TWI745186B - Method of recycling and reusing discarded refractory material - Google Patents

Abstract

A method of recycling and reusing discarded refractory material is provided, and the method includes the steps of: providing a waste refractory material; grinding the waste refractory material to obtain a ground waste refractory material with a particle size ranging between 1 μm and 30 mm; adding the ground waste refractory material into a molten blast furnace slag to obtain a molten waste refractory material; and rapidly cooling the molten waste refractory material by high pressure water of a water quenching equipment to obtain a water-quenched blast furnace slag, which is used for cement and thus achieves the purpose of resource reuse. The water-quenched blast furnace slag includes magnesium oxide, iron oxide, sulfur or any combination thereof. Based on the total weight of water-quenched blast furnace slag, the content of magnesium oxide is between 0wt% and 10wt%, the content of iron oxide is between 0wt% and 3wt%, and the content of sulfur is between 0wt% and 2wt%.

Description

Methods of recycling and reusing waste refractory materials

The present invention relates to a method for recycling and reusing materials, especially a method for recycling and reusing waste refractory materials.

In the process of smelting iron and steel, the furnace body generally uses refractory materials as the furnace lining. Therefore, when the furnace body reaches its service life, the furnace body will be removed, and many waste refractory materials will be produced. Among them, for waste refractories that are not contaminated by molten iron or slag, they can be crushed and added to brand new refractories to prepare recycled refractories. However, for the waste refractories contaminated by molten iron or slag, due to insufficient automatic classification equipment in the steelmaking plant and the waste refractories have been contaminated by molten iron or slag and deteriorated, resulting in the deterioration of the waste refractories. Waste refractory materials contaminated by liquid or slag are not easy to be recycled and reused. In addition, for waste refractories that contain magnesia and are contaminated by molten iron or slag, they will produce hydration after being mixed with water, which will cause expansion, resulting in that the magnesium oxide is affected by molten iron or slag. The contaminated waste refractories are dried and cracked, and the performance and service life of the runner refractories are reduced, so that the waste refractories containing magnesia and contaminated by molten iron or slag cannot be recycled and reused.

Furthermore, if waste refractory materials containing magnesium oxide and/or contaminated by molten iron or slag are buried for disposal, it will cause excessive waste disposal costs and increase the risk of land pollution.

Therefore, the development of a method for recycling waste refractories containing magnesium oxide and/or contaminated by molten iron or slag is a problem that needs to be solved urgently in this field.

In order to solve the above-mentioned problems of the prior art, the object of the present invention is to provide a method for recycling waste refractory materials, by grinding the waste refractory materials and adding molten blast furnace slag containing molten iron, and then through the water quenching process to obtain Water quenched blast furnace stone.

In order to achieve the above objective, the present invention provides a method for recycling waste refractory materials, which includes the steps: Provide a discarded refractory material; Grinding the waste refractory material to obtain a ground waste refractory material, wherein the ground waste refractory material has a particle size range, and the particle size range is between 1 μm and 30 mm; Adding the ground waste refractory material to the molten blast furnace slag containing molten iron to obtain a molten waste refractory material; and Use the high-pressure water of a water quenching equipment to quickly cool the molten waste refractory material to obtain a water quenched blast furnace stone; The water-quenched blast furnace stone includes magnesium oxide, iron oxide, sulfur or any combination thereof. Based on the total weight of the water-quenched blast furnace stone, the content of the magnesium oxide is between 0wt% and 10wt%, and the iron oxide is The content is between 0wt% and 3wt%, and the sulfur content is between 0wt% and 2wt%.

In a specific embodiment, based on the total weight of the water-quenched blast furnace stone, the content of the magnesium oxide is between 0wt% and 7.5wt%, and the content of the iron oxide is between 0wt% and 2wt% , And the sulfur content is between 0wt% and 1wt%.

In a specific embodiment, the waste refractory material is contaminated by molten iron or slag.

In a specific embodiment, the water-quenched blast furnace stone further includes an expansion rate, and the expansion rate is between 0.001% and 0.08%.

In a specific embodiment, the expansion rate is between 0.001% and 0.030%.

In a specific embodiment, the particle size range of the ground waste refractory material is between 1 μm and 1 mm.

In a specific embodiment, the particle size range of the ground waste refractory material is between 1 mm and 5 mm.

In a specific embodiment, the particle size range of the ground waste refractory material is between 5 mm and 10 mm.

In a specific embodiment, the particle size range of the milled waste refractory material is between 10 mm and 30 mm.

In a specific embodiment, the water-quenched blast furnace stone has an amorphous phase structure.

The chemical composition, expansion rate and phase structure of the water-quenched blast furnace stone produced by the recycling method of waste refractory materials of the present invention are in compliance with the CNS specifications of water-quenched blast furnace stone products, and are the same as those without added waste refractory materials. The quality of the raw water-quenched blast furnace stone produced by the blast furnace slag after the water-quenching process is similar. In addition, the method for recycling waste refractories of the present invention can convert the phase structure of waste refractories containing magnesium oxide and/or contaminated by molten iron or slag into a stable amorphous state, which can be used as water-quenched blast furnace cement . Therefore, the waste refractory recycling method of the present invention can greatly reduce the land occupation cost and reduce the risk of land pollution by stacking waste refractory materials containing magnesium oxide and/or contaminated by molten iron or slag. The waste refractories containing magnesium oxide and/or contaminated by molten iron or slag can be converted into valuable water-quenched blast furnace cement to achieve the purpose of resource reuse.

The following is a specific embodiment to illustrate the implementation of the present invention. Those familiar with this technology can understand other advantages and effects of the present invention from the content disclosed in this specification. However, the exemplary embodiments disclosed in the present invention are for illustrative purposes only and should not be construed as limiting the scope of the present invention. In other words, the present invention can also be implemented or applied by other different specific embodiments, and various details in this specification can also be based on different viewpoints and applications, and various modifications and changes can be made without departing from the spirit of the present invention.

Unless otherwise stated herein, the singular forms "a" and "the" used in the specification and the appended patent application include plural entities. Unless otherwise stated herein, the term "or" used in the specification and the appended claims includes the meaning of "and/or".

Preparation Example 1 Preparation of the first waste refractory material, the second waste refractory material, the third waste refractory material, and the fourth waste refractory material

The steps of preparing the first waste refractory material, the second waste refractory material, the third waste refractory material and the fourth waste refractory material include: Provide waste refractories containing magnesium oxide and contaminated by molten iron or slag. As shown in Table 1, based on the content of magnesium oxide, the waste refractories containing magnesium oxide and contaminated by molten iron or slag are classified as Class I waste refractories, Class II waste refractories, Class III waste refractories and Class IV waste refractories, and use the waste refractories that contain magnesium oxide and are contaminated by molten iron or slag Based on the total weight of the material, the magnesium oxide content of the waste refractory material of the first level is ≤5wt%, the magnesium oxide content of the waste refractory material of the second level is between 5wt% and 20wt%, the third level The magnesium oxide content of the waste refractory material is between 20wt% and 40wt% and the magnesium oxide content of the fourth level of the waste refractory material is >40wt%; and Using a crushing grinder (model FCJS-3105, Feng Kushi Machinery), the first level of waste refractories, the second level of waste refractories, the third level of waste refractories and the fourth level of waste refractories The materials were ground and sieved with 30 mm, 10 mm, 3.5 mesh (mesh), and 18 mesh screens to obtain the first waste refractory materials with different particle size ranges as shown in Table 2. The second waste refractory material, the third waste refractory material and the fourth waste refractory material.

Table 1 Component and crystal form of discarded refractories of the first level, discarded refractories of the second level, discarded refractories of the third level, and discarded refractories of the fourth level Waste refractories containing magnesium oxide and contaminated by molten iron or slag The first level of discarded refractory materials (magnesium oxide content ≤ 5wt%) Waste refractory materials of the second level (5wt%＜MgO content≤20wt%) The third level of discarded refractory materials (20wt%＜MgO content≤40wt%) The fourth level of discarded refractory materials (magnesium oxide content>40wt%) Measured magnesium oxide content 2.1wt% 15.3wt% 35.7wt% 69.1wt% The content of other ingredients 97.9wt% 84.7wt% 64.3wt% 30.9wt% Phase structure Crystalline state Crystalline state Crystalline state Crystalline state

Table 2 The particle size range of the first waste refractory material, the second waste refractory material, the third waste refractory material and the fourth waste refractory material Waste refractories containing magnesium oxide and contaminated by molten iron or slag The first waste refractory Second waste refractory The third waste refractory Fourth waste refractory Particle size range Between 1 μm and 1 mm Between 1 μm and 1 mm Between 1 μm and 1 mm Between 1 μm and 1 mm Between 1 mm and 5 mm Between 1 mm and 5 mm Between 1 mm and 5 mm Between 1 mm and 5 mm Between 5 mm and 10 mm Between 5 mm and 10 mm Between 5 mm and 10 mm Between 5 mm and 10 mm Between 10 mm and 30 mm Between 10 mm and 30 mm Between 10 mm and 30 mm Between 10 mm and 30 mm

Comparative Example 1 Preparation of raw water-quenched blast furnace stone

The steps of preparing raw water-quenched blast furnace stone include: Provide blast furnace slag; and The blast furnace slag is rapidly cooled by the high-pressure water of the water quenching equipment to obtain the raw water quenched blast furnace stone.

Example 1 Recycling and reuse of the first waste refractory material with different particle size ranges

The steps to recycle and reuse the first waste refractories with different particle size ranges include: Provide the first sample, the second sample, the third sample and the fourth sample of the first waste refractory material with different particle size ranges, wherein the first sample, the second sample, the third sample and the fourth sample The particle size range of the sample is between 1 μm and 1 mm, between 1 mm and 5 mm, between 5 mm and 10 mm, and between 10 mm and 30 mm; The first sample, the second sample, the third sample and the fourth sample were added to the molten blast furnace slag containing molten iron. The first sample, the second sample, the third sample and the fourth sample were respectively The weight ratio of molten iron to blast furnace slag is 1:100, and the high temperature of molten iron is used to melt the first sample, second sample, third sample, and fourth sample into the blast furnace slag, and obtain the molten steel. The first sample, the fused second sample, the fused third sample, and the fused fourth sample; The melted first sample, the melted second sample, the melted third sample, and the melted fourth sample are respectively rapidly cooled using high-pressure water of a water quenching device to obtain the first water, respectively Quenched blast furnace stone, second water quenched blast furnace stone, third water quenched blast furnace stone and fourth water quenched blast furnace stone.

Example 2 Detecting the composition, expansion rate and phase structure of raw water-quenched blast furnace stone, first water-quenched blast furnace stone, second water-quenched blast furnace stone, third water-quenched blast furnace stone, and fourth water-quenched blast furnace stone

(1) Detect the chemical composition of the original water-quenched blast furnace stone, the first water-quenched blast furnace stone, the second water-quenched blast furnace stone, the third water-quenched blast furnace stone and the fourth water-quenched blast furnace stone

The original water-quenched blast furnace stone, the first water-quenched blast furnace stone, the second water-quenched blast furnace stone, the third water-quenched blast furnace stone, and the fourth water-quenched blast furnace stone are respectively used X-ray fluorescence spectrometer (XRF) ( Model: Rigaku Supermini 200) to detect each chemical component. The results are shown in Table 3.

(2) Detect the expansion rate of the original water-quenched blast furnace stone, the first water-quenched blast furnace stone, the second water-quenched blast furnace stone, the third water-quenched blast furnace stone and the fourth water-quenched blast furnace stone

The raw water-quenched blast furnace stone, the first water-quenched blast furnace stone, the second water-quenched blast furnace stone, the third water-quenched blast furnace stone, and the fourth water-quenched blast furnace stone are respectively tested for their volume expansion by the CNS 1258 hot-pressure expansion test method to calculate Expansion rate, the test results are shown in Table 3.

(3) Detect the phase structure of the original water-quenched blast furnace stone, the first water-quenched blast furnace stone, the second water-quenched blast furnace stone, the third water-quenched blast furnace stone and the fourth water-quenched blast furnace stone

Use X-ray diffractometer (XRD) (model : Bruker, D2 PHASER) The structure of each phase is analyzed, and the analysis results are shown in Table 3.

Table 3 Composition, expansion rate and phase structure of raw water-quenched blast furnace stone, first water-quenched blast furnace stone, second water-quenched blast furnace stone, third water-quenched blast furnace stone and fourth water-quenched blast furnace stone China National Standard (CNS) Specification for Water Quenching Blast Furnace Stone Products Chemical composition (wt%) Expansion rate (%) Phase structure Iron oxide (FeO) Magnesium oxide (MgO) Sulfur (S) ≤3 ≤10 ≤2 ≤0.08 Amorphous Raw water quenched blast furnace stone 0.29 6.51 0.61 +0.022 Amorphous The first water quenched blast furnace stone 0.31 6.52 0.63 +0.022 Amorphous The second water quenched blast furnace stone 0.32 6.61 0.63 +0.023 Amorphous The third water quenched blast furnace stone 0.30 6.56 0.60 +0.022 Amorphous The fourth water quenched blast furnace stone 0.30 6.49 0.59 +0.022 Amorphous

The results show that the chemical composition, expansion rate and phase structure of the first water-quenched blast furnace stone, the second water-quenched blast furnace stone, the third water-quenched blast furnace stone and the fourth water-quenched blast furnace stone are in line with the CNS of the water-quenched blast furnace stone products. specification. It is obvious from this that the first waste refractory materials with different particle size ranges can be completely melted in the blast furnace slag in high-temperature molten iron, and the first water-quenched blast furnace stone and the second water-quenched blast furnace stone produced after the water quenching process The quality of the blast furnace stone, the third water-quenched blast furnace stone and the fourth water-quenched blast furnace stone is similar to the quality of the raw water-quenched blast furnace stone obtained after the blast furnace slag without added waste refractory material is subjected to the water quenching process.

Example 3 Recovery and reuse of the first waste refractory material, the second waste refractory material, the third waste refractory material, and the fourth waste refractory material with a particle size between 1 μm and 1 mm

The steps to recycle and reuse the first waste refractories with different particle size ranges include: Provide the first waste refractory material, the second waste refractory material, the third waste refractory material and the fourth waste refractory material with a particle size range between 1 μm and 1 mm; The first waste refractory material, the second waste refractory material, the third waste refractory material, and the fourth waste refractory material are added to molten blast furnace slag containing molten iron, wherein the first waste refractory material and the second waste refractory material The weight ratio of the waste refractories, the third waste refractories and the fourth waste refractories to the blast furnace slag containing molten iron is 1:100, and the high temperature of the molten iron is used to combine the first waste refractories and the second waste refractories. , The third waste refractory material and the fourth waste refractory material are respectively melted into the blast furnace slag, and the fifth sample after melting, the sixth sample after melting, the seventh sample after melting and the eighth sample after melting are respectively obtained ；

The melted fifth sample, the melted sixth sample, the melted seventh sample, and the melted eighth sample are respectively rapidly cooled using high-pressure water of a water quenching equipment to obtain the fifth water quenching. Blast furnace stone, sixth water quenched blast furnace stone, seventh water quenched blast furnace stone and eighth water quenched blast furnace stone.

Example 4 Detecting the composition, expansion rate and phase structure of raw water-quenched blast furnace stone, fifth water-quenched blast furnace stone, sixth water-quenched blast furnace stone, seventh water-quenched blast furnace stone, and eighth water-quenched blast furnace stone

(1) Detect the chemical composition of the original water-quenched blast furnace stone, the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone, and the eighth water-quenched blast furnace stone

The original water-quenched blast furnace stone, the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone, and the eighth water-quenched blast furnace stone were used to detect each chemical composition by X-ray fluorescence spectrometer. The test results are as follows Table 4 shows.

(2) Detect the expansion rate of the original water-quenched blast furnace stone, the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone and the eighth water-quenched blast furnace stone

The original water-quenched blast furnace stone, the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone, and the eighth water-quenched blast furnace stone were respectively tested for their volume expansion by the CNS 1258 hot-pressure expansion test method to calculate Expansion rate, the test results are shown in Table 4.

(3) Detect the phase structure of the original water-quenched blast furnace stone, the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone and the eighth water-quenched blast furnace stone

The raw water-quenched blast furnace stone, the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone, and the eighth water-quenched blast furnace stone were analyzed by X-ray diffraction instrument to analyze the structure of each phase. The analysis results are shown in Table 4. Shown.

Table 4 Composition, expansion rate and phase structure of raw water-quenched blast furnace stone, fifth water-quenched blast furnace stone, sixth water-quenched blast furnace stone, seventh water-quenched blast furnace stone, and eighth water-quenched blast furnace stone China National Standard (CNS) Specification for Water Quenching Blast Furnace Stone Products Chemical composition (wt%) Expansion rate (%) Phase structure Iron oxide (FeO) Magnesium oxide (MgO) Sulfur (S) ≤3 ≤10 ≤2 ≤0.08 Amorphous Raw water quenched blast furnace stone 0.29 6.51 0.61 +0.022 Amorphous Fifth water quenched blast furnace stone 0.31 6.52 0.63 +0.022 Amorphous The sixth water quenched blast furnace stone 0.32 6.61 0.60 +0.023 Amorphous Seventh water quenched blast furnace stone 0.35 6.82 0.63 +0.023 Amorphous The eighth water quenched blast furnace stone 0.33 7.20 0.65 +0.025 Amorphous

The results show that the chemical composition, expansion rate and phase structure of the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone and the eighth water-quenched blast furnace stone are in line with the CNS of the water-quenched blast furnace stone products. specification. It is obvious from this that the first waste refractory material, the second waste refractory material, the third waste refractory material and the fourth waste refractory material with a particle size range between 1 μm and 1 mm can be completely melted in the high temperature molten iron. The quality of the fifth water-quenched blast furnace stone, the sixth water-quenched blast furnace stone, the seventh water-quenched blast furnace stone and the eighth water-quenched blast furnace stone produced after the water quenching process in the blast furnace slag and no waste refractory materials are added The quality of the raw water-quenched blast furnace stone produced by the blast furnace slag after the water-quenching process is similar.

The results of the above examples show that waste refractories containing magnesia and contaminated by molten iron or slag are crushed, ground and sieved. The crushed, ground and sieved waste refractories containing magnesium oxide and contaminated by molten iron or slag are put into the main blast furnace to mix with the molten iron covered with a layer of blast furnace slag. The high temperature of the molten iron is used to remove the magnesium oxide and the Waste refractories contaminated by molten iron or slag are melted into the blast furnace slag, and then flowed out through the slag runner, and rapidly cooled by the high-pressure water of the water quenching equipment to produce water quenched blast furnace stone. The chemical composition, expansion rate and phase structure of the water-quenched blast furnace stone produced by the recycling method of waste refractory materials of the present invention are in compliance with the CNS specifications of water-quenched blast furnace stone products, and the waste refractory materials are not added. The quality of the raw water-quenched blast furnace stone produced by the blast furnace slag after the water-quenching process is similar.

In addition, the method for recycling waste refractories of the present invention can convert the phase structure of waste refractories containing magnesium oxide and/or contaminated by molten iron or slag into a stable amorphous state, which can be used as water-quenched blast furnace cement . Therefore, the waste refractory recycling method of the present invention can greatly reduce the land occupation cost and reduce the risk of land pollution by stacking waste refractory materials containing magnesium oxide and/or contaminated by molten iron or slag. The waste refractories containing magnesium oxide and/or contaminated by molten iron or slag can be converted into valuable water-quenched blast furnace cement to achieve the purpose of resource reuse.

The above-mentioned embodiments only exemplarily illustrate the recycling method of waste refractory materials of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology can modify and change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the rights of the present invention should be as stated in the scope of patent application described later.

without

Claims (9)

A method for recycling waste refractory materials, comprising the steps of: providing a waste refractory material; grinding the waste refractory material to obtain a ground waste refractory material, wherein the ground waste refractory material has a particle size range, And the particle size range is between 1μm and 30mm; adding the ground waste refractory material to the molten blast furnace slag containing molten iron to obtain a molten waste refractory material; and using a water quenching equipment High-pressure water is used to quickly cool the molten waste refractory material to obtain a water-quenched blast furnace stone; wherein the water-quenched blast furnace stone includes magnesium oxide, iron oxide, sulfur or any combination thereof. By weight, the content of the magnesium oxide is between 0wt% and 10wt%, the content of the iron oxide is between 0wt% and 3wt%, and the content of the sulfur is between 0wt% and 2wt% ; And the water-quenched blast furnace stone has an expansion rate, and the expansion rate is between 0.001% and 0.08%. The recycling method according to claim 1, wherein based on the total weight of the water-quenched blast furnace stone, the content of the magnesium oxide is between 0wt% and 7.5wt%, and the content of the iron oxide is between 0wt% % And 2wt%, and the sulfur content is between 0wt% and 1wt%. The recycling method according to claim 1, wherein the waste refractory material is contaminated by molten iron or slag. The recycling method according to claim 1, wherein the expansion rate is between 0.001% and 0.030%. The recycling method according to claim 1, wherein the particle size range is between 1 μm and 1 mm. The recycling method according to claim 1, wherein the particle size range is between 1 mm and 5 mm. The recycling method according to claim 1, wherein the particle size range is between 5 mm and 10 mm. The recycling method according to claim 1, wherein the particle size range is between 10 mm and 30 mm. The recycling method according to claim 1, wherein the water-quenched blast furnace stone has an amorphous phase structure.