Steel slag treatment method and equipment

Abstract

The invention relates to a steel slag treatment method and equipment, and the steel slag treatment method comprises the following steps: adding a reducing agent into molten steel slag in a rotary injection manner for reduction reaction to obtain a mixed solution of molten steel and reducing slag; and after the mixed liquid is heated, the reducing slag and the molten steel in the mixed liquid are separated. According to the steel slag treatment method, steel separation is thorough, the steel recovery rate is increased, steel slag sensible heat is fully utilized, energy consumption is low, steel slag dynamic conditions are good, and safety and stability are good.

Description

Technical Field

[0001] The present application relates to the field of metallurgical technology, and in particular to a steel slag processing method and equipment. Background Art

[0002] Steel slag mainly includes converter slag, refined slag, casting residue slag, ladle slag, hot metal desulfurization slag, dephosphorization slag, desiliconization slag, etc., among which converter slag accounts for more than 80% of the total steel slag. Converter slag contains a large number of beneficial elements such as CaO, FeO, MnO and MgO that can be recycled, but it also contains harmful elements such as Cr2O3 and P2O5. Some CaO and MgO exist in a free state and expand in volume when exposed to water. According to the different characteristics of steel slag, the main steel slag treatment technologies include hot stewing, hot pouring, drum, wind quenching and water quenching. However, in traditional steel slag treatment technologies, except for the method of magnetic separation of metallic iron, which can recover iron for steelmaking, steel tailings are difficult to use directly or have a low utilization rate, resulting in a waste of resources. Summary of the invention

[0003] Based on this, it is necessary to provide a steel slag treatment method and equipment that can promote steel separation and improve steel recovery rate.

[0004] In one aspect of the present application, a method for treating steel slag is provided, comprising the following steps:

[0005] Adding a reducing agent into the molten steel slag in a rotary spraying manner to carry out a reduction reaction, thereby obtaining a mixed solution of molten steel and reduced slag;

[0006] After the mixed liquid is heated, the reduced slag and the molten steel in the mixed liquid are separated.

[0007] The above-mentioned steel slag treatment method mixes high-temperature molten steel slag and a reducing agent, and the reducing agent is added to the molten steel slag in a rotary blowing manner, which not only maximizes the use of the physical heat of the molten steel slag, but also a large amount of FeO is effectively reduced after the molten steel slag is treated with rotary blowing, thereby improving the recovery rate of steel and promoting the full separation of molten steel; in addition, the mixed liquid of molten steel and reducing slag is heated, which not only improves the fluidity of the mixed liquid, but also buys time for the reduced molten steel to fully fall back, thereby promoting the thorough separation of molten steel and reducing slag, and further improving the recovery rate of steel. If rotary blowing is simply introduced into molten steel slag, it is easy to cause the fluidity of molten steel slag to deteriorate. In the above-mentioned steel slag treatment method, by utilizing the hot molten steel slag and the reducing agent to undergo a full reduction reaction under rotary blowing, the heat of the molten steel slag itself is utilized and combined with heating treatment, synergistically enhancing the effect, improving the fluidity of the molten steel slag, and promoting steel-slag separation.

[0008] The above-mentioned slag treatment method reduces the mass content of P2O5 in the molten slag, which not only reduces the entry of phosphorus into the molten steel, but also is beneficial to the subsequent utilization of the reduced slag and reduces environmental pollution.

[0009] The above-mentioned steel slag treatment method makes full use of the sensible heat of steel slag, has low energy consumption, good steel slag dynamic conditions, and good safety and stability.

[0010] In some embodiments, the rotary blowing satisfies at least one of the following conditions:

[0011] (1) The spraying time of the rotary spraying is 6 minutes to 10 minutes;

[0012] (2) The rotation speed of the rotary spray is 80 rpm to 130 rpm;

[0013] (3) The rotary spraying has a spraying speed of 30 kg / (min·ton of slag) to 50 kg / (min·ton of slag).

[0014] In some embodiments, the rotary blowing satisfies at least one of the following conditions:

[0015] (1) The spraying time of the rotary spraying is 6 minutes to 8 minutes;

[0016] (2) The rotation speed of the rotary spraying is 80 rpm to 90 rpm when the spraying time is 0 to 5 min, and the rotation speed is 120 rpm to 130 rpm when the spraying time is >5 min;

[0017] (3) The spraying speed of the rotary spraying is 30-40 kg / (min·ton of slag) when the spraying time is 0-5 min, and the spraying speed is 41-50 kg / (min·ton of slag) when the spraying time is >5 min.

[0018] In some embodiments, the slag treatment method satisfies at least one of the following conditions:

[0019] (1) The molten steel slag is liquid steel slag after steel is tapped from a converter;

[0020] (2) The temperature of the molten slag is 1560° C. to 1650° C.;

[0021] (3) The reducing agent is at least one of carbon powder and ferrosilicon powder;

[0022] (4) The mass ratio of the reducing agent to the molten steel slag is 1 / 25 to 1 / 20;

[0023] (5) The temperature of the heating treatment is 1420° C. to 1500° C.;

[0024] (6) The heat preservation time of the heating treatment is 20 minutes to 30 minutes.

[0025] In some embodiments, the steel slag treatment method further comprises a steel slag air quenching step, and the steel slag air quenching comprises the following steps:

[0026] After separating the molten steel deposited on the bottom layer, the reducing slag is heated to 40000 Nm at a pressure of 0.3 MPa to 0.6 MPa. 3 / h~100000Nm 3 / h of high-pressure air is sprayed and collected.

[0027] A second aspect of the present application provides a slag processing device, comprising a reduction ladle, a rotary blowing device and a heating device;

[0028] The reduction ladle is used to place molten steel slag;

[0029] The rotary spraying device is used to rotary spray the reducing agent on the molten steel slag in the reduction ladle to perform a reduction reaction;

[0030] The heating device is used to heat the reduction ladle.

[0031] In some embodiments, the slag processing equipment also includes a receiving ladle and a slag pot; a connecting port is opened on the reduction ladle, and a steel outlet is opened at the bottom of the reduction ladle, the connecting port can be selectively connected to the rotary blowing device or the heating device, and the steel outlet can be selectively connected to the receiving ladle or the slag pot.

[0032] In some embodiments, the slag processing equipment further comprises a commutator, wherein the commutator is located below the reduction ladle, and the steel outlet can be selectively connected to the receiving ladle or the slag pot through the commutator.

[0033] In some embodiments, the commutator satisfies at least one of the following conditions:

[0034] (1) The commutator comprises a molten steel guide portion and a slag guide portion connected to each other, and the commutator is movable relative to the reduction ladle so that the molten steel guide portion or the slag guide portion is selectively arranged corresponding to the steel outlet;

[0035] (2) The commutator is made of refractory material.

[0036] In some embodiments, the slag processing equipment meets at least one of the following conditions:

[0037] (1) The slag processing equipment further comprises an air quenching device, wherein the air outlet of the air quenching device faces the slag discharge end of the commutator;

[0038] (2) The slag processing equipment further comprises a sealing plug and a sealing plug fixing plate, wherein the sealing plug is used to seal the steel outlet, and the sealing plug fixing plate is used to be arranged on the outer side of the sealing plug and fix the sealing plug when the sealing plug seals the steel outlet; the sealing plug fixing plate can be slidably connected with the reduction ladle to approach or move away from the steel outlet;

[0039] (3) The slag processing equipment further comprises a slag collecting device, wherein the slag collecting device comprises a slag collecting chamber, wherein the slag collecting chamber is provided with a slag inlet, a slag outlet and a dust exhaust port, and the slag outlet is connected to the slag pot. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of a slag processing device in one embodiment.

[0041] Figure 2 for Figure 1 Schematic diagram of the working status of Sinosteel’s slag processing equipment.

[0042] Figure 3 It is a schematic structural diagram of a commutator in one embodiment.

[0043] Description of reference numerals:

[0044] 1. Reduction ladle; 11. Connecting port; 12. Steel outlet; 2. Heating device; 3. Receiving ladle; 4. Slag pot; 5. Sealing plug; 6. Sealing plug fixing plate; 7. Commutator; 71. Liquid steel guide plate; 72. Slag guide plate; 73. Watershed; 8. Blowing port; 9. Slag collecting device; 91. Slag collecting chamber; 92. Slag inlet; 93. Slag outlet; 94. Dust outlet; 95. Bucket bin; 96. Valve; 10. Platform; 100. Bracket; 101. Liquid steel; 102. Reduction slag. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0047] At present, steel tailings are either difficult to be directly used or the steel recovery rate in the steel tailings is low. Among the traditional technologies, some are to crush the steel tailings and then screen them, and then magnetically separate the iron element for use. This recycling method is not only complicated, with some processes as many as more than a dozen, but also has a low recovery rate; some try to use reducing agents to reduce FeO and then recycle it, but it is often difficult to fully react, not only the steel recovery rate is low, but also the energy consumption is high, which is not worth the cost.

[0048] Based on this, one embodiment of the present application provides a slag treatment method, comprising the following steps:

[0049] Adding a reducing agent into the molten steel slag in a rotary spraying manner to carry out a reduction reaction, thereby obtaining a mixed solution of molten steel and reduced slag;

[0050] After the mixed liquid is heated, the reduced slag and the molten steel in the mixed liquid are separated.

[0051] Understandably, the reduced molten steel gathers in the lower layer because of its density greater than that of the reduced slag, while the reduced slag is in the upper layer.

[0052] The above-mentioned steel slag treatment method mixes high-temperature molten steel slag and a reducing agent, and the reducing agent is added to the molten steel slag in a rotary blowing manner, which not only maximizes the use of the physical heat of the molten steel slag, but also a large amount of FeO is effectively reduced after the molten steel slag is treated with rotary blowing, thereby improving the recovery rate of steel and promoting the full separation of molten steel; in addition, the mixed liquid of molten steel and reducing slag is heated, which not only improves the fluidity of the mixed liquid, but also buys time for the reduced molten steel to fully fall back, thereby promoting the thorough separation of molten steel and reducing slag, and further improving the recovery rate of steel. If rotary blowing is simply introduced into molten steel slag, it is easy to cause the fluidity of molten steel slag to deteriorate. In the above-mentioned steel slag treatment method, by utilizing the hot molten steel slag and the reducing agent to undergo a full reduction reaction under rotary blowing, the heat of the molten steel slag itself is utilized and combined with heating treatment, synergistically enhancing the effect, improving the fluidity of the molten steel slag, and promoting steel-slag separation.

[0053] The above-mentioned slag treatment method reduces the mass content of P2O5 in the molten slag, which not only reduces the entry of phosphorus into the molten steel, but also is beneficial to the subsequent utilization of the reduced slag and reduces environmental pollution.

[0054] The above-mentioned steel slag treatment method makes full use of the sensible heat of steel slag, has low energy consumption, good steel slag dynamic conditions, and good safety and stability.

[0055] In some embodiments, the rotary spraying has a spraying time of 6 to 10 minutes. Under this spraying time, not only is it beneficial for the reducing agent to be uniformly dissolved in the molten slag, avoiding the situation where the local components are too high or too low, and improving the recovery rate of the steel; but also, within this time range, the reaction is sufficient while avoiding the corrosion of the refractory material in the ladle by the slag; in addition, the mixed liquid also has good fluidity.

[0056] As an example, the spraying time of the rotary spraying can be 6 minutes, 7 minutes, 8 minutes, 9 minutes and 10 minutes, or within a range consisting of any two of the aforementioned values ​​as end values.

[0057] In some embodiments, the rotary spraying time is 6 to 8 minutes, which further improves the fluidity of the mixed solution and the recovery rate of steel.

[0058] In some embodiments, the rotation speed of the rotary blowing is 80 rpm to 130 rpm.

[0059] As an example, the rotation speed of the rotary blowing can be 80 rpm, 85 rpm, 90 rpm, 95 rpm, 100 rpm, 105 rpm, 110 rpm, 115 rpm, 120 rpm, 125 rpm and 130 rpm, or within a range consisting of any two of the aforementioned values ​​as end values.

[0060] In some of the embodiments, the rotary blowing has a blowing speed of 30 kg / (min·ton of slag) to 50 kg / (min·ton of slag).

[0061] As an example, the blowing speed of the rotary blowing can be 30 kg / (min·ton of slag), 31 kg / (min·ton of slag), 32 kg / (min·ton of slag), 33 kg / (min·ton of slag), 34 kg / (min·ton of slag), 35 kg / (min·ton of slag), 36 kg / (min·ton of slag), 37 kg / (min·ton of slag), 38 kg / (min·ton of slag), 39 kg / (min·ton of slag), 40 kg / (min·ton of slag), 41 kg / (min·ton of slag), 42 kg / (min·ton of slag), 43 kg / (min·ton of slag), 44 kg / (min·ton of slag), 45 kg / (min·ton of slag), 46 kg / (min·ton of slag), 47 kg / (min·ton of slag), 48 kg / (min·ton of slag), 49 kg / (min·ton of slag), 50 kg / (min·ton of slag), or within the range formed by any two of the aforementioned values ​​as end values.

[0062] In some embodiments, the rotation speed of the rotary spraying is 80 rpm to 90 rpm when the spraying time is 0 to 5 min, and the rotation speed is 120 rpm to 130 rpm when the spraying time is >5 min. The rotation speed increases from slow to fast, so that the reducing agent can be evenly distributed, avoiding uneven distribution of the reducing agent due to excessive centrifugal force, and at this rotation speed, it can avoid excessive crushing of the reducing agent to form a vortex, resulting in a complicated and uncontrollable flow path of the reducing agent, affecting the reaction effect, thereby improving the recovery rate of steel.

[0063] Furthermore, the rotation speed of the rotary spraying is preferably 80 rpm to 85 rpm when the spraying time is 0 to 5 min.

[0064] Furthermore, the rotation speed at >5 min is preferably 120 rpm to 125 rpm.

[0065] In some embodiments, the rotary spraying has a spraying speed of 30-40 kg / (min·ton slag) when the spraying time is 0-5 min, and a spraying speed of 41-50 kg / (min·ton slag) when the spraying time is >5 min. The spraying speed increases from slow to fast to avoid the reducing agent from gathering in a local area, improve the uniformity of the reducing agent distribution, and thus improve the recovery rate of the steel.

[0066] Furthermore, the rotary spraying has a spraying speed of preferably 30 to 35 (kg / min·ton of slag) when the spraying time is 0 to 5 min.

[0067] Furthermore, the injection speed at >5 min is preferably 41-45 (kg / min·ton of slag).

[0068] In some embodiments, the rotation speed of the rotary spraying is 80 rpm to 90 rpm when the spraying time is 0 to 5 min, and the rotation speed is 120 rpm to 130 rpm when the spraying time is >5 min; the spraying speed of the rotary spraying is 30 to 40 kg / (min·ton slag) when the spraying time is 0 to 5 min, and the spraying speed is 41 to 50 kg / (min·ton slag) when the spraying time is >5 min. This further promotes the complete separation of molten steel and reduced slag, and improves the recovery rate of steel.

[0069] In some embodiments, the molten steel slag is liquid steel slag after steel is tapped from a converter.

[0070] In some embodiments, the temperature of the molten slag is 1560°C to 1650°C.

[0071] Furthermore, the molten steel slag is liquid steel slag after steel is tapped from a converter.

[0072] In some embodiments, the reducing agent is a carbon or silicon based material.

[0073] Furthermore, the reducing agent is carbon powder or ferrosilicon powder.

[0074] Furthermore, the reducing agent is carbon-containing dust such as coal powder, coke powder and blast furnace ash, or ferrosilicon powder.

[0075] In some of the embodiments, the mass ratio of the reducing agent to the molten steel slag is 1 / 25 to 1 / 20.

[0076] In some embodiments, the temperature of the heating treatment is ≥ 1420°C.

[0077] In some embodiments, the temperature of the heat treatment is 1420°C to 1500°C.

[0078] As an example, the temperature of the heat treatment can be 1420°C, 1425°C, 1430°C, 1435°C, 1440°C, 1445°C, 1450°C, 1455°C, 1460°C, 1465°C, 1470°C, 1475°C, 1480°C, 1485°C, 1490°C, 1495°C and 1500°C, or a range consisting of any two of the foregoing values ​​as end values. The temperature of the heat treatment is preferably 1450°C to 1500°C.

[0079] In some embodiments, the heat treatment is carried out for a holding time of 20 to 30 minutes.

[0080] As an example, the heat preservation time of the heating treatment is 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min and 30 min, or in a range consisting of any two of the above values ​​as end values, preferably 20 min to 25 min.

[0081] In some of the embodiments, the molten steel slag after the rotary blowing treatment is heated and kept warm by introducing fuel gas.

[0082] Furthermore, the calorific value of the gas is 5000 J / Nm 3 ~12000J / Nm 3 , flow rate is 200Nm 3 / h~1000Nm 3 / h, pressure is 1000Pa~5000Pa.

[0083] In some embodiments, a slag quenching step is further included, wherein the slag quenching step includes the following steps: after separating the molten steel deposited on the bottom layer, the reducing slag is quenched with a pressure of 0.3 MPa to 0.6 MPa and an air volume of 40000 Nm 3 / h~100000Nm 3 / h of high-pressure air is used for blowing and collection. Using wind quenching to collect slag particles can quickly transfer high-temperature slag, realize continuous production, and greatly improve production efficiency.

[0084] For the second aspect of this application, please refer to Figure 1 , provides a slag processing equipment,

[0085] It includes a reduction ladle 1, a rotary blowing device (not shown) and a heating device 2;

[0086] The reduction ladle 1 is used to place molten steel slag;

[0087] The rotary spraying device is used to rotary spray the reducing agent on the molten steel slag in the reduction ladle 1 to carry out a reduction reaction;

[0088] The heating device 2 is used to heat the reduction ladle.

[0089] The above-mentioned slag processing equipment can mix the high-temperature molten slag and the reducing agent in the reducing ladle by placing the molten slag reduction ladle and the rotary blowing device, and the reducing agent can be added to the molten slag in a rotary blowing manner, which not only maximizes the use of the physical heat of the molten slag, but also a large amount of FeO is effectively reduced after the molten slag is treated by the rotary blowing device, thereby improving the recovery rate of steel and promoting the full separation of molten steel; in addition, the mixed liquid of molten steel and reducing slag is heated by the heating device, which not only improves the fluidity of the mixed liquid, but also buys time for the reduced molten steel to fully fall back, thereby promoting the complete separation of molten steel and reducing slag, and further improving the recovery rate of steel. If a rotary blowing device is simply introduced into the molten slag in the reduction ladle, the fluidity of the molten slag will easily deteriorate. The above-mentioned equipment utilizes the hot molten slag in the reduction ladle to carry out a sufficient reduction reaction with the reducing agent sprayed from the rotary blowing device, while utilizing the heat of the molten slag itself and combining it with a heating device for heating treatment, thereby synergistically enhancing the effect, improving the fluidity of the molten slag, and promoting steel-slag separation.

[0090] The above-mentioned slag processing equipment reduces the mass content of P2O5 in the molten slag, which not only reduces the phosphorus element entering the molten steel, but also is beneficial to the subsequent utilization of the reduced slag and reduces environmental pollution.

[0091] The above-mentioned slag processing equipment makes full use of the sensible heat of slag, has low energy consumption, good slag dynamic conditions, and good safety and stability.

[0092] In some embodiments, the heating device 2 is a roaster, which can be a translation type roaster, a clamshell type roaster or a rotary type roaster.

[0093] In some embodiments, the slag processing equipment also includes a receiving ladle 3 and a slag pot 4; a connecting port 11 is opened on the reduction ladle 1, and a steel outlet 12 is opened at the bottom of the reduction ladle 1, and the connecting port 11 can be selectively connected to the rotary blowing device or the heating device 2, and the steel outlet 12 can be selectively connected to the receiving ladle 3 or the slag pot 4.

[0094] It can be understood that the rotary blowing device and the heating device 2 are adapted to the connection port 11 of the reduction ladle 1; when the reduction reaction is performed, the rotary blowing device is connected to the connection port 11, and when the heating treatment is performed, the rotary blowing device is removed from the connection port 11, and then the heating device 2 is connected to the connection port 11. The rotary blowing device can adopt an existing rotary spray gun.

[0095] In some embodiments, the rotary spray gun is arranged on the platform 10; the rotary spray gun can rotate around its axis; the discharge end of the rotary spray gun is arranged in the reduction ladle 1; the rotary spray gun includes a powder spraying pipe, a support pipe and an insulation pipe which are nested in sequence from the inside to the outside; the discharge end of the powder spraying tank is connected to the feed end of the powder spraying pipe through a connecting pipe, which is used to spray the reducing agent powder into the reduction ladle 1; the rotation control device is arranged on the platform 10, and the rotation control device is connected to the support pipe to control the rotation of the rotary spray gun; the rotary spray gun also includes a paddle, when in use, the rotary spray gun is moved from the connection port 1 of the reduction ladle 1 1 is inserted into the molten steel slag so that the molten steel slag buries the blades of the rotary spray gun; in the rotary spray gun, the outermost insulation tube is used to insulate the inner powder spray tube and the support tube; the support tube is connected to the rotation control device to control the rotation of the rotary spray gun around its axis, and the reducing agent powder is sprayed through the powder spray tube, so that the reducing agent powder is sprayed into the molten steel slag through the discharge end of the powder spray tube of the rotary spray gun. At the same time, through the rotation of the rotary spray gun, the blades stir the molten steel slag, which can mix the reducing agent powder and the molten steel slag, so that the molten steel slag generates metal liquid under the action of the reduction reaction.

[0096] In some embodiments, the slag processing equipment further includes a sealing plug 5 and a sealing plug fixing plate 6, wherein the sealing plug 5 is used to seal the steel outlet 12, and the sealing plug fixing plate 6 is used to be arranged on the outside of the sealing plug 5 and fix the sealing plug 5 when the sealing plug 5 seals the steel outlet 12; the sealing plug fixing plate 6 can be slidably connected with the reduction ladle 1 to approach or move away from the steel outlet 12. The steel outlet 12 is blocked by the sealing plug 5 and the sealing plug fixing plate 6 to ensure that the steel outlet 12 of the reduction ladle 1 can still be opened when the static pressure of the slag is low.

[0097] In some embodiments, the slag processing equipment further includes a commutator 7, the commutator 7 is located below the reduction ladle 1, and the steel outlet 12 can be selectively connected to the receiving ladle 3 or the slag pot 4 through the commutator 7. The switching between the molten steel tapping and the reduction slag tapping is achieved by moving the position of the commutator 7; the commutator 7 makes it unnecessary to close the sealing plug fixing plate 6 in the middle when the molten steel is tapped first and the reduction slag is tapped later, and the sealing plug fixing plate 6 only needs to be slid open once to allow the molten steel and the reduction slag in the reduction ladle 1 to be completely discharged.

[0098] In some embodiments, the commutator includes a molten steel guide and a slag guide that are connected to each other, and the commutator can move relative to the reduction ladle so that the molten steel guide or the slag guide is selectively arranged corresponding to the steel outlet. The commutator promotes the complete separation of molten steel and reduction slag, has a simple structure, is flexible and maneuverable, realizes the continuity of the steel-slag separation process, and greatly improves the slag treatment efficiency.

[0099] In some embodiments, the molten steel guide portion and the slag guide portion are both guide surfaces, and the molten steel guide portion and the slag guide portion are connected to form an angle, the molten steel guide portion is inclined from top to bottom toward the receiving ladle, and the slag guide portion is inclined from top to bottom toward the slag pot.

[0100] Furthermore, the angle between the molten steel guide part and the slag guide part is 60 to 120 degrees, preferably 90 to 120 degrees. At this angle, the drainage effect is outstanding, which greatly improves the operating efficiency of the steel-slag separation process.

[0101] Understandably, the above angle refers to Figure 3 c. The molten steel guide part can adopt a molten steel guide plate, and the slag guide part can adopt a slag guide plate.

[0102] In some of these implementations, see Figure 3 The commutator 7 includes a molten steel guide plate 71 and a slag guide plate 72 which are connected to each other. The top edge of the molten steel guide plate 71 and the top edge of the slag guide plate 72 are connected to form a linear watershed 73, and the molten steel guide plate 71 and the slag guide plate 72 are connected at an angle of 60 to 120 degrees. The watershed 73 can be selectively located at the lower left or lower right of the steel outlet 12.

[0103] The commutator 7 can be moved horizontally to the left and right by using mechanical structures such as a mechanical arm. Before the molten steel is discharged, the molten steel guide plate 71 of the commutator 7 is located directly below the sealing plug 5 (the commutator 7 is in the Figure 2 When the molten steel is discharged and the reduction slag begins to appear, the commutator 7 is quickly moved so that the slag guide plate 72 is located directly below the sealing plug 5 to receive the reduction slag (the commutator 7 is in the state a). Figure 2 In the state b in the figure, the watershed 73 is located at the lower left of the steel outlet 12, and the reduced slag slides along the slag guide plate 72 to the top of the blowing port 8. The commutator 7 promotes the complete separation of the molten steel and the reduced slag, has a simple structure, is flexible and maneuverable, and realizes the continuity of the steel-slag separation process.

[0104] In some embodiments, the commutator 7 is made of refractory material.

[0105] In some embodiments, the slag processing equipment further comprises an air quenching device, and the air outlet 8 of the air quenching device is directed toward the slag discharge end of the commutator 7, that is, toward the slag discharge end of the slag guide plate 72. The reduced slag particles are collected in the slag collection chamber by using the air quenching reduced slag, and the reduced slag is allowed to fall freely into the slag pot under the action of gravity by opening the valve of the bucket bin, so that the high-temperature reduced slag in the slag collection chamber can be quickly transferred to achieve continuous production.

[0106] Furthermore, the air blowing port 8 is an air nozzle of an air quenching device.

[0107] In some embodiments, the slag processing equipment also includes a slag collecting device 9, which includes a slag collecting chamber 91, and the slag collecting chamber 91 is provided with a slag inlet 92, a slag outlet 93 and a dust exhaust port 94, and the slag outlet 93 is connected to the slag pot 4.

[0108] In some embodiments, the slag processing equipment works as follows:

[0109] See also Figure 2, the reducing agent is sprayed into the molten steel slag in the reduction ladle 1 by a rotary blowing device for reduction reaction, wherein the rotary nozzle of the rotary blowing device extends from the connection port 11 of the reduction ladle 1 into the molten steel slag for rotary blowing for 6min to 10min, at which time the reduced molten steel 101 is gathered at the bottom of the reduction ladle 1 because of its density being heavier than the reduction slag 102; then the reduction ladle 1 is hoisted to the platform 10, and a roaster is covered on the connection port 11 of the reduction ladle 1. The roaster can be fixed by the bracket 100 on the platform 10, and the roaster is passed through the gas pipeline 21 to heat and keep the mixed liquid after the rotary blowing treatment, and the insulation temperature is controlled to be above 1420°C, and the insulation time is 20min to 30min; then, the sealing plug fixing plate 6 is pushed open so that it no longer presses against the sealing plug 5, and the sealing plug 5 is between the molten steel 101 and the reduction slag 1 02 falls off under double static pressure, and the molten steel 101 falls freely onto the molten steel guide plate 71 of the commutator 7, and slides down the molten steel guide plate 71 into the receiving ladle 3; after the molten steel 101 is discharged, the commutator 7 is quickly moved so that the slag guide plate 72 on it is located directly below the steel outlet 12, and the reduced slag 102 slides down the slag guide plate 72 to above the blowing port 8 of the wind quenching device, and the molten reduced slag 102 is torn into slag particles with a diameter of <10mm by a large amount of high-pressure air ejected from the blowing port 8, and is ejected into the slag collecting chamber 91 through the slag inlet 92 by the high-pressure air, and accumulates in the bucket-shaped bin 95 at the bottom of the slag collecting chamber 91, and the dust and smoke are discharged through the dust removal pipe at the dust outlet 94 at the upper part of the slag collecting chamber 91, and enter the dust removal system for treatment; after the slag particles in the bucket-shaped bin 95 are full, the valve 96 is opened to release the slag particles into the slag tank 4, and transported to the next process for treatment.

[0110] in, Figure 2 It integrates two working states: collecting molten steel and collecting reduced slag.

[0111] The following are specific embodiments.

[0112] Example 1

[0113] At the converter slag processing station of the steel enterprise, a reduction ladle 1 with an inner diameter of 3.8m and a height of 3.5m is used to hold 15t~18t of hot molten slag after steel is tapped from a 210t converter at a time; wherein the temperature of the molten slag is 1600℃;

[0114] Then, the reduction ladle 1 is transported to the rotary spraying processing station, and the carbon powder is sprayed into the molten steel slag in the reduction ladle 1 by the rotary spraying device for reduction reaction, wherein the rotary nozzle of the rotary spraying device extends from the connection port 11 of the reduction ladle 1 into the molten steel slag for rotary spraying, and the reduced molten steel 101 is gathered at the bottom of the reduction ladle 1 because of its density being heavier than the reduction slag 102; wherein, the rotary spraying time is 8 minutes, the rotation speed in the first 5 minutes is 85 revolutions / min, the spraying speed in the first 5 minutes is 35 (kg / min·ton of slag), the rotation speed in the last 3 minutes is 125 revolutions / min, and the spraying speed in the last 3 minutes is 45 (kg / min·ton of slag);

[0115] Then the reduction ladle 1 is hoisted to the slag treatment platform 10, and a roaster is placed on the connection port 11 of the reduction ladle 1. The gas value used is 10000 J / Nm 3 , flow rate is 500Nm 3 / h, the mixed gas with a pressure of 3000Pa is used to heat and keep the molten steel slag, the holding temperature is controlled to be above 1420°C, the holding time is 20min, so that the molten steel 101 is fully gathered at the bottom of the reduction ladle 1; wherein the holding temperature is 1500°C, and the holding time is 20min;

[0116] Next, the sealing plug fixing plate 6 is pushed away so that it no longer presses against the sealing plug 5, and the sealing plug 5 falls off under the dual static pressure of the molten steel 101 and the reducing slag 102, and the molten steel 101 falls freely onto the molten steel guide plate of the commutator 7, and slides down the molten steel guide plate into the receiving ladle 3;

[0117] After the molten steel 101 is discharged, the commutator 7 is quickly moved so that the slag guide plate 72 on it is located directly below the steel outlet 12. The reduced slag 102 slides along the slag guide plate 72 to the top of the blowing port 8 of the wind quenching device. The molten reduced slag 102 is torn into slag particles with a diameter of less than 10 mm by a large amount of high-pressure air ejected from the blowing port 8. The slag particles are then ejected into the slag collecting chamber 91 through the slag inlet 92 and accumulated in the bucket-shaped bin 95 at the bottom of the slag collecting chamber 91. The pressure of the high-pressure air is 0.4 MPa and the air volume is 80000 Nm 3 / h;

[0118] After the air quenching device is sprayed, the tuyere nozzle is closed, the valve 96 of the bucket bin 95 is opened, and the granular slag is released into the slag pot 4 and transported to the next process for treatment; the dust and fume are discharged through the dust removal pipe at the dust discharge port 94 at the upper part of the slag collecting chamber 91 and enter the dust removal system for treatment.

[0119] Example 2

[0120] Example 2 is basically the same as Example 1, except that: the rotary blowing time is 10 minutes, the rotation speed in the first 5 minutes is 90 rpm, the blowing speed in the first 5 minutes is 40 (kg / min·ton of slag), the rotation speed in the last 5 minutes is 130 rpm, and the blowing speed in the last 5 minutes is 50 (kg / min·ton of slag); when heating and keeping warm, the insulation temperature is 1420°C and the insulation time is 30 minutes.

[0121] Example 3

[0122] Example 3 is basically the same as Example 1, except that during rotary spraying, the rotation speed in the first 5 minutes is 110 rpm.

[0123] Example 4

[0124] Example 4 is basically the same as Example 1, except that during rotary spraying, the spraying speed in the first 5 minutes is 50 (kg / min·ton of slag).

[0125] Example 5

[0126] Example 5 is basically the same as Example 1, except that the rotary spraying time is 15 minutes.

[0127] Example 6

[0128] Example 6 is basically the same as Example 1, except that the insulation temperature is 1400°C.

[0129] Example 7

[0130] Example 7 is basically the same as Example 1, except that the insulation time is 10 minutes.

[0131] The reduction slags of Examples 1 to 7 were tested for the mass content of FeO and P2O5. The mass content of FeO in the reduction slags was reduced from 20% to 25% to 4% to 6%, and the mass content of P2O5 was reduced from 1.2% to 2.2% to 0.1% to 0.24%, which effectively improved the recovery rate of molten metal and the recycling rate of slag, thereby improving economic benefits and reducing environmental pollution.

[0132] Moreover, during the rotary spraying treatment, the steel recovery rate was higher when the spraying time was 6min to 8min, or the rotation speed of the rotary spraying was 80 rpm to 90 rpm when the rotary spraying was ≤5min, the rotation speed was 120 rpm to 130 rpm when the rotary spraying was >5min, or the spraying speed was 30 to 40 (kg / min·ton slag) when the rotary spraying was ≤5min, and the spraying speed was 41 to 50 (kg / min·ton slag) when the rotary spraying was >5min. A higher steel recovery rate was obtained when the holding temperature was 1420℃ to 1500℃ or the holding time was 20min to 30min.

[0133] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0134] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for treating steel slag, characterized in that: The following steps are involved: Adding a reducing agent into the molten steel slag in a rotary spraying manner to carry out a reduction reaction, thereby obtaining a mixed solution of molten steel and reduced slag; After the mixed liquid is heated, the reduced slag and the molten steel in the mixed liquid are separated.

2. The steel slag treatment method according to claim 1, characterized in that: The rotary spraying satisfies at least one of the following conditions: (1) The spraying time of the rotary spraying is 6 minutes to 10 minutes; (2) The rotation speed of the rotary spray is 80 rpm to 130 rpm; (3) The spraying speed of the rotary spraying is 30 kg / (min·ton of slag) to 50 kg / (min·ton of slag).

3. The steel slag treatment method according to claim 1, characterized in that: The rotary spraying satisfies at least one of the following conditions: (1) The spraying time of the rotary spraying is 6 minutes to 8 minutes; (2) The rotation speed of the rotary spraying is 80 rpm to 90 rpm when the spraying time is 0 to 5 min, and the rotation speed is 120 rpm to 130 rpm when the spraying time is >5 min; (3) The spraying speed of the rotary spraying is 30-40 kg / (min·ton of slag) when the spraying time is 0-5 min, and the spraying speed is 41-50 kg / (min·ton of slag) when the spraying time is >5 min.

4. The steel slag treatment method according to claim 1, characterized in that: At least one of the following conditions is met: (1) The molten steel slag is liquid steel slag after steel is tapped from a converter; (2) The temperature of the molten slag is 1560° C. to 1650° C.; (3) The reducing agent is at least one of carbon powder and ferrosilicon powder; (4) The mass ratio of the reducing agent to the molten steel slag is 1 / 25 to 1 / 20; (5) The temperature of the heating treatment is 1420° C. to 1500° C.; (6) The heat preservation time of the heating treatment is 20 minutes to 30 minutes.

5. The steel slag treatment method according to any one of claims 1 to 4, characterized in that: The steel slag air quenching step is also included, and the steel slag air quenching includes the following steps: After separating the molten steel deposited on the bottom layer, the reducing slag is heated to 40000 Nm at a pressure of 0.3 MPa to 0.6 MPa. 3 / h~100000Nm 3 / h of high-pressure air is sprayed and collected.

6. A slag processing equipment, characterized in that: It includes a reduction ladle, a rotary blowing device and a heating device; The reduction ladle is used to place molten steel slag; The rotary spraying device is used to rotary spray the reducing agent on the molten steel slag in the reduction ladle to perform a reduction reaction; The heating device is used to heat the reduction ladle.

7. The slag processing equipment according to claim 6, characterized in that: The slag processing equipment also includes a receiving ladle and a slag pot; a connecting port is opened on the reduction ladle, and a steel outlet is opened at the bottom of the reduction ladle. The connecting port can be selectively connected to the rotary blowing device or the heating device, and the steel outlet can be selectively connected to the receiving ladle or the slag pot.

8. The slag processing equipment according to claim 7, characterized in that: The slag processing equipment further comprises a commutator, wherein the commutator is located below the reducing ladle, and the steel outlet can be selectively connected to the receiving ladle or the slag pot through the commutator.

9. The slag processing equipment according to claim 8, characterized in that: The commutator satisfies at least one of the following conditions: (1) The commutator comprises a molten steel guide portion and a slag guide portion connected to each other, and the commutator is movable relative to the reduction ladle so that the molten steel guide portion or the slag guide portion is selectively arranged corresponding to the steel outlet; (2) The commutator is made of refractory material.

10. The slag processing equipment according to claim 8, characterized in that: At least one of the following conditions is met: (1) The slag processing equipment further comprises an air quenching device, wherein the air outlet of the air quenching device faces the slag discharge end of the commutator; (2) The slag processing equipment further comprises a sealing plug and a sealing plug fixing plate, wherein the sealing plug is used to seal the steel outlet, and the sealing plug fixing plate is used to be arranged on the outer side of the sealing plug and fix the sealing plug when the sealing plug seals the steel outlet; the sealing plug fixing plate can be slidably connected with the reduction ladle to approach or move away from the steel outlet; (3) The slag processing equipment further comprises a slag collecting device, wherein the slag collecting device comprises a slag collecting chamber, wherein the slag collecting chamber is provided with a slag inlet, a slag outlet and a dust exhaust port, and the slag outlet is connected to the slag pot.

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