A method for preparing large volume artificial stone rough blocks directly from slag

Abstract

The application provides a method for preparing large-volume artificial stone rough material directly by using slag, and relates to the technical field of comprehensive utilization of metallurgical resources, and comprises the following steps: cooling a high-temperature molten first slag or modified slag to carry out first crystallization, so that molten slurry containing a first crystal phase is obtained; pouring the molten slurry into a large-volume mold and feeding into a kiln, and after solidification, crystallization heat preservation is carried out at 870-1050 DEG C to carry out second crystallization; and then the temperature of the kiln is reduced to 750 DEG C at a speed of 0.1-0.17 DEG C / min, external heating is stopped, and slow annealing and slow cooling annealing are realized only by the internal heat of the blank in the mold, so that the large-volume artificial stone rough material is obtained. The artificial stone rough material further undergoes a stone cutting process and becomes stone products of different models. The method realizes low-energy-consumption production of the artificial stone rough material by taking the slag as a raw material, the produced stone has good performance, and the preparation process is simple.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of comprehensive utilization of metallurgical resources, and particularly relates to a method for directly preparing large-volume artificial stone rough materials from molten slag. BACKGROUND

[0002] Metallurgical slag is a kind of high-temperature waste slag discharged during the smelting of metals, which is complex in composition and contains free heavy metal ions such as manganese, chromium, zinc, nickel and lead, and is easy to diffuse into the environment to cause pollution. There are more than one hundred million tons of molten slag discharged in the country every year, and such a large amount of waste slag not only occupies a large amount of land resources, but also causes great harm to the environment due to the presence of heavy metal elements and sulfides in the waste slag.

[0003] At present, most of the comprehensive utilization of molten slag is for cold slag that has been slowly cooled or water quenched. The patent with the application number 201310544436.2 proposes a controllable temperature die casting process method and equipment for producing cast stone from blast furnace slag, but it needs more conditioning agents, and the proportion of conditioning agents in the mass of molten slag can reach 20%. This means that more energy consumption is needed and the process is more complex, thereby increasing the production cost and making it difficult to achieve large-scale utilization of molten slag. In order to reduce the production cost, the patent with the application number 201010293048.8 directly utilizes the sensible heat of the discharged molten blast furnace slag to melt 0-10 mass% conditioning agents, and then casts and forms. However, the product prepared by this technology is mainly used for landscape stones with low mechanical property requirements, and the mechanical property is poor and the yield is low. The product prepared by the method in the patent cannot be applied to building materials. The patent with the application number 202310775660.6 proposes a method and production equipment for producing cast stone from blast furnace slag containing titanium, and successfully prepares cast stone with good performance. Although the preparation process does not need to add conditioning agents, this method has certain limitations and is only applicable to blast furnace slag containing titanium. At the same time, pressure equipment is needed during high-temperature heat treatment, the process becomes more complex, the cost is high, and it is difficult to apply to other smelting slag. The method for preparing stone materials from molten slag in the prior art is to prepare small-sized plates / blocks according to different molds, which increases the heat treatment energy consumption required by a single plate / block and makes the production process more complex. SUMMARY

[0004] The present application provides a method for directly preparing large-volume artificial stone rough materials from molten slag, to solve the technical problems of high energy consumption, insufficient performance of stone materials and complex preparation process in the prior art.

[0005] To achieve the above-mentioned application purposes, the technical solutions provided by the present application are as follows:

[0006] A method for directly preparing large-volume artificial stone rough materials from molten slag, comprising the following steps:

[0007] S1, cooling the first molten slag discharged from the high temperature industrial process or the second molten slag after adding a modifier online to perform a first crystallization to obtain a molten slurry containing a first crystal phase;

[0008] S2, casting the molten slurry into a large-volume mold and sending it into a kiln. After the slag solidifies, it is crystallized and kept warm at 870-1050° C. for a second crystallization;

[0009] S3. Lower the kiln temperature to 750°C at a rate of 0.1-0.17°C / min, stop external heating, and perform slow annealing and cooling annealing solely by the internal heat of the artificial stone block body in the mold to obtain a large-volume artificial stone block product.

[0010] Preferably, the first slag in S1 contains two or more compounds of MnS, Cr2O3, Fe2O3, FeO, MnO, MgO, and TiO2.

[0011] Preferably, the first slag in S1 is one or more of silicon manganese slag, copper slag, lead-zinc slag, and titanium-containing blast furnace slag that precipitate a high-temperature crystalline phase under high-temperature liquid conditions.

[0012] Preferably, the second slag in S1 is a slag that does not have high-temperature crystal phase characteristics.

[0013] Preferably, the amount of the modifier added in S1 is 4-10 wt% of the second slag.

[0014] Preferably, the modifier in S1 is one or more of chromite, ferrochrome slag, rutile sand, and soda ash.

[0015] Preferably, the first crystal phase in S1 is one or more of manganese sulfide, spinel, perovskite, and olivine.

[0016] Preferably, the crystal phase precipitated by the second crystallization in S2 is one or more of pyroxene, orthoclase, olivine, spinel, perovskite, diopside, and anorthite.

[0017] Preferably, the crystallization holding time in S2 is 5-12 hours.

[0018] Preferably, the finished large-volume artificial stone block in S3 has a dimension of at least one of the three dimensions of length, width and height of ≤60 cm, and a dimension of the smallest dimension of ≥10 cm.

[0019] The large-volume artificial stone rough material prepared by the application is cut and subjected to other cold working to obtain stone products of different types. The stone products of different types refer to various applications of natural stone such as granite or marble, including building decorative stone, pavement stone for roads, parking lots, swimming pools, stations, squares, sidewalks, communities and the like, and also include large stone for road edge stone, sculpture, decoration, road, river, tombstone and the like.

[0020] In the application, the first molten slag or modified molten slag with high-temperature crystal phase characteristics is subjected to high-temperature melting and crystallization, the first crystallization temperature is higher than the second crystallization temperature, and then the product is obtained by pouring and solidification molding and further crystallization at 870-920℃. The first crystallization phase can be obtained by directly water quenching the first molten slag or modified molten slag under high-temperature liquid flow conditions, and the water quenching sample is used to determine whether the crystallization phase is contained. The temperature interval between the highest crystallization temperature and the lowest crystallization temperature in the second crystallization process is not less than 100℃. The pyroxene, melilite, olivine, spinel, perovskite, diopside and anorthite are obtained in the large-volume artificial stone by crystallization, so as to improve the mechanical properties. The second molten slag without high-temperature crystal phase characteristics can be further utilized by adding a modifying agent.

[0021] Compared with the prior art, the above technical scheme has at least the following beneficial effects:

[0022] Compared with the prior art, the application has the following advantages:

[0023] (1) The modifying agent is added or only the molten slag itself is used to generate high-temperature crystalline phases such as manganese sulfide, spinel, perovskite and olivine during the high-temperature melting and cooling process. These mineral crystals can be initially and uniformly crystallized and used as a nucleating agent to ensure uniform crystallization in the stone. Since a special nucleation process is not required, the molten slag can be subjected to the second crystallization during the subsequent cooling process, and the energy consumption is low.

[0024] (2) The molten slag or modified molten slag with a large crystallization interval is selected in the application, and the size of the artificial stone rough material is selected, so that the internal and external temperature differences can be controlled within a certain temperature interval during the subsequent cooling process, which not only ensures that the internal and external parts of the large-volume artificial stone can be crystallized, but also ensures the uniformity of crystallization and the small internal stress, thereby meeting the mechanical requirements of the large-volume stone and having a high yield.

[0025] (3) According to the characteristics of large-volume stone materials, compared with small-size microcrystalline glass or cast stone plates, the internal heat of the large-volume stone materials is more, so that the annealing process almost does not need an external heat source, and after 1-3 hours of stabilization after the crystallization treatment, the annealing and subsequent cooling can be realized only by the internal heat. The annealing process time after crystallization is low, and the energy consumption is low.

[0026] (4) By using the high-temperature sensible heat characteristics of the discharged smelting slag, the second slag without high-temperature crystal phase characteristics is melted by the self-sensible heat of the modification agent (not more than 10 wt%), without additional heating, while achieving the modification purpose, directly casting the modified slag into a stone rough material, avoiding secondary remelting, greatly reducing energy consumption, and realizing the "slag"- "heat" high-value dual utilization of the slag.

[0027] (5) According to the characteristics of industrial bulk slag discharge, the slag is prepared into a stone rough material, which has a larger volume, a simpler preparation process, is more in line with the characteristics of industrial slag discharge, and has lower energy consumption and cost; and can be processed according to different use scenarios and needs, has strong product adaptability, and has broad market prospects. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a diffraction pattern of the water-quenched modified smelting silicon-manganese slag in Example 1;

[0029] Figure 2 is a diffraction pattern of the modified slag in Example 1 in the crystallization interval of 900-1050℃ after solidification;

[0030] Figure 3 is a photo of a stone finished product after cutting of the large-volume slag artificial stone rough material in Example 1;

[0031] Figure 4 is another photo of a stone finished product after cutting of the large-volume slag artificial stone rough material in Example 1;

[0032] Figure 5 is a diffraction pattern of the water-quenched smelting copper slag in Example 2. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present application.

[0034] Example 1

[0035] With 10 tons of molten silicon manganese slag (containing MnS, MnO and MgO, the sum of the three is 9.06 mass%) as raw material, 4% of the mass percentage of the modified agent chromite (containing 40.5 mass% of Cr2O3) is directly added to the slag ladle containing 10 tons of molten silicon manganese slag, and the modified agent is melted by the sensible heat of the slag. The slag with high temperature crystalline phase is obtained, and then the ladle operation is carried out, and the heat preservation is 15 minutes. The modified molten slag is water quenched after heat preservation for 15 minutes under high temperature liquid state condition, and the water quenched sample exists high temperature crystalline phase spinel, and the test figure is as follows Figure 1 ; the modified slag exists mainly the crystalline phase of pyroxene and melilite under the heat treatment condition of 900-1050℃ after the modified slag is solidified, and the related test figure is as follows Figure 2 . The modified slag after ladle homogenization and heat preservation for 15 minutes is cast in a large volume mold (length, width and height are 1.50, 0.45 and 0.65 m respectively), and then it is immediately sent into a high temperature kiln. The kiln heat treatment is set at 900℃ for crystallization and heat preservation for 10h, and then it is cooled to 750℃ at a cooling rate of 0.17℃ / min, and then the heat source is removed, and the stone is naturally cooled in the kiln. Finally, the artificial stone rough material with good performance, strong integrity and excellent cutting performance is obtained. The obtained sample is further cut and processed into plate materials such as Figure 3 and Figure 4 , and the water absorption, bending and compressive strength thereof are 0.19%, 52.24MPa and 142.78MPa respectively, which all meet the requirements of natural stone standard (GB / T18601-2009).

[0036] Example 2

[0037] The molten copper slag (containing Fe2O3, FeO and MgO, the sum of the three is 40.42 mass%) is directly water quenched under high temperature liquid state condition after heat preservation for 25 minutes, and the water quenched sample exists high temperature crystalline phase spinel and olivine; the molten slag exists secondary crystalline phase of olivine and spinel under the heat treatment condition of 900-1170℃ after the slag is solidified, and the related test figure is as follows Figure 5 . The slag is cast in a mold (length, width and height are 2.0, 0.35 and 0.50 m respectively) after heat preservation for 25 minutes, and then it is immediately sent into a high temperature kiln. The kiln heat treatment is set at 900℃ for crystallization and heat preservation for 11h, and then it is cooled to 750℃ at a cooling rate of 0.17℃ / min, and then the heat source is removed, and the stone is naturally cooled in the kiln. The artificial stone rough material with good performance, strong integrity and excellent cutting performance is obtained. The obtained sample is further cut and processed into a shape, and the water absorption, bending and compressive strength thereof are 0.08%, 55.98MPa and 420.38MPa respectively, which all meet the requirements of natural stone standard (GB / T18601-2009).

[0038] Example 3

[0039] The molten titanium-containing blast furnace slag (containing Fe2O3, FeO, TiO2, etc., the total of which is 13.69 mass%) is directly quenched by water under high-temperature liquid conditions, and the quenched sample has a high-temperature crystallization phase of perovskite; the molten slag has crystallization phases of diopside, melilite and perovskite after heat treatment at 870-1100°C. The molten slag is kept for 6 minutes and then cast into a mold (1.5 m in length, 0.65 m in width and 0.50 m in height), and then immediately sent into a high-temperature kiln. The kiln heat treatment is set at 870°C for crystallization and kept for 10 h, and then cooled to 750°C at a rate of 0.12°C / min, and then the heat source is removed, and the stone material is annealed and naturally cooled in the kiln by relying on its own sensible heat, and finally a good artificial stone rough material is obtained, which has good integrity and excellent cutting performance. The obtained sample is further cut and processed into a shape, and the water absorption, bending and compressive strengths thereof are 0.11%, 42.85 MPa and 170.08 MPa, respectively, all of which meet the requirements of the natural stone standard (GB / T 18601-2009).

[0040] Example 4

[0041] 10 tons of molten silicon-manganese slag (containing MnS, MnO and MgO, the total of which is 9.06 mass%) is used as a raw material to prepare a large-volume molten slag artificial stone at a silicon-manganese iron alloy production site. The molten slag is kept for 20 minutes and then quenched by water, and the quenched sample has a high-temperature crystallization phase of manganese sulfide; the molten slag has crystallization phases of diopside and melilite after heat treatment at 900-1050°C. The discharged molten silicon-manganese slag is kept for 20 minutes and then directly cast into a mold (1.50 m in length, 0.45 m in width and 0.65 m in height), and then immediately sent into a high-temperature kiln. The kiln heat treatment is set at 900°C for crystallization and kept for 10 h, and then cooled to 750°C at a rate of 0.12°C / min, and then the heat source is removed, and the stone material is annealed and naturally cooled in the kiln by relying on its own sensible heat, and finally a good artificial stone rough material is obtained, which has good integrity and excellent cutting performance. The obtained sample is further cut and processed into a shape, and the water absorption, bending and compressive strengths thereof are 0.24%, 34.45 MPa and 110.38 MPa, respectively, all of which meet the requirements of the natural stone standard (GB / T 18601-2009).

[0042] Example 5

[0043] In the molten silicon manganese slag (containing FeO, Fe2O3, MnO and MgO, and the sum of the four is 13.79 mass%), 10% of the mass percentage of molten chromium iron slag (containing 8 mass% of Cr2O3) is added as a modifier, mixed and then poured through a tundish, and kept for 10 minutes. The modified molten slag is water quenched after keeping for 10 minutes under high temperature liquid condition, and the water quenched sample contains high temperature crystalline phase manganese sulfide and spinel; the modified slag solidifies and is heat treated at 920-1050℃, and the crystalline phase of augite and melilite is generated. The modified molten slag after pouring is poured into a mold (length, width and height are 1.50, 0.45 and 0.65 m respectively), and then immediately sent into a high temperature kiln. The kiln heat treatment is set at 920℃ for crystallization and keeping for 10h, then cooled to 750℃ at a rate of 0.10℃ / min, then the heat source is removed, the stone material in the kiln is annealed and naturally cooled by relying on its own sensible heat, and finally a good artificial stone raw material with good overall performance and excellent cutting performance is obtained. The obtained sample is further cut and processed, and the water absorption, bending and compressive strengths are 0.09%, 54.69MPa and 310.38MPa respectively, which meet the requirements of natural stone standard (GB / T18601-2009).

[0044] Example 6

[0045] The discharged iron smelting slag (containing Fe2O3, FeO, MgO, and the sum of the three is 12.20 mass%) is added with 9% of rutile sand (containing 92.98 mass% of TiO2) as a modifier. The modified molten slag is water quenched after keeping for 12 minutes under high temperature liquid condition, and the water quenched sample contains high temperature crystalline phase perovskite; the modified slag solidifies and is heat treated at 870-1100℃, and the crystalline phase of diopside, anorthite and perovskite is generated. The mixed modified molten slag is poured through a tundish, and kept for 12 minutes, then directly poured into a mold (length, width and height are 1.5, 0.45 and 0.50 m respectively), and then immediately sent into a high temperature kiln. The kiln heat treatment is set at 870℃ for crystallization and keeping for 12h, then cooled to 750℃ at a rate of 0.10℃ / min, then the heat source is removed, the stone material in the kiln is annealed and naturally cooled by relying on its own sensible heat, and finally a good artificial stone raw material with good overall performance and excellent cutting performance is obtained. The obtained sample is further cut and processed, and the water absorption, bending and compressive strengths are 0.09%, 56.25MPa and 268.00MPa respectively, which meet the requirements of natural stone standard (GB / T18601-2009).

[0046] Example 7

[0047] The water-quenched sample of the molten lead-zinc slag (containing FeO, Fe2O3, MnO and MgO, and the total of the four is 50.06 mass%) under high-temperature liquid condition for 10 minutes has high-temperature crystallization phase spinel; the crystallization phases of the quenched slag under heat treatment condition at 900-1100°C are wustite, spinel, hematite and calcium iron pyroxene. The molten slag discharged from the slag channel is cast in a mold (length, width and height are 1.50, 0.15 and 0.60 m respectively), and then immediately sent into a high-temperature kiln. The kiln heat treatment is set at 1000°C for crystallization for 5h, and then cooled to 750°C at a cooling rate of 0.10°C / min, and then the heat source is removed, the stone in the kiln is annealed and naturally cooled by relying on its own sensible heat, and finally the artificial stone rough material with good performance, strong integrity and excellent cutting performance is obtained. The obtained sample is further cut and processed into a shape, and the water absorption, bending and compressive strengths thereof are 0.05%, 70.65 MPa and 435.38 MPa respectively, all meeting the requirements of the natural stone standard (GB / T18601-2009).

[0048] Example 8

[0049] The molten lead slag (containing Fe2O3, FeO and MgO, and the total of the three is 58.14 mass%) is added with 4% pure alkali as a modifier. The modified molten slag is water-quenched after being kept at high-temperature liquid condition for 15 minutes, and the water-quenched sample has high-temperature crystallization phase magnetite (iron spinel); the crystallization phases of the quenched slag after solidification under heat treatment condition at 900-1150°C are olivine, pyroxene and iron spinel. The modified molten slag is kept for 15 minutes on site, cast in a mold (length, width and height are 1.5, 0.35 and 1.00 m respectively), and then immediately sent into a high-temperature kiln. The kiln heat treatment is set at 1050°C for crystallization for 8h, and then cooled to 750°C at a cooling rate of 0.15°C / min, and then the heat source is removed, and the stone is naturally cooled in the kiln, and finally the artificial stone rough material with good performance, strong integrity and excellent cutting performance is obtained. The obtained sample is further cut and processed into a shape, and the water absorption, bending and compressive strengths thereof are 0.05%, 59.49 MPa and 487.61 MPa respectively, all meeting the requirements of the natural stone standard (GB / T18601-2009).

[0050] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing large volume artificial stone rough blocks directly from molten slag, characterized in that, The method comprises the following steps: S1, cooling the first molten slag discharged from an industrial process or the second molten slag added with a modifying agent to perform first crystallization, to obtain a molten slurry containing a first crystal phase; The first molten slag in S1 is one or more of silicon-manganese slag, copper slag, lead-zinc slag, and titanium-containing blast furnace slag, which can generate high-temperature crystal phases under high-temperature liquid conditions; The second molten slag in S1 is a molten slag without high-temperature crystal phase characteristics, and the modifying agent is one or more of chromite, chromium-iron slag, rutile sand, and soda ash, and the addition amount of the modifying agent is 4-10 wt% of the second molten slag; The first crystal phase in S1 is one or more of manganese sulfide, spinel, perovskite, and olivine; S2, pouring the molten slurry into a large-volume mold and feeding into a kiln, and performing second crystallization by crystallizing and heat preserving at 870-1050 ℃ after the molten slag solidifies; The crystal phase generated by the second crystallization in S2 is one or more of pyroxene, melilite, olivine, spinel, perovskite, diopside, and anorthite; S3, reducing the temperature of the kiln to 750 ℃ at a speed of 0.1-0.17 ℃ / min, stopping external heating, and only relying on the internal heat of the artificial stone roughage blank in the mold to realize slow annealing and slow cooling, to obtain a large-volume artificial stone roughage product.

2. The method for the preparation of large volume artificial stone rough blocks directly using slag according to claim 1, characterized in that, The addition amount of the modifying agent in S1 is 4-9 wt% of the second molten slag.

3. The method for the preparation of large volume artificial stone rough blocks directly using slag according to claim 1, characterized in that, The time of the crystallization heat preservation in S2 is 5-12 h.

4. The method for the preparation of large volume artificial stone rough blocks directly using slag according to claim 1, characterized in that, The large-volume artificial stone roughage product in S3 has a size of ≤60 cm in at least one dimension of length, width, and height, and a size of ≥10 cm in the smallest dimension.

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