Low-temperature chlorination titanium extraction tailing-based magnesium cementing material and preparation method thereof

Abstract

The invention discloses a low-temperature chlorination titanium extraction tailing-based magnesium cementing material and a preparation method thereof. The magnesium cementing material based on the low-temperature chlorination titanium extraction tailings is prepared from the following components in parts by mass: 50 to 70 parts of the low-temperature chlorination titanium extraction tailings, 15 to 25 parts of light calcined magnesia, 3 to 8 parts of magnesium sulfate, 5 to 10 parts of silica fume, 2 to 5 parts of sawdust, 0.3 to 1 part of a dispersing agent, 0.5 to 2 parts of a cement modifier and the balance of water, the water-solid ratio of the low-temperature chlorination titanium extraction tailing-based magnesium cementing material is 0.18 to 0.25. The high value of the solid waste is utilized, the doping amount of the low-temperature chlorination titanium extraction tailings in the low-temperature chlorination titanium extraction tailings-based magnesium cementing material reaches 50-70%, the problem that the solid waste utilization rate of a traditional process is low is solved, the raw material cost is reduced by 35% or above, and residual MgCl2 in the low-temperature chlorination titanium extraction tailings and magnesium sulfate form a dual magnesium source in cooperation with a cementing system, so that the utilization rate of the low-temperature chlorination titanium extraction tailings is increased. And reacting with light calcined MgO to generate magnesium oxysulfate crystals, thereby enhancing the strength.

Description

Technical Field

[0001] This application relates to the field of building materials technology, and in particular to a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material and its preparation method. Background Technology

[0002] Traditional silicate cement-based materials face problems such as high energy consumption and large carbon emissions during production; while ordinary magnesium-based cementitious materials (such as magnesium oxychloride cement) are prone to moisture absorption and efflorescence, resulting in poor durability. Low-temperature chlorination tailings, as a byproduct of titanium dioxide production, are currently mainly disposed of through landfill. These tailings contain abundant active SiO2, Al2O3, and residual MgCl2, and although they possess potential cementitious activity, their utilization rate is less than 5%. Existing tailings-based cementitious materials mostly rely on high-temperature activation or high-content cement, leading to problems such as high cost, low strength, and poor volume stability.

[0003] Therefore, developing a magnesium cementitious material that can effectively utilize the industrial waste of low-temperature chlorination titanium extraction tailings, and overcome the shortcomings of traditional silicate cement-based materials and ordinary magnesium cementitious materials, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, this application provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, which is an environmentally friendly cementitious material that achieves a low-temperature chlorination titanium extraction tailings content of ≥40%, a 28-day compressive strength of ≥35MPa, excellent water resistance (softening coefficient ≥0.85), and a cost reduction of 30%.

[0005] This application provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight, 50 to 70 parts of low-temperature chlorination titanium extraction tailings, 15 to 25 parts of lightly calcined magnesium oxide, 3 to 8 parts of magnesium sulfate, 5 to 10 parts of silica fume, 2 to 5 parts of sawdust, 0.3 to 1 part of dispersant, 0.5 to 2 parts of cement modifier, and the balance being water. The water-to-solid ratio of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material is 0.18 to 0.25.

[0006] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material described above not only effectively utilizes this industrial waste but also overcomes the shortcomings of traditional silicate cement-based materials and ordinary magnesium cementitious materials. This application successfully achieves this goal through specific raw material ratios and preparation processes, significantly improving the utilization rate of the tailings and effectively reducing production costs. Simultaneously, the prepared magnesium cementitious material exhibits excellent physical and mechanical properties and environmental friendliness, demonstrating potential for wide application in multiple fields.

[0007] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes low-temperature chlorination titanium extraction tailings. In some specific implementations, the low-temperature chlorination titanium extraction tailings, by weight, comprises: 40 to 45 parts of silica (which can be 40, 40.5, 41, 41.5, 42, 43, 44, 44.5, or 45 parts), 10 to 12 parts of alumina (which can be 10, 10.5, 11, 11.5, or 12 parts), 12 to 13 parts of iron oxide (which can be 12, 12.2, 12.5, or 13 parts), 14 to 15 parts of magnesium oxide (which can be 14, 14.2, 14.5, 14.8, or 15 parts), and 4 to 5 parts of titanium dioxide (4, 4.2, 4.5, 4.8, or 5 parts). In some specific implementations, the particle size of the low-temperature chlorination titanium extraction tailings is 180 to 200 mesh, specifically 180 mesh, 182 mesh, 185 mesh, 188 mesh, 190 mesh, 192 mesh, 195 mesh, 198 mesh, or 200 mesh. The mass fraction of the low-temperature chlorination titanium extraction tailings is 50 to 70 parts, specifically 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, or 70 parts.

[0008] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes light-burned magnesium oxide. In some specific implementations, the light-burned magnesium oxide comprises, by mass parts: 80 to 85 parts magnesium oxide (which can be 80, 81, 82, 83, 84, or 85 parts), 1 to 2 parts calcium oxide (which can be 1, 1.1, 1.2, 1.4, 1.6, 1.8, or 2 parts), and 6 to 7 parts reduced ignition (which can be 6, 6.2, 6.4, 6.5, 6.8, or 7 parts). The particle size of the light-burned magnesium oxide is 180 to 200 mesh, which can be 180 mesh, 182 mesh, 185 mesh, 188 mesh, 190 mesh, 192 mesh, 195 mesh, 198 mesh, or 200 mesh. The mass fraction of the lightly calcined magnesium oxide is 15 to 25 parts, specifically 15, 16, 18, 20, 22, 24, or 25 parts.

[0009] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes magnesium sulfate. In some specific implementations, the magnesium sulfate, by mass parts, comprises: 99 to 99.9 parts of magnesium sulfate heptahydrate (which can be 99, 99.1, 99.2, 99.4, 99.5, 99.6, 99.8, or 99.9 parts), and 0.01 to 0.02 parts of chloride ions (which can be 0.01, 0.0015, or 0.002 parts). The mass parts of the magnesium sulfate are 3 to 8 parts, which can be 3, 4, 5, 6, 7, or 8 parts.

[0010] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes silica fume. In some specific implementations, the silica fume comprises, by weight parts: 92 to 99.9 parts amorphous silica (which can be 92, 93, 94, 95, 96, 98, 99, or 99.9 parts), 0.1 to 1.5 parts alumina (which can be 0.1, 0.2, 0.5, 1, 1.2, or 1.5 parts), and 0.1 to 1 part iron oxide (which can be...). The silica fume comprises 0.1 parts, 0.2 parts, 0.4 parts, 0.5 parts, 0.8 parts, 1 part, 0.1 parts to 3 parts of carbon (which can be 0.1 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts) and 0.01 parts to 3 parts of water (which can be 0.01 parts, 0.05 parts, 0.1 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts), wherein the specific surface area of ​​the silica fume is 15000 m². 2 / kg to 25000m 2 / kg, wherein the particle size of the silica fume is 0.1μm to 0.3μm. The mass fraction of the silica fume is 5 to 10 parts, and can be 5, 6, 7, 8, 9, or 10 parts.

[0011] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes wood chips. In some specific implementations, the particle size of the wood chips is 2 mm to 6 mm, and the mud content in the wood chips is 0.1% to 10%. The mass fraction of the wood chips is 2 to 5 parts, and can be 2, 3, 4, or 5 parts.

[0012] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes a dispersant. In some specific implementations, the cement modifier includes SH-2152, which is a special cement modifier. The mass fraction of the dispersant is 0.3 to 1 part, and can be 0.3 parts, 0.5 parts, 0.8 parts, or 1 part.

[0013] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes a cement modifier. In some specific implementations, the dispersant includes FS-M800, which is a dedicated dispersant. The cement modifier is present in parts by weight from 0.5 to 2 parts, specifically 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2 parts.

[0014] The low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes water. The remaining amount is water, and the water-to-solid ratio of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material is 0.18 to 0.25, and can be 0.18, 0.19, 0.2, 0.22, 0.24, or 0.25.

[0015] This application also provides a method for preparing a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising:

[0016] Low-temperature chlorination titanium extraction tailings, lightly calcined magnesium oxide, magnesium sulfate, silica fume, sawdust, dispersant, cement modifier and water are mixed, cured and demolded to obtain a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material.

[0017] This application first ball-mills the low-temperature chlorination titanium extraction tailings (moisture content ≤3%) to obtain activated tailings powder. In some specific implementations, the specific surface area of ​​the ball-milled activated tailings powder is ≥400 m² / kg.

[0018] This application then adds activated tailings powder, lightly calcined magnesia powder, silica fume, sawdust, dispersant, and cement modifier to a twin-shaft mixer according to the specified proportions, and mixes them to obtain a dry mix. In some specific implementations, the mixing rate is 300-500 r / min, and the mixing time is 10-15 min.

[0019] This application then dissolves magnesium sulfate in water to prepare a magnesium sulfate aqueous solution. In some specific implementations, the dissolution temperature is 40°C to 50°C, and the concentration of magnesium sulfate in the magnesium sulfate aqueous solution is 20% to 30%, preferably 27%.

[0020] This application then adds an aqueous magnesium sulfate solution to the dry mixture, stirs it using a planetary mixer, pours it into a mold, cures and demolds it, and then cures it to the specified age to obtain a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material. In some specific implementations, the stirring speed is 80-120 r / min, and the stirring time is 3-5 min. In some specific implementations, the curing temperature is 28℃ to 32℃, the curing humidity is 80% to 90%, and the curing time is 20 h to 40 h.

[0021] This application utilizes the high-value utilization of solid waste by incorporating 50-70% of the low-temperature chlorination titanium extraction tailings into a magnesium-based cementitious material. This solves the problem of low solid waste utilization in traditional processes, reduces raw material costs by more than 35%, and, in synergy with the cementing system, allows residual MgCl2 in the low-temperature chlorination titanium extraction tailings to form a dual magnesium source with magnesium sulfate. This reacts with lightly calcined MgO to generate 5Mg(OH)2·MgSO4·7H2O (magnesium sulfate-oxygenated crystals), improving early strength. Silica fume fills the pores, and modifiers inhibit efflorescence. This green process requires no high-temperature calcination throughout, reducing energy consumption by 60% compared to traditional processes and reducing CO2 emissions by 2.3 tons per 10,000 tons of product. Attached Figure Description

[0022] Figure 1 The X-ray diffraction pattern is shown for the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material provided in Example 1 of this application. Detailed Implementation

[0023] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0024] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0025] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0026] The use of any and all instances or exemplary language such as “e.g.” or “include” in this document is intended merely to better illustrate the application and does not constitute a limitation on the scope of the application. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of this application.

[0027] Furthermore, the numerical ranges and parameters used to define this application are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise explicitly stated, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0028] This application provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight, 50 to 70 parts of low-temperature chlorination titanium extraction tailings, 15 to 25 parts of lightly calcined magnesium oxide, 3 to 8 parts of magnesium sulfate, 5 to 10 parts of silica fume, 2 to 5 parts of sawdust, 0.3 to 1 part of dispersant, 0.5 to 2 parts of cement modifier, and the balance being water. The water-to-solid ratio of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material is 0.18 to 0.25.

[0029] This application utilizes the high-value utilization of solid waste by incorporating 50-70% of the low-temperature chlorination titanium extraction tailings into a magnesium-based cementitious material. This solves the problem of low solid waste utilization in traditional processes, reduces raw material costs by more than 35%, and, in synergy with the cementing system, allows residual MgCl2 in the low-temperature chlorination titanium extraction tailings to form a dual magnesium source with magnesium sulfate. This reacts with lightly calcined MgO to generate 5Mg(OH)2·MgSO4·7H2O (magnesium sulfate-oxygenated crystals), improving early strength. Silica fume fills the pores, and modifiers inhibit efflorescence. This green process requires no high-temperature calcination throughout, reducing energy consumption by 60% compared to traditional processes and reducing CO2 emissions by 2.3 tons per 10,000 tons of product.

[0030] The present application is further illustrated below with reference to embodiments. The scope of protection of the present application is not limited to the following embodiments.

[0031] Example 1

[0032] This embodiment provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight parts, 0.5 parts dispersant, 1 part cement modifier, and silica fume (…). ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.3μm, specific surface area 18m² 2 7 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 20 parts of lightly calcined magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), and 5 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl...). - : 0.01%), low-temperature chlorination titanium extraction tailings ( 42.49%; 11.60%; The preparation method of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes: 60 parts of 180-mesh titanium dioxide (12.51%), 3 parts of sawdust (4-6 mm particle size, 2% mud content), and the balance being water, with a water-to-solid ratio of 0.22.

[0033] A certain amount of water was weighed, followed by the dispersant, cement modifier, and silica fume, which were stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, low-temperature chlorinated titanium extraction tailings, and sawdust were weighed, and the mixture was stirred forward for 2 minutes and then reverse for 2 minutes to obtain a uniformly mixed slurry. This slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for the specified age of 28 days, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0034] Product performance: 28-day compressive strength 38.7 MPa, softening coefficient 0.88. The X-ray diffraction pattern of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material provided in Example 1 of this application is shown below. Figure 1 As shown, 517 is magnesium oxysulfate crystal.

[0035] Example 2

[0036] This embodiment provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight parts, 0.3 parts dispersant, 2 parts cement modifier, and silica fume (…). ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.3μm, specific surface area 18m² 2 5 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 15 parts of lightly calcined magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), and 8 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl...). - : 0.01%), low-temperature chlorination titanium extraction tailings ( 42.49%; 11.60%; The preparation method of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes: 70 parts of 180-mesh (12.51%), 2 parts of sawdust (4-6 mm particle size, 2% mud content), and the balance being water, with a water-to-solid ratio of 0.25.

[0037] A certain amount of water was weighed, followed by the dispersant, cement modifier, and silica fume, which were stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, low-temperature chlorinated titanium extraction tailings, and sawdust were weighed, and the mixture was stirred forward for 2 minutes and then reverse for 2 minutes to obtain a uniformly mixed slurry. This slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for the specified age of 28 days, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0038] Product performance: 28-day compressive strength 32.4 MPa, softening coefficient 0.83.

[0039] Example 3

[0040] This embodiment provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight parts, 1 part dispersant, 0.5 parts cement modifier, and silica fume (…). ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.3μm, specific surface area 18m² 2 10 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 25 parts of lightly calcined magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), and 3 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl...). - : 0.01%), low-temperature chlorination titanium extraction tailings ( 42.49%; 11.60%; The preparation method of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes: 50 parts of 180-mesh (12.51%), 5 parts of sawdust (4-6 mm particle size, 2% mud content), and the balance being water, with a water-to-solid ratio of 0.18.

[0041] A certain amount of water was weighed, followed by the dispersant, cement modifier, and silica fume, which were stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, low-temperature chlorinated titanium extraction tailings, and sawdust were weighed, and the mixture was stirred forward for 2 minutes and then reverse for 2 minutes to obtain a uniformly mixed slurry. This slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for the specified age of 28 days, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0042] Product performance: 28-day compressive strength 33.4 MPa, softening coefficient 0.83.

[0043] Example 4

[0044] This embodiment provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight parts, 0.8 parts dispersant, 1.5 parts cement modifier, and silica fume (…). ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 5μm, specific surface area 18m² 2 8 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 22 parts of lightly calcined magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), and 6 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl...). - : 0.01%), low-temperature chlorination titanium extraction tailings ( 42.49%; 11.60%; The preparation method of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes: 55 parts of 180-mesh (12.51%), 4 parts of sawdust (4-6 mm particle size, 2% mud content), and the balance being water, with a water-to-solid ratio of 0.20.

[0045] A certain amount of water was weighed, followed by the dispersant, cement modifier, and silica fume, which were stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, low-temperature chlorinated titanium extraction tailings, and sawdust were weighed, and the mixture was stirred forward for 2 minutes and then reverse for 2 minutes to obtain a uniformly mixed slurry. This slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for the specified age of 28 days, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0046] Product performance: 28-day compressive strength 31.4 MPa, softening coefficient 0.80.

[0047] Example 5

[0048] This embodiment provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight parts, 0.6 parts dispersant, 0.8 parts cement modifier, and silica fume (…). ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.3μm, specific surface area 18m² 2 6 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 18 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl... - : 0.01%), low-temperature chlorination titanium extraction tailings ( 42.49%; 11.60%; The preparation method of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes: 65 parts of 180-mesh (12.51%), 3 parts of sawdust (4-6 mm particle size, 2% mud content), and the balance being water, with a water-to-solid ratio of 0.20.

[0049] A certain amount of water was weighed, followed by the dispersant, cement modifier, and silica fume, which were stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, low-temperature chlorinated titanium extraction tailings, and sawdust were weighed, and the mixture was stirred forward for 2 minutes and then reverse for 2 minutes to obtain a uniformly mixed slurry. This slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for the specified age of 28 days, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0050] Product performance: 28-day compressive strength 30.4 MPa, softening coefficient 0.81.

[0051] Example 6

[0052] This embodiment provides a low-temperature chlorination titanium extraction tailings-based magnesium cementitious material, comprising, by weight parts, 0.7 parts dispersant, 1.2 parts cement modifier, and silica fume (…). ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.3μm, specific surface area 18m² 2 9 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 20 parts of lightly calcined magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), and 7 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl...). - : 0.01%), low-temperature chlorination titanium extraction tailings ( 42.49%; 11.60%; The preparation method of the low-temperature chlorination titanium extraction tailings-based magnesium cementitious material includes: 12.51% CaO, 14.68% CaO, 9.15% MgO, 4.52% TiO2 (180 mesh particle size) 58 parts, sawdust (4-6 mm particle size, 2% mud content) 2.5 parts, with the balance being water, and a water-to-solid ratio of 0.19.

[0053] A certain amount of water was weighed, followed by the dispersant, cement modifier, and silica fume, which were stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, low-temperature chlorinated titanium extraction tailings, and sawdust were weighed, and the mixture was stirred forward for 2 minutes and then reverse for 2 minutes to obtain a uniformly mixed slurry. This slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for the specified age of 28 days, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0054] Product performance: 28-day compressive strength 34.4 MPa, softening coefficient 0.82.

[0055] Comparative Example 1

[0056] This comparative example provides a cementitious material comprising, by weight parts, silica fume ( ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.3μm, specific surface area 18m² 2 10 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 50 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl... - The cementitious material is prepared by comprising: 30 parts of a mixture of 0.01% (0.01%) sawdust (4-6mm particle size, 2% mud content) and 10 parts of water, with a water-to-solid ratio of 0.25.

[0057] A certain amount of water was weighed out, and silica fume was stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, and sawdust were weighed out, and the mixture was stirred forward for 2 minutes and then backward for 2 minutes to obtain a uniformly mixed slurry. The slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for 28 days to the specified age, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0058] Product performance: 28-day compressive strength 26.8MPa, softening coefficient 0.65, cost increase 42%.

[0059] Comparative Example 2

[0060] This comparative example provides a cementitious material comprising, by weight parts, silica fume ( ≥92% amorphous silica ≤1.5%, ≤1.0%, C (carbon) ≤3.0%, moisture ≤3%, particle size 0.1μm, specific surface area 18m² 2 10 parts of magnesium oxide (MgO: 83.2%; CaO: 1.6%; loss on ignition: 6.2%, particle size 180 mesh), 40 parts of magnesium sulfate (MgSO4·7H2O: 99.2%, Cl... - The cementitious material is prepared by comprising: 40 parts of a mixture containing 0.01% (0.01%) of sawdust (4-6 mm particle size, 2% mud content) and 10 parts of water, with a water-to-solid ratio of 0.25.

[0061] A certain amount of water was weighed out, and silica fume was stirred for 2 minutes. Then, lightly calcined MgO, magnesium sulfate, and sawdust were weighed out, and the mixture was stirred forward for 2 minutes and then backward for 2 minutes to obtain a uniformly mixed slurry. The slurry was poured into a mold and cured for 24 hours at 30±2℃ and 85±5% humidity before demolding. It was then naturally cured outdoors for 28 days to the specified age, and its strength performance was tested. After immersion in water for 28 days, the softening coefficient was tested.

[0062] Product performance: 28-day compressive strength 25.4 MPa, softening coefficient 0.62, cost increased by 40%.

[0063] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and application concept of this application, should be included within the scope of protection of this application.

Claims

1. A low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material, characterized by, The low-temperature chlorination titanium extraction tailings include 50-70 parts by mass, the lightly calcined magnesia includes 15-25 parts by mass, the magnesium sulfate includes 3-8 parts by mass, the silica fume includes 5-10 parts by mass, the wood chips include 2-5 parts by mass, the dispersant includes 0.3-1 part by mass, the cement modifier includes 0.5-2 parts by mass, and the rest is water. 2.The low-temperature chloridizing titanium-extracting tailing-based magnesia cementing material according to claim 1, characterized in that, The low-temperature chlorination titanium extraction tailings include 40-45 parts by mass of silicon dioxide, 10-12 parts by mass of aluminum oxide, 12-13 parts by mass of iron oxide, 14-15 parts by mass of magnesium oxide, and 4-5 parts by mass of titanium dioxide. 3.The low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material according to claim 1, characterized in that, The particle size of the low-temperature chlorination titanium extraction tailings is 180-200 mesh. 4.The low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material according to claim 1, characterized in that, The lightly calcined magnesia includes 80-85 parts by mass of magnesium oxide, 1-2 parts by mass of calcium oxide, and 6-7 parts by mass of loss on ignition, and the particle size of the lightly calcined magnesia is 180-200 mesh. 5.The low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material according to claim 1, characterized in that, The magnesium sulfate includes 99-99.9 parts by mass of magnesium sulfate heptahydrate and 0.01-0.02 parts by mass of chloride ions. 6.The low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material according to claim 1, characterized in that, The silica fume comprises, in mass parts, 92 to 99.9 parts of amorphous, non-crystalline silicon dioxide, 0.1 to 1.5 parts of aluminum oxide, 0.1 to 1 part of iron oxide, and 0.1 to 3 parts of carbon, the specific surface area of the silica fume is 15000 m 2 / kg to 25000 m 2 / kg, and the particle size of the silica fume is 0.1 μm to 0.3 μm. 7.The low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material according to claim 1, characterized in that, The particle size of the wood chips is 2-6 mm, and the clay content in the wood chips is 0.1-10%. 8.The low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material according to claim 1, characterized in that, The cement modifier includes SH-2152, and the dispersant includes FS-M800.

9. A method for preparing a low-temperature chloridizing titanium-extracting tailings-based magnesia cementitious material, characterized by, The low-temperature chlorination titanium extraction tailings, the lightly calcined magnesia, the magnesium sulfate, the silica fume, the wood chips, the dispersant, the cement modifier, and the water are mixed, cured, demolded, and the low-temperature chlorination titanium extraction tailings-based magnesia cementitious material is obtained. The curing temperature is 28-32℃, the curing humidity is 80-90%, and the curing time is 20-40h.

10. The method of claim 9, wherein, ​

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