阅读说明：本技术 一种转炉用绿色环保型镁尖晶石质喷补料及其制备和应用 (Environment-friendly magnesium spinel gunning mix for converter and preparation and application thereof ) 是由 刘光平 李媛媛 宋雅楠 尹明强 徐亮 柯极峰 熊元杰 于 2021-08-06 设计创作，主要内容包括：本发明公开了一种转炉用绿色环保型镁尖晶石质喷补料及其制备方法和在转炉维护中的应用。按质量份计,镁尖晶石质喷补料的原料组成包括：镁尖晶石回收料45～80份,镁砂料5～35份,镁质结合剂4～14份,磷酸盐结合剂1～5份,熟石灰微粉2～5份,增稠剂0.05～0.5份,防爆剂0.05～0.5份。本发明不含有沥青和树脂,环境友好,引入镁尖晶石回收料,采用镁质结合剂,使喷补料具有优异的粘附性和抗钢水侵蚀性。本发明实现了废旧耐火材料回收再利用,符合绿色环保的发展要求,保证了喷补料的使用寿命,降低了炼钢成本,利于推广应用。(The invention discloses a green environment-friendly magnesium spinel gunning mix for a converter, a preparation method thereof and application thereof in converter maintenance. The magnesium spinel gunning mix comprises the following raw materials in parts by mass: 45-80 parts of magnesium spinel reclaimed materials, 5-35 parts of magnesium sand materials, 4-14 parts of magnesium binders, 1-5 parts of phosphate binders, 2-5 parts of slaked lime micro powder, 0.05-0.5 part of thickening agents and 0.05-0.5 part of explosion-proof agents. The invention does not contain asphalt and resin, is environment-friendly, introduces magnesium spinel reclaimed materials, and adopts magnesium bonding agent to ensure that the gunning mix has excellent adhesiveness and molten steel erosion resistance. The invention realizes the recycling of waste refractory materials, meets the development requirement of environmental protection, ensures the service life of the gunning mix, reduces the steelmaking cost and is beneficial to popularization and application.)

1. The environment-friendly magnesium spinel gunning mix for the converter is characterized by comprising the following raw materials in parts by mass:

the particle size of the magnesium binder is not more than 5 mu m, the MgO content in the composition is not less than 77.00 wt%, and the SiO content in the composition₂The content is more than or equal to 13.00wt percent, and the ignition loss at 950 ℃ is less than or equal to 6.0wt percent;

MgO and Al in the recycled magnesium spinel material₂O₃The total content of the components is not less than 95 wt%, the particle size is not more than 5mm, and the specific particle size composition is as follows:

10 to 20 parts by mass of 5 to 3mm,

3 to 1mm, 3mm, 20 to 35 parts by mass,

1-0.045 mm, and does not contain 15-25 parts by mass of 1 mm;

the recycled magnesium spinel material is obtained by the following method:

1) recycling the waste magnesium spinel bricks used for RH linings, removing surface impurities, drying, crushing by a jaw crusher and a cone, removing iron by using a magnet in the crushing process, and screening to obtain aggregates with the particle sizes of 5-3 mm, < 3-1 mm and < 1-0.045 mm;

2) and (3) removing false particles attached to the surface of the aggregates with the particle size of 5-3 mm and the aggregate with the particle size of 3-1 mm by using an edge runner mill, improving the roundness of the particles, and screening by using a secondary screen to obtain the high-quality magnesium spinel recycled particles with the particle size of 5-3 mm and the aggregate with the particle size of 3-1 mm.

2. The environment-friendly magnesia spinel gunning mix for the converter according to claim 1, wherein the magnesia material is one or two of sintered magnesia and fused magnesia.

3. The environment-friendly magnesia spinel gunning mix for a converter according to claim 1, wherein the MgO content in the magnesium sand material is not less than 95 wt%.

4. The environment-friendly magnesium spinel gunning mix for the converter according to claim 1, wherein the particle size of the magnesium sand material is less than 1mm, and the specific particle size distribution is as follows in parts by mass:

1 to 0.045mm, and 0 to 20 parts by weight of a filler not containing 1mm,

less than 0.045mm 5-15 parts.

5. The environment-friendly magnesium spinel gunning mix for the converter according to claim 1, wherein the phosphate binder is one or more of sodium hexametaphosphate and sodium tripolyphosphate.

6. The environment-friendly magnesium spinel gunning mix for the converter according to claim 1, wherein the particle size of the slaked lime micro powder is 5-10 μm.

7. The environment-friendly magnesium spinel gunning mix for the converter according to claim 1, wherein the thickener is one or more of carboxymethyl cellulose, carboxymethyl starch ether and calcium lignosulfonate.

8. The environment-friendly magnesium spinel gunning mix for the converter according to claim 1, wherein the explosion-proof agent is compounded by one or more of organic fibers, paper fibers or aluminum powder.

9. The preparation method of the environment-friendly magnesium spinel gunning mix for the converter according to any one of claims 1 to 8, which is characterized by comprising the following steps: adding the magnesia spinel reclaimed material and the magnesia material into a stirrer for premixing for 1-2min, then adding other raw materials, stirring for 3-5min, and discharging to obtain the environment-friendly magnesia spinel gunning mix for the converter.

10. The use of the environment-friendly magnesia spinel gunning mix for the converter according to any one of claims 1 to 8, wherein the amount of water added is 12 wt% to 15.2 wt% of the environment-friendly magnesia spinel gunning mix for the converter.

Technical Field

The invention relates to the technical field of refractory materials for converters, in particular to a green environment-friendly magnesium spinel gunning mix for a converter, and preparation and application thereof.

Background

The converter is the main equipment for converter steelmaking production, and the refractory materials of the converter are easily damaged due to mechanical impact and slag corrosion of the converter in a high-temperature state for a long time. The gunning material is widely applied to the repair of the converter lining, and the repair effect and the frequency of the gunning material directly influence the service life and the production rhythm of the converter. With the continuous increase of the proportion of the scrap steel, the smelting working condition is increasingly severe, and the requirement of refractory materials for converter maintenance is higher and higher. Generally, electrically fused magnesia or sintered magnesia is used as a main raw material for the particle part of the repairing material, and as the magnesia resource is reduced, the price is higher, and the repairing cost is increased. Therefore, the converter repairing material has better furnace repairing effect and low cost, and is more favored by users.

At present, converter gunning materials are classified into two types according to bonding agents: one is hot gunning mix using asphalt and resin as binder, and the other is water system material using metasilicate and phosphate or inorganic matter as binder. The former has long sintering time and long service life, but emits dense smoke and releases a large amount of toxic and harmful gases during construction, and has serious environmental pollution. The latter has short sintering time and is environment-friendly, but the repair material has loose structure, lower strength and shorter service life. Moreover, environmental requirements of many steel mills on the used refractory materials are higher and higher, and converter gunning materials which seriously pollute the environment are rejected by the steel mills more and more.

The graded treatment and the recycling of the used refractory material can reduce the waste of resources and the environmental pollution, and the recycling of the used refractory material has very important significance for reducing the production cost of enterprises, protecting the environment and saving resources. Chinese patent application CN109650914A relates to an environment-friendly converter repairing material for recycling waste magnesia carbon bricks and a preparation method thereof, and the converter repairing material is prepared by using the recycled waste magnesia carbon bricks as preparation raw materials, so that the cost is saved, and the waste recycling is realized. The Chinese patent application CN109320266A relates to a method for producing an environment-friendly quick-drying converter gunning mix by adopting waste magnesia-calcium bricks, and the recycled magnesia-calcium bricks are used as preparation raw materials to prepare a converter patching material, so that the recycling and the efficient utilization of wastes are realized, and the development requirement of environmental protection is met. Chinese patent application CN110563449A relates to an environment-friendly magnesia-carbon gunning mix for an RH furnace and a preparation method thereof, and the magnesia-carbon gunning mix produced by used MgO-C bricks is utilized to achieve the purposes of cost reduction, efficiency improvement and waste recycling.

The waste magnesium spinel brick used in the invention is mainly the waste magnesium spinel brick after recycling RH inner lining, and the materials are mainly magnesia and magnesium aluminate spinel. The waste magnesium spinel bricks produced by the existing steel works are all treated as industrial garbage, which causes resource waste and environmental pollution.

To sum up, in order to meet the requirements of environmental protection, meet the smelting and maintenance requirements of the converter, prolong the service life of the gunning mix of the converter and reduce the resource consumption and the cost, the invention introduces the environment-friendly magnesia spinel gunning mix for the converter, which is prepared by taking a recycled magnesia spinel material as a main raw material, adding a self-produced magnesia binder, a phosphate binder, slaked lime micro powder, a proper thickening agent, an explosion-proof agent and the like, and stirring and mixing.

Disclosure of Invention

Aiming at the defects in the field, the invention provides a green environment-friendly magnesia spinel gunning mix for a converter, wherein waste magnesia spinel bricks which are used for RH linings are recovered and subjected to specific treatment to obtain a magnesia spinel reclaimed material which is suitable for the converter and meets specific index conditions, waste materials are changed into valuable, the magnesia spinel reclaimed material is used as a main material and is uniformly stirred with a small amount of magnesia material, magnesia binder, phosphate binder, slaked lime micro powder, thickener, explosion inhibitor and other components to obtain the magnesia spinel gunning mix.

The green environment-friendly magnesium spinel gunning mix for the converter comprises the following raw materials in parts by mass:

the particle size of the magnesium binder is not more than 5 mu m, the MgO content in the composition is not less than 77.00 wt%, and the SiO content in the composition₂The content is more than or equal to 13.00 wt%, and the ignition loss at 950 ℃ is less than or equal to 6.0 wt%, so as to reduce the influence of impurities with low melting point on the performance of the magnesia spinel gunning material;

MgO and Al in the recycled magnesium spinel material₂O₃The total content of the components is not less than 95 wt%, the particle size is not more than 5mm, and the specific particle size composition is as follows:

10 to 20 parts by mass of 5 to 3mm,

3 to 1mm, 3mm, 20 to 35 parts by mass,

1-0.045 mm, and does not contain 15-25 parts by mass of 1 mm;

the recycled magnesium spinel material is obtained by the following method:

1) recycling the waste magnesium spinel bricks used for RH linings, removing surface impurities, drying, crushing by a jaw crusher and a cone, removing iron by using a magnet in the crushing process, and screening to obtain aggregates with the particle sizes of 5-3 mm, < 3-1 mm and < 1-0.045 mm;

2) and (3) removing false particles attached to the surface of the aggregates with the particle size of 5-3 mm and the aggregate with the particle size of 3-1 mm by using an edge runner mill, improving the roundness of the particles, and screening by using a secondary screen to obtain the high-quality magnesium spinel recycled particles with the particle size of 5-3 mm and the aggregate with the particle size of 3-1 mm.

Unlike the prior art, which generally forms spinel phase in high temperature process, the magnesium spinel gunning mix of the present invention is based on magnesium spinel reclaimed material for the first timeThe material takes a magnesia material as an auxiliary material, adopts a magnesium bonding agent as a bonding agent, and has synergistic effect and synergism among the components. In the spray repair construction process, the magnesium bonding agent can be quickly and uniformly mixed with water at the nozzle of the spray gun, so that the spray repair construction method has excellent spray repair effect and adhesion, and the spray repair lining is more compact and higher in strength due to less water addition. On the other hand, the micro-nano magnesium binder can form a micro-scale forsterite phase in situ at a lower temperature to generate micro-expansion in volume and closed matrix pores, so that the gunning material has excellent slag corrosion resistance and permeability. Furthermore, the aggregate is a high-purity and high-density magnesium spinel reclaimed material, so that the high temperature resistance and molten steel scouring resistance of the gunning mix are improved. The magnesium binder can react with water quickly to form MgO-SiO in the spray repair process₂-H₂And the O binding phase improves the gunning strength, the adhesion and the anti-explosion performance of the gunning material.

The raw materials of the magnesium spinel gunning mix do not contain asphalt and resin, and the environment is not polluted in the using process; the matrix does not contain clay, bentonite or sodium silicate, and a large amount of low-melting phase can not be formed in the material, so that the prepared magnesium spinel gunning material has good high-temperature resistance, slag corrosion resistance and permeability.

Preferably, the magnesia material is one or two of sintered magnesia and fused magnesia.

Preferably, the MgO content in the magnesium sand material is more than or equal to 95 wt%.

For better cooperation with the recycled magnesium spinel material of the invention, and better application in converter maintenance, it is preferable that the particle size of the magnesium sand material is less than 1 mm.

Further preferably, the specific particle size composition of the magnesite material is as follows by mass:

1 to 0.045mm, and 0 to 20 parts by weight of a filler not containing 1mm,

less than 0.045mm 5-15 parts.

The particle sizes in the particle size distribution according to the present invention are all number average particle sizes.

Preferably, the phosphate binder is one or more of sodium hexametaphosphate and sodium tripolyphosphate.

Preferably, the particle size of the slaked lime micro powder is 5-10 μm.

Preferably, the thickener is one or more of carboxymethyl cellulose, carboxymethyl starch ether and calcium lignosulfonate.

Preferably, the explosion-proof agent is compounded by one or more of organic fibers, paper fibers or aluminum powder.

The invention also provides a preparation method of the green environment-friendly magnesium spinel gunning mix for the converter, which comprises the following steps: adding the magnesia spinel reclaimed material and the magnesia material into a stirrer for premixing for 1-2min, then adding other raw materials, stirring for 3-5min, and discharging to obtain the environment-friendly magnesia spinel gunning mix for the converter.

The invention also provides application of the environment-friendly magnesium spinel gunning material for the converter in converter maintenance. The magnesia spinel gunning mix is particularly suitable for gunning maintenance of trunnions of converters, and the water adding amount is 12-15.2 wt% of the green environment-friendly magnesia spinel gunning mix for the converters.

The invention does not contain asphalt and resin, is environment-friendly, introduces magnesium spinel reclaimed materials, and adopts magnesium bonding agent to ensure that the gunning mix has excellent adhesiveness and molten steel erosion resistance. The invention realizes the recycling of waste refractory materials, meets the development requirement of environmental protection, ensures the service life of the gunning mix, reduces the steelmaking cost and is beneficial to popularization and application.

Compared with the prior art, the invention has the main advantages that:

1) the recycled magnesium spinel brick with the specific source has high purity and density, improves the high temperature resistance, scouring resistance and erosion resistance of the gunning material of the converter, saves the resource consumption and reduces the cost of the gunning material.

2) The gunning material adopts the magnesium bonding agent, improves the gunning constructability, reduces the water adding amount,the adhesion is excellent and the strength is high; the forsterite phase is formed in situ at a lower temperature, so that the sintering of a matrix is promoted, and the medium-temperature strength is improved; al in matrix₂O₃、Fe₂O₃And the content of impurities is low, so that the high-temperature performance, slag corrosion resistance and permeability of the gunning material can be improved.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The following examples are conducted under conditions not specified, usually according to conventional conditions, or according to conditions recommended by the manufacturer.

The magnesium spinel reclaimed material is obtained by the following method:

1) recycling the waste magnesium spinel bricks used for RH linings, removing surface impurities, drying, crushing by a jaw crusher and a cone, removing iron by using a magnet in the crushing process, and screening to obtain aggregates with the particle sizes of 5-3 mm, < 3-1 mm and < 1-0.045 mm;

2) and (3) removing false particles attached to the surface of the aggregates with the particle size of 5-3 mm and the aggregate with the particle size of 3-1 mm by using an edge runner mill, improving the roundness of the particles, and screening by using a secondary screen to obtain the high-quality magnesium spinel recycled particles with the particle size of 5-3 mm and the aggregate with the particle size of 3-1 mm.

Examples 1 to 5, comparative example 1

The raw material compositions of the magnesium spinel gunning mix of examples 1 to 5 and the tabular corundum gunning mix of comparative example 1 in parts by mass are shown in table 1, and recovered magnesium spinel (MgO and Al)₂O₃Not less than 95wt percent of the total content of the components, magnesium sand material (MgO content is more than or equal to 95wt percent), or magnesium sand material (MgO content is more than or equal to 95wt percent) and tabular corundum are added into a stirrer to be premixed for 1-2min according to the proportion, then explosion-proof agent and magnesium bonding agent (LIMAGEL-75 high-strength magnesium bonding agent with the granularity of not more than 5 mu m, the MgO content is more than or equal to 77.00wt percent in the components, and SiO is added into the mixture according to the proportion₂More than or equal to 13.00 wt%, less than or equal to 6.0 wt% at 950 ℃, phosphate binder, slaked lime micro powder and thickening agent, and stirring uniformly in a mixer for 3-5min to prepare the corresponding magnesia spinel gunning mix or boardCorundum-like gunning material. The water addition amount, the linear change rate, the volume density, the breaking strength, the compressive strength and the slag invasion index of the magnesia spinel gunning material and the tabular corundum gunning material during gunning are tested, and the test results are shown in Table 3.

TABLE 1

Comparative example 2

The raw material composition of the carbonaceous magnesium gunning mix of comparative example 2 in parts by mass is shown in Table 2, in which 92-grade silica fine powder, namely SiO₂The content is more than or equal to 92 wt%, and all the raw materials are stirred in a mixer for 3-5min to be uniformly mixed to prepare the corresponding carbon-containing magnesia gunning mix. Comparative example 2 is tested the water addition amount of the carbonaceous magnesia gunning material in use, the linear change rate, the volume density, the rupture strength, the compressive strength and the slag invasion index, and the test results are shown in table 3.

TABLE 2

TABLE 3

Therefore, the invention recovers the waste magnesia spinel bricks after the RH lining is used and carries out specific treatment to obtain the magnesia spinel reclaimed materials which are suitable for the converter and meet specific index conditions, changes waste into valuable, takes the magnesia spinel reclaimed materials as the main materials and a small amount of magnesia materials with specific grain size gradation, and the components such as the magnesium bonding agent, the phosphate bonding agent, the hydrated lime micro powder, the thickening agent, the explosion-proof agent and the like are uniformly stirred to obtain the magnesium spinel gunning material, the components have synergistic effect, the water adding amount is low, the density is high when the gunning material is used, the gunning material has good volume stability, high strength and excellent slag corrosion resistance and permeability, is suitable for gunning maintenance of the working lining refractory material of the converter, prolongs the service life of the working lining refractory material, reduces the use consumption of the gunning material, the effect is obviously superior to that of a platy corundum gunning mix which takes carbon-containing magnesia gunning mix and magnesia as main materials and forms magnesium spinel by high-temperature reaction.

Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the above description of the present invention, and equivalents also fall within the scope of the invention as defined by the appended claims.