58results about How to "Shorten the slagging time" patented technology

The method to pour residual hot steel sludge for recovery in steel production comprises: a. after casting, pouring the residual steel sludge into empty ladle; b. conveying the sludge to converter and tapping; c. refining; d. casting; repeating. This invention makes full use of the sulfur capacity and strong reducibility to absorb inclusion and improve liquid steel cleanness rapidly, overcomes the consumption for low-melting, and reduces pollution and cost.

The invention provides a composition for slag formation, which comprises the following components based on the total weight of the composition: 45-65wt% of CaO, 10-20wt% of SiO2, 1-5wt% of MnO, 9-25wt% of MgO and 1.5-5wt% of Al2O3. The invention also provides a preparation method and a use method of the composition. The composition for slag formation provided by the invention can promote slagging in the early stage of smelting semisteel, shorten the slag formation time, and obviously remove phosphorus elements. By adopting the composition for slag formation of the invention for smelting the semisteel, the process is simple, the energy consumption is low, the effect of reducing phosphorus is obvious, the phosphorus content in molten steel is lower than 0.007wt%, and consumption of the semisteel is small when the same amount of steel is obtained by smelting.

The invention relates to a converter less-slag smelting method. The converter less-slag smelting method uniformly adopts a less-slag single-slag mode under the conditions of high iron consumption or low iron consumption and complex molten iron silicon change. The converter less-slag smelting method comprises the following process flows of: finishing tapping, remaining slags, adjusting the slags, splashing the slags, adding scrap steel, mixing molten iron, conducting calculation, conducting blowing, controlling an end point and tapping. In the smelting process, the lance position and the oxygen supply intensity are controlled by referring to the CO value; the end oxidizability is effectively controlled through heat balance accurate calculation; the molten steel oxidizability is reduced through process low lance position control; the alloying cost is effectively reduced; and meanwhile, the final slag oxidizability is reduced; the slag splashing furnace protection effect is promoted; and the furnace condition maintenance cost is effectively reduced.

The invention relates to a slag modifier for converter refining, which comprises the following components by mass percentage: 0-6.0 of CaO, 48-58 of Al2O3, 0-12 of SiO2, 20-25 of Al, and the balance of inevitable impurities. By adding the slag modifier in the processes of tapping, refining and slagging of a converter, the deoxidation cost in the steel making process can be reduced, the desulfurization degree of steel water in the tapping process of the converter can be increased, the slagging time of white line slag refined by a ladle furnace can be shortened, the refining effect can be improved, the oxidizability of refined early slag can be reduced, and the purity of the steel water can be enhanced.

The invention belongs to the technical field of iron and steel smelting and particularly relates to a fluoride-free slagging flux for the electric-arc furnace steelmaking and a preparation method thereof. The invention aims to provide the fluoride-free slagging flux for the electric-arc furnace steelmaking and the preparation method thereof and solve various problems of low slagging speed, poor slag melting effect, fluorine pollution, high cost, serious corrosion of a furnace lining, large dust capacity and the like which are generated due to the case that currently, lime, fluorite, calcium aluminate and iron oxide are used as slags. The fluoride-free slagging flux is characterized by being prepared from the following raw materials in percentage by weight: 20 to 40 percent of spodumene, 15 to 20 percent of red bauxite, 30 to 50 percent of active lime, 5 to 10 percent of iron oxide and 5 to 10 percent of magnesia.

The invention discloses a recycling method of refining hot slag. The recycling method of the refining hot slag comprises the steps that molten steel subjected to LF white slag refining is cast, casting residual hot steel-making slag and casting residual molten steel generated after LF white slag refining are poured into an empty steel ladle, and to-be-refined molten steel, casting residual moltensteel, casting residual hot steel-making slag with the weight being 40-50% and lime of the next cycle are added into an LF refining furnace for LF white slag refining of the next cycle. By means of the recycling method of the refining hot slag, the problems that an LF refining slag cycling technology of the present stage is not mature yet, the LF refining slag comprehensive utilization rate is low, and severe environment pollution and resource waste are caused are solved.

The invention belongs to the technical field of iron and steel metallurgy and in particular relates to a low-cost slag washing method. The low-cost slag washing method comprises the following steps: producing synthetic slag for slag washing in a steel ladle, obtained by casting molten steel, by utilizing refining slag and a deoxidant; then utilizing the produced solid-state synthetic slag with relatively high temperature for slag washing operation of a steel tapping process of the next heat. The method provided by the invention has a simple technology and is low in cost; the consumption of slag production materials is less and the heat of the refining slag is recycled; smooth production is not influenced; compared with cyclic utilization of heat-state refining slag, the low-cost slag washing method has remarkable advantages. Sulfur is effectively removed.

The invention discloses a method for efficiently using converter precipitator dust, belongs to the technical field of converter steel making methods, and is used for efficient reuse of the precipitator dust. The method is characterized in that the precipitator dust is added along with a chute in the process of extracting vanadium to discharge from semisteel; when the vanadium is extracted to discharge from the semisteel by 1/5, a secondary dust removing valve is opened; the chute rotates to add the precipitator dust by one time or two times; after the precipitator dust is added, the precipitator dust is accelerated to melt through front-back movement; the dust removing valve is recovered to a normal state; and after the semisteel is discharged, the iron mixing for converter steel making is prepared. The precipitator dust totally covers the liquid surface of the semisteel to achieve the effect of inhibiting the smoke discharge; the pecipitator dust is molten in a semisteel ladle to form slag to improve the difficulties of making steel slag by the semisteel; and the problems of non-ignition of a converter and explosion venting of an electric field in direct returning of the precipitator dust along with waste steel are solved. The method is an initiate in converter steel making, solves the problem, of capability of effectively using the precipitator dust, not thoroughly solved for a long time, and has the advantages of short flow, high metal yield and low cost.

The invention belongs to the technical field of slag adding of electroslag furnaces, and particularly relates to a slag adding and slagging method of a high-temperature alloy short-electrode electroslag furnace. The slag adding and slagging method of the high-temperature alloy short-electrode electroslag furnace comprises the steps that firstly, slag is placed in a slag adding machine, the slag adding machine is started, and the slag enters a lower smoke hood along a slag adding pipe, then reaches a lower flange, is gathered and aligned on the lower flange, enters a crystallizer, is guided through an electrode cap, finally reaches a bottom pad and starts to be slagged. The slag adding and slagging method of the high-temperature alloy short-electrode electroslag furnace is a simple and smooth feeding mode, the slag can evenly enter the bottom pad of the crystallizer without delay, and the utilization rate of the slag can be increased through the arrangement of the electrode cap; and bysetting proper parameters, the slagging process is smooth, the smelting rhythm can be accelerated, the slag crust thickness is small, the slag inclusion condition is light, and therefore the alloy quality is improved.

The invention discloses a semi-steel less slagging dephosphorization smelting method capable of rapid slagging, and belongs to the technical field of steel smelting. The semi-steel less slagging dephosphorization smelting method includes the following steps that (1) under the condition that slag exists in a converter, the basicity of the slag is adjusted to be 2-2.5 by adding a composite slag forming agent after converter protection by slag splashing, semi-steel is blended, then under the condition of top blowing oxygen supply and bottom blowing gas supply, blowing and slag forming are conducted, the basicity of the slag is controlled to be 1.5-2 by adding the composite slag forming agent in the process of blowing, and after blowing is completed, turning down and slagging are conducted; (2) after slagging in the step (1), the basicity of the final slag is controlled to be 3-4 by adding high-magnesium lime and active lime into the converter under the condition of top blowing oxygen supply and bottom blowing gas supply, blowing is conducted until qualified molten steel is obtained, and slag B existing in the converter is obtained after steel tapping and all slag remaining; and (3) the step (1) and the step (2) are cycled, wherein the original slag existing in the converter in step (1) is the slag B obtained in the step (2).

The invention discloses an integrated embedding type skewback foundation excavation construction method, and relates to bridges. The method comprises the steps that at least two steps are excavated ona slope, specifically, the first step is excavated on the slope at first, then, the second step is excavated below the first step, and the rest steps continue being excavated downwards in sequence, wherein the excavation depth of the first step is the largest, and the excavation depth of the follow-up steps is gradually decreased. The method has the beneficial effects that by arranging the multiple steps, the construction problems of large-gradient excavation and hole opening eccentric compression can be solved, and surrounding soil body displacement can be reduced advantageously; and the construction method is reasonable and reliable, the deslagging time can be shortened, and construction progress is accelerated.

The invention discloses a method for producing steel by using limestone in semisteel steelmaking of top-bottom combined blowing converter. The method comprises the following steps that semisteel is added into a converter, limestone, lime and light-burned dolomite materials are added in batches for slagging and oxygen supply blowing, and after a converter smelting control end point is reached, thesteel is discharged. According to the method, the limestone is used for replacing part of the lime to carry out converter steelmaking production, so that the use amount of the lime and the dependenceof converter semisteel steelmaking on lime slagging are reduced, meanwhile, the production cost can be reduced, and the purposes of energy conservation, emission reduction and environmental friendliness are achieved; in the limestone decomposition process, the generated CO2 reacts with CO generated in the C in the steel in the floating escaping process, so that not only can the adsorption upward floating of the impurities be promoted, but also the effect of the steel slag interface is promoted, the slagging time of the converter is shortened by 0.5-2.0min, the dephosphorization efficiency is improved, and the final dephosphorization rate is more than or equal to 90%.

The invention discloses a blowing method of a converter and an oxygen lance. The blowing method of the converter comprises the following steps: additionally arranging a nitrogen branch on an oxygen supply pipeline of the oxygen lance; and enabling the oxygen lance to simultaneously blow oxygen and high-pressure nitrogen into steel liquid in the converter in the earlier, middle and later stages of blowing. The blowing method and the oxygen lance have the following advantages that the change for equipment is small, and the cost is relatively low; the implementation and operation costs are low, and the operation is simple and convenient; the metal yield is increased, the service life of a copper head of the oxygen lance is prolonged, and the possibility of explosion venting caused by electric dust removal is reduced; the slag discharging time is shortened; the effect of carbon content retaining steel tapping in the final stage of blowing is obvious; meanwhile, the temperature and components in a molten pool are evened; and the problem that the bottom blowing effect of a conventional top and bottom combined blowing converter in the intermediate campaign is not obvious can be solved.

The invention relates to the field of pharmaceutical equipment and provides a high-efficiency water precipitation and concentration system. The high-efficiency water precipitation and concentration system comprises a water precipitation refrigeration pot, a plate and frame filter and a multi-effect concentration system, which are connected in sequence, wherein a dreg discharging hole and a dreg discharging hole cover for closing the dreg discharging hole are arranged at the bottom of the water precipitation refrigeration pot; the dreg discharging hole cover is connected with a discharging assisting part; the discharging assisting part comprises a connecting rod and a backward hooking part which are connected with each other; the connecting rod is connected with the dreg discharging hole cover; the backward hooking part is located in the water precipitation refrigeration pot; a liquid inlet pipe is arranged at the top of the water precipitation refrigeration pot and a liquid outlet pipe is arranged at the lower part of the water precipitation refrigeration pot; one end of the liquid outlet pipe is communicated with the plate and frame filter and a filter is arranged at the other end of the liquid outlet pipe; the filter is located in the water precipitation refrigeration pot. The high-efficiency water precipitation and concentration system has high working efficiency. The invention further provides a traditional Chinese medicine extraction system; the traditional Chinese medicine extraction system comprises the high-efficiency water precipitation and concentration system provided by the invention and has high working efficiency.

The invention relates to a method for blowing high-grade matte through a horizontal rotary furnace. The technical problem is solved that an existing matte blowing method is long in blowing cycle, lowin air supply time rate and low in single furnace output. According to the technical scheme, the method includes the following steps of firstly, selecting the matte at the grade of 70-75% as the blowing raw material; secondly, conducting thermal insulation on a hearth through natural gas when the empty rotary furnace waits for the material; thirdly, adding 50 tonnages of the raw material into therotary furnace for blowing; fourthly, conducting blowing for 30-50 minutes, and then adding 25 tonnages of the raw material into the rotary furnace to continue the blowing; fifthly, conducting blowingfor 25-35 minutes, and then adding 25 tonnages of the raw material into the rotary furnace for blowing for 5 minutes, and then adding quartz stone into the furnace to continue the blowing; sixthly, continuing the blowing for 65-75 minutes, then conducting depositing for 5 minutes, and then discharging residues. When the high-grade matte is blown in the horizontal rotary furnace, a traditional two-cycle blowing method is changed into a single-cycle blowing method, the blowing time is shortened, and the method has the advantages of high safety coefficient, large cold material throughput, low inproduction cost and the like.