Ultrafine tailings instantaneous thermoset granulation high concentration filling system and method

Abstract

The application discloses a superfine tailings instant thermal solidification granulation high-concentration filling system and method, which only granulates classified fine tailings in superfine tailings, significantly improves the overall particle size of the mixed tailings, significantly improves the filling slurry concentration under the condition that the flowability of the filling slurry is unchanged, significantly improves the granulation efficiency and reduces the granulation cost compared with the traditional whole particle size tailings granulation, prepares the filling slurry by mixing the classified fine tailings granulation particles and classified coarse tailings, sufficiently utilizes the supporting effect of the classified coarse tailings, significantly reduces the granulation particle sedimentation, improves the bulk density and simultaneously improves the filling body strength, utilizes the instant high temperature generated by the microwave and the hot-liking characteristics of the slag-based cementing material to make the granulation particles realize solidification in a short time and obtain higher strength, and achieves the instant high-strength thermal solidification purpose, and the application has the characteristics of high filling slurry preparation efficiency, low energy consumption, flexible equipment arrangement and easy concentration, and can effectively solve the problems of low superfine tailings filling concentration, large cementing material consumption and high filling cost.

Description

Technical Field

[0001] This invention belongs to the field of mine backfilling technology, and in particular relates to a high-concentration backfilling system and method for instantaneous thermosetting granulation of ultrafine tailings. Background Technology

[0002] With the high-intensity mining of metal mineral resources, a large amount of metal tailings is usually disposed of by building dams, resulting in a large number of tailings dams. However, tailings dam failures occur frequently, and each failure causes casualties and property damage to varying degrees. Therefore, tailings dams have been listed as one of the major disaster hazards.

[0003] To improve the utilization rate of metal tailings, promoting backfill mining is one of the most effective methods. Backfill mining can make full use of solid wastes such as tailings generated in the production activities of metal mines, reduce surface accumulation and land occupation, and is an effective way to solve the problem of tailings accumulation in metal mines.

[0004] However, with the continuous development and utilization of mineral resources, high-grade and easily sortable rich mineral resources are gradually being depleted. The mining industry is facing problems such as the year-by-year decline in the grade of ore mining boundary, complex mineral co-occurrence relationships, and finer mineral splicing particle size. As a result, the ore needs to be ground to an ultrafine (average particle size less than 30μm) or even an ultrafine (average particle size less than 10μm) particle size level in order to achieve the separation and enrichment of useful minerals.

[0005] Meanwhile, before the advent of full tailings backfilling technology, mines generally used graded tailings for backfilling, resulting in a large amount of unused ultrafine tailings being stockpiled in tailings ponds. Due to the small particle size and large specific surface area of ​​ultrafine tailings, they can easily affect the stability and impermeability of tailings dams, posing serious safety hazards. They are also more likely to cause pollution problems related to heavy metals and dust during the stockpiling process.

[0006] In addition, ultrafine tailings backfill material has the following three significant characteristics: ① Due to its small particle size and large specific surface area, ultrafine tailings has a slow settling velocity and high porosity during thickening, resulting in a generally low underflow concentration after thickening; ② Backfill slurry prepared with ultrafine tailings has the characteristics of high shear yield stress and high dynamic viscosity, thus experiencing greater resistance during pipeline transportation and being prone to pipe blockage accidents; ③ Ultrafine tailings has strong water retention properties. When backfill slurry prepared with ultrafine tailings is transported to the stope, the water in the slurry is difficult to exude, resulting in a large amount of free water in the backfill slurry filled into the stope, thereby reducing the backfill quality.

[0007] Due to the aforementioned characteristics of ultrafine tailings backfill materials, backfill slurries prepared with ultrafine tailings as aggregate have disadvantages such as low concentration and poor strength of the backfill. Therefore, in order to meet the strength requirements of the backfill, a large amount of binder is often added to the slurry, which significantly increases the cost.

[0008] To address this, Chinese patent application number 202410130858.3 discloses a tailings granulation and cementation backfilling process system. This system granulates tailings to obtain spherical tailings particles, which are then cured at room temperature and pressure for over 24 hours before being mixed with cementitious materials and water in a specific ratio to form a backfill slurry. While this method increases the tailings concentration in the backfill slurry by granulating the tailings, the traditional curing method for these particles suffers from long curing times, low efficiency, and high energy consumption during production. Furthermore, the granulation of tailings of all sizes before backfilling, coupled with the fact that the tailings particles range in size from 2.5mm to 10mm, means that larger particles can cause rapid settling of the slurry during pipeline transport, potentially leading to blockages.

[0009] Furthermore, Chinese patent application number 202310898094.8 discloses a coarse aggregate and its preparation method, mixed aggregate, filling slurry, and filling body. This method involves granulating ultrafine tailings, then curing the tailings particles using steam to obtain coarse aggregate. The coarse aggregate is then mixed with the ultrafine tailings to obtain mixed aggregate, which is used to prepare the filling slurry. Although this method uses steam curing, the method of granulating and curing some ultrafine tailings before mixing it with the ultrafine tailings has limited effect on improving the overall particle size distribution of the tailings. The tailings concentration in the filling slurry remains low. Moreover, the tailings particles need to be steam-cured at 45℃ to 65℃ for 10 to 20 days, resulting in excessively long curing time and low curing efficiency. Maintaining a high temperature for an extended period also leads to excessive energy consumption during the curing process, making it economically unsound. Summary of the Invention

[0010] To address the problems existing in the prior art, this invention provides a high-concentration backfilling system and method for instantaneous thermosetting granulation of ultrafine tailings. By granulating only the graded fine tailings from the ultrafine tailings, the overall particle size of the mixed tailings can be significantly increased. While maintaining the fluidity of the backfill slurry, the concentration of the backfill slurry can be significantly increased. Compared with traditional full-size tailings granulation, this significantly improves granulation efficiency and reduces granulation costs. Furthermore, by mixing the granulated graded fine tailings with the graded coarse tailings from the ultrafine tailings to prepare the backfill slurry, the supporting effect of the graded coarse tailings can be fully utilized, significantly reducing particle size. The settling of granulated particles increases the bulk density and further enhances the strength of the backfill. Compared with traditional ambient temperature and pressure curing and steam curing methods, this method utilizes the instantaneous high temperature generated by microwaves and the heat-loving characteristics of slag-based binders, enabling granulated particles to solidify and achieve high strength in a short time, thus achieving the purpose of instantaneous high-strength thermal curing. Compared with traditional ultrafine tailings backfilling technology, this method features high efficiency in backfill slurry preparation, low energy consumption, flexible equipment layout, and easy centralization, effectively solving problems such as low concentration of ultrafine tailings backfill, large amount of binder, and high backfilling cost.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: a high-concentration backfilling system for instantaneous thermosetting granulation of ultrafine tailings, comprising a hydrocyclone, a granulator, a microwave furnace, a mixing tank, and a backfilling pump; the inlet of the hydrocyclone is used to feed ultrafine tailings discharged from the concentrator, and the ultrafine tailings are separated within the hydrocyclone according to their particle size, with graded fine tailings discharged from the top overflow port of the hydrocyclone and graded coarse tailings discharged from the bottom outlet of the hydrocyclone; the graded fine tailings discharged from the top overflow port of the hydrocyclone serve as raw material for the granulator; the granulator is used to prepare granulated particles using graded fine tailings as raw material; the microwave furnace is used to perform instantaneous thermosetting treatment on the granulated particles discharged from the granulator; the mixing tank is used to prepare a backfilling slurry using graded coarse tailings and thermoset granulated particles as raw materials; and the backfilling pump is used to pump the backfilling slurry to the underground mining area.

[0012] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a filter press, and the top overflow port of the hydrocyclone is connected to the feed port of the filter press.

[0013] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a weighing feeder and a first belt conveyor. The outlet of the filter press is connected to the inlet of the weighing feeder, and the outlet of the weighing feeder is connected to the inlet of the first belt conveyor.

[0014] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a mixer. The discharge port of the first belt conveyor is connected to the inlet of the mixer, the discharge port of the mixer is connected to the inlet of the granulator, and the discharge port of the granulator is connected to the inlet of the microwave furnace.

[0015] The ultrafine tailings instantaneous thermal solidification granulation high-concentration filling system also includes a cementing silo, the outlet of which is connected to the inlet of the mixer.

[0016] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a thickener. The bottom outlet of the hydrocyclone is connected to the inlet of the thickener, the outlet of the thickener is connected to the inlet of the mixing tank, and the outlet of the mixing tank is connected to the inlet of the filling pump.

[0017] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a cementitious material silo, the outlet of which is connected to the inlet of the mixing tank.

[0018] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a collection hopper and a second belt conveyor. The discharge port of the microwave furnace is connected to the inlet of the collection hopper, the discharge port of the collection hopper is connected to the inlet of the second belt conveyor, and the discharge port of the second belt conveyor is connected to the inlet of the mixing tank.

[0019] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a sedimentation tank and a clear water tank. The outlet of the filter press is connected to the inlet of the sedimentation tank, the outlet of the sedimentation tank is connected to the inlet of the clear water tank, and one outlet of the clear water tank is connected to the inlet of the granulator, and the other outlet is connected to the inlet of the mixing tank.

[0020] A method for high-concentration backfilling using instantaneous thermosetting granulation of ultrafine tailings, employing the aforementioned high-concentration backfilling system for instantaneous thermosetting granulation of ultrafine tailings, includes the following steps:

[0021] Step 1: The ultrafine tailings discharged from the concentrator are transported to the hydrocyclone through a pipeline. The ultrafine tailings are classified by the hydrocyclone. The classified fine tailings are discharged from the top overflow port of the hydrocyclone, and the classified coarse tailings are discharged from the bottom discharge port of the hydrocyclone.

[0022] Step 2: The graded fine tailings are transported through pipelines to a filter press for dewatering; the graded coarse tailings are transported through pipelines to a thickener for thickening and dewatering.

[0023] Step 3: The graded fine tailings after filter press dewatering are transported to the weighing feeder through pipelines, and the graded fine tailings are weighed by the weighing feeder; the wastewater discharged from the filter press and thickener is collected and introduced into the sedimentation tank, where the wastewater is clarified, and the clarified water is introduced into the clear water tank for storage.

[0024] Step 4: The weighed and graded fine tailings are conveyed to the mixer via the first belt conveyor; the slag-based binder in the binder bin is conveyed to the mixer; the graded fine tailings and slag-based binder are mixed evenly by the mixer until a mixture is obtained.

[0025] Step 5: The obtained mixture is transported to the pellet mill through a pipeline; clean water in the clean water tank is transported to the pellet mill through a metering pump; the mixture after adding water is granulated by the pellet mill until granulated particles are obtained;

[0026] Step 6: The obtained granulated particles are transported to a microwave furnace and subjected to instantaneous thermal curing treatment in the microwave furnace;

[0027] Step 7: First, the solidified granulated particles are conveyed to the collection hopper, and then conveyed to the mixing tank by the second belt conveyor; the thickened and dewatered graded coarse tailings are conveyed to the mixing tank; the slag-based cementitious material in the cementitious material silo is conveyed to the mixing tank; the clean water in the clear water tank is conveyed to the mixing tank by a metering pump; the materials in the tank are stirred evenly in the mixing tank until the filling slurry is obtained.

[0028] Step 8: The filling slurry obtained is transported to the underground mining area by the filling pump through the filling pipeline network until the mine filling operation is completed.

[0029] The beneficial effects of this invention are:

[0030] The present invention relates to a high-concentration backfilling system and method for instantaneous thermosetting granulation of ultrafine tailings. This granulation only involves classifying the fine tailings within the ultrafine tailings, significantly increasing the overall particle size of the mixed tailings. While maintaining the fluidity of the backfill slurry, this significantly increases the concentration of the backfill slurry. Compared to traditional full-size tailings granulation, this method significantly improves granulation efficiency and reduces granulation costs. Furthermore, by mixing the granulated fine tailings with the coarse tailings from the ultrafine tailings to prepare the backfill slurry, the supporting effect of the coarse tailings is fully utilized, significantly reducing the settling of the granulated particles. While increasing the bulk density, it further improves the strength of the filling body; compared with the traditional room temperature and pressure curing and steam curing methods, it utilizes the instantaneous high temperature generated by microwaves and the heat-loving characteristics of slag-based binders, which can enable granulated particles to solidify and obtain high strength in a short time, achieving the purpose of instantaneous high-strength thermal curing; compared with the traditional ultrafine tailings filling technology, it has the characteristics of high filling slurry preparation efficiency, low energy consumption, flexible equipment layout and easy concentration, and can effectively solve the problems of low ultrafine tailings filling concentration, large amount of binder, and high filling cost. Attached Figure Description

[0031] Figure 1 This is a structural principle diagram of an ultrafine tailings instantaneous thermosetting granulation high-concentration backfilling system according to the present invention;

[0032] Figure 2 This is a flowchart illustrating the principle of a high-concentration backfilling method for instantaneous thermosetting granulation of ultrafine tailings based on the tailings particle size change process according to the present invention.

[0033] In the diagram, 1—cyclone separator, 2—granulator, 3—microwave furnace, 4—mixing tank, 5—filling pump, 6—filter press, 7—weighing feeder, 8—first belt conveyor, 9—mixer, 10—cementing silo, 11—thickener, 12—cementing material silo, 13—collecting hopper, 14—second belt conveyor, 15—sedimentation tank, 16—clear water tank, 17—underground mining area. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 As shown, a high-concentration backfilling system for instantaneous thermosetting granulation of ultrafine tailings includes a hydrocyclone 1, a granulator 2, a microwave furnace 3, a mixing tank 4, and a backfilling pump 5. The inlet of the hydrocyclone 1 is used to feed ultrafine tailings discharged from the concentrator. The ultrafine tailings are separated within the hydrocyclone 1 according to their particle size. Graded fine tailings are discharged from the top overflow port of the hydrocyclone 1, and graded coarse tailings are discharged from the bottom outlet of the hydrocyclone 1. The graded fine tailings discharged from the top overflow port of the hydrocyclone 1 serve as raw material for the granulator 2. The granulator 2 is used to prepare granulated particles using graded fine tailings as raw material. The microwave furnace 3 is used to perform instantaneous thermosetting treatment on the granulated particles discharged from the granulator 2. The mixing tank 4 is used to prepare a backfilling slurry using graded coarse tailings and thermoset granulated particles as raw materials. The backfilling pump 5 is used to pump the backfilling slurry to the underground mining area 17.

[0036] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a filter press 6, and the top overflow port of the hydrocyclone 1 is connected to the feed port of the filter press 6.

[0037] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a weighing feeder 7 and a first belt conveyor 8. The outlet of the filter press 6 is connected to the inlet of the weighing feeder 7, and the outlet of the weighing feeder 7 is connected to the inlet of the first belt conveyor 8.

[0038] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a mixer 9. The discharge port of the first belt conveyor 8 is connected to the inlet of the mixer 9, the discharge port of the mixer 9 is connected to the inlet of the granulator 2, and the discharge port of the granulator 2 is connected to the inlet of the microwave furnace 3.

[0039] The ultrafine tailings instantaneous thermal solidification granulation high-concentration filling system also includes a cementing silo 10, the outlet of which is connected to the inlet of the mixer 9.

[0040] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a thickener 11. The bottom outlet of the hydrocyclone 1 is connected to the inlet of the thickener 11, the outlet of the thickener 11 is connected to the inlet of the mixing tank 4, and the outlet of the mixing tank 4 is connected to the inlet of the filling pump 5.

[0041] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a cementitious material silo 12, the outlet of which is connected to the inlet of the mixing tank 4.

[0042] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a collection hopper 13 and a second belt conveyor 14. The discharge port of the microwave furnace 3 is connected to the inlet of the collection hopper 13, the discharge port of the collection hopper 13 is connected to the inlet of the second belt conveyor 14, and the discharge port of the second belt conveyor 14 is connected to the inlet of the mixing tank 4.

[0043] The ultrafine tailings instantaneous thermosetting granulation high-concentration filling system also includes a sedimentation tank 15 and a clear water tank 16. The outlet of the filter press 6 is connected to the inlet of the sedimentation tank 15, and the outlet of the sedimentation tank 15 is connected to the inlet of the clear water tank 16. One outlet of the clear water tank 16 is connected to the inlet of the granulator 2, and the other outlet is connected to the inlet of the mixing tank 4.

[0044] like Figure 2 As shown, a method for high-concentration backfilling using instantaneous thermosetting granulation of ultrafine tailings, employing the aforementioned high-concentration backfilling system for instantaneous thermosetting granulation of ultrafine tailings, includes the following steps:

[0045] Step 1: The ultrafine tailings discharged from the concentrator are transported to hydrocyclone 1 through a pipeline. The ultrafine tailings are classified by hydrocyclone 1. The classified fine tailings are discharged from the top overflow port of hydrocyclone 1, and the classified coarse tailings are discharged from the bottom discharge port of hydrocyclone 1.

[0046] Step 2: The graded fine tailings are transported through a pipeline to the filter press 6, where the graded fine tailings are dewatered by the filter press 6; the graded coarse tailings are transported through a pipeline to the thickener 11, where the graded coarse tailings are thickened and dewatered by the thickener 11.

[0047] Step 3: The graded fine tailings after filter press dewatering are transported to the weighing feeder 7 through a pipeline. The graded fine tailings are weighed by the weighing feeder 7. The wastewater discharged from the filter press 6 and thickener 11 is collected and introduced into the sedimentation tank 15. The wastewater is clarified in the sedimentation tank 15, and the clarified water is introduced into the clear water tank 16 for storage.

[0048] Step 4: The weighed and graded fine tailings are conveyed to the mixer 9 via the first belt conveyor 8; the slag-based binder in the binder bin 10 is conveyed to the mixer 9; the graded fine tailings and slag-based binder are mixed evenly by the mixer 9 until a mixture is obtained.

[0049] Step 5: The obtained mixture is transported to the pellet mill 2 through a pipeline; the clean water in the clean water tank 16 is transported to the pellet mill 2 through a metering pump; the mixture after adding water is granulated by the pellet mill 2 until granulated particles are obtained;

[0050] Step 6: The obtained granulated particles are transported to microwave furnace 3, where they are subjected to instantaneous thermal curing treatment.

[0051] Step 7: The solidified granulated particles are first conveyed to the collection hopper 13, and then conveyed to the mixing tank 4 by the second belt conveyor 14; the thickened and dewatered graded coarse tailings are conveyed to the mixing tank 4; the slag-based cementitious material in the cementitious material silo 12 is conveyed to the mixing tank 4; the clean water in the clear water tank 16 is conveyed to the mixing tank 4 by a metering pump; the materials in the tank are stirred evenly by the mixing tank 4 until the filling slurry is obtained.

[0052] Step 8: The filling slurry obtained by filling pump 5 is transported to the underground mining area 17 through the filling pipeline network until the mine filling operation is completed.

[0053] In addition, after the mine backfilling operation is completed, the clean water in the clear water pool 16 can also be used as rinsing water for the mixing tank 4, so that the wastewater discharged from the filter press 6 and the thickener 11 can be fully utilized as a resource.

[0054] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the present invention are included in the scope of protection of the present invention.

Claims

1. A high-concentration backfilling system for ultrafine tailings instantaneous thermosetting granulation, characterized in that: The system includes a hydrocyclone, granulator, microwave furnace, mixing tank, filling pump, filter press, weighing feeder, first belt conveyor, mixer, cementitious silo, thickener, cementitious material silo, collection hopper, second belt conveyor, sedimentation tank, and clear water tank. The hydrocyclone's inlet is used to feed ultrafine tailings discharged from the mineral processing plant. The ultrafine tailings are separated within the hydrocyclone according to their particle size, with graded fine tailings discharged from the top overflow outlet and graded coarse tailings discharged from the bottom outlet. The top overflow outlet of the hydrocyclone... The discharge outlet of the granulator discharges graded fine tailings as raw material for the granulator; the granulator is used to prepare granulated particles using graded fine tailings as raw material; the microwave furnace is used to perform instantaneous heat curing treatment on the granulated particles discharged from the granulator; the mixing tank is used to prepare filling slurry using graded coarse tailings and heat-cured granulated particles as raw materials; the filling pump is used to pump the filling slurry to the underground mining area; the top overflow outlet of the hydrocyclone is connected to the feed inlet of the filter press; the discharge outlet of the filter press is connected to the feed inlet of the weighing feeder. The following connections are made: the discharge port of the weighing feeder is connected to the inlet of the first belt conveyor; the discharge port of the first belt conveyor is connected to the inlet of the mixer; the discharge port of the mixer is connected to the inlet of the granulator; the discharge port of the granulator is connected to the inlet of the microwave furnace; the discharge port of the cementing silo is connected to the inlet of the mixer; the bottom discharge port of the hydrocyclone is connected to the inlet of the thickener; the discharge port of the thickener is connected to the inlet of the mixing tank; and the discharge port of the mixing tank is connected to the inlet of the filling pump. The following connections are made: the outlet of the cementitious material silo is connected to the inlet of the mixing tank; the outlet of the microwave furnace is connected to the inlet of the collecting hopper, the outlet of the collecting hopper is connected to the inlet of the second belt conveyor, and the outlet of the second belt conveyor is connected to the inlet of the mixing tank; the outlet of the filter press is connected to the inlet of the sedimentation tank, the outlet of the sedimentation tank is connected to the inlet of the clear water tank, and one outlet of the clear water tank is connected to the inlet of the granulator, and the other outlet is connected to the inlet of the mixing tank.

2. A method for high-concentration backfilling of ultrafine tailings through instantaneous thermosetting granulation, employing the high-concentration backfilling system for ultrafine tailings through instantaneous thermosetting granulation as described in claim 1, characterized in that... Includes the following steps: Step 1: The ultrafine tailings discharged from the concentrator are transported to the hydrocyclone through a pipeline. The ultrafine tailings are classified by the hydrocyclone. The classified fine tailings are discharged from the top overflow port of the hydrocyclone, and the classified coarse tailings are discharged from the bottom discharge port of the hydrocyclone. Step 2: The graded fine tailings are transported through pipelines to a filter press for dewatering; the graded coarse tailings are transported through pipelines to a thickener for thickening and dewatering. Step 3: The graded fine tailings after filter press dewatering are transported to the weighing feeder through pipelines, and the graded fine tailings are weighed by the weighing feeder; the wastewater discharged from the filter press and thickener is collected and introduced into the sedimentation tank, where the wastewater is clarified, and the clarified water is introduced into the clear water tank for storage. Step 4: The weighed and graded fine tailings are conveyed to the mixer via the first belt conveyor; the slag-based binder in the binder bin is conveyed to the mixer; the graded fine tailings and slag-based binder are mixed evenly by the mixer until a mixture is obtained. Step 5: The obtained mixture is transported to the pellet mill through a pipeline; clean water in the clean water tank is transported to the pellet mill through a metering pump; the mixture after adding water is granulated by the pellet mill until granulated particles are obtained; Step 6: The obtained granulated particles are transported to a microwave furnace and subjected to instantaneous thermal curing treatment in the microwave furnace; Step 7: First, the solidified granulated particles are conveyed to the collection hopper, and then conveyed to the mixing tank by the second belt conveyor; the thickened and dewatered graded coarse tailings are conveyed to the mixing tank; the slag-based cementitious material in the cementitious material silo is conveyed to the mixing tank; the clean water in the clear water tank is conveyed to the mixing tank by a metering pump; the materials in the tank are stirred evenly in the mixing tank until the filling slurry is obtained. Step 8: The filling slurry obtained is transported to the underground mining area by the filling pump through the filling pipeline network until the mine filling operation is completed.

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