Method for preparing assembled cast stone from magnesium reducing slag

Abstract

The invention relates to the field of comprehensive utilization of resources, in particular to a method for preparing fabricated cast stone from magnesium reducing slag. The method for preparing the fabricated cast stone from the magnesium reducing slag comprises the following steps: heating and melting the magnesium reducing slag, a hardening and tempering agent and a fluxing agent, pouring into a mold of which a connecting part is sprayed with an enhancer, casting, and cooling to obtain the fabricated cast stone, the reinforcer comprises chromium spinel and silicon dioxide. The problem that crystallization is too fast when the magnesium reducing slag is directly applied is solved through component regulation and control, the strength of the cast stone connecting part is enhanced through the technology that the enhancer is sprayed on part of the part and the heat preservation layer is externally coated on the mold, and the method has the advantages of being low in raw material cost, high in production efficiency and suitable for industrial popularization.

Description

Technical Field

[0001] The present invention relates to the field of comprehensive resource utilization, and in particular to a method for preparing assembled cast stone from magnesium reduction slag. Background Art

[0002] Cast stone production represents a promising route for the resource utilization of solid waste. The resulting cast stone material can replace large quantities of natural stone, thus avoiding extensive mountain blasting and ecological damage. Directly using magnesium reduction slag to produce cast stone suffers from rapid and difficult-to-control crystallization due to its high alkalinity, failing to meet the demands of industrial cast stone production. Therefore, rationally regulating the composition of magnesium reduction slag and strengthening its key structural components to enable its use as a primary raw material for cast stone production and its subsequent resource utilization aligns with the industry's green development goals and offers significant application prospects.

[0003] Therefore, research and development of prefabricated cast stone with good mechanical properties prepared by using magnesium reduction slag has great application prospects. Summary of the Invention

[0004] Based on the above, the present invention provides a method for preparing prefabricated cast stone from magnesium-reducing slag. This method utilizes a tempering agent and a flux to adjust the composition of the magnesium-reducing slag before heating and melting it. Furthermore, a strengthening agent is used to micro-strengthen the joints of the cast stone. This method achieves low-cost preparation of prefabricated cast stone from magnesium-reducing slag, resulting in high product strength, a simple process, and ease of implementation.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a method for preparing assembled cast stone with magnesium reduction slag, comprising the following steps:

[0007] The magnesium reduction slag, the tempering agent and the flux are heated and melted, and then poured into a mold with a strengthening agent sprayed on the connection part for casting, and cooled to obtain the assembled cast stone;

[0008] The strengthening agents include chromium spinel and silica.

[0009] The second technical solution of the present invention is an assembled cast stone prepared according to the above method.

[0010] The third technical solution of the present invention is the application of the assembled cast stone in the field of construction.

[0011] The present invention discloses the following technical effects:

[0012] The present invention improves the problem of rapid crystallization faced by direct application of magnesium reduction slag by controlling the composition, and enhances the strength of the cast stone connection parts by spraying a strengthening agent on some parts and applying an insulation layer on the outside of the mold. It has the advantages of low raw material cost, high production efficiency and suitability for industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 Schematic diagram of the mold used in the embodiment of the present invention. DETAILED DESCRIPTION

[0015] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0016] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0017] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0018] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0019] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0020] A first aspect of the present invention provides a method for preparing fabricated cast stone from magnesium-reducing slag, comprising the following steps:

[0021] The magnesium reduction slag, the tempering agent and the flux are heated and melted, and then poured into a mold with a strengthening agent sprayed on the connection part for casting, and cooled to obtain the assembled cast stone;

[0022] The strengthening agents include chromium spinel and silica.

[0023] In a preferred embodiment of the present invention, the components of the magnesium reduction slag include, by mass percentage, SiO2: 30-35%, CaO: 50-60%, MgO: 5-10%, Fe2O3: 2-6% and the balance of inevitable impurities: 1-3%.

[0024] In a preferred embodiment of the present invention, the tempering agent is bauxite; the components of the bauxite include Al2O3: 60-65%, SiO2: 20-30%, Fe2O3: 5-15% and the balance of inevitable impurities: 1-3% by mass; the amount of the tempering agent added is 10% to 17% of the mass of the magnesium reduction slag.

[0025] In a preferred embodiment of the present invention, the flux is borax; and the added amount of the flux is 2% to 5% of the mass of the magnesium reduction slag.

[0026] In a preferred embodiment of the present invention, the mass ratio of the chromium spinel to silicon dioxide is 1:(2-4); the particle size of the strengthener is less than 0.075 mm; and the added amount of the strengthener is 0.05%-0.15% of the mass of the magnesium reduction slag.

[0027] The spraying thickness of the reinforcing agent is 0.03 mm to 0.09 mm.

[0028] In a preferred embodiment of the present invention, the outer side of the mold corresponding to the connection portion is coated with an insulation layer; the thermal conductivity of the insulation layer is 0.08W / m·K to 0.15W / m·K, and the heat-resistant temperature is not lower than 1400°C.

[0029] The purpose of coating the outer side of the mold corresponding to the connection part with an insulation layer is to reduce heat loss during melt casting, ensure slow crystallization of slag in the connection part, strengthen the microcrystalline strengthening effect, and enhance the interface bonding strength; at the same time, avoid deformation of the mold due to local overheating.

[0030] In a preferred embodiment of the present invention, the mold is preheated at a temperature of 400°C to 800°C before the molten slag is poured into the mold.

[0031] The purpose of preheating the mold is to eliminate the sharp temperature difference between the mold and the high-temperature melt, prevent thermal stress from causing cracks on the cast stone surface, and promote the flow of slag to fill the mold fine structure.

[0032] In a preferred embodiment of the present invention, the heating and melting is specifically heating to 1450° C. to 1500° C. and keeping the temperature for 30 minutes.

[0033] The cooling method is room temperature cooling.

[0034] The part where the reinforcing agent is sprayed is the inner side of the mold corresponding to the cast stone connection part.

[0035] A second aspect of the present invention provides an assembled cast stone prepared according to the above method.

[0036] The third aspect of the present invention provides the application of the fabricated cast stone in the field of construction.

[0037] Unless otherwise specified, the technical solutions described in the present invention are all conventional solutions in the field, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0038] The magnesium reduction slag used in the embodiment of the present invention has the following components: SiO2: 30-35%, CaO: 50-60%, MgO: 5-10%, Fe2O3: 2-6%, and other inevitable impurities: 1-3%.

[0039] The components of the bauxite used in the embodiments of the present invention are: Al2O3: 60-65%, SiO2: 20-30%, Fe2O3: 5-15% and other impurities: 1-3%.

[0040] The present invention relates to a detection method: the compressive strength of the working surface and the compressive strength of the connection parts of the assembled cast stone are tested with reference to the standards "GB / T 5072-2008 Test method for compressive strength of refractory materials at room temperature" and "ASTM C1006-07 Standard test method for compressive strength of joint materials".

[0041] The mold used in the embodiment of the present invention is as follows Figure 1 As shown, the dimensions are 200mm×200mm×50mm.

[0042] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0043] Example 1

[0044] Bauxite as a conditioning agent and borax as a flux were added to magnesium reduction slag, heated to 1485°C, and held for 30 minutes. The bauxite content was 11% of the slag mass, and the borax content was 2% of the slag mass. The slag was then poured into a mold, which had been sprayed with a strengthening agent at the joint. The strengthening agent consisted of chromium spinel and silica, with a mass ratio of 1:4. The strengthening agent particles ranged from 0 to 0.075 mm in diameter and were sprayed at a rate of 0.05% of the slag mass. The strengthening agent was applied to the inner side of the mold corresponding to the cast stone joint, with a thickness of 0.03 mm. The mold was then coated with an insulation layer at the joint, with a heat resistance of 1500°C and a thermal conductivity of 0.15 W / m·K. The mold was preheated to 400°C before the slag was poured. After the casting is completed, the mold is removed after natural cooling to obtain the assembled cast stone.

[0045] The main components of the assembled cast stone prepared in this embodiment are: SiO236%, Al2O318%, CaO 32%, MgO6%, Cr2O30.15%, the compressive strength of the working surface is 30MPa, the compressive strength of the connection part is 60MPa, and the wear resistance reaches 0.12g / cm 2 , Vickers hardness reaches 680.

[0046] Example 2

[0047] Bauxite as a conditioning agent and borax as a flux were added to magnesium reduction slag, heated to 1470°C, and melted for 30 minutes. The bauxite content was 14% of the slag mass, and the borax content was 3% of the slag mass. The slag was then poured into a mold, which had been sprayed with a strengthening agent at the joint. The strengthening agent consisted of chromium spinel and silica, with a mass ratio of 1:3. The strengthening agent particles ranged from 0 to 0.075 mm in diameter and were sprayed at a rate of 0.10% of the slag mass. The strengthening agent was applied to the inner side of the mold corresponding to the cast stone joint, with a thickness of 0.06 mm. The mold was then coated with an insulation layer with a thermal conductivity of 0.13 W / m·K at the outer side of the mold corresponding to the joint. The mold was preheated to 500°C before the slag was poured. After casting, the mold was removed from the mold after natural cooling to produce the assembled cast stone.

[0048] The main components of the assembled cast stone prepared in this embodiment are: SiO238%, Al2O321%, CaO 30%, MgO5%, Cr2O30.3%, the compressive strength of the working surface is 41MPa, the compressive strength of the connection part is 65MPa, and the wear resistance reaches 0.10g / cm 2 , Vickers hardness reaches 687.

[0049] Example 3

[0050] Bauxite as a conditioning agent and borax as a flux were added to magnesium reduction slag, heated to 1455°C, and melted for 30 minutes. The bauxite content was 17% of the slag mass, and the borax content was 5% of the slag mass. The slag was then poured into a mold, which had been sprayed with a strengthening agent at the joint. The strengthening agent consisted of chromium spinel and silica, with a mass ratio of 1:2. The strengthening agent particles ranged from 0.075 mm in diameter and were sprayed at a rate of 0.15% of the slag mass. The strengthening agent was applied to the inner side of the mold corresponding to the cast stone joint, with a thickness of 0.09 mm. The mold was then coated with an insulation layer with a thermal conductivity of 0.08 W / m·K at the joint. The mold was preheated to 800°C before the slag was poured. After casting, the mold was removed from the mold after natural cooling to produce the assembled cast stone.

[0051] The main components of the assembled cast stone prepared in this embodiment are: SiO2 40%, Al2O3 24%, CaO 28%, MgO 4%, Cr2O3 0.5%, the compressive strength of the working surface is 49 MPa, the compressive strength of the connection part is 73 MPa, and the wear resistance reaches 0.08 g / cm 2 , Vickers hardness reaches 703.

[0052] Comparative Example 1

[0053] The only difference from Example 3 is that the cast stone mold is not preheated; the remaining steps and parameters are the same as those in Example 1.

[0054] The compressive strength of the assembled cast stone working surface prepared in this comparative example is 18 MPa (decreased by 63.27% compared with Example 3), and the compressive strength of the connection part is 25 MPa (decreased by 65.75% compared with Example 3).

[0055] Comparative Example 2

[0056] The only difference from Example 3 is that the outer side of the mold is not covered with an insulation layer; the remaining steps and parameters are the same as those of Example 1.

[0057] The compressive strength of the assembled cast stone working surface prepared in this comparative example is 28 MPa (down 42.86% compared with Example 3), the compressive strength of the connection part is 45 MPa (down 38.36% compared with Example 3), and the wear resistance is 0.19 g / cm 2 .

[0058] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing assembled cast stone from magnesium reduction slag, characterized in that: The following steps are involved: The magnesium reduction slag, the tempering agent and the flux are heated and melted, poured into a mold with a strengthening agent sprayed on the connection part for casting, and cooled to obtain the assembled cast stone; The strengthening agents include chromium spinel and silicon dioxide.

2. The method for preparing fabricated cast stone from magnesium reduction slag according to claim 1, characterized in that: Calculated by mass percentage, the components of the magnesium reduction slag include: SiO2: 30-35%, CaO: 50-60%, MgO: 5-10%, Fe2O3: 2-6% and the balance of inevitable impurities: 1-3%.

3. The method for preparing assembled cast stone from magnesium reduction slag according to claim 1, characterized in that: The tempering agent is bauxite; in terms of mass percentage, the components of the bauxite include Al2O3: 60-65%, SiO2: 20-30%, Fe2O3: 5-15% and the balance of inevitable impurities: 1-3%; the addition amount of the tempering agent is 10%-17% of the mass of the magnesium reduction slag.

4. The method for preparing assembled cast stone from magnesium reduction slag according to claim 1, characterized in that: The flux is borax; the added amount of the flux is 2% to 5% of the mass of the magnesium reduction slag.

5. The method for preparing assembled cast stone from magnesium reduction slag according to claim 1, characterized in that: The mass ratio of the chromium spinel to silicon dioxide is 1:(2-4); the particle size of the reinforcing agent is less than 0.075 mm; and the added amount of the reinforcing agent is 0.05%-0.15% of the mass of the magnesium reduction slag.

6. The method for preparing fabricated cast stone from magnesium reduction slag according to claim 1, characterized in that: The outer side of the mold corresponding to the connection part is coated with a heat-insulating layer; the heat-insulating layer has a thermal conductivity of 0.08W / m·K to 0.15W / m·K and a heat-resistant temperature of not less than 1400°C.

7. The method for preparing fabricated cast stone from magnesium reduction slag according to claim 1, characterized in that: Before pouring the molten slag into the mold, the mold is preheated at a temperature of 400°C to 800°C.

8. The method for preparing fabricated cast stone from magnesium reduction slag according to claim 1, characterized in that: The heating and melting is specifically heating to 1450° C. to 1500° C. and keeping the temperature for 30 minutes.

9. The assembled cast stone prepared by the method according to any one of claims 1 to 8.

10. Use of the assembled cast stone according to claim 9 in the field of construction.

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