Iron and steel production is more affected by meteorological conditions, which can be divided into raw material part, production part and transportation part.
The raw material part is affected by climatic conditions, mainly in the influence of humidity and temperature on the raw material composition. For example, the raw ore required for blast furnace ironmaking has stricter requirements for moisture. If the climatic conditions are relatively humid, the moisture in the raw materials will be relatively high, which will cause an increase in the cost of the smelting process. Secondly, in winter, due to the low temperature, part of the moisture in the raw material crystallizes, and it must be heated to remove moisture before use. In the process of steelmaking and hot rolling, since the raw materials mainly come from the previous process, the impact on the climate is relatively small.
From the point of view of production, changes in climate conditions are mainly reflected in changes in temperature, humidity, light, wind and other conditions, which have an impact on production. In the case of blast furnace ironmaking, the difference in temperature directly affects the dynamic conditions, such as the size of the blast volume and the control of humidity, etc. In addition, the adequacy of light conditions is related to the production cycle. When the outdoor wind reaches level 6 or above, the time limit for outdoor operations is required.
The influence of climate on transportation conditions is more obvious. The main manifestation is that large climate changes have hindered the transportation of roads, railways and other raw materials. For example, the flood that occurred in the south in 2018 caused the production of southern iron and steel enterprises such as Wuhan Iron and Steel E Steel to stop, and the flood flooded some equipment, causing great losses. Therefore, there must be corresponding countermeasures for protection under abnormal weather conditions.
The altitude and oxygen content of different regions have a great impact on steel production. Judging from the altitude difference of the highlands in my country, there are great differences between the steel enterprises in Qinghai and the enterprises in the east coast in terms of blast furnace ancient style, mainly because Because of the difference in oxygen content in large concentrations. There are no iron and steel enterprises in Tibet so far, mainly because of the local climate conditions.
The iron ores needed for blast furnaces include magnetite, hematite, limonite and other complex semi-raw ores. From mining, transportation, beneficiation, ore washing to simple treatment of raw ore, sintering, pelletizing and other links, the ore is finally smelted into the furnace.
Sintering of ore can improve the strength, strength and reactivity of ore, which can effectively reduce the difficulty and cost of blast furnace smelting. The main raw materials used in sintering include magnetite, limonite, hematite dust ash and other raw materials, mixed coke powder or coal powder, which are spread on the sintering machine, and the fuel is heated and burned by high-temperature hot air, so as to realize the whole The heating reaction of the material layer.
Sinter is one of the basic raw materials for the material structure required by blast furnaces. Sintered ore, pelletized ore, and raw ore have become the basic raw materials for blast furnaces. Under normal circumstances, the proportion of sintered ore accounts for about 70% of the total input.
Cue frames can be classified into the following types according to their production methods, including shaft furnace sintering, chain wall machine-rotary kiln and belt pellets. Among them, the shaft furnace was used relatively early, the grate rotary kiln is currently the most important pellet production method, and the belt roaster is currently a more advanced pellet production method.
At present, there are Shougang, Jingtang Baotou and Anshan Iron and Steel in China who adopt the production method of belt roasting machine.
During the blast furnace smelting process, in order to adjust the overall acidity and alkalinity and composition of the blast furnace charge, some raw ore needs to be added. Raw ores generally use high-grade South African mines, Australian mines or Peruvian mines.
The general requirements of sound control, the reducibility of burst performance, and the content of harmful elements must be within the limited range. Its specific value is related to the requirements of various factories and mines.
Blast furnace ironmaking is a systematic project. Its supporting facilities include raw material supply, hot blast furnace, pulverizing system, dust removal system and power system.
The supply of raw materials includes the supply of upgraded ore pellets, pellets, coke and other miscellaneous ores.
The hot blast stove is the equipment that supplies the blast furnace blast system. For hot blast stoves, it is necessary to ensure the temperature and air volume of the hot blast and the safety of the entire system. Hot blast stoves include top-combustion hot blast stoves, internal combustion hot blast stoves, external combustion hot blast stoves and spherical hot blast stoves.
The pulverizing system is mainly a workshop for batching and grinding raw coal into pulverized coal that meets the requirements. Generally speaking, the requirements for the quality of coal injection in blast furnaces are that the proportion of pulverized coal with particle size below 200 mesh accounts for more than 75%, and the combustibility and explosiveness of pulverized coal must meet the national standards.
The dust removal system is a workshop that automatically collects and summarizes the dust generated in the production process of the ironmaking system and conducts preliminary treatment. And specifically include dry dust removal, wet dust removal and vacuum systems for various parts.
The power system is a supply unit that provides wind, water, electricity and other energy media for the entire ironmaking system. In terms of safety, the power system is the most important part of the safety link in the whole system. Including the cooling water and power supply used by the blast furnace body belong to this part.
The main difference between the top-combustion hot blast stove and the internal combustion hot blast stove is the structure. The specific performance is that the combustion chamber of the top-fired hot blast stove is on the upper part, while the internal combustion hot blast stove is on one side. The details are also very different based on the combustion method and combustion efficiency. Top-fired hot blast stoves, including Kalukin-style hot blast stoves, and internal combustion hot blast stoves are also transformed by some domestic design institutes based on foreign designs. The type and structure size of the hot blast stove are very different, mainly according to the requirements of the production unit.
Since the main product of the blast furnace ironmaking system is high-temperature molten iron, various equipment and systems are exposed to high-temperature erosion and serious damage. Therefore, it is necessary to have a complete and sufficient supply of cooling water, cooling air and other cooling media. The main goal of the blast furnace coolant system is to ensure the safety and stability of the entire ironmaking system. Many equipments in blast furnace ironmaking process, including stave sealing hot air valve, etc., need to be cooled by cooling water.
The operation of blast furnace tapping mainly has the following steps. First judge the time of bottoming out, and then open the tap hole according to the requirements of the blast furnace foreman or furnace chief, so as to ensure the safety and stability of the whole process during the tapping process. In the later stage of the exit point, according to the requirements of the blast furnace foreman or furnace chief and the state of tapping, the iron hole is blocked in time.
The main equipment for blast furnace tapping operation is tapping machine and mud gun.
The blast furnace operation system mainly includes four aspects, including the blast system, the feeding system, the heating system, and the tapping system.
The blowing regime includes the adjustment of relevant parameters of the fan.
Feeding system, including formulating ingredient scheme, feeding, formulating cloth angle and cloth method to adjust airflow.
The thermal system mainly refers to the control of the cooling water of the blast furnace body and the adjustment of relevant parameters of coal injection.
The outlet point system is mainly to open the taphole in time in accordance with the tapping situation of the blast furnace.
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