Method for large-scale utilization of iron extraction tailings of nickel slag in cement-based material
By using a mechanical ball milling process to refine the iron-extracting tailings and mix them with cement, the problem of resource utilization of iron-extracting tailings in nickel slag treatment is solved, efficient and environmentally friendly tailings recycling is achieved, and the risk of heavy metal dissolution and carbon emissions from cement production are reduced.
Patent Information
- Application Number
- CN202510935859.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-09-19
AI Technical Summary
The treatment and disposal of nickel slag tailings from iron extraction is difficult, especially the fact that a closed technical loop for comprehensive resource utilization and large-scale disposal has not yet been formed. There is also a high risk of heavy metal penetration or leaching, and land occupation is serious.
The iron-extracting tailings are refined to a particle size of less than 15 μm using a mechanical ball milling process, and mixed with ordinary Portland cement and standard sand in a certain proportion to prepare a composite slurry. The hydration reaction increases the activity of the volcanic ash, replacing part of the cement, solidifying heavy metals and achieving efficient recovery.
It improves the activity index of iron-extracting tailings, reduces heavy metal dissolution, reduces carbon emissions from cement production, and achieves efficient recovery and high-value utilization of tailings, which is economical and environmentally friendly.
Smart Images
Figure CN120664837A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of recycling iron ore tailings, and in particular to a method for large-scale utilization of nickel slag iron ore tailings in cement-based materials. Background Art
[0002] As the nickel-iron alloy industry continues to expand, the stockpiling of nickel slag, an industrial waste product generated during its production process, has become increasingly serious. Currently, the primary method for disposing nickel slag is landfill, with a comprehensive utilization rate of less than 13%. However, the large-scale storage of nickel slag not only consumes significant land resources but also poses a risk of infiltration or leaching of the heavy metals Cr and Mn it contains. Nickel slag contains a high total iron content of approximately 30%-45%, also known as iron-rich nickel slag. Achieving its full resource utilization requires not only the extraction and recovery of the abundant iron resources within the slag but also the disposal of the approximately 70% remaining secondary tailings after iron extraction, referred to as iron-extraction tailings. Currently, extensive research on the comprehensive utilization of nickel slag focuses on the extraction and recovery of valuable metal elements such as Fe, Ni, and Co from the slag. This process primarily utilizes reduction processes to reduce the iron components in the slag to elemental iron. This process then undergoes high-temperature smelting to separate the iron from the slag, yielding molten iron and iron-extraction tailings. Reduced molten iron can be used in steelmaking or alloy preparation, but there are few research reports on the disposal of the separated iron-extraction tailings, resulting in the inability to form a complete technical closed loop for the comprehensive resource utilization and large-scale disposal of nickel slag. Summary of the Invention
[0003] In response to the above technical problems, the present invention provides a method for large-scale utilization of iron-extracting tailings from nickel slag in cement-based materials.
[0004] In order to achieve the above object, the technical solution of the present invention is as follows: A method for large-scale utilization of nickel slag iron-extraction tailings in cement-based materials, characterized by comprising the following steps: S1 is equipped with steel balls and iron tailings in a ratio of 1:3, and the material is added to a stainless steel mixing tank of a planetary ball mill for ball milling to obtain a fine powder of iron tailings, wherein the median particle size is less than 15μm; S2. According to 45-135 parts: 315-405 parts: 135 parts: 1350 parts of the ratio were weighed to extract iron tailings fine powder, ordinary Portland cement, water and standard sand; S3. Place the iron ore tailings fine powder, ordinary Portland cement, and water weighed in proportion in a mixer and stir at low speed for 30 seconds. At the beginning of the next 30 seconds, add the standard sand weighed in proportion. After the addition is completed, stir at high speed for 90 seconds to obtain a composite slurry. Place the composite slurry into a test mold and vibrate it into shape. After 24 hours, remove it from the mold and place it in a standard curing box for curing.
[0005] Furthermore, in step S1 , the steel balls have diameters of 19.5 mm, 14.5 mm, 11.5 mm, and 10.0 mm, respectively, and their mass ratio is 1:1:1:1.
[0006] Furthermore, in step S1, the loading rate of the material in the stainless steel mixing tank of the planetary ball mill is 65-85%, the rotation speed of the planetary ball mill is 20-50 rpm, and the ball milling time is 5-30 min.
[0007] Furthermore, in step S2, the speed of low-speed stirring is 60±5 r / min, and the speed of high-speed stirring is 125±10 r / min.
[0008] Furthermore, the curing method in the standard curing box in step S2 is curing for 28 days at a temperature of 20±2°C and a relative humidity>95%.
[0009] Furthermore, in step S1, the loading rate of the material in the stainless steel mixing tank of the planetary ball mill is 75%, the rotation speed of the planetary ball mill is 40 rpm, and the ball milling time is 20 min.
[0010] Compared with the prior art, the present invention has the following beneficial effects: the particle size of the secondary tailings is reduced through a mechanical ball milling process, the contact surface area of the hydration reaction is increased, and the pozzolanic activity thereof is thereby improved; then, ordinary Portland cement is replaced in equal proportion to reduce the amount of cement used; when the secondary tailings treated by the ball milling process can replace ordinary Portland cement in equal proportions of 10% to 30%, the 28d activity index can reach above 95%, and the setting time and stability both meet the requirements of GB / T 51003-2014; the dissolution of heavy metal elements Cr and Mn in the iron-extracting tailings is significantly reduced due to the solidification effect of the gelling system, and the dissolution values are far lower than the specified values in GB5058.3-2007 and GB8978-1996; this is conducive to the efficient recovery and high-value reuse of the secondary tailings, and reduces the high carbon emissions generated by the cement industry; the present invention is a short-process, low-cost preparation process, capable of realizing the rapid disposal and monetization of the secondary tailings, and is a method with low investment and significant economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is the technical route and effect diagram of the present invention; Figure 2 This is a particle size distribution diagram of fine powder of iron tailings according to the first embodiment of the present invention; Figure 3 This is a comparison chart of activity indexes of the first embodiment of the present invention; Figure 4 This is a particle size distribution diagram of fine iron tailings powder according to the second embodiment of the present invention; Figure 5This is a comparison chart of activity indexes according to the second embodiment of the present invention; Figure 6 This is a particle size distribution diagram of fine iron tailings powder according to the third embodiment of the present invention; Figure 7 This is a comparison chart of activity indices of the third embodiment of the present invention; Figure 8 This is a particle size distribution diagram of fine iron tailings powder according to the fourth embodiment of the present invention; Figure 9 This is a comparison chart of activity indices according to the fourth embodiment of the present invention; Figure 10 This is a particle size distribution diagram of fine iron tailings powder according to the fifth embodiment of the present invention; Figure 11 This is a comparison chart of activity indices of the fifth embodiment of the present invention; Figure 12 This is a particle size distribution diagram of fine iron tailings powder according to the sixth embodiment of the present invention; Figure 13 This is a comparison chart of activity indices of the sixth embodiment of the present invention; Figure 14 This is a particle size distribution diagram of fine iron tailings powder according to the seventh embodiment of the present invention; Figure 15 This is a comparison chart of activity indices of the seventh embodiment of the present invention; Figure 16 This is a particle size distribution diagram of fine iron tailings powder according to the eighth embodiment of the present invention; Figure 17 This is a comparison chart of activity indices of the eighth embodiment of the present invention; Figure 18 This is a particle size distribution diagram of fine iron tailings powder according to the ninth embodiment of the present invention; Figure 19 This is a comparison chart of activity indices of the ninth embodiment of the present invention; Figure 20 This is a comparison chart of activity indices according to the tenth embodiment of the present invention; Figure 21 This is a comparison chart of activity indices according to the eleventh embodiment of the present invention; Figure 22 This is a comparison chart of activity indices according to the twelfth embodiment of the present invention; Figure 23 This is a comparison chart of activity indices according to the thirteenth embodiment of the present invention. DETAILED DESCRIPTION
[0012] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.
[0013] Example 1: The ball mill speed was set to 20 rpm and the loading rate was 75%. After ball milling for 10 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0014] Experimental results: The specific surface area of the iron ore tailings fine powder is 950m 2 / kg, 45μm square hole sieve residue is 42%, particle size distribution is as follows Figure 2 As shown; 3d activity index 35%, 28d activity index 70%, as Figure 3 shown.
[0015] Example 2: The ball mill speed was set to 30 rpm, the loading rate was 75%, and after ball milling for 10 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0016] Experimental results: The specific surface area of the iron ore tailings fine powder is 1160m 2 / kg, 45μm square hole sieve residue 31%, particle size distribution Figure 4 As shown; 3d activity index 40%, 28d activity index 79%, as Figure 5 shown.
[0017] Example 3: The ball mill speed was set to 40 rpm and the loading rate was 75%. After ball milling for 10 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0018] Experimental results: The specific surface area of the iron ore tailings fine powder is 1381m 2 / kg, 45μm square hole sieve residue is 19%, particle size distribution is as follows Figure 6 As shown; 3d activity index 58%, 28d activity index 87%, as Figure 7 shown.
[0019] Example 4: The ball mill speed was set to 50 rpm and the loading rate was 75%. After ball milling for 10 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0020] Experimental results: The specific surface area of the iron ore tailings fine powder is 1451m 2 / kg, 45μm square hole sieve residue is 17%, particle size distribution is as follows Figure 8 As shown; 3d activity index 61%, 28d activity index 90%, as Figure 9 shown.
[0021] Example 5: The ball mill speed was set to 40 rpm and the loading rate was 65%. After ball milling for 10 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0022] Experimental results: The specific surface area of the iron ore tailings fine powder is 1405 m 2 / kg, 45μm square hole sieve residue is 19%, particle size distribution is as follows Figure 10 As shown; 3d activity index 60%, 28d activity index 89%, as Figure 11 shown.
[0023] Example 6: The ball mill speed was set to 40 rpm and the loading rate was 85%. After ball milling for 10 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain the iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0024] Experimental results: The specific surface area of the iron ore tailings fine powder is 1204 m 2 / kg, 45μm square hole sieve residue is 28%, particle size distribution is as follows Figure 12 As shown; 3d activity index 42%, 28d activity index 81%, as Figure 13 shown.
[0025] Example 7: The ball mill speed was set to 40 rpm and the loading rate was 75%. After ball milling for 5 minutes, the iron slag fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron slag fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron slag-ordinary Portland cement composite slurry. After demolding for 24 hours, the slurry was placed in a standard curing box for curing.
[0026] Experimental results: The specific surface area of the iron ore tailings fine powder is 1166m 2 / kg, 45μm square hole sieve residue 30%, particle size distribution Figure 14 As shown; 3d activity index 48%, 28d activity index 83%, as Figure 15 shown.
[0027] Example 8: The ball mill speed was set to 40 rpm and the loading rate was 75%. After ball milling for 20 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0028] Experimental results: The specific surface area of the iron ore tailings fine powder is 1435m 2 / kg, 45μm square hole sieve residue 15%, particle size distribution Figure 16 As shown; 3d activity index 75%, 28d activity index 95%, as Figure 17 shown.
[0029] Example 9: The ball mill speed was set to 40 rpm and the loading rate was 75%. After ball milling for 30 min, the iron-extracting tailings fine powder was obtained. 315 g of ordinary Portland cement, 135 g of iron-extracting tailings fine powder, 1350 g of ISO standard sand and 135 g of water were weighed and mixed evenly in a mixer to obtain an iron-extracting tailings-ordinary Portland cement composite slurry. After demolding for 24 h, the slurry was placed in a standard curing box for curing.
[0030] Experimental results: The specific surface area of the iron ore tailings fine powder is 1442m 2 / kg, 45μm square hole sieve residue 11%, particle size distribution Figure 18 As shown; 3d activity index 81%, 28d activity index 95%, as Figure 19 shown.
[0031] Example 10: Weigh 405 g of ordinary Portland cement and 45 g of iron ore tailings fine powder, set the ball mill speed to 40 rpm, the loading rate to 75%, and ball mill for 20 min. 1350 g of ISO standard sand and 135 g of water are mixed evenly in a blender to obtain an iron ore tailings-ordinary Portland cement composite slurry. After 24 hours of demolding, place it in a standard curing box for curing.
[0032] Experimental results: After 3 days and 28 days of curing in the standard curing box, the activity index was measured to be 105% and 102% respectively. Figure 20 As shown, the initial setting time is 272 minutes and the final setting time is 323 minutes.
[0033] Example 11: Weigh 382.5 g of ordinary Portland cement and 67.5 g of iron ore tailings fine powder, set the ball mill speed to 40 rpm, the loading rate to 75%, and ball mill for 20 min. 1350 g of ISO standard sand and 135 g of water are mixed evenly in a blender to obtain an iron ore tailings-ordinary Portland cement composite slurry. After 24 hours of demolding, place it in a standard curing box for curing.
[0034] Experimental results: After 3 days and 28 days of curing in a standard curing box, the activity index was measured to be 98% and 103% respectively. Figure 21 As shown, the initial setting time is 286 minutes and the final setting time is 336 minutes.
[0035] Example 12: Weigh 360 g of ordinary Portland cement and 90 g of iron ore tailings fine powder, set the ball mill speed to 40 rpm, the loading rate to 75%, and ball mill for 20 min. 1350 g of ISO standard sand and 135 g of water were mixed evenly in a blender to obtain an iron ore tailings-ordinary Portland cement composite slurry. After 24 hours of demolding, place it in a standard curing box for curing.
[0036] Experimental results: After 3 days and 28 days of curing in a standard curing box, the activity index was measured to be 95% and 101% respectively. Figure 22 As shown, the initial setting time is 337 minutes and the final setting time is 367 minutes.
[0037] Example 13: Weigh 337.5 g of ordinary Portland cement and 112.5 g of iron ore tailings fine powder, set the ball mill speed to 40 rpm, the loading rate to 75%, and ball mill for 20 min. 1350 g of ISO standard sand and 135 g of water are stirred evenly in a blender to obtain an iron ore tailings-ordinary Portland cement composite slurry. After 24 hours of demolding, place it in a standard curing box for curing.
[0038] Experimental results: After 3 days and 28 days of curing in a standard curing box, the activity index was measured to be 89% and 98% respectively. Figure 23As shown, the initial setting time is 343 minutes and the final setting time is 381 minutes.
[0039] The results show that by controlling the mechanical ball milling method, it is possible to stably prepare a material with a specific surface area greater than 1400m 2 / kg, the residue on 45μm square hole sieve is less than 20%, the 3d activity index is not less than 75%, and the 28d activity index is not less than 95% of fine powder; on this basis, considering the tailings disposal capacity, early performance, economic cost and other factors, the optimal replacement rate of iron-extracting tailings fine powder is 20% by adjusting the mix ratio.
[0040] Under the conditions of 40 rpm speed, 75% loading rate and 20 min ball milling, the surface area of more than 1400 m 2 / kg, the residue on 45um square hole sieve is less than 20%, the 3d activity index is not less than 75%, and the 28d activity index is not less than 95%; Through the examples, it is concluded that for every 5% increase in the iron-extracting tailings replacement rate, the 3d activity index decreases by an average of 5% to 8%, and the 28d activity index decreases by an average of 2% to 3%. Taking into account factors such as tailings disposal capacity, early performance, and economic cost, it is concluded that the optimal replacement rate of iron-extracting tailings is 20%.
[0041] The above embodiments illustrate that the present invention not only achieves efficient recovery and high-value reuse of secondary tailings, but also reduces high carbon emissions generated by the cement industry. It is a short-process, low-cost preparation process that can achieve rapid disposal and monetization of secondary tailings. It is a method with low investment and significant economic and environmental benefits.
[0042] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.
Claims
1. A method for large-scale utilization of nickel slag iron-extraction tailings in cement-based materials, characterized in that: The following steps are involved: S1 is equipped with steel balls and iron tailings in a ratio of 1:3, and the material is added to a stainless steel mixing tank of a planetary ball mill for ball milling to obtain a fine powder of iron tailings, wherein the median particle size is less than 15μm; S2. According to 45-135 parts: 315-405 parts: 135 parts: 1350 parts of the ratio were weighed to extract iron tailings fine powder, ordinary Portland cement, water and standard sand; S3. Place the iron ore tailings fine powder, ordinary Portland cement, and water weighed in proportion in a mixer and stir at low speed for 30 seconds. At the beginning of the next 30 seconds, add the standard sand weighed in proportion. After the addition is completed, stir at high speed for 90 seconds to obtain a composite slurry. Place the composite slurry into a test mold and vibrate it into shape. After 24 hours, remove it from the mold and place it in a standard curing box for curing.
2. The method for large-scale utilization of iron-extracting tailings of nickel slag in cement-based materials according to claim 1, characterized in that: In step S1 , the steel balls have diameters of 19.5 mm, 14.5 mm, 11.5 mm, and 10.0 mm, respectively, and their mass ratio is 1:1:1:
1.
3. The method for large-scale utilization of iron-extracting tailings of nickel slag in cement-based materials according to claim 1, characterized in that: In step S1, the material loading rate in the stainless steel mixing tank of the planetary ball mill is 65-85%, the rotation speed of the planetary ball mill is 20-50 rpm, and the ball milling time is 5-30 min.
4. The method for large-scale utilization of iron-extracting tailings from nickel slag in cement-based materials according to claim 1, characterized in that: In step S2, the low-speed stirring speed is 60±5 r / min, and the high-speed stirring speed is 125±10 r / min.
5. The method for large-scale utilization of iron-extracting tailings from nickel slag in cement-based materials according to claim 1, characterized in that: The curing method in the standard curing box in step S2 is curing for 28 days at a temperature of 20±2°C and a relative humidity of >95%.
6. The method for large-scale utilization of iron-extracting tailings from nickel slag in cement-based materials according to claim 3, characterized in that: In step S1, the material loading rate in the stainless steel mixing tank of the planetary ball mill is 75%, the rotation speed of the planetary ball mill is 40 rpm, and the ball milling time is 20 min.