.) ◆The calcined material is low acid leaching (acid concentration 1-2%, sulfuric acid), low production cost, less liquid containing impurities, which is beneficial to process water recycling. 100 tons of ore consumes about 4 tons of sulfuric acid. ◆The leaching slag is mechanically filtered and washed to improve the yield and reduce the surface water and groundwater pollution caused by the slag during the storage process. ◆With the new technology of leachate removal, the product quality can be stably achieved to meet the national standard requirements, and the concentration of pollutants in the wastewater is effectively reduced. ◆ Strengthen wastewater treatment and recycling process, high utilization rate of wastewater recycling, and zero discharge or discharge of wastewater. The wastewater treatment and reuse process and technology developed by the company have passed the expert review in many provincial and municipal environmental protection bureaus and are leading the same industry in the country. 2 misunderstanding of calcification roasting 2.1 equivalent to sodium roasting In the field of vanadium extraction by fire, the illegal small vanadium plant is banned, and a large number of illegal small vanadium smelters have adopted the technology of adding vanadium and roasting vanadium, which has low investment, fast speed and lack of environmental protection facilities, resulting in a series of environmental protection incidents. The stone extraction industry for stone coal has caused serious negative social impacts. In the stone coal vanadium ore mining area, it caused "vanadium change" in society. In addition, some scholars in order to promote the wet process of vanadium extraction process, calcification roasting is directly equivalent to sodium roasting, such as: salt roasting, calcification roasting and other fire process will produce chlorine, hydrogen chloride and other pollutant gases. Such introductions are extremely irresponsible and there is no scientific reason. It is unscientific to make such judgments that calcification roasting has chlorine. According to the balance of materials, everyone knows that substances will not be produced out of thin air, nor will they disappear in a vacuum. Such words should not be written by technical professionals. Calcification roasting has been approved by the environmental protection department in Guizhou, Henan, Xinjiang, Chongqing and other provinces and cities. It has been identified as a clean vanadium extraction technology, which is essentially different from traditional vanadium extraction technology. 2.2 strong ore selectivity The recognition of calcification roasting is not high in China, and some scholars have certain prejudice against it, which is a common phenomenon in the industry. In some literatures, it is often pointed out that calcification roasting is highly selective for ores and is not suitable for industrialization. According to the author's understanding of the industry, these views are quoted in the literature of the last century. In fact, calcification roasting has been continuously broken through long-term industrialization, and the technical bottleneck has been continuously broken. Now it has become a mature industrial technology for extracting vanadium from stone coal. In the process of industrialization and promotion of calcification roasting vanadium technology, the author experienced the operation process of the project and contacted the ore in several provinces. It has been proved that calcification roasting is suitable for most domestic ore extraction. Therefore, the process has strong selectivity to ore. A full stop should be drawn in this century. 2.3 Fire method is pollution In the stone coal vanadium ore mining area, the illegal vanadium smelting boom caused "vanadium change" in the society. This kind of impact is huge. It takes many years of efforts in the stone and vanadium extraction industry to reverse the social image of the industry. Some scholars have even proposed that the introduction of vanadium by fire is a polluting industry view, and it lacks scientific basis and factual basis. The calcification roasting vanadium extraction technology is essentially different from the traditional fire extraction vanadium extraction process, and belongs to the clean vanadium extraction process. The advantages of calcification roasting technology are as described above, and have obvious advantages compared with the existing wet vanadium extraction process. Wet vanadium with an acid generally higher than 20%, thus resulting in high cost and subsequent equipment corrosion; aluminum, iron and heavy metals into the organic solution simultaneously, brought together and extraction process, wastewater complex composition In order to achieve zero-discharge or partial discharge, the process of wastewater treatment is complicated, and the treatment cost and fixed investment are correspondingly increased. At the same time, the filtration of acid tailings is also difficult. The washing efficiency of the belt vacuum filter needs to be improved. The tailing dam corresponding to the thickening machine is a difficult problem. At the same time, the tailings of the vanadium extraction process in the wet process is difficult to use. Finally, wet. The calorific value of stone coal in the process of vanadium extraction is also not effectively utilized. 3 stone coal extraction process The choice of vanadium extraction process has always been a real problem in the industry. Scientifically speaking, in the face of complex and variable vanadium-containing raw materials, there is never a vanadium extraction process that is feasible in all directions. According to the different characteristics of stone coal, the appropriate vanadium extraction process should be selected through the system of metallurgical testing. . Policy factors need to be considered when determining the vanadium extraction process. For areas that are particularly sensitive to water pollution, the vanadium extraction process by wet method and the vanadium extraction process by sodium method are used. Because the amount of wastewater is particularly large, it can be matched with the corresponding wastewater treatment equipment, but it must be especially cautious; areas that are particularly sensitive to air pollution. The vanadium extraction process by fire method should be especially careful. In terms of production cost, ore grade, extraction situation, raw material area price, etc. are all factors that must be considered. In addition, the market for vanadium extraction technology is relatively chaotic, and various technologies are unconventional. Some enterprises invest tens of millions of yuan but cannot produce products, or the technical and economic indicators are low. Whether a technology is mature and reliable, as a company should focus on whether the technology has been successfully applied in industrial practice, and the economics of a technology should be determined by the relevant technical parties to take the complete unit consumption table as the basis for judgment. The author personally believes that the current vanadium extraction enterprises generally ignore the design of the factory. Some enterprises are built while designing. The construction process has repeatedly increased investment. Some enterprises have not designed at all. After the equipment is put into operation, the equipment is not Supporting, can not reach the standard of production, the device will be tested and will continue to face technical changes, seriously affecting the economic benefits of enterprises. Although the length is long, in many aspects, it is difficult to make a statement here, I hope to forgive me. Postscript: Although the vanadium industry is small, its production process is a typical chemical metallurgy technology, which has strong technical characteristics. Enterprises must not underestimate the integrity and complexity of industrial technology. The industry is not mature enough, and the overall level is not constrained by the development of the industry. Vanadium enterprises need certain scientificity to achieve sustainable development. Magnetic Motor Starter ,Permanent Stepper Motor,Pm Stepper Motor,Stepper Gearmotor Permanent Magnets Ningbo Besten Magnet Co., Ltd. , https://www.bestenmagnets.com