A method for preparing black microcrystalline stone from molten nickel-iron slag

Abstract

The present application discloses a method for preparing black microcrystalline stone from molten nickel-iron slag, comprising: mixing the molten nickel-iron slag with a tempering agent, melting and heat-insulating the mixture to obtain a homogenized melt; casting the homogenized melt into a mold to obtain a molded sample; crystallizing the molded sample under a non-oxidizing atmosphere, cooling the molded sample to obtain black microcrystalline stone; and effectively improving the utilization rate of the nickel-iron slag.

Description

Technical Field

[0001] The present application relates to a method for preparing black microcrystalline stone by molten nickel-iron slag, belonging to the technical field of comprehensive resource utilization. Background Art

[0002] Industrial waste slag has the characteristics of large output, many types, difficult flow, and large fluctuations in composition, making it difficult to handle. Ferronickel slag is a solid waste slag produced during the smelting of nickel-iron alloy. As a by-product of the smelting process, large amounts of accumulation not only occupy land resources, but also pose a risk of heavy metal pollution. In the prior art, converting ferronickel slag into microcrystalline glass materials is one of the main research directions. Patent publication number CN101020968A discloses a process for preparing microcrystalline glass using high-temperature molten ferronickel slag, in which most of the iron and nickel are extracted by reduction under high-temperature conditions, and the sensible heat of the molten slag is used to prepare the remaining silicate slag into a microcrystalline glass composite material. However, this method has the following defects: an independent reduction and iron extraction process needs to be set up, resulting in a significant increase in equipment complexity and energy consumption; the residual slag has insufficient nucleation ability, and needs to rely on high-priced nucleation agents to induce crystallization, resulting in increased production costs.

[0003] Black microcrystalline stone has a huge market demand, but the existing preparation technology still has obvious limitations. The patent with publication number CN106242301A discloses a method for preparing black microcrystalline glass bricks using liquid converter slag as the main raw material, which improves the utilization rate of converter slag and makes full use of the sensible heat of the slag to prepare black microcrystalline glass bricks with good wear resistance and rolling resistance. However, this process adds precious metal oxides such as cobalt oxide and nickel oxide as colorants, which increases the production cost to a certain extent. In addition, the existing black microcrystalline stone components often contain iron oxide and manganese oxide. When prepared in an air atmosphere, the surface of the microcrystalline glass is easily oxidized, resulting in discoloration, making the surface appear red and other colors, and the color is mixed and impure, affecting the application range of the sample. Summary of the Invention

[0004] The purpose of this application is to overcome the deficiencies in the prior art and provide a method for preparing black microcrystalline stone from molten nickel-iron slag, thereby reducing production costs and improving the utilization rate of nickel-iron slag.

[0005] To achieve the above objectives, this application is implemented using the following technical solutions:

[0006] A method for preparing black microcrystalline stone from molten nickel-ferronickel slag is provided, comprising:

[0007] Mixing molten nickel-iron slag and a tempering agent in a mass ratio of 7:3 to 19:1, melting and heat-insulating to obtain a homogenized melt;

[0008] casting the homogenized melt into a mold to obtain a molded sample;

[0009] The molded sample is crystallized under non-oxidizing atmosphere and cooled to obtain black microcrystalline stone.

[0010] Furthermore, the temperature range of the crystallization treatment is 800° C. to 950° C., and the time is 5 min to 60 min.

[0011] Furthermore, the melting and holding temperature range is 1442°C to 1568°C, and the holding time is 30min to 150min;

[0012] During the casting, the viscosity of the homogenized melt is 0.1 Pa·s to 2.2 Pa·s.

[0013] Furthermore, the molten nickel-iron slag comprises the following chemical components in percentage by mass:

[0014] SiO2: 40%~60%, MgO: 20%~40%, Fe2O3: 1%~10%, FeO: 1%~5%, Al2O3: 2%~8%, CaO: 0.1%~5%, Cr2O3: 0.1%~5%, MnO: 0.1%~1%, Na2O and K2O: 0.01%~0.5%, and the rest are impurities.

[0015] Furthermore, the homogenized melt comprises the following chemical components in percentage by mass:

[0016] SiO2: 48%~60%, MgO: 18%~38%, Fe2O3: 4%~13%, FeO: 1%~5%, Al2O3: 4%~11%, CaO: 0.5%~6%, B2O3: 0%~6%, Cr2O3: 0.1%~5%, MnO: 0.1%~1%, Na2O and K2O: 0.01%~0.5%.

[0017] Furthermore, the conditioning agent includes a composition adjustment raw material and a clarifying raw material; wherein the mass of the composition adjustment raw material is 98% to 100% of the mass of the conditioning agent, and the mass of the clarifying raw material is 0 to 2% of the mass of the conditioning agent.

[0018] Furthermore, the composition adjustment raw material is any one or more of limestone, quartz sand, borax and diaspore powder; the clarification raw material is a mixture of one or more of industrial-grade antimony oxide and industrial-grade sodium chloride.

[0019] Furthermore, the non-oxidizing atmosphere includes any one or more of nitrogen, argon and CO; the oxygen content in the non-oxidizing atmosphere is 8% to 18%.

[0020] Furthermore, the cooling is carried out at a rate of 2-5°C / min or the product is cooled to below 200°C before being taken out of the furnace.

[0021] Furthermore, the mold is any one of a graphite mold, a cast iron mold and a stainless steel mold.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The method for preparing black microcrystalline stone from molten nickel-iron slag provided in this application realizes the preparation of pure black microcrystalline stone by controlling the atmosphere. The process is simple and makes full use of the sensible heat of the high-temperature slag.

[0024] (2) The steps of preparing black microcrystalline stone do not require the operation of reducing iron and adding colorants, and the black microcrystalline stone will not change color during the preparation process, which effectively improves the purity of the black microcrystalline stone;

[0025] (3) The black microcrystalline stone product is prepared only by nickel-iron slag and a small amount of conditioning agent. The formula is simple, the large-scale production cost is reduced, and the utilization rate of nickel-iron slag reaches 70~95%, realizing the effective utilization of waste resources;

[0026] (4) The various properties of the black microcrystalline stone products produced are higher than the requirements of the microcrystalline stone construction industry standards, and have better hardness, compressive strength, wear resistance, acid and alkali resistance and other properties, thereby improving market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flow chart of a method for preparing black microcrystalline stone from molten nickel-iron slag provided in an embodiment of the present application;

[0028] Figure 2 This is a picture of the black microcrystalline stone sample obtained in Example 1;

[0029] Figure 3 This is the XRD pattern of the sample obtained in Example 1;

[0030] Figure 4 This is a picture of the black microcrystalline stone sample obtained in Example 2;

[0031] Figure 5 This is a cross-sectional view of the sample obtained in Example 3;

[0032] Figure 6 This is a cross-sectional view of the sample obtained in Example 4;

[0033] Figure 7 This is a picture of the black microcrystalline stone sample obtained in Example 5;

[0034] Figure 8 This is the XRD pattern of the red part of the sample obtained in Example 5. DETAILED DESCRIPTION

[0035] The technical solution of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application.

[0036] This application provides a method for preparing black microcrystalline stone by molten nickel-iron slag, the process flow is as follows Figure 1 As shown, including:

[0037] (1) High-temperature molten nickel-iron slag is directly fed into the slag bag at 1442℃~1568℃, and a tempering agent is added; the content of nickel-iron slag is 70%~95%, and the content of tempering agent is 5%~30%;

[0038] Conditioning agents are divided into component adjustment raw materials and clarifying raw materials. The quality of component adjustment raw materials is 98%~100% of the quality of the conditioning agent, and the quality of clarifying raw materials is 0~2% of the quality of the conditioning agent.

[0039] The raw materials for composition adjustment are a mixture of one or more of limestone, quartz sand, borax, and diaspore powder. The clarification raw materials are a mixture of one or more of industrial-grade antimony oxide and industrial-grade sodium chloride. The specific amounts of the raw materials added should be based on the actual composition of the molten nickel-iron slag used, ensuring that the homogenized melt is within the required range.

[0040] (2) After adding the conditioning agent, keep the mixture at a temperature above 1442°C, preferably 1442°C to 1568°C, for 30 min to 150 min for homogenization.

[0041] (3) The homogenized melt is poured into a mold to obtain a molded sample; the melt viscosity during the casting process is 0.1 Pa·s~2.2 Pa·s.

[0042] (4) The molded sample is placed in a crystallization furnace and crystallized under atmosphere control throughout the process. The crystallization temperature is 800℃~950℃ and the crystallization time is 5min~60min. The atmosphere control process controls the oxygen content by introducing a non-oxidizing atmosphere. The oxygen content after control is 8%~18%. The non-oxidizing atmosphere is any one or more of nitrogen, argon, and CO.

[0043] (5) After the crystallization is completed, the temperature is lowered at a rate of 2℃ / min~5℃ / min or the furnace is cooled to below 200℃ and then taken out of the furnace to obtain black microcrystalline stone.

[0044] In the specific embodiments, unless otherwise specified, the experimental environment and parameter conditions of each group in the test remain consistent except for the differences clearly stated.

[0045] In certain embodiments of the present application, the molten ferronickel slag comprises:

[0046] SiO2: 40%~60%, MgO: 20%~40%, Fe2O3: 1%~10%, FeO: 1%~5%, Al2O3: 2%~8%, CaO: 0.1%~5%, Cr2O3: 0.1%~5%, MnO: 0.1%~1%, Na2O and K2O: 0.01%~0.5%, and the rest are impurities.

[0047] In some other embodiments of the present application, the composition of the molten nickel-iron slag is as follows:

[0048] (1) SiO2: 44.25%, MgO: 33.21%, Fe2O3: 14.27%, FeO: 1.38%, Al2O3: 3.04%, CaO: 0.93%, Cr2O3: 1.20%, MnO: 0.71%, Na2O and K2O: 0.14%.

[0049] (2) SiO2: 47.52%, MgO: 34.25%, Fe2O3: 9.27%, FeO: 1.40%, Al2O3: 3.27%, CaO: 1.34%, Cr2O3: 1.25%, MnO: 0.54%, Na2O and K2O: 0.24%.

[0050] In some embodiments of the present application, the melt after homogenization includes: SiO2: 48%~60%, MgO: 18%~38%, Fe2O3: 4%~13%, FeO: 1%~5%, Al2O3: 4%~11%, CaO: 0.5%~6%, B2O3: 0%~6%, Cr2O3: 0.1%~5%, MnO: 0.1%~1%, Na2O and K2O: 0.01%~0.5%.

[0051] In a specific embodiment, the melt composition after homogenization includes:

[0052] (1) SiO2: 50.32%, MgO: 27.57%, Fe2O3: 10.44%, FeO: 1.21%, Al2O3: 4.11%, CaO: 0.82%, B2O3: 3.11%, Cr2O3: 1.05%, MnO: 0.62%, Na2O and K2O: 0.12%.

[0053] (2) SiO2: 45.14%, MgO: 32.54%, Fe2O3: 8.81%, FeO: 1.33%, Al2O3: 5.83%, CaO: 1.27%, Cr2O3: 1.19%, MnO: 0.51%, Na2O and K2O: 0.23%, B2O3: 0.83%.

[0054] (3) SiO2: 50.32%, MgO: 23.25%, Fe2O3: 9.99%, FeO: 1.07%, Al2O3: 4.11%, CaO: 1.20%, B2O3: 8.11%, Cr2O3: 0.84%, MnO: 0.50%, Na2O and K2O: 0.08%.

[0055] The following is a further description of the method for preparing black microcrystalline stone from molten nickel-iron slag based on atmosphere control provided in this application.

[0056] Example 1:

[0057] This embodiment provides a method for preparing black microcrystalline stone by melting nickel-iron slag, and the specific process is as follows:

[0058] (1) The raw materials mainly include molten nickel-iron slag and tempering agent, with the nickel-iron slag accounting for 86% of the total mass percentage and the tempering agent accounting for 14% of the total mass percentage; the component adjustment raw material in the tempering agent is a mixture of limestone, aluminum ore powder and borax, accounting for 13% of the total mass percentage; the clarified raw material component is industrial grade antimony oxide, accounting for 1% of the total mass percentage.

[0059] (2) The composition of the molten nickel-iron slag is as follows by mass percentage: SiO2: 44.25%, MgO: 33.21%, Fe2O3: 14.27%, FeO: 1.38%, Al2O3: 3.04%, CaO: 0.93%, Cr2O3: 1.20%, MnO: 0.71%, Na2O and K2O: 0.14%.

[0060] (3) The molten nickel-iron slag was directly added to the slag bag, and a tempering agent was added, and the mixture was kept at 1550°C for 120 min. The composition of the glass melt obtained after mixing and homogenization was as follows: SiO2: 50.32%, MgO: 27.57%, Fe2O3: 10.44%, FeO: 1.21%, Al2O3: 4.11%, CaO: 0.82%, B2O3: 3.11%, Cr2O3: 1.05%, MnO: 0.62%, Na2O and K2O: 0.12% by mass.

[0061] (4) When the slag viscosity is 0.6 Pa·s, pour it into the mold.

[0062] (5) The formed product is sent to a crystallization furnace and CO is introduced. At this time, the oxygen content in the atmosphere is 14%, the nitrogen content is 52%, and the CO content is 33%. Crystallization treatment is carried out at a crystallization temperature of 900°C. After keeping the temperature for 45 minutes, it is cooled with the furnace to obtain black microcrystalline stone.

[0063] (6) The microcrystalline stone samples were cut and polished to obtain samples. The sample pictures are as follows: Figure 2As shown, the upper half of the attached figure is an appearance diagram, and the lower half is a cross-sectional diagram; Figure 2 It can be seen that the surface and interior of the sample are black, the surface is bright, there are almost no pores inside, and the whole is relatively dense. 3+ :Fe 2+ The ratio is 1.5.

[0064] The XRD results of the samples are as follows Figure 3 As shown, the main crystal phase is aegirine, with a large amount of forsterite and low-iron forsterite phases. The sample density is 3.42g / cm -3 , compressive strength 345MPa, flexural strength 142MPa, wear rate 1.2%, water absorption rate 0.018%, good acid and alkali resistance, and excellent performance indicators.

[0065] Example 2:

[0066] This embodiment provides a method for preparing black microcrystalline stone by molten nickel-iron slag, and the specific process is as follows:

[0067] (1) The raw materials mainly include molten nickel-iron slag and tempering agent. Nickel-iron slag accounts for 95% of the total mass percentage; tempering agent accounts for 5% of the total mass percentage, of which the composition adjustment raw material is a mixture of aluminum ore powder and borax, accounting for 4% of the total mass percentage, and the clarifying raw material is industrial-grade antimony oxide, accounting for 1% of the total mass percentage.

[0068] (2) The composition of the molten nickel-iron slag is as follows by mass percentage: SiO2: 47.52%, MgO: 34.25%, Fe2O3: 9.27%, FeO: 1.40%, Al2O3: 3.27%, CaO: 1.34%, Cr2O3: 1.25%, MnO: 0.54%, Na2O and K2O: 0.24%.

[0069] (3) The molten nickel-iron slag was directly added to the slag bag, and a tempering agent was added, and the mixture was kept warm at 1568°C for 150 min. The composition of the glass melt obtained after mixing and homogenization was as follows: SiO2: 45.14%, MgO: 32.54%, Fe2O3: 8.81%, FeO: 1.33%, Al2O3: 5.83%, CaO: 1.27%, Cr2O3: 1.19%, MnO: 0.51%, Na2O and K2O: 0.23%, B2O3: 0.83%.

[0070] (4) When the slag viscosity is 0.1 Pa·s, pour it into the mold.

[0071] (5) The formed product is sent to a crystallization furnace and CO is introduced. At this time, the oxygen content in the atmosphere is 18%, the nitrogen content is 50%, and the CO content is 32%. Crystallization treatment is carried out at a crystallization temperature of 950°C. After keeping the temperature for 60 minutes, the product is cooled at a cooling rate of 5°C / min to obtain black microcrystalline stone.

[0072] (6) The microcrystalline stone samples were cut and polished to obtain samples. The sample pictures are as follows: Figure 4 As shown, the upper half of the attached figure is the appearance diagram, and the lower half is the cross-sectional diagram; according to Figure 4 It can be seen that the surface and interior of the sample are black, the surface is shiny, there are almost no pores inside, and the overall density is relatively dense, with a density of 3.38g / cm -3 , compressive strength 338MPa, flexural strength 140MPa, wear rate 1.2%, water absorption rate 0.021%, good acid and alkali resistance, and excellent performance indicators.

[0073] Example 3:

[0074] This embodiment provides a method for preparing black microcrystalline stone by molten nickel-iron slag, and the specific process is as follows:

[0075] (1) The raw materials mainly include molten nickel-iron slag and tempering agent. Nickel-iron slag accounts for 70% of the total mass percentage; tempering agent accounts for 30% of the total mass percentage, of which the composition adjustment raw material is a mixture of quartz sand, limestone, aluminum stone powder and borax, accounting for 28% of the total mass percentage; the clarifying raw material is industrial-grade antimony oxide, accounting for 2% of the total mass percentage.

[0076] (2) The composition of the molten nickel-iron slag is as follows by mass percentage: SiO2: 44.25%, MgO: 33.21%, Fe2O3: 14.27%, FeO: 1.38%, Al2O3: 3.04%, CaO: 0.93%, Cr2O3: 1.20%, MnO: 0.71%, Na2O and K2O: 0.14%.

[0077] (3) The molten nickel-iron slag was directly added to the slag bag, and a tempering agent was added, and the mixture was kept warm at 1442°C for 30 min. The composition of the glass melt obtained after mixing and homogenization was as follows: SiO2: 50.32%, MgO: 23.25%, Fe2O3: 9.99%, FeO: 1.07%, Al2O3: 4.11%, CaO: 1.20%, B2O3: 8.11%, Cr2O3: 0.84%, MnO: 0.50%, Na2O and K2O: 0.08% by mass.

[0078] (4) When the slag viscosity is 2.2 Pa·s, pour it into the mold.

[0079] (5) The formed product is sent to a crystallization furnace and CO is introduced. At this time, the oxygen content in the atmosphere is 8%, the nitrogen content is 54%, and the CO content is 38%. Crystallization treatment is carried out at a crystallization temperature of 800°C. After keeping the temperature for 5 minutes, the temperature is cooled at a cooling rate of 2°C / min to obtain black microcrystalline stone.

[0080] (6) The microcrystalline stone sample is cut and polished to obtain a sample. The cross section of the sample is as follows: Figure 5 As shown, Figure 5 The sample is black inside, with almost no pores and is dense overall. The sample density is 3.22 g / cm -3 , compressive strength 310MPa, flexural strength 113MPa, wear rate 1.4%, water absorption rate 0.030%, good acid and alkali resistance, and excellent performance indicators.

[0081] Example 4:

[0082] This embodiment provides a method for preparing black microcrystalline stone by molten nickel-iron slag, and the specific process is as follows:

[0083] (1) The raw materials mainly include molten nickel-iron slag and tempering agent. Nickel-iron slag accounts for 86% of the total mass percentage; tempering agent accounts for 14% of the total mass percentage, of which the composition adjustment raw material is a mixture of limestone, aluminum ore powder, and borax, accounting for 13% of the total mass percentage; the clarifying raw material is industrial-grade antimony oxide, accounting for 1% of the total mass percentage.

[0084] (2) The composition of the molten nickel-iron slag is as follows by mass percentage: SiO2: 44.25%, MgO: 33.21%, Fe2O3: 14.27%, FeO: 1.38%, Al2O3: 3.04%, CaO: 0.93%, Cr2O3: 1.20%, MnO: 0.71%, Na2O and K2O: 0.14%.

[0085] (3) The molten nickel-iron slag was directly added to the slag bag, and a tempering agent was added, and the mixture was kept at 1550°C for 120 min. The composition of the glass melt obtained after mixing and homogenization was as follows: SiO2: 50.32%, MgO: 27.57%, Fe2O3: 10.44%, FeO: 1.21%, Al2O3: 4.11%, CaO: 0.82%, B2O3: 3.11%, Cr2O3: 1.05%, MnO: 0.62%, Na2O and K2O: 0.12% by mass.

[0086] (4) When the slag viscosity is 0.6 Pa·s, pour it into the mold.

[0087] (5) The formed product is sent to a crystallization furnace and nitrogen is introduced. At this time, the oxygen content in the atmosphere is 10% and the nitrogen content is 89%. Crystallization treatment is carried out at a crystallization temperature of 900°C. After keeping the temperature for 60 minutes, it is cooled with the furnace to obtain black microcrystalline stone.

[0088] (6) The microcrystalline stone sample is cut and polished to obtain a sample. The sample section is as follows: Figure 6 As shown, Figure 6 The sample surface and interior are black, with almost no pores and a relatively dense overall appearance. The sample density is 3.48 g / cm -3 , compressive strength 340MPa, flexural strength 138MPa, wear rate 1.3%, water absorption rate 0.015%, good acid and alkali resistance, and excellent performance indicators.

[0089] Embodiment 5:

[0090] This embodiment is an atmosphere comparison example. The atmosphere control process in Example 1 is removed, and microcrystalline stone is prepared in an air atmosphere. The specific process is as follows:

[0091] (1) The raw materials mainly include molten nickel-iron slag and tempering agent. Nickel-iron slag accounts for 86% of the total mass percentage; tempering agent accounts for 14% of the total mass percentage, of which the composition adjustment raw material is a mixture of limestone, aluminum ore powder, and borax, accounting for 13% of the total mass percentage; the clarifying raw material is industrial-grade antimony oxide, accounting for 1% of the total mass percentage.

[0092] (2) The composition of the molten nickel-iron slag is as follows by mass percentage: SiO2: 44.25%, MgO: 33.21%, Fe2O3: 14.27%, FeO: 1.38%, Al2O3: 3.04%, CaO: 0.93%, Cr2O3: 1.20%, MnO: 0.71%, Na2O and K2O: 0.14%.

[0093] (3) The molten nickel-iron slag was directly added to the slag bag, and a tempering agent was added, and the mixture was kept at 1550°C for 120 min. The composition of the glass melt obtained after mixing and homogenization was as follows: SiO2: 50.32%, MgO: 27.57%, Fe2O3: 10.44%, FeO: 1.21%, Al2O3: 4.11%, CaO: 0.82%, B2O3: 3.11%, Cr2O3: 1.05%, MnO: 0.62%, Na2O and K2O: 0.12% by mass.

[0094] (4) When the slag viscosity is 0.6 Pa·s, pour it into the mold.

[0095] (5) The formed product is sent to a crystallization furnace for crystallization treatment in an air atmosphere at a crystallization temperature of 900°C. After keeping the temperature for 60 minutes, the product is cooled with the furnace to obtain black microcrystalline stone.

[0096] (6) The cast stone samples were cut and polished to obtain samples. The sample pictures are as follows: Figure 7 As shown, the upper half of the attached figure is an appearance diagram, and the lower half is a cross-sectional diagram; Figure 7 It can be seen that the interior of the sample is black, but the surface has changed color significantly and is red, which does not achieve the black effect and cannot meet the process requirements. The red part of Fe 3+ :Fe 2+ The ratio is 2.8, Fe 3+ The content increased significantly;

[0097] The XRD results of the red part of the sample are as follows Figure 8 As shown, the main crystal phase of the sample is forsterite, with a certain amount of ferromagnesian olivine, but no aegerite phase.

[0098] Example 6:

[0099] In this embodiment, 100% molten nickel-iron slag is used to prepare black microcrystalline stone, and the tempering agent in Example 1 is removed. The effect of the tempering agent in this application is compared. The specific process is as follows:

[0100] (1) The raw material is molten nickel-iron slag, and the nickel-iron slag accounts for 100% of the total mass percentage.

[0101] (2) The composition of the molten nickel-iron slag is as follows by mass percentage: SiO2: 44.25%, MgO: 33.21%, Fe2O3: 14.27%, FeO: 1.38%, Al2O3: 3.04%, CaO: 0.93%, Cr2O3: 1.20%, MnO: 0.71%, Na2O and K2O: 0.14%.

[0102] (3) Add the molten nickel-iron slag directly into the slag bag and keep it at 1550℃ for 120 minutes.

[0103] (4) The sample is melted and kept warm at the predetermined temperature. If the viscosity does not reach the required range, the slag is poured into the mold when the viscosity reaches 2.5 Pa·s.

[0104] (5) The formed product is sent to a crystallization furnace and CO is introduced. At this time, the oxygen content in the atmosphere is 14%, the nitrogen content is 52%, and the CO content is 33%. Crystallization treatment is carried out at a crystallization temperature of 900°C. After keeping the temperature for 60 minutes, it is cooled with the furnace to obtain black microcrystalline stone.

[0105] (6) The microcrystalline stone sample was cut and polished to obtain the sample. The sample density was 2.30 g / cm -3 , compressive strength 125MPa, flexural strength 76MPa, wear rate 4.8%, water absorption rate 3.2%, low acid and alkali resistance, and performance indicators are significantly poor.

[0106] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for preparing black microcrystalline stone from molten nickel-iron slag, characterized in that: include: The molten nickel-iron slag and the tempering agent are mixed in a mass ratio of 7:3 to 19:1, melted and heat-insulated to obtain a homogenized melt; the tempering agent comprises a composition adjustment raw material and a clarification raw material; the mass of the composition adjustment raw material is 98% to 100% of the mass of the tempering agent, and the mass of the clarification raw material is 0 to 2% of the mass of the tempering agent; casting the homogenized melt into a mold to obtain a molded sample; The molded sample is crystallized under a non-oxidizing atmosphere and cooled to obtain black microcrystalline stone; the oxygen content in the non-oxidizing atmosphere is 8% to 18%.

2. The method according to claim 1, characterized in that The temperature range of the crystallization treatment is 800° C. to 950° C., and the time is 5 min to 60 min.

3. The method according to claim 1, characterized in that The temperature range of the melting and heat preservation is 1442°C to 1568°C, and the heat preservation time is 30min to 150min; During casting, the viscosity of the homogenized melt is 0.1Pa·s~2.2Pa·s.

4. The method according to claim 1, wherein The molten nickel-iron slag comprises the following chemical components in percentage by mass: SiO2: 40%~60%, MgO: 20%~40%, Fe2O3: 1%~10%, FeO: 1%~5%, Al2O3: 2%~8%, CaO: 0.1%~5%, Cr2O3: 0.1%~5%, MnO: 0.1%~1%, Na2O and K2O: 0.01%~0.5%.

5. The method according to claim 1, wherein The homogenized melt comprises the following chemical components in percentage by weight: SiO2: 48%~60%, MgO: 18%~38%, Fe2O3: 4%~13%, FeO: 1%~5%, Al2O3: 4%~11%, CaO: 0.5%~6%, B2O3: 0%~6%, Cr2O3: 0.1%~5%, MnO: 0.1%~1%, Na2O and K2O: 0.01%~0.5%.

6. The method according to claim 1, characterized in that The composition adjustment raw material is any one or more of limestone, quartz sand, borax and aluminum stone powder; The clarification raw material is a mixture of one or more of industrial-grade antimony oxide and industrial-grade sodium chloride.

7. The method according to claim 1, characterized in that The non-oxidizing atmosphere includes any one or more of nitrogen, argon and CO.

8. The method according to claim 1, characterized in that The cooling is carried out at a rate of 2°C / min to 5°C / min or the steel is cooled to below 200°C before being taken out of the furnace.

9. The method according to claim 1, characterized in that The mold is any one of a graphite mold, a cast iron mold and a stainless steel mold.

Images