CN1718762A - Blast furnace and converter for molten iron hearth large scale desulfurization or three eliminating simultaneously - Google Patents
Blast furnace and converter for molten iron hearth large scale desulfurization or three eliminating simultaneously Download PDFInfo
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Abstract
The present invention relates to a molten iron pretreatment process. It is characterized by spreading soda on the molten iron flowing after sand hole of cast house to make desulfurization, dephosphorization and desiliconization and even extract vanadium when the schreyerite is smelted. Said flowed molten iron can be used for substituting existent power injection metallurgy. The molten slag is easy to melt and is good in fluidity, so that it is suitable for promptly trapping slag, making molten iron separation and preventing rephosphorization. From molten slag and overflowed smoke and dust the Na2O in the soda can be completely recovered, and the phosphate fertilizer as side product can be produced.
Description
The invention relates to the pretreatment of large-scale desulphurization in front of a molten iron furnace, even simple dephosphorization, desiliconization and vanadium extraction from vanadium-containing molten iron, reduces the cost of pure steel and common steel, and completely liberates the operation of a blast furnace or other iron-making furnaces, a converter or other steel-making furnaces.
The slagging system in the blast furnace ironmaking process requires slag: (1) in controlling [ Mn]in molten iron]、[Si]The melting temperature and the melting property temperature are as low as possible and the viscosity is low under the condition of reducing the elements; (2) the higher alkalinity is needed to ensure that the sulfur S in the molten iron is removed sufficiently]Ability ([ S]]Less than or equal to 0.03 percent). Sometimes, a certain amount of MgO is added toimprove the thermal stability and chemical stability of the slag and adapt to the fluctuation of furnace temperature and charge ingredients. Thus, SiO is contained in the gangue in smelting low-grade iron ore2High Al content in raw and fuel2O3At higher temperature, the slag-iron ratio of high alkalinity iron making is increased, sometimes even as high as 600-.
The invention aims to provide a novel stokehold large-scale desulphurization process for liberating blast furnace ironmaking.
Various external desulphurization methods exist in the existing iron-making process, most of desulphurization is carried out for lightening the desulphurization task of the next steel-making process, and the desulphurization treatment is carried out on the outside-model molten iron which appears only occasionally: spreading desulfurizing agent in molten iron ditch, continuous feeding plane flow method, eddy flow or mechanical or electromagnetic stirring or rotary drum rotation method, etc., adding desulfurizing agent in molten iron tank, shaking, mechanical or bubble stirring, bubble pump, blowing desulfurizing agent, inserting bell jar or refractory rod into desulfurizing agent, feeding wire, pouring into tank, vacuum method, electrolysis method, etc. Or separating the desulfurized slag from the molten iron before the desulfurized slag enters the steel-making furnace. The desulfurizer comprises soda powder, NaOH, lime, Ca (OH)2Dolomite, limestone, powdered carbon, graphite, CaC2Calcium cyanamide, colemanite, fluorite, CaCl2，Al2O3The desulfurizing and dephosphorizing synthetic slag, propane, magnesium particles, magnesium coke, magnesium alloy and the like, and mixtures of different compositions thereof, or some additives are additionally added to promote or buffer the desulfurizing reaction. The popular and effective molten iron desulfurizing method is to spray lime series desulfurizing agent into molten iron tank and then to spray magnesium or lime and magnesium mixed desulfurizing agent in certain amount to raise the utilization rate of magnesium and comprehensive deep desulfurizing efficiency and obtain excellent desulfurizing effect. But the equipment investment is large, and the method is not suitable for actual conditions that most manufacturers in China have small hot metal ladles, and transport is tense.
The present invention is characterized in that [ S]in molten iron is largely removed by a low-cost desulfurization method in front of a blast furnace (including a cupola furnace or other molten iron producing furnaces)]Not only the desulfurization task of the steel-making process is reduced, but also the load of costly desulfurization in a blast furnace or a cupola furnace or other molten iron producing furnaces is mainly reduced. The method mainly makes full use of the dynamic condition that a blast furnace casting house is large, the flowing distance is long, and the blast furnace casting house is arranged at a high position to be flushed into a molten iron tank, namely the good casting process, and continuously and uniformly sprinkles or sprinkles a desulfurizer along with molten iron flow above a small well which gushes molten iron behind a skimmer, so that the desulfurizer and the molten iron flow through a molten iron ditch together, and then the molten iron tank is arranged at the high position to be flushed into the molten iron tank, and thus the desulfurizer and the molten iron can be generally in full contact: according to the principle of motion relativity, molten iron which is continuously shown by all elements in the back gushing of a skimmer (also called a sand port and a slag bridge) receives a uniformly and continuously sprinkled desulfurizer and sprays the desulfurizer into the canned molten iron, and the contact reaction areas are almost the same. It is confirmed bythe test result of lime desulfurization (better effect of the desulfurizer is sprayed after the skimmer). And the skimmer can be specially designed according to requirements, for example, the diameter of a small molten iron well behind a slag retaining dam of the skimmer is designed to be smaller (the height difference of the molten iron liquid level between the front and the rear of the small well is naturally increased, so that the flow is not changed) or the skimmer is designed in other appropriate modes to ensure that the molten iron gushes more violently or is contacted with the desulfurizer more comprehensively. The method has the advantages of small investment and quick effect, does not need to invest a large amount of investment to build a desulfurization station (the station not only increases a new pollution source in a plant area, but also only slag skimming causes iron loss which accounts for half of the process cost), and can be successfully implemented by common manufacturers in a short period. Experiments show that the cheap desulfurizer is slightly modified and continuously usedUniformly sprinkled into the molten iron ditch (though not sprinkled at a small well behind the skimmer), and a skimmer is arranged at a proper distance downstream of the molten iron ditch to remove slag, so that the sulfur in the molten iron can be reduced to below double zero: [ S]]0.002%. If the slag skimmer is scattered on molten iron gushed from a small well behind the slag skimmer, the effect is better. So that no large investment is spent at all on what desulfurization stations are built. Certainly, the desulfurizer can be uniformly sprayed on the gushed molten iron at the small well behind the added skimmer again to enhance the desulfurization effect. The skimmer may also be simple without storing molten iron. Or one or more positions at a proper distance downstream of the molten iron tank or at the position of shunting molten iron to each molten iron tank, or a molten iron storage or non-molten iron storage type skimmer or a special skimmer is arranged in front of the molten iron nozzle of each molten iron tank to remove the molten slag at the previous position, and the desulfurizing agent or other desulfurizing agents are continuously and uniformly sprayed or sprinkled on the molten iron sprayed on the molten iron, so that the effect of stopping slag for multiple times and sprinkling the desulfurizing agent for multiple times is better. The skimming tool or the special skimming tool has a proper angle of a slag dam or a small diameter of a small hole of molten iron behind the skimming tool or other proper designs to separate the slag iron more quickly and completely in time or immediately or gush the subsequent molten iron more violently or contact the desulfurizing agent more comprehensively, or separate the slag from the molten iron by a slag raking method or a gas blowing method or other slag discharging methods or different combinations of various methods, wherein the discharged slag amount is more or less or the elemental substance or the compound thereof on the surface of the molten iron under the condition of no slag. This is achieved byBesides, it also can add magnesium or magnesium alloy or aluminium alloy or calcium alloy or manganese alloy or other suitable metals or their alloys or various suitable metal alloys with different combinations, and can fully utilize the good dynamic condition of the tapping process of making molten iron be high-charged into the molten iron tank to intensify desulfurization reaction, and can remove the slag from the molten iron tank by using slag-raking machine or other mode in the steel-smelting plant, or when the molten iron is poured out of the molten iron tank, it can use slag-blocking device to block slag or use gas-blowing method to block slag in the tank or use other slag-removing method to separate slag from iron. Or by the gas purging method or mechanical skimming method or other slag-removing method or different combinations of the above methods on the molten iron surface of the molten iron tank or mixer or other vessel filled with pretreated molten ironSlag iron separation and the like. The gas used in the gas purging method is nitrogen or oxygen or air or hydrogen or CO2Or is CO or CH4Or propane or as coke oven gas or as blast furnace gas or as inert gas or as other suitable gas or as a different combination of the above. These methods are both much more economical and better than building a desulfurization station. Obviously, the desulfurization can be greatly and deeply carried out. Therefore, the sulfur content in the raw materials and the fuel for iron making can be unlimited. Namely liberating the raw and fuel used in blast furnace ironmaking production.
As for the method for adding magnesium or magnesium alloy and magnesium coke into a hot metal ladle, like spraying lime powder, the spraying method or the method for inserting a bell jar or a refractory inserting rod into the hot metal ladle is commonly used at present, and the equipment is complicated and heavy and has high operation danger. Thermodynamic calculations and tests show that the vapor pressure of magnesium is quite large at the temperature of molten iron, and a large amount of magnesium vapor generated suddenly can explode and splash the molten iron outside a molten iron tank. In addition, as the longer the magnesium desulfurization action time is, the higher the utilization rate is, the more excellent the magnesium is added from the molten iron runner, and the separation of the desulfurization slag and the molten iron is carried out before the magnesium is put into a steel making furnace in a steel plant. It is recommended that liquid magnesium or its alloy be cast into porous cast iron blocks, and then the porous openings of the cast iron blocks are placed downward into the molten iron runner, so that the generation speed of magnesium vapor dissolved in molten iron is controlled to a suitable level according to the size of the pores and the amount of the cast iron blocks placed. The magnesium flows through the long molten iron channel along with the molten iron flow, is filled into the molten iron tank at the height, and is subjected to long-time desulfurization reaction in the process of being transported to a steel plant, so that the desulfurization effect which is better than that of the magnesium or magnesium alloy immersed into the molten iron tank can be achieved. In order to prevent the porous cast magnesium iron blocks from floating upwards in the molten iron channel, a plurality of porous cast magnesium iron blocks can be stacked, or the porous cast magnesium iron blocks are made into a vertical type and have a certain height and are vertically arranged in the molten iron channel. The porous cast iron block can be made by a special person by taking iron on site in front of the furnace without purchasing the porous cast iron block outside, and other porous cast magnesium iron blocks or iron alloy blocks are not excluded. Or casting liquid magnesium or magnesium alloy into a porous refractory brick, cooling, placing the porous refractory brick into an iron runner, and applying a certain pressure to prevent the porous refractory brick from floating upwards in the iron runner, or making a vertical porous refractory brick with a certain height, or applying a certain pressure to the vertical porous refractory brick. Such porous refractory blocks may be used multiple times. The magnesium material used by the cast magnesium or magnesium alloy can be replaced by crude magnesium (intermediate product for preparing magnesium) so as to reduce the cost. The method is simple and easy to implement, and has higher desulfurization efficiency.
The requirement of the current smelting process on the viscosity of the molten slag is based on the smooth operation of a blast furnace, and the requirement of the desulfurization reaction between iron slag is mainly met. Al (Al)2O3The slag alkalinity (binary) or total alkalinity (ternary) is required to be higher when the content is higher, so that the slag amount is increased. The maximum viscosity of the slag which can be smoothly tapped from the blast furnace is 20-25 poise (P) (2.0-2.5 Pa.s). The slag compositions (except for the cross-hatched area) shown in the following chart were found to meet the above viscosity requirement in the temperature range of 1350-. FIG. 1 is a viscosity curve corresponding to different temperatures of slag with different slag numbers in group 1 in the table; FIG. 2 is a viscosity curve corresponding to different temperatures of slag with different slag numbers in group 2 in the table; FIG. 3 is a viscosity curve corresponding to different temperatures for slag with different slag numbers in the 3 groups in the table; FIG. 4 is a viscosity curve corresponding to different temperatures for slag having different slag numbers in 4 groups in the table; FIG. 5 is a graph showing the viscosity curves at different temperatures for the slags of different compositions of slag numbers in the 5 groups in the table; FIG. 6 is a viscosity curve corresponding to different temperatures for slag of different slag numbers in 6 groups in the table; FIG. 7 is a graph showing the viscosity curves at different temperatures for the slags of the different slag numbers in the 7 groups of the table. Some low MgO synthetic slag is added with a part of MgO, which can further improve the thermal stability and chemical stability. The lowest viscosity area of the blast furnace slag is between 0.8 and 1.2 (binary alkalinity) and 1.2 and 1.4 (total alkalinity) from the viewpoints of alkalinity and total alkalinity. The basicity is in the range of 0.9-1.2, and the stability is better by adding proper MgO (5-15%). However, alkalinity less than 0.9 is more stable. Why is the above-mentioned inexpensive stokehole desulfurization guaranteed, and does not use 0.9 basicity? It has been calculated that the basicity of blast furnace slag can be reduced by at least 0.1or more using the above-described inexpensive stokehole desulfurization method. For example, the grade of the iron ore currently used in a certain iron-making plant is lower, and SiO in the iron ore gangue2The content is as high as 7-10% (only 1-4 in rich ore)% of the total amount of the slag, the available slag alkalinity is 1.11. The iron ratio of the blast furnace slag is as high as about 600kg/TP (300 kg/Tp or above abroad). Al carried by iron ore, flux and fuel2O3Accounting for about 8.5% and about 50kg/TP, and the content of the stable MgO, 7.2%, is about 45 kg/TP. If CaO is reduced, the binary basicity CaO%/SiO is reduced2% is 1.0, [ S]]The content is only increased from 0.019% to 0.025%, and the content is still less than 0.03% and is primary ferrosulfurous water. The blast furnace ironmaking slagging system can completely eliminate the slag desulfurizationThe capacity is that the desulfurization is put in front of the furnace, so the reduction range of the slag alkalinity is far more than 0.1, the yield is increased, and the coke ratio is also far more than 2.5-3.5 percent. It should be said that this is a new major economic growth point for existing blast furnaces. The low-alkalinity slag does not have the problem of corroding the furnace lining, the function of discharging the slag out of the alkali metal in the furnace is larger, the furnace washing is not needed, the furnace washing only needs to be stably operated at low temperature, and the increase of the low alkalinity [ Si]Can be offset by low temperatures. Because the steel-making pig iron is not added with manganese ore raw material, the low alkalinity pair [ Mn]can be basically not considered]The effect of the reduction. In addition, the restriction of sulfur in raw materials and fuel is eliminated, and the method for deep desulfurization in front of the furnace can completely liberate the blast furnace once.
Because the desulfurization in the furnace is not considered, only one limit is required in a slagging system, namely a proper low viscosity and melting temperature. This creates favorable conditions for blast furnace smelting of various furnace materials to establish a slagging system. For example, low-alkalinity operation has been adopted in many cases such as barium-containing blast furnace slag, high-grade slag, fluorine-containing rare earth slag, smelting high-aluminum high-magnesium iron ore and the like. The desulfurization capability is low, if the large-scale deep desulfurization in front of the furnace is adopted, a more favorable and proper slagging system can be further prepared by laboratory tests and production practices.
In order to reduce the alkalinity of the slag, acid and alkali double-ball sintered ore or high and low alkalinity ball sintered ore can be considered in the common blast furnace, and the slag components only need to be adjusted according to the viscosity of the slag. The furnace using the high-alkalinity sinter can reduce the usage of the high-alkalinity sinter, and if the acid pellets are insufficient, natural lump ore (such as Australian ore) or acid pellet sinter can be supplemented properly so as to maintain lower slag alkalinity. Can reduce the alkalinity to1.05 or less, while an inexpensive stokehole defluidization is carried out in order to obtain as great an operating benefit as possible for the blast furnace. Some manufacturers can consider adopting cold-bonded pellets or carbon-containing pellets and the like for the acid furnace charge. In summary, the smelt gangue contains SiO2The lower slag basicity of the blast furnace with the higher low-grade iron ore is further positioned through laboratory tests and production practices of the blast furnace, and the economic benefit is obvious.
In addition, in order to avoid using low-strength self-fluxing sintered ore when reducing the alkalinity of slag, a novel sintered ore, namelya novel high-alkalinity sintered ore is recommended, and acid pellet sintered ore is sintered and clamped. Namely, acid pellets are clamped in the high-alkalinity sintering ore, and the alkalinity is adjusted according to the amount of the high-alkalinity sintering ore and the acid pellets so as to obtain proper low final slag alkalinity of the blast furnace.
The above-mentioned desulfurizing agent, soda powder, cannot be mentioned here, and it not only can simply and effectively implement molten iron desulfurization, but also can implement dephosphorization and desilicification, i.e. three-step desilicification and even removing vanadium from molten iron when smelting vanadium-titanium ore, and completely liberate all steel-making furnace operations including converter:
it is known that the improvement of the purity of steel products can significantly improve the performance and the service life of the steel products, and therefore, the market demand of some high value-added steel products represented by pure steel is increasing. Therefore, steel production enterprises are enabled to actively ascend pure steel production and research and develop the production process of pure steel. Therefore, how to stably produce the pure steel in large scale, large batch and low cost (the production cost is not higher than that of the traditional steel) is one of the important topics which are being researched by the modern metallurgy workers.
The traditional process method for producing the common steel is to take a steel-making furnace as a unique refining container, take decarburization and temperature rise as main targets, and simultaneously complete metallurgical tasks of desiliconization, dephosphorization, desulfurization, deoxidation, inclusion removal, alloying and the like. Such multiple high-temperature heterogeneous chemical reactions are carried out simultaneously in the same vessel, which involves many complex contradictions. Such as the contradiction between dephosphorization and desulfurization: dephosphorization is an oxidation reaction, and high FeO slag is beneficial to dephosphorization, which is very unfavorable for desulfurization in reducing atmosphere. And rephosphorization occurs at the tapping target temperature-high temperature. Obviously, the process cannot meet the purity required by pure steel production, and the result is undoubtedly high consumption and low efficiency, the smelting process is difficult to control to accurately reach the target, and the smelting cost is greatly increased.
In order to meet the requirement of pure steel production, a complex metallurgical process needs to be divided into a plurality of basic process units such as desulfurization, desiliconization, dephosphorization, decarburization, temperature rise, deoxidation control of inclusions, alloying fine adjustment of components and the like, and the basic process units are independently operated. The impurity content in the pure steel is 50-100 ppm (1 x 10)-6) On an order of magnitude level. Developed countries have been able to produce C in large industrial scale production]+[S]+[P]+T.O+[N]+[H]And the total amount of impurities is less than 50 ppm. The molten iron triple-separation is required to be treated with the improvement of the purity of the molten steel [ S]]、[P]The content is less than 0.015 percent and 150ppm (deep desulfurization and phosphorus are carried out according to the requirement of steel grades). The relevant chemical reactions have therefore approached essentially the theoretical limit level, so that the reverse reactions of their metallurgical reactions become infinite. Such as: only after the pretreatment of three times is carried out in more than 20 continuous furnaces, the pollution of condensed high-phosphorus and sulfur slag on the converter lining to molten steel can be avoided. This requires a blast furnace molten iron full-scale three-removal pretreatment process, and requires that the blast furnace molten iron components and temperature must be stable and have small fluctuation. It is ensured that the metallurgical processes are carried out under optimal thermodynamic and kinetic conditions. The transmission process is not a limiting link of the chemical reaction, and the enlargement of the reaction interface, namely the reaction contact area, is an effective means for accelerating the chemical reaction. Aiming at different converters, the following two process flows are specifically adopted:
a large converter mainly used for producing ultra-pure steel adopts a special molten iron desulphurization station and converter desiliconization and dephosphorization process at present. The molten iron desulphurization station adopts a magnesium and lime system desulfurizer to complete desulphurization tasks, desiliconization and dephosphorization tasks are completed in a special converter, and refining converter slag and slagging materials are used as a dephosphorizing agent for molten iron dephosphorization to promote slagging under a low-temperature condition during slagging, and simultaneously, the bottom blowing stirring strength is increased to enhance steel slag reaction.
The medium and small sized converter mainly for producing general purity steel uses molten iron transportation and storage equipment as at presentThe reactor is used for simultaneously carrying out dephosphorization and desulfurization treatment. Blast furnaces must be operated with low silicon, tapping [ Si]]Controlling the content below 0.4 percent, and continuously desiliconizing the molten iron [ Si]in the tapping process]Less than 0.15 percent, simultaneously desulfurizing and dephosphorizing in a molten iron tank, and controlling CaO/O by adopting a powder injection process21.5-3.0 percent and the solid oxygen/gas oxygen ratio is less than or equal to 60 percent to control the temperature drop of the molten iron, and the processed molten iron [ S%]、[P]The contents are all 0.015 percent less (deep desulfurization and phosphorus are carried out according to the requirements of steel grades).
The stokehole molten iron bath was subjected only to desiliconization and occasionally to a desulfurization test and No. outside molten iron treatment. The desiliconization agent is iron scale, sinter, concentrate powder and lime, etc.: the blast furnace low-silicon operation, the molten iron [ Si]is controlled below 0.4% during tapping, and continuous desiliconization treatment is carried out after a skimmer in the tapping process, so that the molten iron [ Si]is less than 0.15%; the iron desulfurizer used in the iron runner test or treatment is soda powder, lime, etc. Dephosphorization operation is not carried out before the furnace, and dephosphorization is mostly carried out in a hot metal ladle or a metal mixer.
In order to stably realize large-scale and large-batch production of pure steel, and ensure that the production cost of the pure steel is not higher than that of traditional steel, or the production cost of the pure steel is reduced while the quality of common steel is ensured, the single working procedures are organically connected, and the whole process is ensured to be fast and efficiently connected. The present invention is characterized in that: one dose of soda is uniformly sprayed or scattered on the gushed molten iron behind the sand opening (namely, the gushed molten iron is utilized to simplify the currently prevailing powder spraying metallurgy) and the molten slag is blocked in time, so that the three-step separation can be quickly and efficiently completed:
it is well known that soda desulfurization ([ S]]Final (a Chinese character of 'gan')0.001%), desilication ([ Si]]Final (a Chinese character of 'gan')Trace) is no problem. What is unknown about how dephosphorization will occur, if rephosphorization will occur? Thermodynamic analysis indicated that the answer was positive. As shown in fig. 8: in molten iron with sufficient soda slag (equivalent to 40kg/tp) [ Si]Equilibrium a measured at<0.2%[0]2.5ppm, dephosphorizing to [ P]]0.011-0.001% (○ air and ● oxygen blow hardly differ) soda ash slag makes the activity (log) of the product logap2o5Less than or equal to-29, obviously superior to the loga of CaO saturated slagp2o5Not less than-25.8. Cause prolapse of [ C]]A is caused to be[0]Decrease the possibility of rephosphorizationIs when [ C]]Dephosphorization begins again with a slight decrease. That is to say, the free energy of the reaction is nearly equal and fluctuates mutually, just like the high-carbon dephosphorization operation of a converter. There are launder-type furnaces similar to the present invention: the desiliconization is carried out in a sectional way, and then the industrial test of adding 20kg/tp of soda and 45 tons of iron per hour is carried out reversely (at the outlet of the pretreated molten iron), and the result is shown in figure 9, and the effect of dephosphorizing to 0.015 percent is achieved. The temperature of molten iron is controlled below 1350 ℃ by adding scrap steel in oxygen blowing. (Na)2O/SiO2) More than 2, (T.Fe) less than 7 percent, little slag, good fluidity and little iron.
The invention can overcome the defects of the process to ensure that the three-step separation is carried out more thoroughly: dephosphorization is affected by temperature, and the lower the temperature, the more thorough dephosphorization is. Soda, however, is characterized by a large temperature drop (about 2-3 deg.c/kg), which is disadvantageous and advantageous: soda powder is uniformly scattered or sprinkled at the position of the small-well gushing molten iron behind the sand opening, and the function of cooling is justutilized: when a proper amount of soda (according to requirements) is melted and decomposed, the local micro-unit molten iron on the surface can be cooled to 1250 ℃ or even lower (not in time of thermal equilibrium with the internal molten iron) in a flash time, wherein [ P]is]Immediate formation of gaseous product P4O10The phosphorus compounds adsorbed in the slag can be timely removed by a downstream slag stopper to rapidly leave the system, and the phosphorus return is seldom generated. Namely, the gushed molten iron continuously and comprehensively reveals all elements contained in the gushed molten iron, and is in full contact with the continuously-gushed and sprinkled soda powder for a flash time, so that restrictive factors of mass transfer and the like of reactants and products in a metal phase and a slag phase are eliminated, and the three deaths are instantly completed. This advantage is not present in laboratory, launder furnace tests.
The molten iron can be desiliconized by iron oxide sheet or sinter ore or iron concentrate powder and lime (not only increasing the yield of the molten iron but also simplifying slag recovery), and then desulfurized and dephosphorized by soda; optionally adding iron ore concentrate powder or SiO into soda2Properly preserving silicon and fully desulfurizing; the carbonaceous iron runner can also retain carbon. Sometimes, the temperature of the molten iron is too low, so that oxygen can be properly added; therefore, the normal operation of tapping and steel making can be ensured under any condition. Of course, the non-carbonaceous channel lining iron channel section can be decarburized to realize the steelmaking operation in front of the blast furnace.
In addition to the above-mentioned desulfurizationA skimmer or a special slag stopper which does not store molten iron can be added at one or more positions on the molten iron hook at a proper distance, and soda powder isscattered or sprinkled at the position where the molten iron is sprayed for a plurality of times. The skimmer or the special slag stopper or the small hole diameter of the molten iron behind the skimmer is designed to be smaller or other suitable designs to make the subsequent molten iron gush more fiercely or the molten iron ditch behind the skimmer is specially designed to make the molten iron generate one or more sudden drop(s) to make the molten iron contact with the soda more completely, or to make the skimmer or the skimmer have a suitable slag dam angle or other suitable designs to timely or immediately more thoroughly block the absorbable gas product SO2、P4O10And removing slag. The slag can be purged by the gas or the gas can be used together with the gas, so that adverse reactions such as rephosphorization can be effectively prevented. Thereby ensuring the three-way separationThe process is carried out under optimal thermodynamic and kinetic conditions. Therefore, the process has a great potential of three-step separation capacity! Is a challenge for powder injection metallurgy. It can also be used for external refining treatment before continuous casting of molten steel.
Because the soda has strong desulfurization effect, the limitation on the sulfur content of the molten iron is avoided, and the blast furnace can be operated at the lowest furnace temperature and alkalinity under the condition of ensuring the smooth operation of the blast furnace by requiring low silicon. Thereby realizing coke reduction and efficiency improvement with low silicon and low slag ratio, and further improving and optimizing the furnace charge structure. So that the blast furnace operation is further thoroughly liberated.
In addition, the molten iron successfully realizes three-separation, namely the full-amount three-separation, which is originally a long-term strive target for the converter, namelythe converter is completely liberated: the converter feeds molten iron subjected to the three-step decarburization treatment, so that the metallurgical task of the converter is only decarburization and temperature rise; the less slag or even no slag smelting is the inevitable result after the three-step treatment; the result is favorable for realizing the high-speed blowing of the converter; the components of the three-added de-molten iron are very stable, and very favorable conditions are provided for the intelligent control of a converter by a computer: the accurate control of the converting terminal point and direct tapping without turning down the furnace can be realized; the reduction of the blowing time and the smelting period and the reduction of the times of slag pouring can greatly reduce the erosion of the furnace lining, and the application of the slag splashing process technology can greatly improve the service life of the converter. Therefore, the three-step process technology in front of the molten iron furnace can completely release the operation of the blast furnace and the converter.
Compared with other three-removing methods, the process of the invention has the following advantages:
1. the three-removal process is simplified:
① the favorable dynamic condition of the molten iron after the skimmer is used to replace powder spraying metallurgy, the sprayed molten iron receives the reactant which is thrown evenly and has almost the same contact reaction area with the reactant sprayed into the molten iron, the skimmer can be designed specially according to the requirement, for example, the diameter of the small hole of the molten iron after the slag dam can be designed to be smaller or other suitable designs to make the molten iron sprayed more fiercely or contact with the soda more completely;
②, the erosion of the lining material of the conventional desulphurization and dephosphorization vessel by soda and other reactants is avoided, and the replacement-the front iron runner itself needs to be frequently renewed and constructed;
③ the consumption of the spray gun is saved by uniformly throwing or spraying the reactant;
④ the reaction slag is easy to melt and has good fluidity, and is particularly suitable for blocking slag and separating molten iron in time, thereby avoiding the problems of inconvenient slag removal in a tank and a furnace, easy carrying of iron, installation of a slag remover with large investment and the like;
⑤ the sulfur, phosphorus and even silicon and vanadium are removed simultaneously by only one soda reactant and a slag stopper, while the conventional three-step removal requires a plurality of furnace materials and synthetic slag as mentioned above, and the three-step removal respectively carries out the complicated procedures of desulfurization, dephosphorization and desilication.
2. The process cost is low: can completely recover Na as effective component from smoke dust or reaction residue2O and the conversion and utilization create new economic benefits, thereby greatly reducing the process cost:
① when the molten iron contains no vanadium, CO is introduced into the three-step slag-removing leaching solution2The required soda Na can be reduced and precipitated after being cooled from 100 ℃ to normal temperature2CO3：
Filtering and calcining:
or directly producing liquid or solid caustic soda products.
② there is a large amount of Nain the smoke gas2CO3Returning Na by cyclone or cloth bag dust removal2CO3Feed tank ① recovery of converted Na from slag2CO3All the soda can be practically and effectively recycled completely (all the pipelines are arranged along the ground or underground, and the operation in front of the furnace cannot be influenced). Thereby greatly reducing the process cost.
③ removing SO in the overflow gas2、P4O10、CO2And the calcium salt precipitate is formed by directly introducing lime water together with air:
towards the formation of Ca3(PO4)2And CaCO3、CaSO4Adding sulfuric acid to the precipitate to generate a saleable phosphate fertilizer superphosphate:
gaseous product SO2、P2O5、CO2Etc. may also cooperate with NO2Water is added to form saleable sulfuric acid and phosphoric acid. Reoxidation of NO in spilled NO to NO in the presence of air2Can be repeatedly used:
3. when smelting vanadium-containing molten iron, the slag by-product is expensive:
① vanadium can be extracted by blowing hot air (or bottom blowing) to molten triple-deslag before furnace to make V in it2O3Oxidation to V2O5Or sodium metavanadate NaVO3Or other vanadium compounds. Form with Na2CO3Is soluble state-converted vanadium slag (vanadium calcine). All soluble sodium salt is dissolved and leached by heating water. Adjusting the pH value to neutral solution as much as possible, adding excessive ammonium salt (4-10mol NH) at about 60 deg.C4Cl/1molV2O5). Slowly cooling to room temperature or lower under continuous stirring to precipitate NH4VO3Crystallizing, filtering and drying. If the pH is adjusted to 7-9 before, most of the impurities precipitate out with stirring at 70-90 ℃ for a long time. Alum can be added to reduce SiO in solution2The content of (a). Obtained NH4VO3Is very pure.
② filtering off NH4VO3And then, the by-product can be continuously separated out at zero degree: (NH)4)2HPO4(1810.00/t, import: 2120-2184.00/t, overseas $ 172-4H2PO4(1290.00/t, 172-4HCO3(NH in Hot Water4)2CO3Possibly decomposed), are good nitrogen and phosphorus compound fertilizers.
③ filtering the mother liquor, evaporating to obtain saturated NaCl solution, introducing ammonia and CO2NaHCO can be separated out3. The required soda can be recovered through filtering and calcining, and the purchase can be reduced to reduce the process cost. Separating out NH before introducing ammonia into mother liquor and returning4VO3。
④ recycling the gaseous products as before.
4. There are, of course, other methods for effectively separating and recycling the slag, such as ion exchangers.
5. Therefore, the three-dehydration process is a new hot metal three-dehydration pretreatment process which is circular, economical, resource-saving, environment-friendly and sustainable in development and completely accords with scientific development.
The concept mechanism is also suitable for smelting other various liquid metals: various carbonates or other suitable reactants are used for purification refining treatment at the metal turbulent flow surging position. Such as: the molten iron is treated by replacing soda with dolomite (the using amount is more than that of the soda due to the larger atomic weight of Ca and Mg); refining treatment before continuous casting of molten steel; purifying and refining the liquid copper by using soda, and the like.
The content of the claims of the invention is as follows:
1. a new hot metal pretreatment process for the operation of a blast furnace or other iron making furnaces, converters or other steel making furnaces by large desulphurization in front of a hot metal furnace or simultaneous dephosphorization and desilication liberation is provided, the existing blast furnace iron making is used for ensuring the smooth smelting, the qualified hot metal is produced, the slag is often required to have lower melting temperature, melting property temperature and viscosity, and certain high alkalinity is required to ensure the sufficient capability of removing the sulfur in the hot metal, the external desulphurization is not generally carried out, or the external desulphurization is carried out on the individual external iron or for lightening the desulphurization task of the next steel making process, and the method for the external desulphurization of the used hot metal comprises the following steps: spreading desulfurizing agent in molten iron ditch, continuous adding plane flow method, eddy flow or mechanical or electromagnetic stirring or rotary drum rotation method, etc. adding desulfurizing agent into molten iron tank, shaking, mechanical or bubble stirring, bubble pump, spraying desulfurizing agent, inserting bell jar or refractory inserting rod into desulfurizing agent, feeding wire, pouring into tank, vacuum method, electrolysis method, etc.; the desulfurizer includes soda, NaOH, lime, dolomite, Ca (OH)2Limestone, charcoal, graphite, CaC2Calcium cyanamide, colemanite, fluorite, CaCl2，Al2O3The traditional production of common steel uses steel-making furnace as only refining container, and uses decarbonization and temp. rise as main goal, and at the same time implements desiliconization, dephosphorization, desulfurization, deoxidation, impurity removal and alloying, and in the same container at the same time implements such high-temp. heterogeneous chemical reactions, including many complex chemical reactionsContradiction of (2), for example: the high FeO slag in an oxidation environment is beneficial to dephosphorization, but is very unfavorable for desulfurization in a reducing atmosphere, and for example, rephosphorization occurs at a tapping target temperature-high temperature, steelmaking in a container is undoubtedly high in consumption and low in efficiency, and smelting is difficult to control to accurately reach a target, so the method needs to be divided into a plurality of process units such as molten iron three-removal (desulfurization, desiliconization and dephosphorization), decarburization, heating, deoxidation and inclusion control, alloying fine adjustment components and the like, particularly a large converter mainly used for producing ultra-clean steel is adopted at present, a special molten iron desulfurization station + converter desiliconization and dephosphorization process is adopted, the molten iron desulfurization station adopts a magnesium-blowing desulfurizer to desulfurize, desiliconization and dephosphorization are carried out in the converter, a refining converter slag is added with a slagging agent (promoting low-temperature slagging) to serve as a dephosphorizing agent of molten iron, and simultaneously bottom blowing is strengthened to enhance steel; the medium-small converter mainly for producing general purity steel adopts molten iron transportation and storage equipment as reactor, and at present, it adopts the processes of dephosphorization and desulfurization treatment, and the blast furnace must be operated with low silicon content, and the molten iron (Si)]Controlling the content below 0.4%, and using iron scale, sinter, concentrate and lime powder to make molten iron [ Si]in the tapping process]Less than 0.015 percent; the front iron runner is not yet taken offPhosphorus removal is mostly carried out in hot metal ladles or mixers, sometimes with simultaneous removal of sulfur and phosphorus in the ladles, by controlling CaO/O by powder injection21.5-3.0 percent of solid/gas oxygen, less than or equal to 60 percent of solid/gas oxygen, and processed molten iron [ S%]、[P]The content is less than 0.015 percent (deep desulfurization and phosphorus are carried out according to the requirements of steel grades), the invention is characterized in that the desulfurizer, the dephosphorizer, the desiliconizer or different compositions thereof are sprayed or respectively sprayed on the molten iron which is continuously and comprehensively exposed by gushing at the rear small well of a blast furnace, a cupola furnace or other molten iron producing furnaces (also called a sand port and a slag bridge), or the sulfur in the molten iron is greatly and cheaply removed, thereby effectively lightening the high-cost desulfurization load in the blast furnace, the cupola furnace or other molten iron producing furnaces, realizing the operation of low-melting slag alkalinity, low temperature and low slag ratio and low coke ratio, further improving and optimizing the furnace material structure, and completely releasing the blast furnace and other iron-making furnaces; or besides desulfurization, further dephosphorizing or desiliconizing or extracting vanadium in the molten iron for smelting the schreyerite or different combinations thereof to ensure that the steel-making furnace is made to beThe performance and the service life of steel products are greatly improved to produce pure steel, and because the molten iron successfully realizes the three-way separation of the total amount, the aim of trying to achieve the steel-making furnace including the converter for a long time is originally achieved, namely the steel-making furnace is completely liberated: the steelmaking furnace has three decarburization and heating tasks only by using molten iron for decarburization; the less slag smelting is also the inevitable result after the three-step removal treatment; meanwhile, the high-speed converting of the steel furnace is facilitated; because the composition of the third molten iron is very stable, extremely favorable conditions are provided for the computer intelligent control of the steelmaking furnace, the accurate control of the converting terminal point and the direct tapping without turning down the furnace can be realized; the short blowing period and the reduced slag pouring times greatly reduce the erosion of the furnace lining, greatly improve the service life of the converter or other steel making furnaces, and in short, the large-scale desulfurization or the triple-removal in front of the blast furnace can completely liberate the operation of the blast furnace or other iron making furnaces, the converter or other steel making furnaces.
2. The invention as claimed in claim 1, wherein the desulfurizing agent or dephosphorizing agent or desiliconizing agent or their different compositions are uniformly and continuously sprinkled or sprinkled on the molten iron gushed from the small well behind the skimmer or special skimmer of the blast furnace or cupola or other ironmaking furnace by pneumatic conveying of a spray tank or by spiral feeder or other suitable conveying means, or the molten iron skimmer or special skimmer is stored or not stored at a suitable distance downstream thereof to remove the molten iron, or the molten iron gushed from the small well behind the skimmer or special skimmer is uniformly and continuously sprinkled or sprinkled again with the trisubricating agent or their different compositions to enhance the trisubbing effect, or the molten iron gushed from one or more downstream thereof or from the position of the molten iron skimmer or special skimmer is provided with molten iron or not stored in front of the molten iron stream of each molten iron tank, while the molten iron gushed from the one position is removed, then continuously and uniformly scattering or spraying the three-desquamating agent or different compositions thereof at a plurality of positions on the later gushed molten iron, or adding magnesium or magnesium alloy or aluminum alloy or calcium alloy or manganese alloy or other suitable metals or alloys thereof or alloys of different combinations of the metals, designing the skimmer or the special skimmer or designing the diameter of a small hole for the later gushed molten iron to be smaller or other suitable structures to ensure that the molten iron is sprayed on the later gushed molten ironThe molten iron is mixed and contacted with the three-component reaction removing agent more completely by gushing the molten iron more fiercely or by specially designing the molten iron runner behind the skimmer, or the slag blocking dam is provided with a proper angle or other proper structure to separate the slag iron more quickly and thoroughlyin time or instantly so as to prevent the rephosphorization, or the slag iron is separated by a slag removing method or a gas blowing method or other slag removing methods or different combinations of the methods when the slag is blocked, the discharged slag amount is more or less or the slag is not discharged, the simple substance or the compound on the surface of the molten iron is discharged, or the slag in the molten iron tank is discharged by various slag removing machines or other slag removing methods when the molten iron is poured out of the molten iron tank without the skimmer, or the slag is blocked in the molten iron tank to separate the molten iron by the slag blocking machine or the gas blowing method or other slag removing methods or different combinations of the gas blowing methods when the molten iron is poured out of the molten iron tank, or the molten iron is fully filled with the molten iron or the molten iron mixing furnace or other molten iron mixed furnace or other molten iron after the pretreatment Separating iron and slag on the surface of molten iron in the container, wherein the gas used in the gas purging method is nitrogen or oxygen or air or hydrogen or CO2Or is CO or CH4Or propane or as coke oven gas or as blast furnace gas or as inert gas or as other suitable gas or as a different combination of the above.
3. The invention according to claims 1 and 2 is characterized in that the magnesium or magnesium alloy is added to the molten iron runner before the molten iron enters the molten iron pot by casting liquid magnesium or magnesium alloy into a porous cast iron block which is cast in advance, and after cooling, the porous cast magnesium cast iron block is placed into the molten iron runner with the orifice facing downwards, or a plurality of blocks are piled up, or a vertical porous cast magnesium cast iron block with a certain height, or other porous cast magnesium iron blocks or iron alloy blocks, or crude magnesium is used toreplace the cast magnesium or magnesium alloy.
4. The method of the present invention according to claims 1 and 2 is characterized in that the magnesium or magnesium alloy is added to the molten iron runner before the molten iron enters the molten iron pot by casting liquid magnesium or magnesium alloy into a porous refractory brick prepared in advance, and after cooling, the porous cast magnesium refractory brick is placed into the molten iron runner with its opening facing downward, or a certain pressure is applied to it, or a vertical porous cast magnesium refractory brick of a certain height is made, or a certain pressure is applied again, or crude magnesium is used to replace the cast magnesium or magnesium alloy.
5. The invention as claimed in claims 1 and 2' is characterized in that the blast furnace burden structure uses a small amount of high-alkalinity sinter ore, and a large amount of acid pellet ore, natural lump ore, cold-bonded pellet ore, carbon-containing pellet ore, or acid and alkali double-pellet ore, high and low-alkalinity pellet ore without high-alkalinity sinter ore to adjust the alkalinity of blast furnace slag to be lower than that of normal slag by more than 0.01.
6. The invention is characterized in that the blast furnace burden structure is used for novel high-alkalinity inclusion-sintered acid pellet ore for inclusion-sintering acid pellets in high-alkalinity sintered ore to obtain proper final slag alkalinity, or the alkalinity of blast furnace slag is reduced by more than 0.01 compared with the normal slag alkalinity.
7. The invention according to claims 1 and 2' is characterized in that the molten iron is pretreated with soda, or the molten iron is simultaneously desulfurized, dephosphorized, desilicated, vanadium-removed (vanadium-extracted) in the smelting of schreyerite, decarburized in the special non-carbonaceous liner section to achieve steel-making, or desilicated, dephosphorized, desulfurized, or vanadium-removed in the smelting of schreyerite, or decarburized in the special non-carbonaceous liner section, or different combinations thereof, or SiO is added to soda2Or concentrate powder or different combinations thereof, or iron scale or sinter ore or concentrate plus lime powder or other desiliconizing agent or different compositions thereof are uniformly and continuously sprinkled or sprinkled on the tap hole or desiliconized at the molten iron gushed after one or more skimmers before soda, or iron scale or sinter ore or concentrate plus lime powder or other desiliconizing agent or different compositions thereof are mixed with the soda for use, or the soda in the smoke and the gaseous P are recovered by a proper method2O5、SO2Or recovering sodium oxide in the slag: or converted into soda or into caustic soda or into phosphate fertilizer or other compounds, or converted into vanadium oxide or sodium metavanadate or other vanadium compounds from slag for recycling when smelting vanadium-titanium ore, so as to create new economic benefit and reduce process cost.
8. The invention as claimed in claims 1 and 2' is characterized by the concept of contact reaction of the metal liquid in the turbulent spring with various elements contained in the metal liquid, or the application of the method in the proper pyrometallurgical refining of various liquid metals, the purification refining of the metal turbulent spring with various proper reactants, such as replacing soda with dolomite; refining treatment before continuous casting of molten steel; purifying the liquid copper with soda; or applied to the optimization and modification of chemical processes such as suitable hydrometallurgy and other suitable liquid-solid and liquid-liquid (especially with different specific gravity) phase reactions and the like.
Note: the viscosity curves of the synthetic slag with various components in the groups 1-7 at different temperatures are shown in the attached figures 1-7.
Claims (8)
1. A new hot metal pretreatment process for the operation of a blast furnace or other iron making furnaces, converters or other steel making furnaces by large desulphurization in front of a hot metal furnace or simultaneous dephosphorization and desilication liberation is provided, the existing blast furnace iron making is used for ensuring the smooth smelting, the qualified hot metal is produced, the slag is often required to have lower melting temperature, melting property temperature and viscosity, and certain high alkalinity is required to ensure the sufficient capability of removing the sulfur in the hot metal, the external desulphurization is not generally carried out, or the external desulphurization is carried out on the individual external iron or for lightening the desulphurization task of the next steel making process, and the method for the external desulphurization of the used hot metal comprises the following steps: spreading desulfurizing agent in molten iron ditch, continuous adding plane flow method, eddy flow or mechanical or electromagnetic stirring or rotary drum rotation method, etc. adding desulfurizing agent into molten iron tank, shaking, mechanical or bubble stirring, bubble pump, spraying desulfurizing agent, inserting bell jar or refractory inserting rod into desulfurizing agent, feeding wire, pouring into tank, vacuum method, electrolysis method, etc.; the desulfurizer includes soda, NaOH, lime, dolomite, Ca (OH)2Limestone, charcoal, graphite, CaC2Calcium cyanamide, colemanite, fluorite, CaCl2，Al2O3The traditional production of common steel uses a steel-making furnace as a unique refining container, and takes decarburization and heating as main targets, and simultaneously completes desilication, dephosphorization, desulfurization, deoxidation, impurity removal and alloying, and the simultaneous completion of so many high-temperature heterogeneous chemical reactions in the same container inherently contains many complex contradictions, such as: the high FeO slag in an oxidation environment is beneficial to dephosphorization, but is very unfavorable for desulfurization in a reducing atmosphere, and for example, rephosphorization occurs at a tapping target temperature-high temperature, steelmaking in a container is undoubtedly high in consumption and low in efficiency, and smelting is difficult to control to accurately reach a target, so the method needs to be divided into a plurality of process units such as molten iron three-removal (desulfurization, desiliconization and dephosphorization), decarburization, heating, deoxidation and inclusion control, alloying fine adjustment components and the like, particularly a large converter mainly used for producing ultra-clean steel is adopted at present, a special molten iron desulfurization station + converter desiliconization and dephosphorization process is adopted, the molten iron desulfurization station adopts a magnesium-blowing desulfurizer to desulfurize, desiliconization and dephosphorization are carried out in the converter, a refining converter slag is added with a slagging agent (promoting low-temperature slagging) to serve as a dephosphorizing agent of molten iron, and simultaneously bottom blowing is strengthened to enhance steel; the medium-small converter mainly for producing general purity steel adopts molten iron transportation and storage equipment as reactor, and at present, it adopts the processes of dephosphorization and desulfurization treatment, and the blast furnace must be operated with low silicon content, and the molten iron (Si)]Controlling the content below 0.4%, and using iron scale, sinter, concentrate and lime powder to make molten iron [ Si]in the tapping process]Less than 0.015 percent; the molten iron runner before the furnace is not dephosphorized, most of the molten iron runners are dephosphorized in a molten iron tank or a mixed iron furnace, sometimes, the molten iron tank is simultaneously desulfurized and dephosphorized, and a powder injection process is adopted to control CaO/O21.5-3.0 percent of solid/gas oxygen, less than or equal to 60 percent of solid/gas oxygen, and processed molten iron [ S%]、[P]The content should be less than 0.015% (deep desulfurization and phosphorus removal according to the steel grade), the invention is characterized in that the desulfurizer, the dephosphorizing agent, the desiliconizing agent or different compositions thereof are sprayed or scattered on the small well behind the front skimmer (also called sand mouth and slag bridge) of a blast furnace or a cupola furnace or other molten iron producing furnaces to continuously and fully expose the contained elements, or the sulfur in the molten iron is removed at low cost greatly,thereby effectively reducing the high-cost desulfurization load in the blast furnace or cupola furnace or other molten iron producing furnaces, realizing the operation of low slag alkalinity, low temperature and low slag ratio and low coke ratio, further improving and optimizing the furnace charge structure, and completely liberating blast furnaces and other iron making furnaces; or besides desulfurization, dephosphorization or desilication or extraction of vanadium or different combinations thereof in the molten iron of the vanadium-titanium ore are further carried out, so that the steel-making furnace can produce pure steel for greatly improving the performance and service life of the steel, and because the molten iron successfully realizes the total removal of three, the steel-making furnace is completely liberated for the purpose of trying to achieve for a long time originally for all steel-making furnaces including the converter: the steelmaking furnace has three decarburization and heating tasks only by using molten iron for decarburization; the less slag smelting is also the inevitable result after the three-step removal treatment; meanwhile, the high-speed converting of the steel furnace is facilitated; because the composition of the third molten iron is very stable, extremely favorable conditions are provided for the computer intelligent control of the steelmaking furnace, the accurate control of the converting terminal point and the direct tapping without turning down the furnace can be realized; the short blowing period and the reduced slag pouring times greatly reduce the erosion of the furnace lining, greatly improve the service life of the converter or other steel making furnaces, and in short, the large-scale desulfurization or the triple-removal in front of the blast furnace can completely liberate the operation of the blast furnace or other iron making furnaces, the converter or other steel making furnaces.
2. The invention is characterized in that the desulfurizing agent or the dephosphorizing agent or the desiliconizing agent or the different compositions thereof are evenly and continuously scattered or sprayed on the molten iron gushed from the small well behind the slag skimmer or the special slag skimmer of the blast furnace or the cupola furnace or other ironmaking furnaces by pneumatic conveying of a spray tank or by a screw feeder or other suitable conveying modes, or a molten iron skimmer or a special skimmer with or without molten iron storage is arranged at a proper distance downstream of the molten iron skimmer to remove the molten slag, or evenly and continuously scattering or spraying the three-way removing agent or different compositions thereof again on the gushed molten iron at the small well behind the additionally arranged skimmer or the specially-made skimmer so as to enhance the three-way removing effect, or one or more positions at proper downstream distance or at the position for shunting molten iron to each molten iron tank, or a molten iron storage type skimmer or a special skimmer is arranged in front of the molten iron nozzle of each molten iron tank for blocking.While the last slag is being produced, the three kinds of desquamating agents or their different compositions are continuously and uniformly sprinkled or sprinkled at several places on the later gushed molten iron, or magnesium alloy or aluminum alloy or calcium alloy or manganese alloy or other suitable metals or their alloys of different combinations are added, the skimmer or special skimmer is designed, or the small hole diameter of the later gushed molten iron is designed to be smaller or other suitable structure to gush the molten ironThe molten iron is mixed and contacted with the three-component removal reaction agent more completely by one or more sudden drop height generated by the molten iron after the slag skimmer is designed more fiercely or specially, or the slag-blocking dam of the molten iron is provided with a proper angle or other proper structures to enable slag iron to be separated more quickly and thoroughly in time or in real time so as to prevent rephosphorization and the like, or the slag iron is separated by a slag skimming method, a gas blowing method or other slag-removing methods or different combinations of the methods during slag-blocking, the amount of the removed slag is more or less or no slag, simple substances or compounds on the surface of the molten iron are discharged, or the slag skimmer is not arranged to a steel plant, the slag in the molten iron tank is discharged by various slag skimming machines or other slag-removing methods during pouring the molten iron out of the molten iron tank, or the slag skimmer is arranged to shield the molten iron or the slag is blocked in the tank by the gas blowing method so as to separate the molten iron from the molten iron tank, or the molten iron is mixed with the molten iron or other molten iron tank which is fully pretreated, or by the gas blowing method or The slag and iron are separated from the molten iron surface, and the gas used in the gas blowing method is nitrogen or oxygen or air or hydrogen or CO2Or is CO or CH4Or propane or as coke oven gas or as blast furnace gas or as inert gas or as other suitable gas or as a different combination of the above.
3. The invention according to claims 1 and 2 is characterized in that the magnesium or magnesium alloy is added to the molten iron runner before the molten iron enters the molten iron pot by casting liquid magnesium or magnesium alloy into a porous cast iron block which is cast in advance, and after cooling, the porous cast magnesium cast iron block is placed into the molten iron runner with the orifice facing downwards, or a plurality of blocks are piled up, or a vertical porous cast magnesium cast iron block with a certain height, or other porous cast magnesium iron blocks or iron alloy blocks, or crude magnesium is used to replace the cast magnesium or magnesium alloy.
4. The method of the present invention according to claims 1 and 2 is characterized in that the magnesium or magnesium alloy is added to the molten iron runner before the molten iron enters the molten iron pot by casting liquid magnesium or magnesium alloy into a porous refractory brick prepared in advance, and after cooling, the porous cast magnesium refractory brick is placed into the molten iron runner with its opening facing downward, or a certain pressure is applied to it, or a vertical porous cast magnesium refractory brick of a certain height is made, or a certain pressure is applied again, or crude magnesium is used to replace the cast magnesium or magnesium alloy.
5. The invention as claimed in claims 1 and 2' is characterized in that the blast furnace burden structure uses a small amount of high-alkalinity sinter ore, and a large amount of acid pellet ore, natural lump ore, cold-bonded pellet ore, carbon-containing pellet ore, or acid and alkali double-pellet ore, high and low-alkalinity pellet ore without high-alkalinity sinter ore to adjust the alkalinity of blast furnace slag to be lower than that of normal slag by more than 0.01.
6. The invention is characterized in that the blast furnace burden structure is used for novel high-alkalinity inclusion-sintered acid pellet ore for inclusion-sintering acid pellets in high-alkalinity sintered ore to obtain proper final slag alkalinity, or the alkalinity of blast furnace slag is reduced by more than 0.01 compared with the normal slag alkalinity.
7. The invention according to claims 1 and 2' is characterized in that the molten iron is pretreated with soda, or the molten iron is simultaneously desulfurized, dephosphorized, desilicated, vanadium-removed (vanadium-extracted) in the smelting of schreyerite, decarburized in the special non-carbonaceous liner section to achieve steel-making, or desilicated, dephosphorized, desulfurized, or vanadium-removed in the smelting of schreyerite, or decarburized in the special non-carbonaceous liner section, or different combinations thereof, or SiO is added to soda2Or concentrate powder or different combinations thereof, or iron scale or sinter ore or concentrate plus lime powder or other desiliconization agents or different compositions thereof are uniformly and continuously scattered or sprayed at the iron tap hole orDesiliconizing molten iron sprayed from one or more skimmers before soda, or mixing iron scale or sintered ore or concentrate with lime powder or other desiliconizing agent or their mixture with the above soda, or recovering soda and gaseous P in smoke by appropriate method2O5、SO2Or recovering sodium oxide in the slag: or converted into soda or into caustic soda or into phosphate fertilizer or other compounds, or converted into vanadium oxide or sodium metavanadate or other vanadium compounds from slag for recycling when smelting vanadium-titanium ore, so as to create new economic benefit and reduce process cost.
8. The invention as claimed in claims 1 and 2' is characterized by the concept of contact reaction of the metal liquid in the turbulent spring with various elements contained in the metal liquid, or the application of the method in the proper pyrometallurgical refining of various liquid metals, the purification refining of the metal turbulent spring with various proper reactants, such as replacing soda with dolomite; refining treatment before continuous casting of molten steel; purifying the liquid copper with soda; or applied to the optimization and modification of chemical processes such as suitable hydrometallurgy and other suitable liquid-solid and liquid-liquid (especially with different specific gravity) phase reactions and the like.
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| CN101306928B (en) * | 2008-06-20 | 2011-09-21 | 北京世纪地和科技有限公司 | Pre- desiliconizing method from fly ash or slag |
| CN104353557A (en) * | 2014-10-09 | 2015-02-18 | 昆明冶金研究院 | Method for reducing sulphur content in iron ore concentrate through flotation process |
| CN107955855A (en) * | 2016-10-16 | 2018-04-24 | 铁东区强东冶金技术咨询服务中心 | The method of no slag gasification removing Sulfur Content in Hot Iron phosphorus silicon |
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| CN112593048A (en) * | 2020-12-09 | 2021-04-02 | 攀钢集团西昌钢钒有限公司 | Semisteel desulfurization method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101306928B (en) * | 2008-06-20 | 2011-09-21 | 北京世纪地和科技有限公司 | Pre- desiliconizing method from fly ash or slag |
| CN104353557A (en) * | 2014-10-09 | 2015-02-18 | 昆明冶金研究院 | Method for reducing sulphur content in iron ore concentrate through flotation process |
| CN107955855A (en) * | 2016-10-16 | 2018-04-24 | 铁东区强东冶金技术咨询服务中心 | The method of no slag gasification removing Sulfur Content in Hot Iron phosphorus silicon |
| CN109652641A (en) * | 2018-11-19 | 2019-04-19 | 北京汉唐环保科技股份有限公司 | Ilmenite cleaning device |
| CN112593048A (en) * | 2020-12-09 | 2021-04-02 | 攀钢集团西昌钢钒有限公司 | Semisteel desulfurization method |
| CN113652524A (en) * | 2021-08-17 | 2021-11-16 | 山西太钢不锈钢股份有限公司 | Smelting method of steel for extremely-low-oxygen medium-high-carbon railway wheel |
| CN113652524B (en) * | 2021-08-17 | 2022-11-08 | 山西太钢不锈钢股份有限公司 | Smelting method of steel for extremely-low-oxygen medium-high-carbon railway wheel |
| CN115505668A (en) * | 2022-11-23 | 2022-12-23 | 华北理工大学 | Movable molten iron desiliconizing and dephosphorizing method |
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