Method for measuring content of all gangue in power coal

Abstract

The invention relates to a method for measuring the content of all gangues in power coal, which comprises the following steps: crushing raw material coal, carrying out floating and sinking separation treatment, fully separating the coal from the gangues, and calculating to obtain the content of the gangues in the raw material coal, so that the relatively accurate content of the gangues can be obtained. The surfactant and the dispersing agent in the heavy liquid composition form a thermodynamically stable solution under the repulsive action of the same charges. When the heavy liquid composition is in contact with the coal raw material, due to the fact that the compressed double electric layers and the surfactant get close to each other and the double electric layers are overlapped, a coil of the dispersing agent tends to curl up, a repulsion area between the surfactant and the dispersing agent is reduced, a dense two-dimensional separation trend is generated, and then coal and gangue in the coal raw material can be fully separated.

Description

Technical Field

[0001] The present disclosure relates to the field of coal processing, and in particular, to a method for determining the total gangue content in thermal coal. Background Art

[0002] Gangue usually refers to the general term for rocks produced during the production of coal, which is generally composed of carbonaceous mudstone, sandstone, limestone, etc. In view of the current coal seam conditions and mining methods in coal mines, the amount of gangue accumulation is increasing. Given that the ash content in gangue is usually greater than 50% and the calorific value generally reaches 3.3-8.3MJ / kg, the output and stacking of gangue are at risk of spontaneous combustion and pyrite oxidation, and produce a large amount of toxic and harmful gases such as SO2, CO2 and CO, which cause serious pollution to the environment. Not only that, the large amount of gangue stacking also occupies a lot of valuable land resources.

[0003] The existing thermal power generation industry uses low calorific value fuel generators to process a large amount of stacked coal gangue. However, due to the excessive gangue content in thermal coal and the uneven distribution of coal, the requirements of the normal operating conditions of the application equipment are exceeded, which will inevitably cause the coal mill failure rate to increase, the maintenance workload to increase, the pulverizing output to decrease, and the coal powder fineness to exceed the standard. It will also cause the boiler combustion condition to be poor and the load to drop suddenly, and even the boiler to extinguish, which seriously affects the safe, economical and stable operation level of the generator set. It can be seen that the accurate determination of the gangue content in thermal coal has become an important basis for controlling the gangue content in thermal coal, scientifically blending and efficient utilization of gangue resources, providing an important basis for the adjustment of the operating conditions of coal mills and boilers and fault diagnosis, and has important guiding significance for the safe, economical and stable operation of generator sets.

[0004] The existing standard for determining gangue content in the coal industry is the mass fraction of gangue with a particle size greater than 50 mm, which cannot objectively, scientifically and accurately reflect the total gangue content in thermal coal. It is obviously not suitable for the actual application of accurate determination of the total gangue content of thermal coal in industries such as thermal power generation and steelmaking. Summary of the invention

[0005] The purpose of the present invention is to provide a method for determining the total gangue content in thermal coal, so as to solve the problem in the prior art that the total gangue content in thermal coal cannot be objectively, scientifically and accurately reflected.

[0006] In order to achieve the above object, the present disclosure provides a method for determining the total gangue content in thermal coal, the measuring method comprising: S1, crushing the raw coal to obtain raw coal particles; S2, subjecting the raw coal particles and the heavy liquid composition to a floating and sinking separation process to obtain floating coal and gangue sediments; The heavy liquid composition includes an inorganic salt, a surfactant, a dispersant and water; The density ρ of the heavy liquid composition is 30-55 kg / m 3 ; S3. Obtaining the total gangue content in the raw coal according to the weight of the gangue sediment and the raw coal.

[0007] Optionally, based on the total weight of the heavy liquid composition, the content of the inorganic salt is 40-70 wt %, the content of the surfactant is 3-10 wt %, the content of the dispersant is 10-30 wt %, and the content of water is 10-40 wt %.

[0008] Optionally, the particle size of the raw coal particles is 0.1~0.3mm.

[0009] Optionally, the inorganic salt comprises zinc chloride and / or zinc bromide; The surfactant is a nonionic surfactant; the nonionic surfactant includes one or more of fatty acid glycerides, fatty acid sorbitan and polysorbate; The dispersant includes one or more of triethylhexyl phosphoric acid, sodium lauryl sulfate, methyl amyl alcohol, cellulose derivatives, polyacrylamide and fatty acid polyethylene glycol ester.

[0010] Optionally, the dispersant is a mixture of triethylhexyl phosphoric acid and sodium dodecyl sulfate; the weight ratio of triethylhexyl phosphoric acid to sodium dodecyl sulfate in the dispersant is (0.9~1.1):1.

[0011] Optionally, the weight ratio of the surfactant to the dispersant in the heavy liquid composition is (1.5~2.0):1.

[0012] Optionally, step S2 includes: S21, subjecting the raw coal particles and the heavy liquid composition to mixing, stirring and static stratification in sequence to obtain a floating and sinking mixed material; S22, using the first filter cloth hopper and the second filter cloth hopper in sequence to remove the coal floating on the upper layer of the floating and sinking mixed materials to obtain the floating coal and the gangue-containing heavy liquid; S23, removing the heavy liquid composition in the gangue-containing heavy liquid to obtain the gangue sediment.

[0013] Optionally, the mixing and stirring conditions include: relative to 1g of the raw coal particles, the addition amount of the heavy liquid composition is 1-3mL, the speed of the stirring device is 400r / min, and the mixing and stirring time is 10-20min; The standing and stratification time is 40 to 100 minutes.

[0014] Optionally, the pore size of the first filter cloth hopper is 0.3 mm, and the pore size of the second filter cloth hopper is 0.1 mm.

[0015] Optionally, step S2 further includes: S24, drying the gangue sediment at a temperature of 45-50° C. for 0.5-3 h; S25, subjecting the gangue sediment to a decarbonization treatment at a temperature of 800-900° C. for 1-5 hours.

[0016] Through the above technical scheme, the raw coal is subjected to crushing and floating separation treatment in turn, the coal and gangue are fully separated, and the gangue content in the raw coal is obtained by calculation, so that a relatively accurate total gangue content can be obtained. The surfactant and dispersant in the heavy liquid composition form a thermodynamically stable solution under the repulsion of the same charge. When the heavy liquid composition contacts the coal raw material, due to the compression of the double electric layer, the surfactants approach each other, the double electric layers overlap, the coils of the dispersant tend to curl up, and the repulsion zone between the surfactant and the dispersant is reduced, resulting in a dense two-dimensional separation trend, thereby enabling the coal and gangue in the coal raw material to be fully separated.

[0017] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 The present invention discloses a flow chart of a method for determining the total gangue content in thermal coal. DETAILED DESCRIPTION

[0019] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0020] The present disclosure provides a method for determining the gangue content in thermal coal, the measuring method comprising: S1, crushing the raw coal to obtain raw coal particles; S2, subjecting the raw coal particles and the heavy liquid composition to a floating and sinking separation process to obtain floating coal and gangue sediments; The heavy liquid composition includes an inorganic salt, a surfactant, a dispersant and water; The density ρ of the heavy liquid composition is 30-55 kg / m 3 ; S3. Obtaining the total gangue content in the raw coal according to the weight of the gangue sediment and the raw coal.

[0021] Through the above technical scheme, the raw coal is subjected to crushing and floating separation treatment in turn, the coal and gangue are fully separated, and the gangue content in the raw coal is obtained by calculation, so that a relatively accurate total gangue content can be obtained. The surfactant and dispersant in the heavy liquid composition form a thermodynamically stable solution under the repulsion of the same charge. When the heavy liquid composition contacts the coal raw material, due to the compression of the double electric layer, the surfactants approach each other, the double electric layers overlap, the coils of the dispersant tend to curl up, and the repulsion zone between the surfactant and the dispersant is reduced, resulting in a dense two-dimensional separation trend, thereby enabling the coal and gangue in the coal raw material to be fully separated.

[0022] In one embodiment, the particle size of the raw coal particles is 0.1~0.3mm.

[0023] In a preferred embodiment, the particle size of the raw coal particles is 0.2 mm.

[0024] In one embodiment, step S1 further includes: allowing a certain amount of raw coal to enter a crushing device for crushing, and the crushed particles are sorted through a sieve with an aperture of 0.3 mm, and particles with a particle size of less than 0.3 mm fall below, and particles with a particle size of more than 0.3 mm are retained above the sieve. The oversize is returned to the crushing device for further crushing until the weight of the oversize accounts for less than 0.5% of the weight of the raw coal, and the crushing is considered to be completed. At this time, the oversize and undersize are mixed as raw coal particles.

[0025] In an optional embodiment, the undersize material can be sorted through a sieve with an aperture of 0.1 mm, and the particles with a particle size of less than 0.1 mm can fall below, while the particles with a particle size of 0.1-0.3 mm can be retained above the sieve. In this embodiment, when the particles with a particle size of less than 0.1 mm are subjected to floating and sinking separation treatment, due to the high density of the heavy liquid composition, smaller particles may float together, affecting the accuracy of the determination of the total gangue content. However, there are very few particles with smaller particle sizes in the crushed material, and the weight is very small compared to the total raw coal. When the amount of crushed raw coal is large, this step can be omitted, and when the amount of crushed raw coal is small, this step can be considered to be added.

[0026] In one implementation, step S2 includes: S21, subjecting the thermal coal particles and the heavy liquid composition to mixing, stirring and static stratification in sequence to obtain a floating and sinking mixture; S22, using the first filter cloth hopper and the second filter cloth hopper in sequence to remove the coal floating on the upper layer of the floating and sinking mixed materials to obtain the floating coal and the gangue-containing heavy liquid; S23, removing the heavy liquid composition in the gangue-containing heavy liquid to obtain the gangue sediment; S24, drying the gangue sediment at a temperature of 45-50° C. for 0.5-3 h; S25, subjecting the gangue sediment to a decarbonization treatment at a temperature of 800-900° C. for 1-5 hours.

[0027] In this embodiment, the raw coal is mixed with the heavy liquid composition, and under the synergistic effect of the components in the heavy liquid composition, almost all of the coal can float above the liquid phase, while the materials with higher density such as gangue are deposited at the bottom of the liquid phase. Then, the floating coal is scooped out using a filter cloth hopper with different pore sizes, so that the coal and the gangue can be fully separated, and the weight of the gangue in the raw coal is accurate, which can improve the accuracy of the determination of the gangue content in the raw coal.

[0028] In one embodiment, based on the total weight of the heavy liquid composition, the content of the inorganic salt is 40-70 wt %, the content of the surfactant is 3-10 wt %, the content of the dispersant is 10-30 wt %, and the content of water is 10-40 wt %.

[0029] In a preferred embodiment, based on the total weight of the heavy liquid composition, the content of the inorganic salt is 45-65% by weight, the content of the surfactant is 4-8% by weight, the content of the dispersant is 12-26% by weight, and the content of water is 15-38% by weight.

[0030] In a further preferred embodiment, based on the total weight of the heavy liquid composition, the content of the inorganic salt is 50-60 wt %, the content of the surfactant is 5-6 wt %, the content of the dispersant is 15-22 wt %, and the content of water is 20-35 wt %.

[0031] In one embodiment, the inorganic salt comprises zinc chloride and / or zinc bromide.

[0032] In a preferred embodiment, the inorganic salt is zinc chloride.

[0033] In a preferred embodiment, the density ρ of the heavy liquid composition is 40-55 kg / m 3 .

[0034] In a further preferred embodiment, the density ρ of the heavy liquid composition is 45-53 kg / m 3 .

[0035] In one embodiment, the surfactant is a nonionic surfactant; the nonionic surfactant includes one or more of fatty acid glycerides, fatty acid sorbitan and polysorbate.

[0036] In a preferred embodiment, the surfactant is fatty acid sorbitan and / or polysorbate.

[0037] In one embodiment, the dispersant includes one or more of triethylhexyl phosphoric acid, sodium lauryl sulfate, methyl amyl alcohol, cellulose derivatives, polyacrylamide and fatty acid polyethylene glycol esters.

[0038] In a preferred embodiment, the dispersant is a mixture of triethylhexyl phosphoric acid and sodium dodecyl sulfate.

[0039] In a further preferred embodiment, the weight ratio of triethylhexyl phosphate to sodium dodecyl sulfate in the dispersant is (0.9-1.1):1.

[0040] In another preferred embodiment, the weight ratio of triethylhexyl phosphoric acid to sodium dodecyl sulfate in the dispersant is 1:1.

[0041] In one embodiment, the weight ratio of the surfactant to the dispersant is (1.5~2.0):1.

[0042] In a preferred embodiment, the weight ratio of the surfactant to the dispersant is (1.6-1.8):1.

[0043] In the above embodiment, the inorganic salt is used in the heavy liquid composition to increase the density of the heavy liquid composition and provide a separation basis for the full separation of coal and gangue. The surfactant and dispersant are used in the heavy liquid composition to promote the accelerated dispersion and separation of coal and gangue in the raw coal particles through the synergistic effect of the two.

[0044] In one embodiment, the method for preparing the heavy liquid composition of the present disclosure comprises: adding an inorganic salt to a certain amount of water to form a density of ρ 30-55 kg / m 3 Then add a surfactant and a dispersant thereto, stir evenly, and finally add water thereto to make the density ρ of the heavy liquid composition return to 30~55kg / m 3 .

[0045] In this embodiment, in the case of repulsion between the surfactant and the dispersant due to the same charge, a mutually repulsive zone is maintained between the diffuse double layers of the surfactant and the dispersant coils, and a thermodynamically stable solution can be formed. When the surfactant and the dispersant are fully mixed, due to the compression of the double layers, the surfactants are close to each other, the double layers overlap, the polymer coils tend to curl up, the repulsive zone between the surfactant and the dispersant molecules is reduced, and a dense two-dimensional separation trend begins to be generated, which can then form an effective separation effect for the coal and gangue in the raw coal particles therein.

[0046] In one embodiment, the mixing and stirring conditions in step S21 include: the addition amount of the heavy liquid composition is 1-3 mL relative to 1 g of the raw coal particles.

[0047] In a preferred embodiment, the amount of the heavy liquid composition added is 1.5-2.5 mL relative to 1 g of the raw coal particles.

[0048] In a further preferred embodiment, the amount of the heavy liquid composition added is 1.9 to 2.1 mL relative to 1 g of the raw coal particles.

[0049] In this embodiment, by using a suitable addition ratio of raw coal particles and heavy liquid composition, the separation effect can be optimized and the separation effect can be improved.

[0050] In one embodiment, the standing and stratifying time in step S21 is 40 to 100 minutes.

[0051] In a preferred embodiment, the standing and stratifying time in step S21 is 50 to 80 minutes.

[0052] In one embodiment, the mixing and stirring and the standing and stratification in step S21 can be performed in the same device, or can be performed in two devices respectively. Preferably, the mixing and stirring and the standing and stratification are performed in the same device.

[0053] In one embodiment, the device used for the mixing and stirring described in step S21 is conventionally selected in the art, and this application does not make special requirements. For example, the mixing and stirring device is a magnetic stirring device. It should be noted that the speed and stirring time of the stirring device are determined according to the addition amount of the raw coal particles and the heavy liquid composition. For example, the speed of the stirring device disclosed in the present invention is 400r / min, and the mixing and stirring time is 10-20min.

[0054] In one embodiment, the pore size of the first filter cloth hopper is 0.3 mm, and the pore size of the second filter cloth hopper is 0.1 mm.

[0055] In one embodiment, the method of removing the heavy liquid composition in the gangue-containing heavy liquid described in step S23 is a conventional choice in the art, and this application does not make any special requirements. For example, the heavy liquid composition can be directly poured out, or the gangue-containing heavy liquid can be sent to a filtering device for filtration.

[0056] In an optional embodiment, the gangue sediment is washed with water to remove the heavy liquid composition remaining on the surface of the gangue, thereby further improving the accuracy of the gangue content determination.

[0057] In one embodiment, the gangue content in the raw coal in step S3 refers to the percentage of the weight of the gangue sediment obtained in step S24 to the weight of the raw coal.

[0058] In one embodiment, if Figure 1 As shown, the method for determining the gangue content in thermal coal includes: S1. A certain amount of raw coal is fed into a crushing device for crushing. The crushed particles are sorted through a sieve with an aperture of 0.3 mm. Particles with a particle size of less than 0.3 mm fall below, and particles with a particle size of more than 0.3 mm are retained above the sieve. The oversize is returned to the crushing device for further crushing until the weight of the oversize accounts for less than 0.5% of the weight of the raw coal. The crushing is considered to be completed. At this time, the oversize and undersize are mixed as raw coal particles. S21, add inorganic salt to a certain amount of water to form a density of 30~55kg / m 3 Then add a surfactant and a dispersant thereto, stir evenly, and finally add water thereto to make the density ρ of the heavy liquid composition return to 30~55kg / m 3 , obtaining a heavy liquid composition; based on the total weight of the heavy liquid composition, the content of the inorganic salt is 40-70% by weight, the content of the surfactant is 3-10% by weight, the content of the dispersant is 10-30% by weight, and the content of water is 10-40% by weight; The thermal coal particles and the heavy liquid composition are sequentially mixed and stirred and allowed to stand for stratification to obtain a floating and sinking mixture; the mixing and stirring conditions include: relative to 1g of the raw coal particles, the addition amount of the heavy liquid composition is 1-3mL, the speed of the stirring device is 400r / min, the mixing and stirring time is 10-20min; the standing stratification time is 40-100min; S22, using a first filter cloth hopper with a pore size of 0.3 mm and a second filter cloth hopper with a pore size of 0.1 mm in sequence to remove the coal floating on the upper layer of the floating and sinking mixed materials, to obtain the floating coal and the gangue-containing heavy liquid; S23, removing the heavy liquid composition in the gangue-containing heavy liquid to obtain the gangue sediment; S24, drying the gangue sediment at a temperature of 45-50° C. for 0.5-3 h; S25, subjecting the gangue sediment to a decarbonization treatment at a temperature of 800-900° C. for 1-5 hours; S3. Obtaining the gangue content in the raw coal according to the weight of the gangue sediment and the raw coal.

[0059] The following examples will further illustrate the present invention, but are not intended to limit the present invention. Unless otherwise specified, the reagents used in the examples are all analytically pure. The raw coal used in the examples is a mixture of 86.5% by weight of coal produced from the Mengxi No. 2 open-pit coal mine and 13.5% by weight of gangue.

[0060] Example 1 Methods for determining the total gangue content in thermal coal include: S1. 500 g of raw coal is fed into a crushing device for crushing to obtain raw coal particles with a particle size of 0.2±0.1 mm; the particle size of the raw coal particles meets the requirement of 0.5% of the weight of the oversize; S21. Add zinc chloride to water to form a density of 48 kg / m 3 Then, a surfactant (sorbitan fatty acid) and a dispersant (a mixture of triethylhexyl phosphoric acid and sodium dodecyl sulfate in a ratio of 1:1) were added thereto, stirred evenly, and finally water was added thereto to return the density ρ of the heavy liquid composition to 48 kg / m 3 , obtaining a heavy liquid composition; based on the total weight of the heavy liquid composition, the content of the inorganic salt is 55% by weight, the content of the surfactant is 5% by weight, the content of the dispersant is 20% by weight, and the content of water is 20% by weight; The thermal coal particles and 1000 mL of the heavy liquid composition were placed in a 2000 mL glass container with a built-in magnetic stirring function, the magnetic stirrer was started, and the mixture was stirred at a speed of 400 r / min for 15 min; then the magnetic stirrer was turned off, and the mixture was allowed to stand for 60 min to separate into layers, thereby obtaining a floating and sinking mixture; S22, using a first filter cloth hopper with a pore size of 0.3 mm and a second filter cloth hopper with a pore size of 0.1 mm in sequence to remove the coal floating on the upper layer of the floating and sinking mixed materials, to obtain the floating coal and the gangue-containing heavy liquid; S23, removing the heavy liquid composition in the gangue-containing heavy liquid to obtain the gangue sediment; S24, drying the gangue sediment at a temperature of 50° C. for 0.5 h; S25, subjecting the gangue sediment to a decarbonization treatment at a temperature of 850° C. for 3 h to obtain 64 g of dry gangue sediment; S3. Obtaining the total gangue content in the raw coal according to the weight of the gangue sediment and the raw coal.

[0061] The total gangue content in the raw coal is shown in Table 1.

[0062] Example 2 The method for determining the total gangue content in thermal coal is the same as that in Example 1, except that the surfactant is polysorbate, based on the total weight of the heavy liquid composition, the content of the inorganic salt is 56% by weight, the content of the surfactant is 6% by weight, the content of the dispersant is 15% by weight, and the content of water is 23% by weight. The weight of the obtained dried gangue sediment is 64.5 g, and the total gangue content in the raw coal is shown in Table 1.

[0063] Example 3 The method for determining the total gangue content in thermal coal is the same as that in Example 1, except that, based on the total weight of the heavy liquid composition, the content of the inorganic salt is 35% by weight, the content of the surfactant is 12% by weight, the content of the dispersant is 6% by weight, and the content of water is 47% by weight. The weight of the obtained dried gangue sediment is 42.5 g, and the total gangue content in the raw coal is shown in Table 1.

[0064] Example 4 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that the particle size of the raw coal particles is 0.5±0.1 mm. The weight of the obtained dried gangue sediment is 41 g. The total gangue content in the raw coal is shown in Table 1.

[0065] Example 5 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that the dispersant is triethylhexyl phosphoric acid. The weight of the obtained dry gangue sediment is 43 g. The total gangue content in the raw coal is shown in Table 1.

[0066] Example 6 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that the weight ratio of triethylhexyl phosphate to sodium dodecyl sulfate is 1.5: 1. The weight of the obtained dried gangue sediment is 41 g, and the total gangue content in the raw coal is shown in Table 1.

[0067] Example 7 The method for determining the total gangue content in thermal coal is the same as that in Example 1, except that the weight ratio of the surfactant to the dispersant is 1.3: 1. The weight of the obtained dried gangue sediment is 40.5 g, and the total gangue content in the raw coal is shown in Table 1.

[0068] Example 8 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that 300 g of raw coal particles and 1000 mL of the heavy liquid composition are mixed and stirred. The weight of the obtained dry gangue sediment is 22.8 g. The total gangue content in the raw coal is shown in Table 1.

[0069] Example 9 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that the density ρ of the heavy liquid composition is 40 kg / m 3 The weight of the dried gangue sediment obtained was 58 g. The total gangue content in the raw coal is shown in Table 1.

[0070] Example 10 Methods for determining the total gangue content in thermal coal include: S1. 480 g of raw coal is fed into a crushing device for crushing to obtain raw coal particles with a particle size of 0.2±0.1 mm; the particle size of the raw coal particles meets the requirement of 0.5% of the weight of the oversize; S21, add zinc chloride into water to form a density of 52kg / m 3 Then add a surfactant (fatty acid glyceride) and a dispersant (methyl amyl alcohol) thereto, stir evenly, and finally add water thereto to make the density ρ of the heavy liquid composition return to 52kg / m 3 , obtaining a heavy liquid composition; based on the total weight of the heavy liquid composition, the content of the inorganic salt is 56% by weight, the content of the surfactant is 5.5% by weight, the content of the dispersant is 18% by weight, and the content of water is 20.5% by weight; The thermal coal particles and 1000 mL of the heavy liquid composition were placed in a 2000 mL glass container with a built-in magnetic stirring function, the magnetic stirrer was started, and the mixture was stirred at a speed of 450 r / min for 10 min; then the magnetic stirrer was turned off, and the mixture was allowed to stand for 70 min to separate into layers, thereby obtaining a floating and sinking mixture; S22, using a first filter cloth hopper with a pore size of 0.3 mm and a second filter cloth hopper with a pore size of 0.1 mm in sequence to remove the coal floating on the upper layer of the floating and sinking mixed materials, to obtain the floating coal and the gangue-containing heavy liquid; S23, removing the heavy liquid composition in the gangue-containing heavy liquid to obtain the gangue sediment; S24, drying the gangue sediment at a temperature of 45° C. for 1 h; S25, subjecting the gangue sediment to a decarbonization treatment at a temperature of 850° C. for 3 h to obtain 66 g of dry gangue sediment; S3. Obtaining the total gangue content in the raw coal according to the weight of the gangue sediment and the raw coal.

[0071] The total gangue content in the raw coal is shown in Table 1.

[0072] Comparative Example 1 The gangue content in the raw coal was determined by the method of MT / T 1 "Method for Determination of Gangue Content and Lower Limit of Commercial Coal". This method mainly uses a 50mm aperture round hole sieve to pick out all the gangue (including pyrite) in the sieve, and then weigh the weight of the sieve and the sieve under the sieve respectively with an accuracy of 0.001, and calculate the gangue content. 11g of dry gangue sediment was obtained by the method of MT / T 1 "Method for Determination of Gangue Content and Lower Limit of Commercial Coal". The total gangue content in the raw coal is shown in Table 1.

[0073] Comparative Example 2 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that the heavy liquid composition is replaced by an equal weight suspension of magnetite powder and water, and the density of the suspension is the same as in Example 1. The weight of the obtained dry gangue sediment is 62 g, and the total gangue content in the raw coal is shown in Table 1.

[0074] Comparative Example 3 The method for determining the total gangue content in thermal coal is the same as in Example 1, except that the density ρ of the heavy liquid composition is 25 kg / m 3 The weight of the dried gangue sediment obtained was 53 g. The total gangue content in the raw coal is shown in Table 1.

[0075] Table 1 Total gangue content and relative error in raw coal of the embodiment and comparative example

[0076] As shown in Table 1, according to the comparison of the data in Examples 1 to 10 and Comparative Example 1, it can be seen that the determination method disclosed in the present invention can obtain a more accurate total gangue content compared with the existing MT / T 1 "Determination method of gangue content and lower limit rate of commercial coal". According to the comparison of the data in Example 1 and Comparative Example 2, the heavy liquid composition of this patent has the characteristics of low suspension rate for small-particle gangue compared with the existing suspension, which can further improve the accuracy of the determination of total gangue content. According to the comparison of the data in Examples 1 to 10 and Comparative Example 3, the density of the heavy liquid composition is 30~55kg / m 3 When measuring the gangue content in the raw coal, the accuracy can be improved.

[0077] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0078] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0079] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for determining the total gangue content in thermal coal, characterized in that: The measurement method includes: S1, crushing the raw coal to obtain raw coal particles; S2, subjecting the raw coal particles and the heavy liquid composition to a floating and sinking separation process to obtain floating coal and gangue sediments; The heavy liquid composition includes an inorganic salt, a surfactant, a dispersant and water; The density of the heavy liquid composition is 30-55 kg / m 3 ; S3. Obtaining the gangue content in the raw coal according to the weight of the gangue sediment and the raw coal.

2. The measuring method according to claim 1, characterized in that Based on the total weight of the heavy liquid composition, the content of the inorganic salt is 40-70% by weight, the content of the surfactant is 3-10% by weight, the content of the dispersant is 10-30% by weight, and the content of water is 10-40% by weight.

3. The measuring method according to claim 1, characterized in that The particle size of the raw coal particles is 0.1-0.3 mm.

4. The measuring method according to claim 1, characterized in that The inorganic salt includes zinc chloride and / or zinc bromide; The surfactant is a nonionic surfactant; the nonionic surfactant includes one or more of fatty acid glycerides, fatty acid sorbitan and polysorbate; The dispersant includes one or more of triethylhexyl phosphoric acid, sodium lauryl sulfate, methyl amyl alcohol, cellulose derivatives, polyacrylamide and fatty acid polyethylene glycol ester.

5. The measuring method according to claim 1, characterized in that The dispersant is a mixture of triethylhexyl phosphoric acid and sodium lauryl sulfate; The weight ratio of triethylhexyl phosphoric acid to sodium dodecyl sulfate in the dispersant is (0.9-1.1):

1.

6. The measuring method according to claim 1, characterized in that The weight ratio of the surfactant to the dispersant in the heavy liquid composition is (1.5-2.0):

1.

7. The measuring method according to claim 1, characterized in that Step S2 includes: S21, subjecting the raw coal particles and the heavy liquid composition to mixing, stirring and static stratification in sequence to obtain a floating and sinking mixed material; S22, using the first filter cloth hopper and the second filter cloth hopper in sequence to remove the coal floating on the upper layer of the floating and sinking mixed materials to obtain the floating coal and the gangue-containing heavy liquid; S23, removing the heavy liquid composition in the gangue-containing heavy liquid to obtain the gangue sediment.

8. The measuring method according to claim 7, characterized in that The mixing and stirring conditions include: relative to 1g of the raw coal particles, the addition amount of the heavy liquid composition is 1-3mL, the speed of the stirring device is 400r / min, and the mixing and stirring time is 10-20min; The standing and stratification time is 40 to 100 minutes.

9. The measuring method according to claim 7, characterized in that The pore size of the first filter cloth hopper is 0.3 mm, and the pore size of the second filter cloth hopper is 0.1 mm.

10. The measuring method according to claim 1, characterized in that Step S2 also includes: S24, drying the gangue sediment at a temperature of 45-50° C. for 0.5-3 h; S25, subjecting the gangue sediment to a decarbonization treatment at a temperature of 800-900° C. for 1-5 hours.

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