A gunning material for improving the performance of RH semi-dry gunning sintering and a preparation method thereof

Abstract

This invention relates to a spraying material for improving the sintering performance of RH semi-dry spraying and its preparation method. The spraying material is prepared from the following raw materials in parts by weight: 45-90 parts sintered magnesia granules, 15-30 parts sintered magnesia powder (180 mesh), 2-6 parts sodium hexametaphosphate or sodium tripolyphosphate, 2-6 parts sodium bentonite, 2-6 parts quicklime, 2-6 parts solid sodium silicate, 0.05-0.1 parts fiber, and 20-25 parts composite sintering improver. The composite sintering improver is a mixture of iron tailings powder, jade powder, and aluminum ash. By optimizing and improving the sintering performance of existing semi-dry spraying materials, it is made suitable for spraying and maintenance of RH impregnated pipes, enhancing adhesion, optimizing sintering properties, and improving erosion resistance, thereby improving the performance of RH spraying materials and effectively extending the service life of RH impregnated pipes and circulation pipes.

Description

Technical Field

[0001] This invention relates to refractory materials for RH vacuum refining equipment in steel plants, and more particularly to a spraying material for improving the sintering performance of RH semi-dry spraying and its preparation method. Background Technology

[0002] In recent decades, RH vacuum refining technology has made great progress, evolving from a single degassing function to a multi-functional system including vacuum degassing, decarburization, oxygen blowing decarburization, powder injection desulfurization, temperature compensation, inclusion removal, and uniform temperature and composition. It has become the most commonly used secondary refining metallurgical method for smelting high-quality steel.

[0003] Among them, the RH immersion tube is the most important refractory material in the RH vacuum refining process. During operation, the RH vacuum insertion tube is directly immersed in molten steel at temperatures above 1600℃ for 30-40 minutes. The chromium-free ring bricks (or magnesia-chrome ring bricks) in the RH immersion tube are subjected to erosion and corrosion by the molten steel, with a typical corrosion rate of 0.5-0.8 mm / bottle. The outer castable layer is also subjected to erosion and corrosion by the molten steel. Furthermore, due to the significant difference in thermal expansion coefficients between the steel structural components and the outer castable layer (nearly 10 times), the outer castable layer experiences both melting and cracking damage during high-temperature use. Without routine repair and maintenance, both the inner chromium-free ring bricks (or magnesia-chrome ring bricks) and the outer castable layer are highly susceptible to damage, resulting in short service life and disrupting the smooth operation of the steel mill's refining production.

[0004] To achieve the ideal service life, RH-impregnated tubes are generally maintained using offline spraying. This involves using sprayed material to mitigate some of the erosion of the inner chromium-free ring brick (or magnesia-chrome ring brick) and outer castable layer by molten steel. The commonly used method is semi-dry spraying, also known as hot offline spraying, using a semi-dry spraying machine. The sprayed material is typically magnesia or magnesia-calcium alloy. Semi-dry spraying can extend the service life of RH-impregnated tubes to a certain extent, basically meeting the spraying needs of 80–250t refining processes.

[0005] Currently, the commonly used semi-dry spraying materials often have a short service life, typically only 1-3 cans, due to their poor sintering performance. This means that spraying is usually done every 1-2 cans, which cannot meet the requirements of the fast-paced RH vacuum refining process. Therefore, improving the sintering performance of spraying materials is urgently needed. Summary of the Invention

[0006] The purpose of this invention is to provide a spraying material and its preparation method that improves the sintering performance of RH semi-dry spraying. By optimizing and improving the sintering performance of existing semi-dry spraying materials, it makes them suitable for spraying and maintenance operations of RH impregnated pipes, enhances adhesion, optimizes sintering properties, and improves corrosion resistance, thereby improving the performance of RH spraying materials and effectively extending the service life of RH impregnated pipes and circulating pipes.

[0007] To achieve the above objectives, the present invention employs the following technical solution:

[0008] A spraying material for improving the sintering performance of RH semi-dry spraying is disclosed. The spraying material is prepared from the following raw materials in parts by weight: 45-90 parts sintered magnesia granules, 15-30 parts sintered magnesia powder (180 mesh), 2-6 parts sodium hexametaphosphate or sodium tripolyphosphate, 2-6 parts sodium bentonite, 2-6 parts quicklime, 2-6 parts solid sodium silicate, 0.05-0.1 parts fiber, and 20-25 parts composite sintering improver. The composite sintering improver is a mixture of iron tailings powder, jade powder, and aluminum ash. The magnesium oxide content in the sintered magnesia is 92wt%-97wt%.

[0009] In the composite sintering improver, the ratio of iron tailings powder: jade powder: aluminum ash is 1:(0.5-2):(6-10).

[0010] Aluminum ash is a waste product from the electrolytic aluminum process, containing 65wt% to 70wt% metallic aluminum.

[0011] The iron tailings slag contains 6wt%–17wt% Fe2O3, 3%–5% FeO, 30wt%–80wt% SiO2, 1wt%–13wt% Al2O3, 1wt%–14wt% MgO, and 1wt%–18wt% CaO.

[0012] The jade powder contains 20wt%–43wt% MgO, 40wt%–63wt% SiO2, ≤11wt% CaO, 10wt%–20wt% H2O (water of crystallization), and ≤1wt% Fe2O3; the jade powder particle size is 120–180 mesh.

[0013] The sintered magnesia granules contain 25-50 parts with a particle size of 3-1 mm and 20-40 parts with a particle size <1 mm.

[0014] The composite sintering improver is made of iron tailings powder, Xiuyan jade powder, and aluminum ash. When the composite sintering improver is added to the spraying material, the aluminum ash contains a certain amount of metallic aluminum powder (generally containing 40%-70% metallic aluminum). When the metallic aluminum powder comes into contact with the high-temperature spraying part of the RH impregnation pipe or RH circulation pipe, it reacts with oxygen in the air and releases a large amount of heat. This promotes the production of viscous silicate composite solid solution mineral phases—composite spinel mineral phases—from the iron tailings powder and Xiuyan jade powder (ferrous iron, ferric iron, silica, calcium oxide, alumina, and magnesium oxide from magnesia) in a short time. This effectively improves the adhesion and sintering performance of the RH spraying material, thereby improving its service life.

[0015] Aluminum is a common additive in existing refractory materials, but its function varies depending on the amount added. Generally, it has three functions depending on the amount added: 1) When aluminum is added at 0.05% to 0.5%, it acts as an explosion retardant. This is because Al reacts with H2O to produce Al(OH)3 and H2, and the hydrogen gas forms open channels during the discharge process, which facilitates the discharge of water vapor; 2) When aluminum is added at 0.5% to 3%, it acts as an antioxidant; 3) When aluminum is added at 3% to 5%, it acts as a metal bonding agent at 1100℃.

[0016] In this invention, the aluminum content exceeds 5%, and its function is to utilize the exothermic aluminothermic reaction. The large amount of heat causes the spraying material matrix to quickly form a viscous liquid phase, that is, to produce a sintered liquid phase, which firmly bonds the spraying material to the spraying surface. At this time, aluminum ash acts as a metal welding agent in the spraying material.

[0017] A method for preparing a spraying material to improve the sintering performance of RH semi-dry spraying includes the following steps:

[0018] 1) Preparation of composite sintering improver: Dry the iron tailings to a very high standard, then add it to a special ball mill to grind it into powder to 150-180 mesh to obtain qualified iron tailings powder. Accurately weigh the purchased Xiuyan jade powder, aluminum ash and self-made iron tailings powder according to the weight ratio. Put the three weighed materials into the mixer at one time. Use a cone mixer or V-type mixer to mix for 10-30 minutes. After mixing evenly, discharge the material and bag it for later use.

[0019] Accurately weigh the following materials according to their weight ratios: 3-1mm sintered magnesia granules, 1-0mm sintered magnesia granules, 180-mesh sintered magnesia powder, sodium hexametaphosphate or sodium tripolyphosphate, sodium bentonite, quicklime, solid sodium silicate, fiber, and composite sintering improver. Pack them into bags and set aside for later use.

[0020] 2) The mixing equipment for finished RH spraying material is generally a horizontal twin-shaft mixer. The weighed sintered magnesia granules and fibers are added to the twin-shaft mixer and mixed for 3-8 minutes. After stopping the machine, the remaining weighed 180-mesh sintered magnesia powder, sodium hexametaphosphate or sodium tripolyphosphate, sodium bentonite, quicklime, solid sodium silicate, and composite sintering improver are added to the twin-shaft mixer and mixed a second time for 5-10 minutes. The resulting spraying material is then discharged, bagged, and inspected for quality before being stored for shipment.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1) This invention introduces a composite sintering improver into RH spraying material for the first time. The residual metallic aluminum in the aluminum ash undergoes an exothermic aluminum-oxygen reaction when heated, which promotes a rapid reaction between sintered magnesia particles, sintered magnesia fine powder, binder and additives, and composite sintering improver. This generates a large number of beneficial viscous spinel solid solution mineral phases, such as magnesium aluminum spinel solid solution (melting point 2250℃) and iron aluminum spinel (melting point 1780℃), which optimizes the physical and chemical properties of the spraying material and significantly improves its adhesion and sinterability.

[0023] 2) This invention marks the first time that iron tailings powder and Xiuyan jade powder have been introduced as sintering agents into RH-coated refractory patching materials. This abandons the outdated notion that refractory materials and building materials are incompatible. These two materials, as common and inexpensive solid waste materials, have been widely used in the building materials industry in recent years. This invention, through research on the main silicate phases of these two materials, demonstrates that under high-temperature conditions, they can react with sintered magnesia to produce viscous spinel solid solution mineral phases, such as magnesia-alumina spinel solid solution (melting point 2250°C) and iron-alumina spinel (melting point 1780°C). The formation of these solid solutions as high-temperature mineral phases significantly improves the high-temperature performance of RH-coated patching materials, enhances their erosion and scour resistance, and thus extends their service life. Introducing these common building materials into the field of refractory materials, especially into RH-coated patching materials, is unprecedented.

[0024] 3) Aluminum ash, iron tailings powder, and Xiuyan jade powder are common and inexpensive solid waste materials. By introducing refractory materials through this invention, the cost of raw materials can be greatly reduced, the competitiveness of products can be improved, a large amount of waste solid waste materials can be effectively consumed, the environment can be improved, and green and sustainable development can be achieved.

[0025] This invention, by introducing a composite sintering improver, successfully improves the sintering performance and other medium-to-high temperature physical properties of ordinary RH spraying materials. Furthermore, it has achieved excellent results in steel plant applications. Spraying operations were performed on two pairs of RH impregnation pipes and RH circulation pipes in two steel plants. Compared with the original spraying material, the spraying material of this invention, due to its significantly improved sintering performance, ensures a longer service life for the RH impregnation pipes and RH circulation pipes. The physicochemical properties of the spraying material of this invention are shown in Table 1.

[0026] Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to examples:

[0029] Example 1:

[0030] Taking a steel plant in Hunan as an example, the main technical parameters are shown in Table 2 below.

[0031] Table 2 Main Technical Parameters of a Certain Converter Plant

[0032] Serial Number project unit numerical values Remark 1 Normal steel output of converter t ～220 2 230t molten steel ladle free space height mm 350～400 Shenggang 230 tons of molten steel 3 Maximum steel output of converter t 230 4 Average smelting cycle of converter min ～36 5 Average tapping temperature of converter ℃ 1660 6 Average casting time in continuous casting min 33

[0033] The product range to be smelted in the RH furnace of a certain converter plant includes: ultra-low carbon steels such as SPHE and IF steels, X70-X100 pipeline steels, high-grade non-oriented silicon steels, oriented silicon steels, high-grade ship plate steels, engineering machinery steels, wear-resistant steels, etc.

[0034] The refining process route is as follows:

[0035] Converter - Argon Blowing Station - LF Refining Furnace - Continuous Casting;

[0036] Converter - Argon Blowing Station - LF Refining Furnace - RH Refining Furnace - Continuous Casting;

[0037] Converter - Argon Blowing Station - RH Refining Furnace - Continuous Casting;

[0038] Converter - Argon Blowing Station - Continuous Casting;

[0039] The normal service life requirements for refractory materials in each part are shown in Table 3;

[0040] Table 3. Normal service life requirements of refractory materials for various parts of the RH vacuum tank in Example 1.

[0041] Part Impregnated tubes bottom lower part Central upper part Alloy Inlet Hot bending pipe Furnace lifespan ≥110 ≥220 ≥330 ≥1000 ≥1700 ≥1000 ≥3800

[0042] Note: Bottom, lower part, middle part, upper part, and alloy inlet all refer to different parts of the overall vacuum tank.

[0043] To achieve the above production goals, the RH semi-dry spraying material of this invention can be implemented through the following technical solutions:

[0044] A novel RH spraying material for optimizing sintering performance is composed of the following raw materials in the following weight proportions: 28 parts sintered magnesia granules (3-1mm), 35 parts sintered magnesia granules (1-0mm), 18 parts sintered magnesia powder (180 mesh), 2.5 parts sodium hexametaphosphate, 2.5 parts sodium bentonite, 4 parts quicklime, 4 parts solid sodium silicate, 0.1 parts fiber, and 22 parts composite sintering improver. The fiber is made of polypropylene fiber, with a length of 15mm and a melting point less than 120℃.

[0045] The composition ratio of the composite sintering improver in Example 1 is: iron tailings powder: Xiuyan jade powder: aluminum ash = 1:0.5:8, where the parameters and specifications of iron tailings powder, Xiuyan jade powder and aluminum ash are shown in Table 4.

[0046] Table 4 Parameters and Specifications of Composite Sintering Improver in Example 1

[0047]

[0048] The composite sintering improver is made of iron tailings powder, Xiuyan jade powder, and aluminum ash. When the composite sintering improver is added to the spraying material, the aluminum ash contains a certain amount of metallic aluminum powder (68%). When the metallic aluminum powder comes into contact with the high-temperature spraying part of the RH impregnation pipe or RH circulation pipe, it reacts with oxygen in the air and releases a large amount of heat. This promotes the production of viscous silicate composite solid solution mineral phases—composite spinel mineral phases—in a short time by the mineral phases such as divalent iron, trivalent iron, silicon dioxide, calcium oxide, aluminum oxide, and magnesium oxide in the iron tailings powder and Xiuyan jade powder. This effectively improves the adhesion and sintering performance of the RH spraying material, thereby improving the service life of the spraying material.

[0049] The process flow diagram of the production method is shown below. Figure 1 The specific method is as follows:

[0050] 1. Preparation of composite sintering improver. Dry the iron tailings to a high standard, then grind them into powder using a dedicated ball mill to a mesh size of 150-180, thus obtaining qualified iron tailings powder. Accurately weigh the purchased Xiuyan jade powder, aluminum ash, and self-made iron tailings powder according to the weight ratio. Add all three weighed materials at once to a mixer using a conical mixer. Mix for 25 minutes until uniformly mixed, then discharge and bag for later use.

[0051] 2. Accurately weigh the following materials according to their weight ratios: 3-1mm sintered magnesia particles, 1-0mm sintered magnesia particles, 180-mesh sintered magnesia powder, sodium hexametaphosphate, sodium bentonite, quicklime, solid sodium silicate, fiber, and composite sintering improver. Pack them into bags and set aside for later use.

[0052] 3. The mixing equipment for finished RH spraying material is generally a horizontal twin-shaft mixer. Weigh out the 3-1mm sintered magnesia particles, 1-0mm sintered magnesia particles, and fibers, and add them to the twin-shaft mixer. Mix for 6 minutes. After stopping the mixer, add the remaining weighed 180-mesh sintered magnesia powder, sodium hexametaphosphate, sodium bentonite, quicklime, solid sodium silicate, and composite sintering improver to the twin-shaft mixer. Mix again for 8 minutes. After stopping the mixer, discharge the material, bag it, and after inspection and approval, it can be stored for shipment.

[0053] The RH spraying material of this invention was tested on the impregnation tubes and circulation tubes of two RH vacuum tanks in a converter plant in Hunan Province. A total of 108 spraying operations were performed. Compared with the original RH spraying material, the service life of the spraying material of this invention was increased by 18.22% due to improved sintering performance and enhanced erosion resistance. Compared with the previous method, while reducing the number of spraying operations by 43 throughout the experiment, the service life of both pairs of RH impregnation tubes and RH circulation tubes all met the standard, averaging 120.5 tank cycles (compared to the original average of 118 tank cycles), saving a total of 9.6 tons of spraying material. Simultaneously, due to the use of some solid waste materials, the cost per ton of the RH spraying material of this invention was reduced by 338 yuan / ton, significantly improving the material's cost-effectiveness.

[0054] Example 2:

[0055] Taking a steel plant in Shandong as an example, the relevant smelting conditions are shown in Table 5.

[0056] Table 5 Basic process parameters of the 120-ton converter in Example 2

[0057] Serial Number Parameter name unit Design value Remark 1 Converter nominal capacity t 120 2 Average steel production per furnace in converter t 130-135 (T) 3 Full height of furnace shell mm 9200 (H) 4 Furnace shell outer diameter mm 6430 (D) 5 Full height of furnace shell / outer diameter of furnace shell 1.43 (H / D) 6 Full height of the furnace mm 7850 (h) 7 Furnace inner diameter mm 4800 <![CDATA[(d 上 )]]> 8 depth of the karst pool mm 1303 <![CDATA[(h 池 )]]> 9 New furnace internal volume <![CDATA[m 3 ]]> 117.15 (VL) 10 Furnace volume ratio <![CDATA[m 3 / t]]> 0.90 <![CDATA[V L / T]]> 11 Steel tapping angle Spend 12 12 Tap hole diameter mm 150 13 Maximum operating torque KN.m 2800 14 Furnace lining weight t 314 15 Furnace shell weight t 215

[0058] Pure oxygen blowing time: 17 min;

[0059] Oxygen consumption per ton of steel: 53 Nm 3 / t;

[0060] Total oxygen supply Q = 28000 Nm 3 / hr;

[0061] Oxygen supply intensity = 3.4 Nm 3 / t.min;

[0062] Gun positions: Basic gun position 1700mm, highest gun position 1900mm, lowest gun position 1500mm.

[0063] RH mainly involves steel grades such as Q345B, Q345C, Q345D, Q345E, cold-rolled series (SPHE, SPHD), deep-drawing steel series (IF steel), pipeline steel series (X65M, X56, X70 and above grades, with low production volume), pressure vessel steel series (Q245R, Q345R, Q370R), ship plate series (A, B, D, DH grades), bridge and construction steel series (Q345qD), and high-strength building steel (Q345GJC).

[0064] Processing modes and processing times: Light processing, vacuum time 15-18 min; This processing, vacuum time 18-22 min; Deep decarburization processing, vacuum time 30-35 min.

[0065] Average service life of various parts of the RH vacuum chamber (under normal production conditions):

[0066] Upper groove: 1000 times; Hot bending tube: 3000 times;

[0067] Lower tank: 300 times; Immersion tube: 80 times.

[0068] To achieve the above production goals, the RH semi-dry spraying material of this invention can be implemented through the following technical solutions:

[0069] A novel RH spraying material for optimizing sintering performance is composed of the following raw materials in the following weight proportions: 22 parts sintered magnesia 3-1mm, 40 parts sintered magnesia 1-0mm, 20 parts sintered magnesia powder 180 mesh, 3 parts sodium tripolyphosphate, 2.5 parts sodium bentonite, 3.5 parts quicklime, 3 parts solid sodium silicate, 0.07 parts fiber, and 24 parts composite sintering improver. The fiber is made of polypropylene fiber, with a length of 15mm and a melting point less than 120℃.

[0070] In Example 2, the composition ratio of the composite sintering improver is: iron tailings powder: Xiuyan jade powder: aluminum ash = 1:0.8:9, where the parameters and specifications of iron tailings powder, Xiuyan jade powder and aluminum ash are shown in Table 6.

[0071] Table 6 Parameters and Specifications of Composite Sintering Improver in Example 1

[0072]

[0073] The composite sintering improver is made of iron tailings powder, Xiuyan jade powder, and aluminum ash. When the composite sintering improver is added to the spraying material, the aluminum ash contains a certain amount of metallic aluminum powder (69%). When the metallic aluminum powder comes into contact with the high-temperature spraying part of the RH impregnation pipe or RH circulation pipe, it reacts with oxygen in the air and releases a large amount of heat. This promotes the production of viscous silicate composite solid solution mineral phases—composite spinel mineral phases—in a short time by the mineral phases such as divalent iron, trivalent iron, silicon dioxide, calcium oxide, aluminum oxide, and magnesium oxide in the iron tailings powder and Xiuyan jade powder. This effectively improves the adhesion and sintering performance of the RH spraying material, thereby improving the service life of the spraying material.

[0074] The process flow diagram of the production method is shown below. Figure 1 The specific method is as follows:

[0075] 1. Preparation of composite sintering improver. Dry the iron tailings to a high standard, then grind them into powder using a dedicated ball mill to a mesh size of 150-180, thus obtaining qualified iron tailings powder. Accurately weigh the purchased Xiuyan jade powder, aluminum ash, and self-made iron tailings powder according to the weight ratio. Add all three weighed materials at once to a mixer using a conical mixer. Mix for 25 minutes until uniformly mixed, then discharge and bag for later use.

[0076] 2. Accurately weigh the following materials according to their weight ratios: 3-1mm sintered magnesia particles, 1-0mm sintered magnesia particles, 180-mesh sintered magnesia powder, sodium tripolyphosphate, sodium bentonite, quicklime, solid sodium silicate, fiber, and composite sintering improver. Pack them into bags and set aside for later use.

[0077] 3. The mixing equipment for finished RH spraying material is generally a horizontal twin-shaft mixer. Weigh out 3-1mm sintered magnesia particles, 1-0mm sintered magnesia particles, and fibers, and add them to the twin-shaft mixer. Mix for 8 minutes. After stopping the machine, add the remaining weighed 180-mesh sintered magnesia powder, sodium tripolyphosphate, sodium bentonite, quicklime, solid sodium silicate, and composite sintering improver to the twin-shaft mixer. Mix again for 10 minutes. After stopping the machine, discharge the material, bag it, and after inspection and approval, it can be stored for shipment.

[0078] The RH spraying material of this invention was tested on the impregnation tubes and circulation tubes of three RH vacuum tanks in a steel plant in Shandong Province. A total of 133 spraying operations were performed. Compared with the original RH spraying material, the service life of the new spraying material increased by 26.11% due to improved sintering performance and enhanced corrosion resistance. Compared to the previous method, while reducing the number of spraying operations by 47 throughout the experiment, the service life of both pairs of RH impregnation tubes and RH circulation tubes all met the standards, averaging 90.33 tank cycles (compared to the original average of 85 tank cycles), saving a total of 9.3 tons of spraying material. Simultaneously, by using some solid waste materials, the cost per ton of the new RH spraying material was reduced by 353 yuan / ton, significantly improving the material's cost-effectiveness and gaining user approval.

[0079] The physicochemical performance indicators of spraying in Examples 1 and 2 are shown in Table 7.

[0080] Table 7. Physicochemical performance indicators of spraying in the examples.

[0081]

[0082]

Claims

1. A gunning material for improving the performance of RH semi-dry gunning and sintering, characterized in that, The gunning mixture is prepared from the following raw materials in parts by weight: sintered magnesia granules 45-90 parts, sintered magnesia powder 180 mesh 15-30 parts, sodium hexametaphosphate or sodium tripolyphosphate 2-6 parts, sodium-based bentonite 2-6 parts, slaked lime 2-6 parts, solid sodium silicate 2-6 parts, fiber 0.05-0.1 parts, and composite sintering improver 20-25 parts, wherein the composite sintering improver is a mixture of iron tailings powder, jade powder and aluminum ash; In the composite sintering improver, the iron tailings powder:jade powder:aluminum ash = 1:(0.5-2):(6-10); The iron tailings powder is obtained by grinding iron tailings slag, wherein the Fe2O3 content of the iron tailings slag is 6wt%-17wt%, the FeO content is 3wt%-5wt%, the SiO2 content is 30wt%-80wt%, the Al2O3 content is 1wt%-13wt%, the MgO content is 1wt%-14wt%, and the CaO content is 1wt%-18wt%. The MgO content of the jade powder is 20wt%-43wt%, the SiO2 content is 40wt%-63wt%, the CaO content is ≤11wt%, the crystal water H2O content is 10wt%-20wt%, and the Fe2O3 content is ≤1wt%; the particle size of the jade powder is 120-180 mesh.

2. The shot mix for improving the performance of RH semi-dry shot sintering according to claim 1, wherein The aluminum ash is a process waste of electrolytic aluminum, wherein the metallic aluminum content is 65wt%-70wt%.

3. The shot mix for improving the performance of RH semi-dry shot sintering according to claim 1, wherein the shot mix is characterized by, In the sintered magnesia granules, the particle size of 3-1mm is 25-50 parts, and the particle size of <1mm is 20-40 parts.

4. A method of producing a gunning material for improving the RH semi-dry process gunning and sintering performance according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: 1) preparing the composite sintering improver: drying the iron tailings slag, grinding to 150-180 mesh to obtain the iron tailings powder, and then mixing the jade powder, aluminum ash and iron tailings powder in a mixing machine for 10-30 minutes, and then discharging and packaging for standby use; 2) adding the sintered magnesia granules and fiber into a stirring machine and mixing for 3-8 minutes, then adding the sintered magnesia powder 180 mesh, sodium hexametaphosphate or sodium tripolyphosphate, sodium-based bentonite, slaked lime, solid sodium silicate and composite sintering improver into the stirring machine for secondary mixing for 5-10 minutes to obtain the gunning mixture.

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