阅读说明：本技术 一种利用高含铁烧结镁砂生产低成本镁质预制件的方法 (Method for producing low-cost magnesium prefabricated part by using high-iron-content sintered magnesia ) 是由 虞畅 严培忠 张美杰 李国群 翁小燕 马安平 于 2021-08-06 设计创作，主要内容包括：本发明公开一种利用高含铁烧结镁砂生产低成本镁质预制件的方法,具体涉及镁质预制件技术领域,具体包括以下步骤：步骤一：制备废镁铁尖晶石颗粒,步骤二：磨细分级,步骤三：取镁砂、硅微粉、碳化硅、三聚磷酸钠、六偏磷酸钠和有机纤维备用,步骤四：水化烘干,步骤五：按重量百分比取料,步骤六：制取混合料,步骤七：制取浇筑料,步骤八：制取中间包预制件。本发明本发明通过将原有的镁质预制件的生产过程中需要用到的镁橄榄砂替换成废镁铁尖晶石颗粒,并将价格较高的纯镁或者95-96镁砂替换成92-93镁砂,大大降低了镁质预制件的生产成本,不会造成镁质预制件的开裂情况,比镁橄榄砂具有更好的耐用性,使镁质预制件的综合性能得到提高。(The invention discloses a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia, and particularly relates to the technical field of magnesium prefabricated parts, which specifically comprises the following steps: the method comprises the following steps: preparing waste pleonaste particles, and the second step: grinding and grading, and step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use, and the fourth step is that: hydration and drying, and step five: taking materials according to weight percentage, and the sixth step: preparing a mixture, and the seventh step: preparing a pouring material, and the eighth step: and (5) preparing a tundish prefabricated member. According to the invention, the magnesium olive sand required in the production process of the original magnesium prefabricated member is replaced by the waste magnesium hercynite particles, and the pure magnesium with higher price or 95-96 magnesium sand with higher price is replaced by 92-93 magnesium sand, so that the production cost of the magnesium prefabricated member is greatly reduced, the cracking condition of the magnesium prefabricated member cannot be caused, the magnesium prefabricated member has better durability than the magnesium olive sand, and the comprehensive performance of the magnesium prefabricated member is improved.)

1. A method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia is characterized by comprising the following steps of: the method specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding the magnesite into 92-93 magnesite grains with the granularity of 180-200 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw material in water for 20-24h, then extracting the waste pleonaste particle raw material for drying, taking the cycle as a cycle, and entering the next procedure after 2-4 cycles;

step five: taking 20-35% of 10-5mm waste magnesium-iron spinel, 20-35% of 5-3mm waste magnesium-iron spinel, 10-15% of 3-1mm waste magnesium-iron spinel particle raw material, 10-15% of 1-0mm waste magnesium-iron spinel particle raw material, 10-20% of 200-mesh magnesia particles, 2-4% of silicon carbide, 3-6% of silicon micropowder, 0.2-0.6% of sodium tripolyphosphate, 0.1-0.2% of sodium hexametaphosphate and 0.1-0.15% of organic fiber for later use according to weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 2-4 min, and performing 3-5 times of circulation to obtain the pouring material;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

2. The method for producing the low-cost magnesium preform by using the high-iron content sintered magnesite according to claim 1, wherein the method comprises the following steps: in the second step, the waste magnesia-iron spinel particle raw material waste magnesia-iron spinel brick comprises 15-25 wt% of the waste magnesia-iron spinel particle raw material with the particle size of 10-5mm and 20-30 wt% of the waste magnesia-iron spinel particle raw material with the particle size of 5-3 mm.

3. The method for producing the low-cost magnesium preform by using the high-iron content sintered magnesite according to claim 1, wherein the method comprises the following steps: the magnesite grains in the third step are sintered magnesite, the MgO content of the magnesite is more than or equal to 35%, and the Fe2O3 content is less than or equal to 25%.

4. The method for producing the low-cost magnesium preform by using the high-iron content sintered magnesite according to claim 1, wherein the method comprises the following steps: in the third step, the silicon micropowder is silicon micropowder with the content of SiO2 being more than or equal to 94%, the length of the organic fiber is 2-5 mm, and the melting point is 15-175 ℃.

5. The method for producing the low-cost magnesium preform by using the high-iron content sintered magnesite according to claim 1, wherein the method comprises the following steps: and the waste magnesium iron is dried in the fourth step by putting the waste magnesium iron into the heat-insulating space and introducing hot air into the heat-insulating space for drying.

6. The method for producing the low-cost magnesium preform by using the high-iron content sintered magnesite according to claim 1, wherein the method comprises the following steps: and the concrete adding mode of the silicon carbide and the organic fiber in the sixth step is that the silicon carbide and the organic fiber are uniformly added into the stirrer according to the weight ratio, and the mixture is stirred while being added, so that the formed mixture is more uniform.

7. The method for producing the low-cost magnesium preform by using the high-iron content sintered magnesite according to claim 1, wherein the method comprises the following steps: the temperature is controlled to be 200-300 ℃ when the heat treatment is carried out in the step eight, and the time is 20-24 h.

Technical Field

The invention belongs to the technical field of magnesium prefabricated parts, and particularly relates to a method for producing a low-cost magnesium prefabricated part by using high-iron-content sintered magnesia.

Background

In order to improve the heat resistance of fiber products and simultaneously realize the simplification of the assembly of the furnace building prefabricated member so as to improve the installation efficiency, the fiber is processed into a certain standard shape product to meet the requirements of the shape of the furnace, and the process is called a prefabricated member method. Representative articles are folded blocks, felt units, and the like. With the continuous promotion of steel smelting technology, the requirements on the use performance of refractory materials are gradually rigorous, but at the same time, another important problem faced by refractory material production enterprises is the continuous rising of the price of raw materials, and the magnesia refractory materials take magnesite, seawater magnesia, dolomite and the like as raw materials, and take periclase as a main crystal phase, and the content of magnesia is more than 80%. Belongs to an alkaline refractory material. Pure magnesium or 95-96 magnesite is often used to make magnesium preforms.

The magnesium prefabricated parts on the market at present are all made of high-price 95-96 magnesite, the market price of the 95-96 magnesite is high, and meanwhile, low-grade magnesite which is not easy to hydrate is not used for replacing 95 and 96 magnesite to produce the magnesium prefabricated parts, so that the cost is high when the magnesium prefabricated parts are made, and the magnesium prefabricated parts cannot be used in a large scale.

Disclosure of Invention

The invention provides a method for producing a low-cost magnesium prefabricated part by using high-iron-content sintered magnesite, and aims to solve the problems that the existing magnesium prefabricated parts in the market are all prepared by using high-price 95-96 magnesite, the market price of 95-96 magnesite is high, and low-grade magnesite which is not easy to hydrate is not used for replacing 95 and 96 magnesite to produce the magnesium prefabricated part, so that the cost is high when the magnesium prefabricated part is prepared, and the magnesium prefabricated part cannot be used in a large scale.

The invention is realized in such a way, and provides the following technical scheme: a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding the magnesite into 92-93 magnesite grains with the granularity of 180-200 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw material in water for 20-24h, then extracting the waste pleonaste particle raw material for drying, taking the cycle as a cycle, and entering the next procedure after 2-4 cycles;

step five: taking 20-35% of 10-5mm waste magnesium-iron spinel, 20-35% of 5-3mm waste magnesium-iron spinel, 10-15% of 3-1mm waste magnesium-iron spinel particle raw material, 10-15% of 1-0mm waste magnesium-iron spinel particle raw material, 10-20% of 200-mesh magnesia particles, 2-4% of silicon carbide, 3-6% of silicon micropowder, 0.2-0.6% of sodium tripolyphosphate, 0.1-0.2% of sodium hexametaphosphate and 0.1-0.15% of organic fiber for later use according to weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 2-4 min, and performing 3-5 times of circulation to obtain the pouring material;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

In a preferred embodiment, in the step two, the weight percentages of the waste magnesium iron spinel particle raw materials of 10-5mm and 5-3mm are 15-25% and 20-30%, respectively.

In a preferable embodiment, the magnesite grain in the third step is sintered magnesite, wherein the content of MgO in the magnesite is more than or equal to 35%, and the content of Fe2O3 is less than or equal to 25%.

In a preferable embodiment, the silica powder in the third step is silica powder with SiO2 content not less than 94%, the length of the organic fiber is 2-5 mm, and the melting point is 15-175 ℃.

In a preferred embodiment, the waste magnesium iron is dried in the fourth step by placing the waste magnesium iron into a heat-insulating space and introducing hot air into the heat-insulating space for drying.

In a preferred embodiment, the silicon carbide and the organic fiber in the sixth step are added in a specific manner, the silicon carbide and the organic fiber are uniformly added into the stirrer according to the weight ratio, and the mixture is stirred while being added, so that the formed mixture is more uniform.

In a preferred embodiment, the temperature of the heat treatment in the step eight is controlled to be 200 ℃ to 300 ℃ and the time is 20 to 24 hours.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention replaces the magnesium olive sand needed in the production process of the original magnesium prefabricated member with the waste magnesium hercynite particles, pure magnesium with higher price or 95-96 magnesite is replaced by 92-93 magnesite, so that the production cost of the magnesium prefabricated part is greatly reduced, and the bending strength and the compressive strength of the magnesium prefabricated part are only properly reduced while the raw material cost is reduced, the cracking condition of the magnesium prefabricated part is not caused, when the magnesium prefabricated member is produced by using all magnesium or 95-96 magnesium, 92-93 magnesium sand which is not easy to hydrate and partial waste magnesium hercynite particles are introduced, which can achieve better effect than the magnesium olive sand, meanwhile, the prices of the waste magnesium iron tip crystals and the 92-93 magnesium are relatively low, and the waste magnesium iron tip crystals and the 92-93 magnesium have better durability than the magnesium olive sand, so that the comprehensive performance of the magnesium prefabricated part is improved;

2. through preparing the mixture, with the magnesite grain, sodium tripolyphosphate, stir in sodium hexametaphosphate and the silica powder addition mixer, obtain the magnesite grain, sodium tripolyphosphate, sodium hexametaphosphate and silica powder mixture, waste magnesium iron spinel granule raw materials is added in the rethread stirring, add carborundum and organic fiber in the mixer afterwards, separately put into the mixer one by one with the raw materials and stir, improve the mixed degree of raw materials, the stability of whole magnesium prefab has been improved greatly, and can guarantee the intensity of prefab, prevent the prefab fracture.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding magnesite into 92 magnesite grains with the granularity of 180 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw materials in water for 20h, then extracting the waste pleonaste particle raw materials for drying, taking the cycle as a cycle, and entering the next procedure after 2 cycles;

step five: taking 20% of 10-5mm waste hercynite, 25% of 5-3mm waste hercynite, 10% of 3-1mm waste hercynite particle raw material, 10% of 1-0mm waste hercynite particle raw material, 10% of 200-mesh magnesia particles, 2% of silicon carbide, 3% of silicon micropowder, 0.2% of sodium tripolyphosphate, 0.1% of sodium hexametaphosphate and 0.1% of organic fiber for later use according to the weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 2min, and taking the mixture as a cycle to obtain the pouring material after 3 cycles;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

Example 2:

a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding magnesite into 92 magnesite grains with the granularity of 190 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw materials in water for 21h, then extracting the waste pleonaste particle raw materials for drying, taking the cycle as a cycle, and entering the next procedure after 3 cycles;

step five: taking 25% of 10-5mm waste hercynite, 20% of 5-3mm waste hercynite, 12% of 3-1mm waste hercynite particle raw material, 13% of 1-0mm waste hercynite particle raw material, 12% of 200-mesh magnesite particles, 3% of silicon carbide, 4% of silicon micropowder, 0.25% of sodium tripolyphosphate, 0.15% of sodium hexametaphosphate and 0.12% of organic fiber for later use according to the weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 3min, and taking the mixture as a cycle to obtain the pouring material after 4 cycles;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

Example 3:

a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding magnesite into 93 magnesite grains with the granularity of 195 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw materials in water for 22h, then extracting the waste pleonaste particle raw materials for drying, taking the cycle as a cycle, and entering the next procedure after 4 cycles;

step five: taking 30% of 10-5mm waste hercynite, 30% of 5-3mm waste hercynite, 15% of 3-1mm waste hercynite particle raw material, 15% of 1-0mm waste hercynite particle raw material, 18% of 200-mesh magnesia particles, 4% of silicon carbide, 5% of silicon micropowder, 0.5% of sodium tripolyphosphate, 0.2% of sodium hexametaphosphate and 0.15% of organic fiber for later use according to the weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 4min, taking the mixture as a cycle, and obtaining the pouring material after 5 cycles;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

Example 4:

a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding magnesite into 93 magnesite grains with the granularity of 200 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw materials in water for 24h, then extracting the waste pleonaste particle raw materials for drying, taking the cycle as a cycle, and entering the next procedure after 4 cycles;

step five: taking 35% of 10-5mm waste hercynite, 35% of 5-3mm waste hercynite, 15% of 3-1mm waste hercynite particle raw material, 15% of 1-0mm waste hercynite particle raw material, 20% of 200-mesh magnesia particles, 4% of silicon carbide, 6% of silicon micropowder, 0.6% of sodium tripolyphosphate, 0.2% of sodium hexametaphosphate and 0.15% of organic fiber for later use according to the weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 4min, taking the mixture as a cycle, and obtaining the pouring material after 5 cycles;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

Example 5:

a method for producing a low-cost magnesium prefabricated part by using high-iron content sintered magnesia specifically comprises the following steps:

the method comprises the following steps: preparing waste pleonaste particles, preparing qualified waste pleonaste bricks, spraying water on the waste pleonaste bricks to ensure that the waste pleonaste bricks are kept in a water bath state before being crushed, and crushing the waste pleonaste bricks into the waste pleonaste particles to obtain the waste pleonaste particles;

step two: grinding and grading the waste magnesium iron spinel particles into four waste magnesium iron spinel particle raw materials with different particle sizes of 10-5mm, 5-3mm, 3-1mm and 1-0mm for later use;

step three: taking magnesia, silicon micropowder, silicon carbide, sodium tripolyphosphate, sodium hexametaphosphate and organic fiber for later use; grinding magnesite into 93 magnesite grains with the granularity of 195 meshes for later use;

step four: carrying out hydration treatment on waste magnesium-iron spinel particle raw materials: soaking the waste pleonaste particle raw materials in water for 24h, then extracting the waste pleonaste particle raw materials for drying, taking the cycle as a cycle, and entering the next procedure after 2 cycles;

step five: taking 20% of 10-5mm waste hercynite, 35% of 5-3mm waste hercynite, 15% of 3-1mm waste hercynite particle raw material, 10% of 1-0mm waste hercynite particle raw material, 15% of 200-mesh magnesia particles, 3.5% of silicon carbide, 3% of silicon micropowder, 0.4% of sodium tripolyphosphate, 0.2% of sodium hexametaphosphate and 0.1% of organic fiber for later use according to the weight percentage;

step six: preparing a mixture, adding the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder into a stirrer for stirring to obtain a mixture of the magnesia particles, the sodium tripolyphosphate, the sodium hexametaphosphate and the silicon micropowder, adding the waste magnesia-hercynite particle raw material obtained in the step four into the mixture in the stirrer, and then adding silicon carbide and organic fibers into the stirrer to obtain a mixture

Step seven: preparing a pouring material, adding the mixture obtained in the step six and 1-3 wt% of water into a stirrer, stirring for 4min, and taking the mixture as a cycle to obtain the pouring material after 4 cycles;

step eight: and C, preparing a tundish prefabricated member, pouring the pouring material obtained in the step seven into a tundish prefabricated member mould, compacting the pouring material, and carrying out wet curing, dry curing and heat treatment to obtain the tundish prefabricated member.

The low-cost magnesium preforms produced from the high-iron content sintered magnesite prepared in the above examples 1 to 5 were tested, and the following data were obtained:

	breaking strength (Mpa)	Compressive strength (Mpa)	Cracking condition
				Example 1	12	72.8	Is free of
Example 2	12	72.2	Is free of
				Example 3	10.2	70.2	Is free of
Example 4	9.0	68.5	Is free of
				Example 5	9.7	69.8	Is free of

As can be seen from the above table, in example 3, the raw material mixing ratio is moderate, the magnesite used in the production of the waste hercynite brick has a high grade and a high degree of compactness, and the content of magnesium oxide in the waste hercynite brick is found to be high, and it is found that no crack occurs after the formation and the high-temperature heat treatment of the magnesia retaining wall into which the waste hercynite brick particles are introduced, and the weight ratio of the magnesia of the sintered magnesia particles is increased, which leads to the appropriate reduction of the flexural strength and the compressive strength of the preform, but is within a relatively safe data range. The performance index of the brick is approximately linearly changed along with the increase of the content of the waste magnesia-hercynite brick particles. The folding strength of the common silica micro powder combined magnesium prefabricated member is about 12MPa, the density is high, the CaO content is low, iron is contained, and the silicon content is relatively high 92 and 93 magnesite, the magnesite can avoid the problem that 90 sintered magnesite is easy to hydrate and crack, the price is proper when the prefabricated member is used in the magnesium prefabricated member, the prefabricated member is lower than magnesia olive sand, the prefabricated member has better durability, the manufacturing cost of the magnesium prefabricated member can be greatly reduced by using 92 and 93 magnesite, and the strength of the magnesium prefabricated member is ensured.

And finally: the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.