1430 results about "Decarburization" patented technology

A multi-purpose, multi-oxy-fuel High Temperature Power Burner/Injector/Oxygen Lance, Mechanical System Apparatus Device, for steelmaking from recycled scrap and/or virgin ferrous charge, which can be employed in multi-oxy-fuel (natural gas; pulverized carbonaceous matter; heavy oil), especially by Oxygen Combusted mixture of Natural Gas/Pulverized Carbonaceous Matter in High Temperature Power Burner Mode, for efficient and rapid melting of solid ferrous charge (cold or preheated) in a special steelmaking Metallurgical Furnace or Open Hearth Furnace, Tandem Furnace, BOF, EAF, as its augmenting or only source of thermal energy; more than one Device in Oxygen-Natural Gas/Pulverized Carbonaceous Matter Power Burner Mode, can be employed as the only source of thermal energy in a modified, originally Electric Arc Furnace, as total replacement of Graphite Electrodes and Electric Arc System, the replacement being noticeably more primary energy efficient than the thermal energy provided by Graphite Electrode/Arc System; it also can be employed in an Solid Particles Injector Mode, for injecting of adequately granulated carbonaceous materials or lime into the molten steel for its carburizing or for foamy slag control; further it can be employed in a natural gas shrouded, pulsating oxygen stream, for vertically to the charge oriented soft blow supersonic Oxygen Injection Lance Mode, for decarburization of the molten metal contained in the hearth of the metallurgical furnace and foamy slag control; in one of the embodiments-generally arcuate-pivotally mounted, liquid media cooled composite body, is pivoted into and out of a furnace vessel through a small opening in the shell wall for auto-regulated constant optimal positioning of the Composite Body Tip against solid or molten charge, in each and all multi-purpose modes; furthermore, when inserted into the furnace vessel, the arcuate composite body can be rotated about its longitudinal axis for directing the oxy-fuel high temperature flame towards unmolten charge in the furnace; in an other-generally linear-embodiment, the liquid cooled composite body is attached to the mast type carrier allowing vertical movement of the composite body which enters the furnace vessel through a small opening in the furnace roof; the bimetallic, liquid cooled special tip assembly of both-arcuate and linear embodiments-of the composite body includes easy replaceable, independent, multi-opening nozzles, mounted in a protective, retracted position inside of the liquid cooled special tip assembly.

An improved method and apparatus for metal melting, refining and processing, particularly adapted to steel making in an electric arc furnace. The method provides auxiliary thermal energy to the steel making process, particulate injection for the formation of slag and foamy slag, and oxygen injection for the decarburization of the melt, for the formation of foamy slag and for post combustion burning of carbon monoxide. The burner includes two injection barrels for providing finely pulverized particles and for providing either a supersonic or a subsonic primary flow of an oxidizing gas. The barrels are positioned side by side in a nozzle at the entrance of a flame shaping chamber of a fluid cooled combustion chamber. The nozzle also contains a plurality of fuel orifices for the providing pressurized fuel to the combustion chamber and a plurality of oxidizing gas orifices for providing a secondary flow of an oxidizing gas around the periphery of the nozzle. Because all of the flows of fuel, oxidizing gas and particulates pass through the flame shaping chamber, they are all substantially directed to the same location in the electric arc furnace. The directionality of the flows allows the burner to heat a localized spot of the slag with thermal energy from the oxidation of the fuel, from the oxidation of oxidizable components in the slag or the melt by the lancing of supersonic oxidizing gas, or from any combination of these. Once a spot in the slag is sufficiently heated, a flow of carbon is directed to the localized hot spot in the slag to reduce the FeO, and other oxides, in the slag to carbon monoxide and produce foamy slag. The particulate carbon introduction can be accompanied by further oxidizing gas injection before, during or after the carbon injection.

The invention discloses a removal technology of removing coal-fired flue gas pollutants and a device thereof. The technology is as follows: an SCR denitration method is first used for removing NOX in the flue gas; then a dust collector is used for removing dusts and ash particles in the flue gas; then a wet calcium-based desulphurization method is used for removing SO2 in the flue gas; then an MEA decarburization process is used for absorbing the SO2 in the flue gas; simultaneously, a pregnant solution of a generated alkanolamine solution is heated, analyzed and regenerated and the generated barren solution of the alkanolamine solution is continuously and cyclically used; and the analyzed CO2 gas with high concentration is produced to be liquid carbon dioxide of industrial grade with high purity after being cooled, gas-liquid separated, dried, compressed and condensed. The device consists essentially of an SCR denitration reactor, the dust collector, a wet calcium-based desulphurization reactor, an MEA decarburization absorption tower, a regeneration tower, a gas-liquid separator, a dryer, a compressor, a condenser and the like which are connected with each other by pipes. The device has simple and compact overall design, low investment and operation costs, and stable and reliable work and can conduct classified integration processing and highly efficient simultaneous removal on every pollutant in the coal-fired flue gas.

An improved method and apparatus for EAF steelmaking wherein the method provides additional thermal energy to the steel making process, carbon injection for the formation of foamy slag, and oxygen injection for the decarburization of the melt, the formation of foamy slag and post combustion burning of carbon monoxide. The apparatus comprises a unique burner configuration which has a central conduit for alternatively supplying fluid hydrocarbon fuel or particulate carbon with a carrier gas which are discharged through a exit opening. The fuel or carbon is mixed with a high speed, preferably supersonic, stream of oxidizing gas. The high speed stream of oxidizing gas is provided by an annular supersonic nozzle which causes the oxidizing gas to surround the fuel or the particulates with an annular flow. The annular nozzle design can be adjusted to direct the flows of particulates and oxidizing gases in the areas and shapes desired for efficient management of the steelmaking process. Optionally, the burner can have another conduit for the secondary supply of a pressurized flow of hydrocarbon fluid fuel to a series of apertures which surround the annular flow. Further, optionally, the burner can have another conduit for the supply of a pressurized flow of a secondary oxidizing gas to a series of apertures which surround the annular flow.

The invention provides a method for removing various gaseous pollutants from smoke gas, which is used for solving the problem of limitation of the control and government technology on various pollutants in the smoke gas. The invention utilizes an absorption tower for fully removing SO2, NOX, mercurial vapor and CO2 in the smoke gas, the lower part of the absorption tower is provided an absorptionpulp tank, the middle of the absorption tower is provided with a spraying pipe, the upper part of the absorption tower is provided with an oxidizing agent pipe, the absorption tower is provided with partition boards in the vertical direction, both sides of the partition boards are respectively a desulfurization work section and a denitration and decarburization work section, the upper part of theabsorption tower is a communication oxidization region, the smoke gas enters the desulfurization work section from an inlet of the absorption tower to complete the removal of SO2 and HCL, the smoke gas continuously goes upwards to enter the oxidization region, and NOX is oxidized into water-soluble high oxide in the oxidization region and then enters the denitration and decarburization work section to complete the removal of the NOX, the mercurial vapor and the CO2. The invention breaks through the technical bottlenecks of complicated equipment and high running cost for simultaneously removing various gaseous pollutants from the smoke gas in the prior art. The process method and the device of the invention have the unique novelty.

The invention belongs to the gas separation technology area, it relates to a decarbonization solution which recycles or removes the carbon dioxide gas from the mixed gas which contains carbon dioxide, said invention specially relates to an ethoxyl ethylenediamine decarbonization solution. Its characteristic lies in: the invention has designed a new compound decarbonization solution which is composed of the main absorption component, the aid absorption component, the activation component, the corrosion inhibitor, the oxidation inhibitor and the water. Among, the main absorption component is AEE, the aid absorption component is AMP, MDEA and TEA, the activation component is MEA, DEA and PZ, the corrosion inhibitor is vitriol sour sodium, the oxidation inhibitor is the sodium sulfite and the cupric acetate. The effect and the profit of the invention are that it can be used in recycling many kinds of chemical industry reaction exhaust, the carbon dioxide of the combustion flue gas and the mixed gas, may also used in removing the carbon dioxide of town gas, the natural gas and so on, the merit of the decarbonization fluid is that the absorption capacity is big, purification is high, desorption rate is big, regeneration energy consumption is low.

The invention discloses a technological method for producing high-purity low-iron aluminum sulfate by using coal ash and comprehensively utilizing the coal ash, comprising the following steps of: carrying out mechanical activation, flotation decarburization, magnetic separation for deferrization, aluminum extraction with sulfuric acid, solid-liquid separation, concentration of aluminum sulfate crude liquor, organic alcohol alcoholization for acid rinse, organic alcohol alcoholization for deferrization and aluminum sulfate dewatering and drying on the coal ash to obtain the high-purity low-iron aluminum sulfate with low Fe content. The invention solves the problems on impurity removal and purification of the aluminum sulfate in the recycling process of the coal ash, simplifies the process flow, reduces the energy consumption, solves the technical problem of overlarge accumulation of secondary residue quantity, achieves high extraction ratio of aluminum contained in the coal ash, and realizes the recycling of organic alcohol and sulfuric acid and the comprehensive utilization of side products including unburnt black, magnetic iron powder, iron-containing aluminum sulfate crystals, high-silicon-dust active mineral blending materials or novel silicon-magnesium cement, and the like. The technological method has the advantages of simple process, short flow, easiness for control of a production process, high aluminum extraction ratio, low impurity content of products and stable quality.

The invention discloses a heating method used for preventing the high carbon strip billet from decarburizing. The strip billet is heated in the heating furnace, and the heating process comprises the preheating period, heating period, and heat soaking period. The invention is characterized in that the micro positive pressure and the weak oxidizability environment are adopted during the heating process to heat the strip billet. In the invention method, the heating time is reduced, the standing time of the billet in the high temperature area is reduced, the depth of the decarburizing layer on the surface of the billet can be controlled in a shallow scope, the metal recovery ratio is enhanced; the fuel consumption is reduced, the energy is economized; and compared with the method of coating a protecting layer on the surface of the billet, the cost and the labor intensity are reduced.

The invention relates to a hardening and tempering high-strength steel plate for wood based panel equipment and a production method of the steel plate, and belongs to the field of manufacturing low-alloy high-strength structural steel. The steel plate consists of the following chemical components in percentage by weight: 0.18 to 0.24 percent of C, 0.20 to 0.50 percent of Si, 0.80 to 1.20 percent of Mn, more than or equal to 0.02 percent of P, more than or equal to 0.01 percent of S, 0.20 to 0.50 percent of Mo, 0.20 to 0.50 percent of Ni, 0.70 to 1.00 percent of Cr, more than or equal to 0.003percent of B, 0.017 to 0.030 percent of Nb, 0.040 to 0.050 percent of V, 0.017 to 0.026 percent of Ti, and the balance of Fe and inevitable impurities. The production method of the steel plate comprises the following steps of: electric furnace smelting, vacuum decarburization /vacuum arc decarburization (VD/VOD) furnace vacuum decarburization, ladle furnace (LF) furnace refining, continuous casting (die casting), billet steel (ingot) clearing, heating, plate rolling, hardening and tempering, steel plate checking and polishing, tempering, sampling inspection, and warehousing. The hardening andtempering high-strength steel plate for the wood based panel equipment adopts Cr-Ni-Mo-B system micro-alloy elements for composite strengthening, and acquires good obdurability matching through a reasonable heat treatment process, and simultaneously the welding performance of a thick plate is not reduced.

The invention discloses a boron-contained centrifugal composite high-speed steel roller, which comprises an outer layer of the high-speed steel roller, a middle layer of the high-speed steel roller and a core of the high-speed steel roller. The manufacturing method includes steps of smelting, interrupted front treatment, roller pouring, annealing, rough machining, double tempering, finish machining and testing. By the method, three-layer composite roller technology is adopted in the boron-contained centrifugal composite high-speed steel roller, composite ability of the outer layer of the high-speed steel roller and the core of the high-speed steel roller is increased, the roller is less prone to spalling, high in rigidity and accident resistant ability, fine in abrasion resistance, safe in use, low in energy consumption and short in cycle in heat treatment, oxidation and decarburization of the roller and roller breakage in use are avoided. The manufacturing method is simple and hot quenching process is omitted.

The invention provides an iso-butane, n-butane and butylene separation and purification method. C4 raw materials are successively put into a C3 decarburization tower, a C5 decarburization tower, an iso-butane tower, an n-butane tower and a stripping tower to obtain high-purity iso-butane, n-butane and butylene. Solvents are cyclically utilized. The iso-butane, n-butane and butylene separation and purification method has the technical advantages that not only can equipment investment be reduced, but also the advantages of extractive distillation are used and the energy consumption is reduced.

The invention relates to a process for smelting ultra-low-carbon steel, which comprises melted iron pretreatment desulfuration, converter smelt, LF furnace refining, RH vacuum process and continuous casting procedure in turn. Converter smelt tapping adopts non deoxidization tapping, steel which is tapped off is refined by LF ladle furnace before carried out melt iron vacuum decarburization processing, wherein refining is mainly used to proceed modifying property processing and further desulfuration and heating for top slag of melted iron, and the melted iron is reinforced with positive oxygen blowing decarburization after shifted into a RH vacuum container. The process can control carbon, nitrogen and sulfur in steel to preset objects which are required, and has excellent castability when a casting machine casted, thereby realizing casting by several furnaces.

The invention discloses a zinc-plated hot-formed steel plate or steel strip with excellent cold bending performance and a manufacturing method thereof. The zinc-plated hot-formed steel plate or steelstrip comprises a base plate with a surface decarburization layer thickness of 20 [mu]m or below and a zinc coating with an adhesion amount of 10-100 g/m<2> on the base plate. The constituent weight percentage of the base plate is C: 0.1-0.8%, Si: 0.05-2.0%, Mn: 0.5-3.0%, P: <=0.1%, S: <=0.05%, Al: <=0.1%, N: <=0.01%, and the balance Fe and unavoidable impurities. The average size of original austenite grains of the base plate is 15 [mu]m or below. The hot-formed steel plate or steel strip has a continuous and complete coating, no cracks extending to the base plate and excellent cold bending performance on the basis of meeting the conditions that the tensile strength of the base plate after hot-forming is 1500 MPa and the elongation after breaking is 5%.

The invention relates to a control method for preventing nozzle clogging in a casting process of ultra-low carbon-aluminium deoxidized molten steel, and belongs to the technical field of a steelmaking technology. The technical scheme is that a process path of molten iron desulfurization treatment, converter smelting, converter steel tapping, Rheinstahl Heraeus (RH) vacuum treatment, and continuous casting of a dual-flow slab is adopted to smelt ultra-low carbon steel, so that the castability of the ultra-low carbon-aluminium deoxidized molten steel is improved; the oxygen content of the molten steel of a converter blowing end-point, the carbon content and the temperature of the endpoint are reasonably controlled; a favorable condition is provided for RH vacuum decarburization; pouring is protected in a continuous casting manner; secondary oxidization of the molten steel is prevented by adopting blowing-argon sealing protection of a long-nozzle and a submersed nozzle; secondary oxidization of the molten steel is prevented by using an alkaline covering agent; an occluded foreign substance in the molten steel is well adsorbed; the castability of the ultra-low carbon-aluminium deoxidized molten steel is improved; the targets of no choking of the submersed nozzle and no change of the submersed nozzle in a complete multi-furnace continuous casting process are achieved. Thus, the effect on a casting blank caused by replacement of the submersed nozzle is avoided.

The invention discloses a methanation process of synthetic natural gas (SNG) prepared from coal. Purified and decarbonized synthetic gas prepared from coal is divided into three parts, wherein the first part of synthetic gas enters into a first methanation reactor after being mixed with recycle air, gas at the outlet of the first methanation reactor enters into a second methanation reactor after being mixed with the second part of synthetic gas, the gas at the outlet of the second methanation reactor enters in to a third methanation reactor after being mixed with the third part of synthetic gas, after the gas is cooled in the third methanation reactor, part of the gas enters into a cyclic compressor to be boosted to be used as the recycle gas, other gases sequentially enter into a fourth methanation reactor, a fifth methanation reactor and a sixth methanation reactor to be subjected to methanation reaction, the dry basis content of methane in the gas at the outlet of the final methanation reactor is larger than 95%, and then the SNG meeting the requirement is obtained through cooling, compressing and dehydrating. The invention has the advantages of small recycle gas quantity, high energy utilization ratio and small investment.

The invention belongs to the field of metallurgy, is a process for producing pipeline steel by converter-RH-LF-continuous casting, comprising converter process and terminal control, oxygen-remaining steel-tapping process, RH decarburization desaeration process, RH deoxidation alloying process and LF desulfurization process. By using RH oxygen-remaining natural decarburization, the invention can reduce the burden of converter decarburization and lower the oxidizability of molten steel, better meet the quality requirements of X70, X80 pipeline steel to low carbon and high purity. Pipeline steel produced by the converter-RH-LF-continuous casting has carbon content stably controlled in a range of 0.035% to 0.050% in accordance with objective composition requirement, no more than 0.006% of N, no more than 0.0003% of H, 0.013% of P, 0.002% of S, no more than 1.5 levels of inclusion thick series and no more than 1.5 levels of inclusion fine series.

The invention discloses a method for smelting high-grade non-oriented silicon steel with excellent magnetism. The method comprises the following steps of: 1) smelting, namely smelting the following chemical components: less than or equal to 0.005 weight percent of C, 2.6 to 3.4 weight percent of Si, 0.2 to 0.5 weight percent of Mn, less than or equal to 0.2 weight percent of P, less than or equal to 0.005 weight percent of S, 0.3 to 1.6 weight percent of Al, less than or equal to 0.005 weight percent of N, less than or equal to 0.005 weight percent of O, less than or equal to 0.0015 weight percent of Ti, and the balance of Fe and inevitable inclusions, and modifying ladle top slag in the tapping process of a converter so as to ensure that the ladle top slag comprises 30 to 37 weight percent of CaO, 7 to 20 weight percent of SiO2, 35 to 45 weight percent of Al2O3, 5 to 9 weight percent of MgO, and 0.6 to 2.6 weight percent of T.Fe+MnO when the Ruhrstahl-Heraeus (RH) refining treatment begins; 2) performing RH refining, namely deoxidizing by using ferrosilicon when the decarburization of the RH refining is finished, wherein the adding speed of the ferrosilicon is less than or equal to 12.5kg/ton/min; and 3) adding 0.5 to 2.0 kg of calcium alloy into each ton of molten steel for the denaturation control of inclusions after the deoxidization and alloying are performed through the RH refining.

The invention relates to a method for processing Fischer-Tropsch synthesis tail gas, which comprises the steps of decarburization, membrane separation, low temperature oil washing, tail gas conversion and pressure swing adsorption(PSA). The method is characterized in that tail gas from a Fischer-Tropsch synthesis apparatus is passed through a decarburization unit for removing CO2 component; decarburization tail gas is sent to a membrane separation unit for recovering hydrogen, membrane separation penetration gas with rich hydrogen is boosted and then sent to a PSA unit for hydrogen production, also can be returned to the Fischer-Tropsch synthesis apparatus after boosting, the membrane separation unit can be returned to the Fischer-Tropsch synthesis apparatus according to the required gas with any H2/CO proportion, membrane separation non-penetration gas can be passed through a low temperature oil washing unit for recovering liquefied gas component and then sending to a tail gas conversion unit, and also can be sent to the tail gas conversion unit directly for hydrogen production; in the tail gas conversion unit, oil washing dry gas or membrane separation non-penetration gas are conversed, methane and hydrocarbons components are conversed to crude synthetic gas; the conversed crude synthetic gas converses CO and H2O to CO2 and H2, the conversed gas after decarburization removes CO2 to obtain hydrogen rich gas, the hydrogen rich gas is passed through the PSA unit for recovering hydrogen, hydrogen in the PSA unit can be used for whole plant, the analytic gas can be used as fuel gas.

The invention discloses a method for preparing a magnesium metal and a by-product by vacuum carbothermic reduction with serpentine minerals. The method comprises the following steps: using serpentine mineral powder as a raw material; adding a carbonaceous reducing agent which is 1 to 2 times of the theoretical quantity of carbon required for completely reducing magnesium silicate in the serpentine; adding a catalyst, and mixing the materials evenly to obtain a mixed raw material; pressing the mixed raw material into spherical or blocky ball agglomerations and drying the ball agglomerations; putting the dried ball agglomerations into a vacuum furnace, controlling the vacuum degree in the furnace to between 10 and 500 Pa, raising the temperature to between 500 and 700 DEG C, and keeping the temperature for 20 to 60 minutes to remove crystal water and clinker the materials; keeping the vacuum degree in the furnace, raising the temperature to between 1,200 and 1,500 DEG C, and reducing the magnesium silicate and oxides of metallic iron and nickel at a constant temperature for 30 to 60 minutes; and condensing magnesium vapor obtained from the reduction on a magnesium condenser into crystallized magnesium, recycling the metallic iron and the metallic nickel in the slag through magnetic separation, and preparing the slag after the magnetic separation into industrial silicon carbide through decarburization and purification.

A method and an apparatus for advantageously introducing a flame, a high velocity oxidizing gas, and a high velocity particulate flow into a furnace for metal melting, refining and processing, for example, steel making in an electric arc furnace. The steel making process of an electric arc furnace is made more efficient by shortening the time of the scrap melting phase, introducing a more effective high velocity oxidizing gas stream into the process sooner to decarburize the melted metal and introducing a more effective particulate injection to reduce FeO, form or foam slag and/or recarburize. Improved efficiency is obtained by mounting a fixed burner/lance and carbon injector lower and closer to the hot face of the furnace refractory at an effective injection angle. This mounting technique shortens the distance that the flame of the burner has to melt through scrap to clear a path to the molten metal, and shortens the distance the high velocity oxygen and high velocity particulates travel to the slag-metal interface. One method includes supplying a plurality of oxidizing reaction zones with the high velocity oxidizing gas to decarburize the melted metal and a plurality of particulate reaction zones with high velocity flows of particulate carbon for reducing FeO and/or forming foamy slag. The particulate reaction zones are located on the downstream side of the oxidizing gas reaction zones so as to minimize any effect of the reduction reaction on the decarburization reaction and to recover a part of the hot FeO produced in the oxidizing gas reaction zones.

The invention relates to the technology field of an antioxidation coating, in particular to a stainless steel high-temperature oxidation-resistant coating and the application thereof, and solves the problems in the prior stainless steel oxidation-resistant coating such as complex production process, high cost, low protection temperature, narrow painting temperature range and so on. The stainless steel high temperature oxidation-resistant coating is prepared with organic powdered ore in an amount of 30 to 50 parts; an inorganic binder in an amount of 50 to 70 parts; a suspending agent in an amount of 0.1 to 1 part; and water in an amount of 200 parts. The stainless steel high temperature oxidation-resistant coating is applicable to oxidation protection/decarburization when semi-finished nickel chromium stainless steel products are heated for 0.5 to 30 hours at the temperature of 800 DEG C to 1500 DEG C, and is sprayed or coated on stainless steel surfaces within the range from room temperature to 500 DEG C. The coating thickness ranges from 50 Mu m to 300 Mu m. The coating formed at the high temperature forms a vitreous dense coating during high-temperature processing of a stainless steel basal body, and prevents oxygen from spreading on the surface of the stainless steel basal body, thus resisting oxidation, alleviating depletion and decarburization of microelements on stainless steel surfaces, and improving the rolling quality of the surface of the base body. The raw materials used for preparing the coating are cheap, and the coating is friendly to the environment. The preparation process is simple. The high-temperature oxidation and melting loss of various semi-finished nickel chromium stainless steel products is reduced by more than 90 percent, and the output and the yield of good plate blanks can be improved.

The invention relates to a converter less-slag smelting process, belonging to the converter steelmaking field. The invention has the following main process characteristics: decarburization slag and dephosphorization slag with high dephosphorization rate in the dephosphorization period and decarburization period and high poured phosphorus content are recycled in the converter blowing process and the aims of reducing the consumption of converter lime and reducing the consumption of the steel material can be achieved. The converter smelting process is divided to a dephosphorization period and a decarburization period. In the dephosphorization period, lower flow is adopted for blowing, slag is poured after the dephosphorization period, the slag-removing rate is more than 30%; slag is conserved after the decarburization period, the decarburization slag is recycled, the dephosphorization efficiency is increased to reduce the additive amount of lime; the lime of the dephosphorization period is reduced gradually and the lime of the decarburization period is increased gradually, with the increase of heats; the balance can be achieved after 3-5 heats; and compared with the normal smelting method, the total consumption of lime of the method is reduced by 30%-60% when the balance is achieved.

The invention discloses an RH vacuum refining method of ultra-low carbon stainless steel, and the method uses a unique vacuum smelting principle of a RH vacuum circulation device; during an initial stage of RH vacuum refining, the nitrogen content of an incoming material of molten steel is decreased to meet an object requirement by using the vacuum condition; a decarburization mode combining forced decarburization with free decarburization is adopted at an RH refining work station; during denitrification and decarburization, the circulation flow rate of the molten steel is changed by different vacuum degrees and the increase of the gas flow so as to reach the purpose of rapid denitrification and decarburization; finally the temperature and the component are adjusted so as to meet the component requirement for ultra-low carbon stainless steel. Therefore, with the present production condition, variety extension of steel enterprises is realized, and requirements of stainless steel in various markets are met.

The invention relates to a processing flow of FT synthetic oil, which comprises hydrogenation, low-temperature oil washing, decarburization and PSA. The invention is characterized in that the synthetic oil is mixed with hydrogen via a filter, and enters a hydrogenated prerefining reactor after heat exchange, then enters a hydrogenated refining reactor after the synthetic oil is heated to 300 to 380 DEG C by a heating furnace; oxygen-containing compounds, unsaturated hydrocarbons and metal impurities in the raw material are extracted; the hydrogenated refined product enters a high thermal separator for separation of oil phase and gas phase after heat exchange, and enters a hydrocracking reactor for hydrocracking after heat exchange and heating of the heating furnace; the cracked product and the refined product are mixed to enter a fractionation system; a combined flow with two stages connected in series is adopted for the hydrogenated refining reactor and the hydrocracking reactor which share a recycle hydrogen system; a fractionation system is shared by the hydrogenated refined oil and the hydrocracked oil; and a three-column process flow is adopted for the fractionation system. The invention has the advantages of low gas consumption of the low-temperature oil washing process, high recovery of light hydrocarbons, less matching investment, and reduction of energy consumption and improvement of hydrogen recovery rate due to the decarburization process.

A base steel sheet has a hot-dip galvanized layer formed on a surface thereof, in which, in a steel sheet structure in a range of ⅛ thickness to ⅜ thickness centered around ¼ thickness of a sheet thickness from a surface, a volume fraction of a retained austenite phase is 5% or less, and a total volume fraction of phases of bainite, bainitic ferrite, fresh martensite, and tempered martensite is 40% or more, an average effective crystal grain diameter is 5.0 μm or less, a maximum effective crystal grain diameter is 20 μm or less, and a decarburized layer with a thickness of 0.01 μm to 10.0 μm is formed on a surface layer portion, in which a density of oxides dispersed in the decarburized layer is 1.0×10¹² to 1.0×10¹⁶ oxides/m², and an average grain diameter of the oxides is 500 nm or less.

The invention provides a method for producing high-purity pure iron, which comprises the following steps of: (1) preliminary desulphurization of molten iron: controlling the sulphur content of molten iron charged into a revolving furnace at 0.002%-0.015%; (2) smelting of the revolving furnace: dephosphorizing by using the double slag process, tapping slag after dephosphorization, changing slag, controlling C to be less than 0.03% and P to be less than 0.008% at blowing end, carrying out slag-blocked tapping and aluminium deoxidation, and hanging pots at temperature of above 1635 DEG C; (3) slagging off: removing more than 95% of oxidizing slag; (4) RH deep decarburization: controlling RH charging temperature to be above 1615 DEG C, controlling C to be less than 0.002% and Als to be from 0.020% to 0.035% at smelting end, and controlling the discharging temperature to be above 1645 DEG C; (5) LF (Low Frequency) deep decarburization: adding a deep dephosphorizing agent before entering anLF station, stirring with argon gas, adding a slagging constituent after entering the LF station, stirring with a great amount of argon gas, controlling C to be less than 0.0025%, S to be less than 0.0015%, Als to be less than 0.010% and discharging temperature to be from 1600 DEG C to 1605 DEG C; and (6) continuous casting of plate blanks. The invention has the advantages of low production cost and high efficiency; and the purity of the produced product reaches more than 99.9%.

The invention relates to a microalloying third-generation car spring flat steel and a preparing method thereof. The microalloying third-generation car spring flat steel comprises, by weight percentage, 0.48%-0.60% of C, 0.4%-0.8% of Si, 0.60%-1.00% of Mn, 0.80%-1.20% of Cr, 0.01%-0.05% of Nb, 0.0005%-0.003% of B, not larger than 0.025% of P, not larger than 0.025% of S, not larger than 0. 25% of Cu, not larger than 0.35% of Ni, not larger than 0.02% of Ti and the balance Fe. The preparing method includes the steps of blast furnace molten iron production, molten iron desulphurization, converter smelting, LF refining, RH vacuum treatment, square billet protection pouring, square billet heating, rolling, cooling bed slow cooling and fixed-size shearing. According to the microalloying third-generation car spring flat steel and the preparing method, niobium and boron microalloying and the silica content more suitable for the spring steel high elasticity ultra-low decarburization trend are adopted, the proper clean steel smelting process, rolling process and slow cooling control technology are adopted in a combined manner, and the high-end car spring flat steel having uniform texture, good hardenability, reasonably-matched comprehensive mechanicalness and good hardenability is developed.

The invention relates to a control method of decarburization of a continuously cast bloom for spring steel wire rods. The method comprises the following steps of: 1) performing smelting and continuous casting to form the bloom; 2) performing subsection heating on the continuously cast bloom under the reducing atmosphere; 3) rolling, wherein the rolling temperature is controlled at 960 to 1,010 DEG C; and 4) cooling the continuously cast bloom to room temperature, wherein the cooling velocity in two phase areas of austenite and ferrite is controlled at 15 DEG C per minute at least. The method can prolong the service cycle of springs, is suitable for producing the continuously cast bloom for the spring steel wire rods of any components, and does not produce full decarburization.

The invention discloses a process method for treating coking wastewater. The process method solves the technical problems that a micro-electrolysis method has hardening, channeling and narrow applicability of a pH range and a biochemical treatment process has long flow, large occupied area, poor impact load resistance and high expense. The method comprises a physical-chemical treatment unit consisting of a micro-electrolysis reactor and a settling tank; in the micro-electrolysis reactor, scrap iron, scrap copper and a lightweight blocky material are used as fillers; the pH of inlet water is between 2.0 and 6.0; the waterpower retention time is between 20 and 60 minutes; the method adopts air aeration; the method also comprises a filtering type inner circulating three-phase fluidized bed reactor biochemical treatment unit, and immobilized activated sludge balls are utilized to realize simultaneous denitrification and decarburization; the pH of inlet water is between 7.2 and 8.5; the concentration of dissolved oxygen is between 2 and 6mg/L; the temperature is between 28 and 32 DEG C; the waterpower retention time is between 20 and 40h; the COD of outlet water reaches secondary standard of integrated wastewater discharge standard; and volatile phenol, ammonia nitrogen and chroma reach primary standard of integrated wastewater discharge standard.

The invention relates to novel high-strength, fatigue-resistant and non-decarburized alloy spring steel, which comprises the following chemical components by weight percentage: 0.56-0.64 percent of C, 0.80-1.10 percent of Si, 0.80-1.20 percent of Mn, less than or equal to 0.035 percent of P, less than or equal to 0.03 percent of S, 0.80-1.20 percent of Cr, 0.60-1.00 percent of Mo, 0.20-0.30 percent of V, 0.05-0.12 percent of Nb, 0.01-0.06 percent of N, 0.02-0.07 percent of RE, and the balance of Fe. The invention also relates to a preparation method of the alloy spring steel and a steel wire thereof. The surface of the alloy spring steel of the invention has no decarburization, cracking or other defects. Moreover, compared with the prior art, the tensile strength, the fatigue life and other performances of the alloy spring steel are all improved significantly.