Water-saving type filling material prepared from multi-source coal-based solid waste and preparation method of water-saving type filling material

Abstract

The invention provides a water-saving type filling material prepared from multi-source coal-based solid waste and a preparation method of the water-saving type filling material, and relates to the technical field of filling materials. The water-saving filling material prepared from the multi-source coal-based solid waste comprises the following raw materials in parts by mass: 40-50 parts of fly ash, 20-25 parts of furnace slag, 4-5 parts of carbide slag, 5 parts of desulfurized gypsum and 25-30 parts of coal gangue. The water-saving filling material prepared by the invention can completely absorb five solid wastes, and meanwhile, the additionally added water amount is remarkably reduced. According to the method, other expensive agents do not need to be additionally added, rolling and other operations are not needed either, and the treatment cost is remarkably reduced.

Description

Technical Field

[0001] The invention relates to the technical field of filling materials, and in particular to a water-saving filling material prepared by using multi-source coal-based solid waste. Background Art

[0002] There are a large number of mine pits and excavations in the mining areas of the Northwest, which need to be backfilled in time. At the same time, mining areas also produce a large amount of solid waste, such as fly ash, coal gangue, etc. The existing technology uses fly ash and other solid waste as backfill materials, which often adds a lot of water, which is not suitable for the water-scarce areas of the Northwest.

[0003] Therefore, reducing the water consumption of backfill materials and obtaining a water-saving backfill material prepared from multi-source coal-based solid waste is a current research hotspot. Summary of the invention

[0004] Based on this, the present invention provides a water-saving filling material prepared from multi-source coal-based solid waste and a preparation method thereof. The present invention uses five solid wastes, namely fly ash, slag, carbide slag, desulfurized gypsum and coal gangue, as raw materials to prepare a backfill filling material. The present invention can realize the resource utilization of solid waste, and the filling material can reduce water consumption.

[0005] The water-saving filling material prepared from multi-source coal-based solid wastes in the present invention includes the following raw materials in parts by weight:

[0006] 40-50 parts of fly ash, 20-25 parts of slag, 4-5 parts of carbide slag, 5 parts of desulfurization gypsum, and 20-30 parts of coal gangue.

[0007] In one embodiment, the water-saving filling material prepared from multi-source coal-based solid wastes of the present invention comprises the following raw materials in parts by weight:

[0008] 44.7 parts of fly ash, 22.3 parts of slag, 5 parts of carbide slag, 5 parts of desulfurized gypsum, and 23 parts of coal gangue.

[0009] In one embodiment, the water-saving filling material prepared from multi-source coal-based solid wastes of the present invention comprises the following raw materials in parts by weight:

[0010] 42 parts of fly ash, 21 parts of slag, 4 parts of carbide slag, 5 parts of desulfurized gypsum, and 28 parts of coal gangue.

[0011] In one embodiment, the water-saving filling material prepared from multi-source coal-based solid wastes of the present invention comprises the following raw materials in parts by weight:

[0012] 43.3 parts of fly ash, 21.7 parts of slag, 5 parts of carbide slag, 5 parts of desulfurized gypsum, and 25 parts of coal gangue.

[0013] In one embodiment, the water-saving filling material prepared from multi-source coal-based solid wastes of the present invention comprises the following raw materials in parts by weight:

[0014] 44.7 parts of fly ash, 22.3 parts of slag, 4 parts of carbide slag, 5 parts of desulfurized gypsum, and 24 parts of coal gangue.

[0015] The present invention also provides a method for preparing the water-saving filling material prepared from multi-source coal-based solid waste, comprising the following steps:

[0016] S1. Add water to the weighed fly ash and stir evenly to obtain fly ash with a water content of 25% to 26.5%;

[0017] S2, mixing the weighed slag, carbide slag, desulfurized gypsum and coal gangue evenly, adding water and continuing to stir to obtain a mixture with a water content of 5-15%;

[0018] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0019] Preferably, the moisture content of the fly ash after treatment in step S1 is 15%.

[0020] Preferably, the water content of the mixture in step S2 is 10%.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The water-saving filling material prepared by the present invention can completely absorb the five types of solid wastes, while significantly reducing the amount of additional water added. The present invention does not require the addition of other expensive agents, nor does it require operations such as rolling, which significantly reduces the processing cost. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present invention clearer, the preferred embodiments of the present invention are further described in detail in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] A water-saving filling material prepared from multi-source coal-based solid waste, the specific preparation steps are as follows:

[0026] S1. Weigh 42 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0027] S2, weigh 21 kg of slag, 4 kg of carbide slag, 5 kg of desulfurized gypsum and 28 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0028] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0029] Example 2

[0030] A water-saving filling material prepared from multi-source coal-based solid waste, the specific preparation steps are as follows:

[0031] S1. Weigh 43.3 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0032] S2, weigh 21.7 kg of slag, 4 kg of carbide slag, 5 kg of desulfurized gypsum and 26 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0033] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0034] Example 3

[0035] S1. Weigh 44.7 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0036] S2, weigh 21.3 kg of slag, 5 kg of carbide slag, 5 kg of desulfurized gypsum and 23 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0037] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0038] Example 4

[0039] S1. Weigh 42 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0040] S2, weigh 21 kg of slag, 4 kg of carbide slag, 5 kg of desulfurized gypsum and 28 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0041] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0042] Example 5

[0043] S1. Weigh 43.3 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0044] S2, weigh 21.7 kg of slag, 5 kg of carbide slag, 5 kg of desulfurized gypsum and 25 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0045] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0046] Example 6

[0047] S1. Weigh 44.7 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0048] S2, weigh 22.3 kg of slag, 4 kg of carbide slag, 5 kg of desulfurized gypsum and 24 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0049] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0050] Example 7

[0051] S1. Weigh 42 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0052] S2, weigh 21 kg of slag, 5 kg of carbide slag, 5 kg of desulfurized gypsum and 27 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0053] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0054] Example 8

[0055] S1. Weigh 43.3 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0056] S2, weigh 21.7 kg of slag, 4 kg of carbide slag, 5 kg of desulfurized gypsum and 26 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0057] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0058] Example 9

[0059] S1. Weigh 44.7 kg of fly ash, add water and stir evenly to obtain fly ash with a water content of 15%;

[0060] S2, weigh 22.3 kg of slag, 4 kg of carbide slag, 5 kg of desulfurized gypsum and 24 kg of coal gangue, mix them evenly, add water and continue stirring to obtain a mixture with a water content of 10%;

[0061] S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

[0062] The water content of the filling materials prepared in Examples 1 to 9 was tested, as shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] The filling materials prepared in Examples 1 to 9 were made into concrete bricks and subjected to strength tests. The specific operations are as follows:

[0067] Before pouring the filling material into the mixture, brush the bottom and side of the plastic mold with engine oil, stir evenly, and then pour the filling material into the plastic mold at one time. To make the slurry overflow the surface of the specimen mold, use a smooth ruler to scrape off the overflowing slurry around and knock the specimen mold to expel the air inside. After standing for a period of time until the specimen is solidified and formed, immediately cover the surface of the specimen mold with a plastic film, place it in an environment with a room temperature of 24°C and stand it for about 20 hours, then use a demolding tool to demold and remove the test block. After demolding, number the appropriate specimen blocks in sequence, and ensure that the specimen blocks are intact. After everything is completed, it should be immediately covered with a film and placed in a concrete carbonization curing box for 28 days of curing. The curing conditions are temperature: 25°C and relative humidity maintained at 90%. After curing, a block specimen is obtained.

[0068] The force and strength tests of the block specimens are shown in Table 2. The force and strength tests are carried out in accordance with GB / T50081-2019 Test Method for Physical and Mechanical Properties of Concrete.

[0069] Table 2

[0070] Force value (KN) Strength (MP) Example 1 65.81 6.3 Example 2 81.59 7.8 Example 3 86.63 8.2 Example 4 78.8 7.5 Example 5 99.19 9.4 Example 6 76.67 7.1 Example 7 62.08 5.9 Example 8 60.46 5.7 Example 9 61.11 5.8

[0071] The block samples prepared in Examples 1 to 9 were subjected to leaching tests, as shown in Table 3.

[0072] The leaching experiment was carried out using the horizontal oscillation method of HJ 557 solid waste leaching toxicity leaching method

[0073] a. Principle of the method

[0074] Using pure water as the leaching agent, the process of solid waste being leached by surface water or groundwater in specific circumstances is simulated, and the harmful components in the solid waste are leached into the environment.

[0075] b. Reagents and Materials

[0076] Extraction agent: Water, GB / T 6682, Grade II

[0077] c. Instruments and equipment

[0078] 1) Oscillation equipment: reciprocating horizontal oscillation device with adjustable frequency.

[0079] 2) Extraction bottle: 2L wide-mouth bottle with screw cap and inner cover, made of inert material (such as glass or polyethylene, etc.) that cannot leach or adsorb the components contained in the sample.

[0080] 3) Filters

[0081] Ⅰ Filtration device: pressurized filtration device or vacuum filtration device. Centrifugal separation device can also be used for samples that are difficult to filter.

[0082] Ⅱ Filter membrane: 0.45μm microporous filter membrane.

[0083] 3) Balance: accuracy not less than ±0.01g.

[0084] 4) Sieve: Teflon-coated sieve, pore size 3 mm.

[0085] d. Experimental steps

[0086] 1) Determination of moisture content

[0087] ⅠAccording to the water content of solid waste, weigh 20-100g sample, place in a pre-dried constant weight container with a lid, dry at 105℃, keep constant weight to ±0.01g, and calculate the water content of the sample. (The material of the container must not react with the waste)

[0088] Ⅱ When the sample contains an initial liquid phase, the sample should be pressure filtered and the moisture content of the filter residue should be measured. The measurement steps are shown in Ⅰ. The moisture content and dry solid percentage of the sample are calculated based on the total sample volume (the sum of the initial liquid phase and the filter residue weight). (The sample after the moisture content is measured shall not be used for leaching toxicity testing)

[0089] 2) Leaching step

[0090] Ⅰ When the sample contains an initial liquid phase, the sample should be filtered using a pressure filter and a filter membrane. If the dry solid percentage is less than or equal to 9%, the initial liquid phase obtained is the leachate and is directly analyzed; if the dry solid percentage is greater than 9%, the filter residue is leached, and the initial liquid phase is mixed with the entire leachate for analysis.

[0091] Ⅱ Weigh a sample with a dry weight of 100g and place it in a 2L extraction bottle. According to the water content of the sample and the liquid-solid ratio of 10:1 (L / kg), calculate the required volume of the extractant, add the extractant, cover the bottle tightly and fix it vertically on the horizontal oscillation device, adjust the oscillation frequency to 110+10 times / min and the amplitude to 40mm, oscillate at room temperature for 8h, remove the extraction bottle, and let it stand for 16h. If gas is generated during the oscillation process, the extraction bottle should be opened regularly in the fume hood to release excessive pressure.

[0092] Ⅲ Install the filter membrane on the pressure filter, filter and collect the leaching liquid, and store it according to the requirements of the analytical method of each analyte.

[0093] IV Unless digestion will result in loss of the metal to be analyzed, the leachate used for metal analysis should be digested as required by the analytical method.

[0094] 3) Quality Assurance and Quality Control

[0095] Ⅰ For every 20 samples or each batch of samples (when the sample size is less than 20), at least one leaching blank should be prepared.

[0096] Ⅱ At least one spiked recovery sample should be made for each batch of samples. Take the sieved sample and divide it into two equal parts. Add a known amount of the standard sample of the analyte to one of them, perform extraction analysis according to the prescribed steps, and calculate the recovery rate of the analyte.

[0097] ⅢFor every 10 samples, at least one parallel sample should be made.

[0098] IV The sample leaching experiment should be completed within the time specified in the table or in the relevant analytical method.

[0099] Table 3 Maximum retention time of samples

[0100]

[0101] The block sample was placed in water for immersion for 24 hours, the block sample was taken out, and the content of each element in the water was tested.

[0102] Table 4

[0103]

[0104]

[0105] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A water-saving filling material prepared from multi-source coal-based solid waste, characterized in that: The invention comprises the following raw materials in parts by weight: 40-50 parts of fly ash, 20-25 parts of slag, 4-5 parts of carbide slag, 5 parts of desulfurization gypsum, and 25-30 parts of coal gangue.

2. The water-saving filling material prepared from multi-source coal-based solid waste according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 44.7 parts of fly ash, 22.3 parts of slag, 5 parts of carbide slag, 5 parts of desulfurized gypsum, and 23 parts of coal gangue.

3. The water-saving filling material prepared from multi-source coal-based solid waste according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 42 parts of fly ash, 21 parts of slag, 4 parts of carbide slag, 5 parts of desulfurized gypsum, and 28 parts of coal gangue.

4. The water-saving filling material prepared from multi-source coal-based solid waste according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 43.3 parts of fly ash, 21.7 parts of slag, 5 parts of carbide slag, 5 parts of desulfurized gypsum, and 25 parts of coal gangue.

5. The water-saving filling material prepared from multi-source coal-based solid waste according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 44.7 parts of fly ash, 22.3 parts of slag, 4 parts of carbide slag, 5 parts of desulfurized gypsum, and 24 parts of coal gangue.

6. The method for preparing a water-saving filling material using multi-source coal-based solid waste according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Add water to the weighed fly ash and stir evenly to obtain fly ash with a water content of 12% to 20%; S2, mixing the weighed slag, carbide slag, desulfurized gypsum and coal gangue evenly, adding water and continuing to stir to obtain a mixture with a water content of 25-26.5%; S3, mixing the fly ash treated in S1 with the mixture in step S2 to obtain a water-saving filling material.

7. The preparation method according to claim 6, characterized in that: The water content of the fly ash after treatment in step S1 is 15%.

8. The preparation method according to claim 6, characterized in that: The water content of the mixture in step S2 is 10%.

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