Mine backfill material based on metallurgical solid wastes and preparation method therefor

Abstract

The present application relates to the field of mine control. Disclosed are a mine backfill material based on metallurgical solid wastes and a preparation method therefor. The mine backfill material comprises 5%-14% of a cementing material and 86%-95% of iron ore tailing slime, wherein the formulation of the cementing material specifically consists of 5%-10% of an activator, 5%-10% of desulfurization ash, 10%-20% of steel slag powder and 60%-75% of ore slag powder. The present invention fully utilizes the metallurgical solid waste resources to prepare the mine backfill material, which effectively solves the problem of accumulation of solid wastes in great quantity, such as steel slag, blast furnace slag, desulfurization ash, etc. which are generated during metallurgical processes, reduces the occupation of precious arable land resources, reduces the degree of pollution to the environment, realizes the reuse of resources and confirms the sustainable development requirement. The present invention can effectively improve the comprehensive utilization rate of steel slag and use desulfurization ash, thereby solving the solid waste problem for Ansteel Group Corporation. Moreover, the present mine backfill material has a flexible formulation, wherein the ratios of the activator, desulfurization ash, steel slag powder and ore slag powder in the cementing material and the proportion of the iron ore tailing slime can be adjusted according to different requirements, so as to adapt to different engineering scenarios.

Description

Metallurgical solid waste-based mine filling material and preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of mine treatment, in particular to a metallurgical solid waste-based mine filling material and a preparation method thereof. BACKGROUND

[0002] In today's society, the rapid development of industry has brought many challenges, among which the rapid development of the metallurgical industry has not only made a great contribution to economic construction, but also produced a large amount of metallurgical solid waste resources; steel tailings, as one of the main waste in the metallurgical process, have a huge output; these steel tailings usually contain various metal oxides and other complex components, if not properly handled, not only occupy a large amount of land resources for stacking, but also may release harmful substances through the process of wind erosion, water erosion and other processes under the long-term action of natural environment, causing pollution to the surrounding soil and water.

[0003] Blast furnace slag is also a solid waste product that cannot be ignored in the metallurgical process; the large accumulation of blast furnace slag not only occupies valuable arable land resources, reducing the land area available for agricultural production and ecological construction; on the other hand, due to its complexity, it may react under certain conditions to produce harmful gases or leachate, posing a potential threat to the atmospheric environment and groundwater, while sulfur ash, as an environmental by-product of the metallurgical process, also faces disposal problems; a large amount of desulfurization ash, if simply stacked, not only wastes space, but also may have adverse effects on the surrounding ecological environment due to the residual chemical components; at the same time, mining activities continue, producing a large amount of tailings slurry every year; due to its special physical properties and chemical composition, these tailings slurry cannot be directly backfilled; if traditional solidification methods are used to treat tailings slurry, the cost is extremely high, which puts a heavy economic burden on mining enterprises; the large accumulation of tailings slurry not only occupies a large amount of land resources, but also may cause a series of environmental problems; for example, long-term accumulation of tailings slurry may leak into the ground, polluting groundwater sources and affecting the safety of drinking water for surrounding residents; at the same time, under the action of natural conditions such as rainwater erosion, harmful substances in the tailings slurry may enter the soil, causing soil pollution and affecting vegetation growth and ecological balance.

[0004] In order to solve the above problems, it is a promising solution to explore the use of solid waste resources produced by metallurgy to prepare mine filling materials; this not only effectively treats a large amount of accumulated metallurgical solid waste, avoiding pollution of the environment and occupying valuable space resources, but also enables the effective filling and utilization of iron mine tailings slurry, achieving waste utilization, promoting resource recycling and sustainable development. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a mine filling material based on metallurgical solid waste and a preparation method thereof, which solves the problems of a large amount of metallurgical solid waste resources generated in the metallurgical process and a large amount of tailings slurry generated in the mining process every year, affecting land resources and the environment.

[0006] To achieve the above object, the present application is implemented by the following technical scheme: a mine filling material based on metallurgical solid waste, characterized in that it comprises 5%-14% of gel material and 86%-95% of iron ore tailings slurry; wherein the ratio of the gel material is specifically 5%-10% of an activator, 5%-10% of desulfurization ash, 10%-20% of steel slag powder and 60%-75% of slag powder.

[0007] Preferably, the concentration of the iron ore tailings slurry is 70%-75%.

[0008] A preparation method of a mine filling material based on metallurgical solid waste, comprising the following steps:

[0009] S1. Preparing raw materials: preparing an activator, desulfurization ash, steel slag powder, slag powder and iron ore tailings slurry according to the proportions;

[0010] S2. Gel material preparation: first, pour the steel slag powder and slag powder into the stirring drum and start the stirring drum to stir the steel slag powder and slag powder at a low speed, then slowly add the desulfurization ash while continuing to stir, so that the desulfurization ash is fully dispersed in the mixed powder, then evenly sprinkle the activator into the mixing device, and increase the stirring speed to a medium speed to ensure that the activator can fully contact and react with other ingredients;

[0011] S3. Monitoring and adjusting: during the mixing process, sample the stirring sample every certain period of time for component detection to ensure that the proportions of the components meet the requirements, and if a proportion deviation is found, the missing materials are added in time to ensure the accuracy of the proportions;

[0012] S4. Mixing of gel material and slurry: further add the iron ore tailings slurry to the stirred gel material in batches, and start the stirrer to stir for 2-3 hours, and the ratio of the iron ore tailings slurry to the gel material is 1:10;

[0013] S5. Shaping and performance testing: pour the mixed material into a mold and use a vibrating machine to vibrate appropriately to expel the air therein, so that the material is more compact, and the material is maintained for a specified number of days to completely shape the material, then the material is taken out, and the compressive strength of the material is tested to ensure that the compressive strength reaches more than 2.5 MPa, meeting the use requirements of users.

[0014] Preferably, the specific stirring speed in step S2 is: low speed stirring is 30-50 revolutions per minute, medium speed stirring is 80-120 revolutions per minute.

[0015] Preferably, the specific stirring time in step S2 is: the steel slag powder and the slag powder are stirred at low speed, the stirring time is about 5-10 minutes; the desulfurization ash is fully dispersed in the mixed powder, the stirring time is about 3-5 minutes; the activator is uniformly scattered into the mixing device, and the stirring time is about 8-10 minutes.

[0016] Preferably, the specific monitoring time in step S3 is every 5-6 minutes.

[0017] Preferably, the specific batch in step S4 is divided into 7-8 times, and the time interval of each time adding the tailing mud is 15-20 minutes.

[0018] Preferably, the specific vibrator parameter in step S5 is: the vibrator use time is 3-8 minutes, and the vibrator frequency is 2000-5000 times / minute.

[0019] Preferably, the specified number of days of maintenance in step S5 is 28-30 days.

[0020] The application of a mine filling material based on metallurgical solid waste, as described in any one of claims 1-2, is applied in the field of mine governance, especially in the field of metal mines and coal mines.

[0021] The application provides a mine filling material based on metallurgical solid waste and a preparation method thereof.

[0022] 1. The application prepares a mine filling material by fully utilizing metallurgical solid waste resources, effectively solves the accumulation problem of a large amount of steel tailings, blast furnace slag and desulfurization ash and other solid wastes generated in the metallurgical process, reduces the occupation of valuable arable land resources, reduces the degree of environmental pollution, realizes the reuse of resources, meets the requirements of sustainable development, can effectively improve the comprehensive utilization rate of steel tailings, digest desulfurization ash, and solve the solid waste problem of Anshan.

[0023] 2. The mine filling material formula of the application is flexible, and the proportion of the activator, desulfurization ash, steel slag powder and slag powder in the gel material can be adjusted according to different needs, and the proportion of the iron ore tailing mud can be adjusted, so that different engineering scenes can be adapted, and the applicability of the material is improved.

[0024] 3. The application sets the monitoring and adjusting system, accurately samples, analyzes and calculates the proportion deviation of the material, can timely find and adjust the improper proportioning condition, improves the quality of the finished product, so as to ensure that the product quality output from the mixing device is more stable and meets the standard.

[0025] 4、The present application is provided with a calculation module, which makes the detection and calculation of the missing materials in the sample more accurate, ensures the accuracy of subsequent material addition, and prevents the occurrence of excessive material addition

[0026] 5、The present application further calculates the overall deviation by calculating the deviation of each component, which can comprehensively and accurately grasp the overall situation of material proportioning, which helps to timely discover potential proportioning imbalance problems, not only can quickly adjust in the production process to avoid the accumulation of deviation leading to product quality decline, but also can provide strong data support for optimizing production process and formula, thereby further improving the quality stability and reliability of mine filling materials, reducing production cost, and enhancing the competitiveness of products in the market. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a flow chart of the preparation method of the present application;

[0028] Figure 2 is a flow chart of the monitoring system of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described below with reference to the drawings of the present application specification, obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0030] Embodiment one:

[0031] Please refer to Figure 1, the present application provides a kind of mine filling material based on metallurgical solid waste, including gel material 9%, iron ore tailings mud 91%;

[0032] Wherein the proportioning of gel material is specifically 5% of activator, 5% of desulfurization ash, 20% of steel slag powder, 70% of slag powder, and the concentration of iron ore tailings mud is 70%.

[0033] A preparation method of a mine filling material based on metallurgical solid waste, comprising the following steps:

[0034] S1. Prepare raw materials: prepare activator, desulfurization ash, steel slag powder, slag powder and iron ore tailings mud according to the proportion respectively;

[0035] S2. Gel material production: First, the steel slag powder and slag powder are poured into the mixing drum, and the mixing drum is started to stir the steel slag powder and slag powder at low speed, the stirring time is about 5-10 minutes, after preliminary stirring, the desulfurization ash is slowly added, and the stirring is continued, so that the desulfurization ash is fully dispersed in the mixed powder, the stirring time is about 3-5 minutes, then the activator is evenly scattered into the mixing device, the stirring speed is increased to medium speed, to ensure that the activator can fully contact with other ingredients and react, the stirring time is about 8-10 minutes, wherein the low speed stirring is 30-50 revolutions per minute, and the medium speed stirring is 80-120 revolutions per minute;

[0036] S3. Monitoring and adjusting: During the mixing process, the monitoring and adjusting system is used to take samples every 5 minutes to detect the composition of the stirring sample, to ensure that the proportion of each component meets the requirements, if the proportion deviation is found, the missing materials are added in time to ensure the accuracy of the proportion;

[0037] The monitoring and adjusting system comprises a sampling module, which samples the materials in the mixing device and transmits the extracted sample to a spectral analysis module, the sampling module is connected with the spectral analysis module, the spectral analysis module analyzes the proportion of the sample and compares the proportion of the sample with the specified proportion, the spectral analysis module is connected with a calculation module, the calculation module is responsible for accurately calculating the specific missing proportion, and the calculation module is provided with a deviation formula for calculating each component and a total deviation formula, the calculation module is connected with a control feeding module, the control feeding module receives the conclusion from the calculation module and opens the corresponding material discharge valve according to the conclusion to supplement the proportion of the materials;

[0038] The deviation formula for calculating each component is: i = C i -R i

[0039] The total deviation is calculated as:

[0040] Wherein:

[0041] D i : represents the deviation of a certain component; C i : the actual mass fraction (percentage) of the i-th component in the sample; R i : the specified mass fraction (percentage) of the i-th component; n: represents the number of components;

[0042] If it is necessary to evaluate the qualification of the sample, a threshold value can be set, when D i is less than the threshold value, the sample is qualified, when there is an i such that D i is greater than the threshold value, the sample is unqualified and the components need to be adjusted;

[0043] S4. Mixing the gel material with the mud: Add 70% iron ore tailings mud to the mixed gel material in batches, and start the mixer to mix for 2 hours. Specifically, the batches are divided into 7 times, with an interval of 15-20 minutes between each addition of tailings mud. The ratio of iron ore tailings mud to gel material is 1:10.

[0044] S5. Molding and Performance Testing: Pour the mixed material into the mold and use a vibrator to properly compact it, expelling air and making the material more dense. After 28 days of curing to ensure the material is fully molded, remove the material and conduct a compressive strength test to ensure that its compressive strength reaches 2.5MPa or higher, meeting the user's requirements.

[0045] The beneficial effects of Example 1: It makes full use of metallurgical solid waste resources, including steel slag powder, ore slag powder, desulfurization ash and activators, and reuses solid waste that may otherwise pollute the environment, reducing the occupation of arable land and environmental pollution caused by solid waste dumping. Through a specific preparation method, the cementitious material is mixed with iron ore tailings mud at a ratio of 1:10, and after 28 days of curing, the compressive strength can reach more than 2.5MPa, which meets the requirements for mine filling and provides stable support for the mine.

[0046] Example 2:

[0047] A mine filling material based on metallurgical solid waste, comprising 14% gel material and 86% iron ore tailings mud;

[0048] The specific proportions of the gel material are: 10% activator, 10% desulfurization ash, 20% steel slag powder, and 60% slag powder.

[0049] Based on Example 1, steps S4 and S5 in a method for preparing a mine filling material based on metallurgical solid waste are modified as follows:

[0050] S4. Mixing the gel material with the slurry: Add 70% iron ore tailings slurry to the mixed gel material in batches, and start the mixer to mix for 2 hours. Specifically, the batches are divided into 7 times, with an interval of 15-20 minutes between each addition of tailings slurry. The ratio of iron ore tailings slurry to gel material is 1:6.

[0051] S5. Molding and performance test: pour the mixed material into the mold and use the vibrator to vibrate appropriately, expel the air in it, make the material more dense, the vibrator parameter is that the vibrator is used for 3-8 minutes, the vibrator frequency is 2000-5000 times / minute, and the material is completely formed after 28 days of maintenance. The material is taken out, and the compressive strength test is carried out to ensure that the compressive strength reaches 4.1 MPa or more, meeting the user's use requirements.

[0052] The beneficial effect of example two: by adjusting the proportion of activator, desulfurization ash, steel slag powder and slag powder in the gel material, and changing the mixing ratio with iron ore tailings mud to 1:6, the compressive strength of the final product after 28 days of maintenance reaches 4.1 MPa or more, which is suitable for mine filling scenes with higher strength requirements.

[0053] Example three:

[0054] A mine filling material based on metallurgical solid waste, comprising 5% of gel material and 95% of iron ore tailings mud;

[0055] The ratio of the gel material is specifically 10% of activator, 5% of desulfurization ash, 10% of steel slag powder and 75% of slag powder.

[0056] On the basis of example one, the S4 and S5 steps in the preparation method of a mine filling material based on metallurgical solid waste are changed:

[0057] S4. Mixing of gel material and mud: add iron ore tailings mud with a concentration of 70% to the stirred gel material in batches, and start the stirrer for 2 hours, wherein the specific batch is divided into 7 times, and the time interval for adding tailings mud each time is 15-20 minutes, and the ratio of iron ore tailings mud to gel material is 1:20

[0058] S5. Molding and performance test: pour the mixed material into the mold and use the vibrator to vibrate appropriately, expel the air in it, make the material more dense, and perform 28 days of maintenance, so that the material is completely formed. The material is taken out, and the compressive strength test is carried out to ensure that the compressive strength reaches 1.8 MPa or more, meeting the user's use requirements.

[0059] The beneficial effect of example three: efficient use of tailings mud, the proportion of gel material is only 5%, the proportion of iron ore tailings mud is as high as 95%, which greatly improves the utilization rate of tailings mud and has important significance for the treatment of a large amount of tailings mud. At the same time, under the condition of low use amount of gel material, the product still has a compressive strength of 1.8 MPa or more after 28 days of maintenance through reasonable proportioning and preparation method, saving metallurgical solid waste resources.

[0060] Comparative experiment:

[0061] Purpose of the experiment: compare the performance differences of the mine filling materials based on metallurgical solid waste prepared in Example One, Example Two and Example Three

[0062] Experimental process:

[0063] Prepare raw materials according to the material ratio of the three examples respectively: Example One: gel material 9% (activator 5%, desulfurization ash 5%, steel slag powder 20%, slag powder 70%), iron ore tailings mud 91%, tailings mud concentration 70%. Example Two: gel material 14% (activator 10%, desulfurization ash 10%, steel slag powder 20%, slag powder 60%), iron ore tailings mud 86%, tailings mud concentration 70%. Example Three: gel material 5% (activator 10%, desulfurization ash 5%, steel slag powder 10%, slag powder 75%), iron ore tailings mud 95%, tailings mud concentration 70%.

[0064] I. Compressive strength test:

[0065] Randomly select multiple test pieces from the cured materials of Example One, Example Two and Example Three respectively, and ensure that the number of test pieces of each example is not less than 5 to improve the accuracy of the test results.

[0066] Place the test pieces stably on the workbench of the pressure testing machine, and ensure that the center of the test piece is aligned with the loading center of the pressure testing machine

[0067] Start the pressure testing machine, apply pressure to the test piece at a constant loading rate (0.5 MPa per minute) and continue loading until the test piece fails, and record the pressure value at the time of failure.

[0068] The pressure values of the 5 test pieces of Example One at the time of failure are 2.6 MPa, 2.7 MPa, 2.5 MPa, 2.8 MPa and 2.9 MPa, and the average value is 2.7 MPa;

[0069] The pressure values of the 5 test pieces of Example Two at the time of failure are 4.2 MPa, 4.3 MPa, 4.1 MPa, 4.4 MPa and 4.5 MPa, and the average value is 4.3 MPa;

[0070] The pressure values of the 5 test pieces of Example Three at the time of failure are 1.9 MPa, 1.8 MPa, 2.0 MPa, 1.85 MPa and 1.75 MPa, and the average value is 1.86 MPa.

[0071] Conclusion:

[0072] The results show that the compressive strength of Example Two is the highest, that of Example One is second, and that of Example Three is the lowest.

[0073] The higher content of gel material in Example Two helps to improve the compressive strength of the material.

[0074] II. Flowability Test:

[0075] A number of test pieces were randomly selected from the cured materials of Example One, Example Two and Example Three respectively, ensuring that the number of test pieces for each example was not less than 5, to improve the accuracy of the test results.

[0076] The inner wall of the slump cone was moistened and placed on a flat ground to ensure its position was fixed.

[0077] The mixed materials of Example One, Example Two and Example Three were respectively loaded into the slump cone in three layers, with each layer being inserted and tamped 25 times with a tamper, and the insertion and tamping should be in a spiral direction from the outside to the center.

[0078] After being filled, the excess material was scraped off with a spatula to make the top of the slump cone level with the surface of the material.

[0079] The slump cone was slowly lifted vertically, and the material was allowed to slump naturally under the action of gravity.

[0080] The height of the material slump was measured with a ruler, which was the slump value. The flowability index of each example was taken as the average value of 5 repeated measurements.

[0081] After measurement, the average slump value of Example One was 200 mm, the average slump value of Example Two was 180 mm, and the average slump value of Example Three was 160 mm.

[0082] Conclusion:

[0083] Example Two had the best flowability, which was probably due to the higher content of gel material making the material more uniform and easy to flow. Example One and Example Three had relatively poor flowability.

[0084] III. Setting Time Test:

[0085] The materials of Example One, Example Two and Example Three were respectively loaded into standard test molds according to the standard method.

[0086] The test mold containing the material was placed on the base of the Vicat apparatus, and the pointer of the Vicat apparatus was adjusted.

[0087] The state change of the material was observed from the start of water addition.

[0088] When the material began to lose plasticity, the time was recorded as the initial setting time.

[0089] Continuing to observe, when the material completely loses plasticity, record the time at this moment as the final setting time. Each example is repeated 3 times, and the average value is taken as the setting time of the example.

[0090] Suppose after testing, the initial setting time of example one is 3 hours, and the final setting time is 5 hours; the initial setting time of example two is 3.5 hours, and the final setting time is 6 hours; the initial setting time of example three is 2.5 hours, and the final setting time is 4.5 hours.

[0091] Conclusion: The setting time of example three is the shortest, which may be due to the higher content of the accelerator accelerating the hydration reaction of the material. The setting time of example one and example two is the longest.

[0092] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A metallurgical solid waste-based mine filling material, characterized by, The gel material 5%-14%, iron ore tailings mud 86%-95%; wherein the ratio of the gel material is specifically 5%-10% of the activator, 5%-10% of the desulfurization ash, 10%-20% of the steel slag powder, and 60%-75% of the slag powder.

2. A metallurgical solid waste based mine filling material as claimed in claim 1, wherein, The concentration of the iron ore tailings mud is 70%-75%.

3. A preparation method of the metallurgical solid waste-based mine filling material according to any one of claims 1-2, comprising the following steps: S1. Preparing raw materials: preparing the activator, the desulfurization ash, the steel slag powder, the slag powder, and the iron ore tailings mud according to the proportions; S2. Gel material preparation: first, the steel slag powder and the slag powder are poured into the stirring barrel, and the stirring barrel is started to stir the steel slag powder and the slag powder at a low speed; after preliminary stirring, the desulfurization ash is slowly added while the stirring is continued to make the desulfurization ash fully dispersed in the mixed powder; then, the activator is evenly scattered into the mixing device, and the stirring speed is increased to a medium speed to ensure that the activator can fully contact and react with other ingredients; S3. Monitoring and adjustment: during the mixing process, the ingredients of the stirring sample are detected every certain time to ensure that the proportions of the ingredients meet the requirements; if the proportion deviation is found, the missing materials are added in time to ensure the accuracy of the proportions; S4. Mixing of the gel material and the mud: the iron ore tailings mud is added to the stirred gel material in batches, and the stirrer is started to stir for 2-3 hours, and the proportion of the iron ore tailings mud to the gel material is 1:10; S5. Molding and performance testing: the mixed material is poured into a mold, and a vibrating machine is used for appropriate vibration to expel the air in the material, make the material more compact, and perform maintenance for a specified number of days; after the material is completely formed, the material is taken out, and the compressive strength of the material is tested to ensure that the compressive strength reaches more than 2.5 MPa, meeting the user's usage requirements.

4. The method of claim 1, wherein the metallurgical solid waste-based mine filling material is prepared by the steps of: The specific stirring speed in step S2 is: the low-speed stirring is 30-50 revolutions per minute, and the medium-speed stirring is 80-120 revolutions per minute. ​ 5. The method for preparing a mine filling material based on metallurgical solid waste according to claim 1, characterized in that, The specific stirring time in step S2 is: the steel slag powder and the slag powder are stirred at a low speed for about 5-10 minutes; the desulfurization ash is fully dispersed in the mixed powder for about 3-5 minutes; and the activator is evenly scattered into the mixing device for about 8-10 minutes.

6. The method of claim 1, wherein the metallurgical solid waste based mine filling material is prepared by the steps of: The specific monitoring time in step S3 is every 5-6 minutes.

7. The method for preparing a mine filling material based on metallurgical solid waste according to claim 1, characterized in that, The specific batch in step S4 is 7-8 times, and the time interval for adding the tailings mud each time is 15-20 minutes.

8. The method for preparing a mine filling material based on metallurgical solid waste according to claim 1, characterized in that, The specific vibrating machine parameters in step S5 are: the vibrating machine is used for 3-8 minutes, and the vibrating machine frequency is 2000-5000 times per minute.

9. The method for preparing a mine filling material based on metallurgical solid waste according to claim 1, characterized in that, The specified number of days of maintenance in step S5 is 28-30 days.

10. Use of a metallurgical solid waste-based mine filling material, characterized in that, The metallurgical solid waste-based mine filling material according to any one of claims 1-2 is applied in the mine governance field, especially in the metal mine field and the coal mine field.

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