A method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings and the magnesium-based cementitious materials

Abstract

This application provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings and the magnesium-based cementitious materials themselves, relating to the field of mineral processing. The method includes: drying and first homogenizing phosphate rock flotation tailings, followed by calcination to obtain a first material; homogenizing the first material with activated magnesium oxide to obtain a second material; and mixing the second material with a conditioning agent to obtain a magnesium-based cementitious material; wherein the conditioning agent includes at least one of magnesium chloride and magnesium sulfate. The resulting novel magnesium-based cementitious material possesses excellent physicochemical properties such as short setting time and high compressive strength. Furthermore, the phosphorus-containing minerals remaining in the phosphate tailings can improve the water resistance of the magnesium-based material within the novel cementing system.

Description

Technical Field

[0001] This application relates to the field of mineral processing, and in particular to a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings and the magnesium-based cementitious materials. Background Technology

[0002] Phosphate rock is non-renewable and non-recyclable, making it a one-time mineral resource. Therefore, how to reduce and destock phosphate tailings and make rational use of them has become an urgent technical problem to be solved.

[0003] To address the current lack of effective resource utilization methods for the flotation tailings of phosphate rock, it is necessary to develop a new composite cementitious material system to solve the problem of phosphate tailings treatment while providing a low-cost raw material for the cementitious material industry. Summary of the Invention

[0004] The purpose of this application is to provide a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings and the magnesium-based cementitious materials themselves, so as to solve the above-mentioned problems.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, comprising:

[0007] The tailings from the collophane flotation process are dried, homogenized, and then calcined to obtain the first material.

[0008] The first material is homogenized with active magnesium oxide to obtain a second material; the second material is mixed with a conditioning agent to obtain a magnesium-based cementitious material.

[0009] The conditioning agent includes at least one of magnesium chloride and magnesium sulfate.

[0010] Optionally, the phosphate rock flotation tailings include dolomite, apatite, and quartz.

[0011] Optionally, the dolomite content in the collophane flotation tailings is 75-90%.

[0012] Optionally, the CaO content in the collophane flotation tailings is 50-60%, and the MgO content is 10-20%.

[0013] Optionally, the particle size of the collophane flotation tailings in the 70-90% fraction is not higher than 0.074 mm.

[0014] Optionally, the initial moisture content of the collophane flotation tailings is 10-18%.

[0015] Optionally, the calcination temperature is 760-800℃ and the time is 20-40 min.

[0016] Optionally, the mixing ratio of the first material to the active magnesium oxide is 60-80 wt%: 20-40 wt%.

[0017] Optionally, the activation coefficient θ (%) of magnesium oxide in the second material is related to the material and kiln filling rate α (%), calcination temperature T (°C), and calcination time t (min) as follows: θ = 0.6 × (T / 800) + 0.2 (20 / α) + 0.2 (t / 30);

[0018] Among them, the kiln filling rate α is not higher than 20%, the calcination temperature T is 760-780℃, and the calcination time t is 20-40min.

[0019] Optionally, the relationship between the amount of conditioning agent β added and the activation coefficient of magnesium oxide θ, the amount of phosphate rock flotation tailings m1, the dolomite content M1 in the flotation tailings, and the amount of active magnesium oxide m2 is: β = (θ × m1 × M1 × 0.16 + m2) × 0.23.

[0020] This application also provides a magnesium-based cementitious material, which is prepared using the method for preparing magnesium-based cementitious materials from the flotation tailings of the phosphate rock.

[0021] Compared with the prior art, the beneficial effects of this application include:

[0022] The novel magnesium-based cementitious material prepared in this application has excellent physical and chemical properties such as short setting time and high compressive strength. At the same time, the phosphorus-containing minerals remaining in the phosphorus tailings can play a role in improving the water resistance of the magnesium-based material in the novel cementitious system. This method makes full use of the natural mineral endowment of high magnesium content in phosphate flotation tailings, transforming this bulk industrial solid waste, phosphorus tailings, into a raw material for cementitious materials. While solving the problem of comprehensive utilization of phosphorus tailings, it provides a low-cost and high-efficiency raw material for the cementitious materials industry, significantly reducing the raw material and energy consumption costs of cementitious materials. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0024] Figure 1 A schematic diagram of the process flow for preparing magnesium-based gel materials from phosphate rock flotation tailings provided in the embodiments;

[0025] Figure 2 The magnesium-based gel material prepared in Example 1. Detailed Implementation

[0026] As used in this article:

[0027] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0028] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0029] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0030] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0031] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (where K is any number representing a multiplier). It is important to understand that, unlike parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0032] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0033] To better explain the technical solution provided in this application, the technical solution will be explained in its entirety before the embodiments.

[0034] In a first aspect, this application provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, comprising:

[0035] The tailings from the collophane flotation process are dried, homogenized, and then calcined to obtain the first material.

[0036] The first material is homogenized with active magnesium oxide to obtain a second material; the second material is mixed with a conditioning agent to obtain a magnesium-based cementitious material.

[0037] The conditioning agent includes at least one of magnesium chloride and magnesium sulfate.

[0038] In one optional embodiment, the phosphate rock flotation tailings include dolomite, apatite, and quartz.

[0039] In one optional embodiment, the dolomite content in the collophane flotation tailings is 75-90%.

[0040] Optionally, the dolomite content in the collophane tailings can be 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, or any value between 75% and 90%.

[0041] In one optional embodiment, the CaO content in the phosphate rock flotation tailings is 50-60%, and the MgO content is 10-20%.

[0042] Optionally, the CaO content in the collophane flotation tailings can be 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, or any value between 50% and 60%; the MgO content can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any value between 10% and 20%.

[0043] In an optional embodiment, the particle size of the collophane flotation tailings in the 70-90% fraction may not exceed 0.074 mm.

[0044] In one optional embodiment, the initial moisture content of the collophane flotation tailings is 10-18%.

[0045] Optionally, the moisture content of the collophane flotation tailings can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or any value between 10% and 18%.

[0046] In one optional embodiment, the calcination temperature is 760-800°C and the time is 20-40 min.

[0047] Optionally, the calcination temperature can be 760℃, 765℃, 770℃, 775℃, 780℃, 785℃, 790℃, 795℃, 800℃, or any value between 760℃ and 800℃; the calcination time can be 20 min, 22 min, 24 min, 26 min, 28 min, 30 min, 32 min, 34 min, 36 min, 38 min, 40 min, or any value between 20 min and 40 min.

[0048] In an optional embodiment, the mixing ratio of the first material to the active magnesium oxide is 60-80 wt%: 20-40 wt%.

[0049] Optionally, the mixing ratio of the first material to active magnesium oxide can be 60wt%:40wt%, 70wt%:30wt%, 80wt%:20wt%, or any value between 60-80wt%:20-40wt%.

[0050] In an optional embodiment, the activation coefficient θ (%) of magnesium oxide in the second material is related to the material and kiln filling rate α (%), calcination temperature T (°C), and calcination time t (min) as follows: θ = 0.6 × (T / 800) + 0.2 (20 / α) + 0.2 (t / 30).

[0051] Among them, the kiln filling rate α is not higher than 20%, the calcination temperature T is 760-780℃, and the calcination time t is 20-40min.

[0052] In an optional embodiment, the relationship between the amount of conditioning agent β added and the activation coefficient θ of magnesium oxide, the amount m1 of the phosphate rock flotation tailings, the dolomite content M1 in the flotation tailings, and the amount m2 of the activated magnesium oxide is: β = (θ × m2) / ( ... 1× M 1× (0.16 + m2) × 0.23.

[0053] Secondly, this application also provides a magnesium-based cementitious material, which is prepared using the method for preparing magnesium-based cementitious materials from the flotation tailings of the phosphate rock.

[0054] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0055] The collophane tailings used in the examples contained 59.32% CaO and 15.45% MgO. Calcium and magnesium in the collophane tailings mainly existed in the form of dolomite. The types and contents of minerals in the collophane tailings are shown in Table 1.

[0056] Table 1. Types and contents of minerals in collophane flotation tailings

[0057]

[0058] Example 1

[0059] This embodiment provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the process flow of which is as follows: Figure 1 As shown, the specific process is as follows:

[0060] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 80%, and a dolomite content of 80%.

[0061] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 800℃ for 30 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the activation coefficient of magnesium oxide: θ=0.6(800 / 800)×0.2(30 / 30)×0.2(20 / 20)=1; the activation coefficient of magnesium oxide in the first material was calculated to be 1.

[0062] The first material and activated magnesium oxide were homogenized in a ratio of 60wt%:40wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the formula β = (1×80%). × 60% × (0.16 + 40%) × 0.23 = 10.96%, after mixing, a magnesium-based cementitious material is obtained, such as... Figure 2 As shown. The conditioning agent is magnesium chloride.

[0063] Example 2

[0064] This embodiment provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0065] Provided is collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 70%, and a dolomite content of 75%.

[0066] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 760℃ for 40 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the activation coefficient of magnesium oxide: θ=0.6(760 / 800)×0.2(40 / 30)×0.2(20 / 20)=1.04; the activation coefficient of magnesium oxide in the first material was calculated to be 1.04 (when the activation coefficient is greater than 1, it is calculated as 1).

[0067] The first material and activated magnesium oxide were homogenized in a ratio of 80wt%:20wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the ratio β = (1×75%). × 80% × (0.16 + 20%) × 0.23 = 6.81%, after mixing, a magnesium-based cementitious material is obtained. Among them, the conditioning agent is magnesium chloride.

[0068] Example 3

[0069] This embodiment provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0070] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 90%, and a dolomite content of 90%.

[0071] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 780℃ for 20 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the activation coefficient of magnesium oxide: θ=0.6(780 / 800)×0.2(20 / 30)×0.2(20 / 20)=0.92, the activation coefficient of magnesium oxide in the first material was calculated to be 0.92.

[0072] The first material was homogenized with activated magnesium oxide at a ratio of 70wt%:30wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the ratio β = (0.92 × 90%). × 70% × (0.16 + 30%) × 0.23 = 9.03%, after mixing, a magnesium-based cementitious material is obtained. Among them, the conditioning agent is magnesium chloride.

[0073] Example 4

[0074] This embodiment provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0075] Provided is collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 70%, and a dolomite content of 75%.

[0076] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 760℃ for 40 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the activation coefficient of magnesium oxide: θ = 0.6(760 / 800) × 0.2(40 / 30) × 0.2(20 / 20) = 1.03;

[0077] The activation coefficient of magnesium oxide in the first material was calculated to be 1.03 (when the activation coefficient is greater than 1, it is counted as 1).

[0078] The first material and activated magnesium oxide were homogenized in a ratio of 80wt%:20wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the ratio β = (1×75%). × 80% × (0.16 + 20%) × 0.23 = 6.81%, after mixing, a magnesium-based cementitious material is obtained. Among them, the conditioning agent is magnesium sulfate.

[0079] Example 5

[0080] This embodiment provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0081] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 90%, and a dolomite content of 90%.

[0082] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 780℃ for 20 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the magnesium oxide activation coefficient: θ=0.6(780 / 800)×0.2(20 / 30)×0.2(20 / 20)=0.92, the calculated magnesium oxide activation coefficient in the first material was 0.92.

[0083] The first material was homogenized with activated magnesium oxide at a ratio of 70wt%:30wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the ratio β = (0.92 × 90%). × 70% × (0.16 + 30%) × 0.23 = 9.03%, after mixing, a magnesium-based cementitious material is obtained. Among them, the conditioning agent is magnesium sulfate.

[0084] Comparative Example 1

[0085] This comparative example provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0086] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 80%, and a dolomite content of 80%.

[0087] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 700℃ for 30 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the magnesium oxide activation coefficient: θ=0.6(700 / 800)×0.2(30 / 30)×0.2(20 / 20)=0.93, the calculated magnesium oxide activation coefficient in the first material was 0.93.

[0088] The first material and activated magnesium oxide were homogenized in a ratio of 60wt%:40wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the ratio β = (0.93 × 80%). × 60% × (0.16 + 40%) × 0.23 = 10.84%, after mixing, a magnesium-based cementitious material is obtained. Among them, the conditioning agent is magnesium chloride.

[0089] Comparative Example 2

[0090] This comparative example provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0091] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 80%, and a dolomite content of 80%.

[0092] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 900℃ for 30 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the magnesium oxide activation coefficient: θ=0.6(900 / 800)×0.2(30 / 30)×0.2(20 / 20)=1.08, the calculated magnesium oxide activation coefficient in the first material was 1.08.

[0093] The first material and activated magnesium oxide were homogenized in a ratio of 60wt%:40wt% to obtain the second material; the second material and a conditioning agent were then mixed according to the formula β = (1.08 × 80%). × 60% × (0.16 + 40%) × 0.23 = 11.11%, after mixing, a magnesium-based cementitious material is obtained. Among them, the conditioning agent is magnesium chloride.

[0094] Comparative Example 3

[0095] This comparative example provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0096] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 80%, and a dolomite content of 80%.

[0097] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 700℃ for 30 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the magnesium oxide activation coefficient: θ=0.6(700 / 800)×0.2(30 / 30)×0.2(20 / 20)=0.925, the calculated magnesium oxide activation coefficient in the first material was 0.925.

[0098] The first material and active magnesium oxide were homogenized in a ratio of 60wt%:40wt% to obtain the second material. The second material and a 15% conditioning agent were then added and mixed to obtain a magnesium-based cementitious material. The conditioning agent was magnesium chloride.

[0099] Comparative Example 4

[0100] This comparative example provides a method for preparing magnesium-based cementitious materials from phosphate rock flotation tailings, the specific process of which is as follows:

[0101] Provide collophane flotation tailings to be processed, with an initial moisture content of 15%, a fineness of -0.074mm of 80%, and a dolomite content of 80%.

[0102] After drying and first homogenization of the phosphate rock flotation tailings, the first material was obtained by low-temperature calcination at 700℃ for 30 minutes in a rotary kiln. The kiln filling rate was 20%. Based on the magnesium oxide activation coefficient: θ=0.6(700 / 800)×0.2(30 / 30)×0.2(20 / 20)=0.925, the calculated magnesium oxide activation coefficient in the first material was 0.925.

[0103] The first material and active magnesium oxide were homogenized in a ratio of 60wt%:40wt% to obtain the second material. The second material and a 5% conditioning agent were then added and mixed to obtain a magnesium-based cementitious material. The conditioning agent was magnesium chloride.

[0104] The performance and cost of the magnesium-based cementitious materials prepared in each embodiment and comparative example are shown in Table 2.

[0105] Table 2 Information on magnesium-based cementitious materials prepared in the examples and comparative examples

[0106]

[0107] Table 2 shows that the calcination temperature, kiln filling rate, and calcination time of phosphate tailings all have a significant impact on the compressive strength of the subsequent cementitious materials. When the kiln filling rate α is in the range of 0-20%, the calcination temperature T is in the range of 760-780℃, and the calcination time t is in the range of 20-40 min, the magnesium oxide activity conversion coefficient of the phosphate tailings is within a reasonable range. The 7-day compressive strength of the cementitious materials prepared based on the magnesia activity conversion rate of magnesium oxide in the phosphate tailings is above 30 MPa. The 28-day compressive strength is above 50 MPa, and both magnesium chloride and magnesium sulfate can be used as conditioning agents. When the calcination temperature is too high, the holding time is too long, and the kiln filling rate is low, the conversion coefficient of active magnesium oxide in the phosphate tailings is within a reasonable range, but the performance of the cementitious material is poor. This is mainly because a large amount of active calcium oxide in the phosphate tailings decomposes, which has an adverse effect on the cementing system. When the calcination temperature is low, the holding time is low, and the kiln filling rate is high, the conversion coefficient of active magnesium oxide in the phosphate tailings is low, resulting in poor performance of the cementitious material.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0109] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A method of preparing a magnesium-based cementitious material from collophanite flotation tailings, characterized in that, The application relates to a magnesium-based cementing material and a preparation method thereof. The collophanite flotation tailings are dried and first homogenized, and then calcined to obtain a first material; The first material is second homogenized with active magnesium oxide to obtain a second material, and the second material is mixed with a tempering agent to obtain the magnesium-based cementing material; The tempering agent comprises at least one of magnesium chloride and magnesium sulfate; The relationship between the activation coefficient theta (%) of magnesium oxide in the first material and the kiln filling rate alpha (%), the calcination temperature T (℃) and the calcination time t (min) is theta=0.6x(T / 800)+0.2(20 / alpha)+0.2(t / 30); The kiln filling rate alpha is not higher than 20%, the calcination temperature T is 760-780 ℃, and the calcination time t is 20-40 min; The relationship between the added amount beta of the tempering agent, the activation coefficient theta of the magnesium oxide, the amount m1 of the first material, the dolomite content M1 in the collophanite flotation tailings and the amount m2 of the active magnesium oxide is beta=(theta*m1*M1*0.16+m2)*0.

23.

2. The method of producing magnesium-based cementitious material from collophanite flotation tailings according to claim 1, characterized in that, The collophanite flotation tailings comprise dolomite, apatite and quartz, and the content of dolomite in the collophanite flotation tailings is 75-90%.

3. The method of producing magnesium-based cementitious material from collophanite flotation tailings according to claim 2, characterized in that, The content of CaO in the collophanite flotation tailings is 50-60%, and the content of MgO is 10-20%.

4. The method of producing magnesium-based cementitious material from collophanite flotation tailings according to claim 1, characterized in that, The particle size of the collophanite flotation tailings with a particle size of 70-90% is not higher than 0.074 mm.

5. The method of producing magnesium-based cementitious material from collophanite flotation tailings according to claim 1, characterized in that, The initial moisture content of the collophanite flotation tailings is 10-18%.

6. The method of producing magnesium-based cementitious material from collophanite flotation tailings according to claim 1, characterized in that, The mixing ratio of the first material and the active magnesium oxide is 60-80 wt%:20-40 wt%.

7. A magnesium-based cementitious material characterized by, The magnesium-based cementing material is prepared by the method.

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