Arsenic fixing composition in coal washing process and use method of arsenic fixing composition

Abstract

The invention relates to an arsenic fixing composition in a coal washing process and a use method of the arsenic fixing composition, in the arsenic fixing composition, dolomite powder, an auxiliary absorbent and a catalyst generate a good synergistic effect, so that arsenic in a product of the coal washing process is adsorbed after being converted, the content of arsenic in the product of the coal washing process can be reduced, and the yield of the product of the coal washing process is improved. The removal efficiency of the arsenic element is improved. The dolomite powder which is low in price, low in preparation cost and wide in raw material source is adopted as the main adsorbent, the problem of environmental pollution in a traditional coal washing process can be solved, and the environmental protection performance of the coal washing process is improved. The composition of the petroleum sulfide and the Fe-Mn composite oxide is adopted as the auxiliary absorbent, on one hand, sulfur elements in the petroleum sulfide can convert trivalent arsenic in the coal into pentavalent arsenic, and absorption of the absorbent is facilitated; on the other hand, Fe and Mn in the Fe-Mn composite oxide can form iron sulfide and manganese sulfide with the S element, and the situation that sulfur enters washing water to cause environmental pollution is avoided.

Description

Technical Field

[0001] The present disclosure relates to the field of coal arsenic fixation, and in particular, to an arsenic fixation composition in a coal washing process and a method for using the composition. Background Art

[0002] Coal is the main energy source for my country's power development. At present, coal-fired power plants account for 70% of the total installed capacity in my country, and coal used for thermal power generation accounts for more than 60% of the total coal sales in the country. Thermal power plants are the largest users of coal. Arsenic in coal is one of the important harmful elements of environmental pollution. Therefore, the pollution problem of arsenic in the environment has attracted more and more attention.

[0003] Arsenic is a poison that seriously endangers human health. It can bind to the sulfhydryl groups of intracellular enzyme proteins in the human body and make them inactive, thereby affecting the metabolism of human tissues and causing cell death. It can also cause disorders in nerve cell metabolism and cause nervous system diseases. Although my country has clear regulations on the mass fraction of arsenic in coal, the arsenic produced by the combustion of high-arsenic coal is discharged into the atmosphere and enriched in fly ash, food, etc., which in turn causes important environmental problems and endangers human health.

[0004] At present, a very effective way to reduce the many environmental problems caused by arsenic in the process of coal utilization is to wash the raw coal. However, during the washing process, a small part of the arsenic in the coal is analyzed into the washing water, and most of it is distributed into various washing products, such as clean coal, medium coal, fine coal, coal slime, coal gangue, etc., which will bring great harm to the human living environment. Summary of the invention

[0005] The purpose of the present invention is to provide a solid arsenic composition in a coal washing process and a method for using the same, so as to solve the problems in the prior art of high arsenic content in the coal obtained by the washing process and environmental pollution caused by arsenic in the wastewater generated by the washing process.

[0006] In order to achieve the above-mentioned object, the present disclosure provides a solid arsenic composition in a coal washing process, the solid arsenic composition comprising dolomite powder, a surfactant, an auxiliary absorbent, a catalyst and a dispersant; The auxiliary absorbent includes a composition of petroleum sulfide and Fe-Mn composite oxide; Based on the total weight of the solid arsenic composition, the content of the dolomite powder is 40-70% by weight, the content of the surfactant is 1-10% by weight, the content of the auxiliary absorbent is 10-30% by weight, the content of the catalyst is 10-30% by weight, and the content of the dispersant is 1-10% by weight.

[0007] Optionally, based on the total weight of the solid arsenic composition, the content of the dolomite powder is 50-60 weight %, the content of the surfactant is 4-7 weight %, the content of the auxiliary absorbent is 20-28 weight %, the content of the catalyst is 20-25 weight %, and the content of the dispersant is 3-7 weight %.

[0008] Optionally, the particle size of the dolomite powder is less than 100 mesh; The sulfur content in the petroleum sulfide is 5.0-10.0 ppm; The iron oxide in the Fe-Mn composite oxide includes Fe 2 O 3 , FeO and Fe 3 O 4 One or more of the above, manganese oxides include MnO.

[0009] Optionally, the surfactant includes a copolymer of polysiloxane and acrylic acid and / or a copolymer of polysiloxane and acrylate; the molecular weight of the copolymer in the surfactant is 300-400.

[0010] Optionally, the surfactant includes polydimethylsiloxane-b-polymethacrylic acid and polydimethylsiloxane-b-polymethyl methacrylate; Based on the total weight of the surfactant, the content of the polydimethylsiloxane-b-polymethacrylic acid is 50-60% by weight, and the content of the polydimethylsiloxane-b-polymethyl methacrylate is 40-50% by weight.

[0011] Optionally, the weight ratio of the petroleum sulfide to the Fe-Mn composite oxide is (1.5-4.0):1.

[0012] Optionally, the catalyst comprises slaked lime.

[0013] Optionally, the dispersant is selected from phosphate ester salt type polymers; the phosphate ester salt type polymers include a combination of aryl phosphate ester salt polymers, fatty alcohol polyoxyethylene ether phosphate ester salt polymers and alkyl alcohol amide phosphate ester salt polymers; Based on the total weight of the phosphate-type polymer, the content of the aryl phosphate polymer is 40-70% by weight, the content of the fatty alcohol polyoxyethylene ether phosphate polymer is 15-25% by weight, and the content of the combination of alkyl alcohol amide phosphate polymer is 15-25% by weight.

[0014] Optionally, the weight ratio of the dolomite powder to the auxiliary absorbent is (1.5~3.5):1.

[0015] The second aspect of the present disclosure provides a method for using the solid arsenic composition described in the first aspect, the method comprising allowing the solid arsenic composition and coal to enter a coal washing device for coal washing treatment; the weight ratio of the solid arsenic composition to the coal is (0.2~0.3):1.

[0016] Through the above technical scheme, the dolomite powder, auxiliary absorbent and catalyst in the solid arsenic composition disclosed in the present invention produce a good synergistic effect, so that the arsenic in the product of the coal washing process is adsorbed after conversion, which can reduce the arsenic content in the product of the coal washing process and improve the removal efficiency of the arsenic element. The use of dolomite powder with low price, low preparation cost and wide raw materials as the main adsorbent can reduce the environmental pollution problems in the traditional coal washing process and improve the environmental performance of the coal washing process. The composition of petroleum sulfide and Fe-Mn composite oxide is used as an auxiliary absorbent. On the one hand, the sulfur element in petroleum sulfide can convert trivalent arsenic in coal into pentavalent arsenic, which is convenient for the absorbent to absorb; on the other hand, Fe and Mn in Fe-Mn composite oxide can form iron sulfide and manganese sulfide with S element to avoid sulfur entering the washing water and causing environmental pollution. Adding a catalyst to the solid arsenic composition can promote the effect of arsenic conversion treatment and further improve the removal efficiency of arsenic.

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

[0018] The specific embodiments of the present disclosure are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0019] The present disclosure provides a solid arsenic composition in a coal washing process, the solid arsenic composition comprising dolomite powder, a surfactant, an auxiliary absorbent, a catalyst and a dispersant; The auxiliary absorbent includes a composition of petroleum sulfide and Fe-Mn composite oxide; Based on the total weight of the solid arsenic composition, the content of the dolomite powder is 40-70% by weight, the content of the surfactant is 1-10% by weight, the content of the auxiliary absorbent is 10-30% by weight, the content of the catalyst is 10-30% by weight, and the content of the dispersant is 1-10% by weight.

[0020] Through the above technical scheme, the dolomite powder, auxiliary absorbent and catalyst in the solid arsenic composition disclosed in the present invention produce a good synergistic effect, so that the arsenic in the product of the coal washing process is adsorbed after conversion, which can reduce the arsenic content in the product of the coal washing process and improve the removal efficiency of the arsenic element. The use of dolomite powder with low price, low preparation cost and wide raw materials as the main adsorbent can reduce the environmental pollution problems in the traditional coal washing process and improve the environmental performance of the coal washing process. The composition of petroleum sulfide and Fe-Mn composite oxide is used as an auxiliary absorbent. On the one hand, the sulfur element in petroleum sulfide can convert trivalent arsenic in coal into pentavalent arsenic, which is convenient for the absorbent to absorb; on the other hand, Fe and Mn in Fe-Mn composite oxide can form iron sulfide and manganese sulfide with S element to avoid sulfur entering the washing water and causing environmental pollution. Adding a catalyst to the solid arsenic composition can promote the effect of arsenic conversion treatment and further improve the removal efficiency of arsenic.

[0021] In one embodiment, the dolomite powder described in the present disclosure refers to the dolomite powder obtained by crushing. In this embodiment, dolomite is a sedimentary carbonate rock, mainly composed of dolomite, quartz, feldspar, calcite and clay minerals. It is generally grayish white, brittle, hard, and easy to scratch with iron tools. It slowly bubbles or does not bubble when exposed to dilute hydrochloric acid, and its appearance is very similar to limestone.

[0022] In one embodiment, the particle size of the dolomite powder is less than 100 mesh.

[0023] In one embodiment, the porosity of the dolomite powder is 30-50%.

[0024] In this embodiment, the crushing method of dolomite powder is a conventional choice in the art, and this application does not make special requirements. For example, after crushing by a crushing device, a 100-mesh screen is used for separation. The material below the screen is the dolomite powder, and the material on the screen is returned to the crushing device for crushing and further screening. When the porosity of the dolomite powder is within the appropriate parameters, it can absorb more arsenic while ensuring the strength of the dolomite powder.

[0025] In one embodiment, the surfactant described in the present disclosure includes a copolymer of polysiloxane and acrylic acid and / or a copolymer of polysiloxane and acrylate.

[0026] In a preferred embodiment, the surfactant includes polydimethylsiloxane-b-polymethacrylic acid and polydimethylsiloxane-b-polymethyl methacrylate.

[0027] In a further preferred embodiment, the content of the polydimethylsiloxane-b-polymethacrylic acid is 50-60% by weight, and the content of the polydimethylsiloxane-b-polymethyl methacrylate is 40-50% by weight. In this embodiment, the ratio between the components in the surfactant can be flexibly adjusted according to actual needs, for example, the content of the polydimethylsiloxane-b-polymethacrylic acid in the surfactant can be one of 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight and 60% by weight, or any two of the range; the content of the polydimethylsiloxane-b-polymethyl methacrylate in the surfactant can be one of 40% by weight, 41% by weight, 42% by weight, 43% by weight, 44% by weight, 45% by weight, 46% by weight, 47% by weight, 48% by weight, 49% by weight and 50% by weight, or any two of the range.

[0028] In one embodiment, the molecular weight of the copolymer in the surfactant is 300 to 400. In this embodiment, the two ends of the surfactant used in the present disclosure are respectively a hydrophilic end and a hydrophobic end, the hydrophilic end extends into the aqueous solution, and the hydrophobic end is connected to the agglomerating agent molecule. The use of two copolymers with different hydrophobic ends can be combined with different substances of the formed network structure macromolecules, further improving the surface activity of the formed network structure macromolecules. The molecular weight of the copolymer in the surfactant can be flexibly set according to the properties of the formed network structure macromolecules, for example, the molecular weight of the copolymer in the surfactant is 310, 330, 350, 380 or any range between two.

[0029] In one embodiment, the petroleum sulfide disclosed in the present invention is a conventional choice in the art, and this application does not make special requirements. For example, the source of the petroleum sulfide can be produced by a gasoline catalytic distillation unit, a polyphenylene sulfide production unit, or a gasoline etherification unit.

[0030] In one embodiment, the sulfur content in the petroleum sulfide is 5.0-10.0 ppm.

[0031] In a preferred embodiment, the sulfur content in the petroleum sulfide can be flexibly adjusted according to the source of coal. For example, the sulfur content in the petroleum sulfide can be one of 5.0 ppm, 6.0 ppm, 8.0 ppm, 9.0 ppm and 10.0 ppm or a range between any two of them.

[0032] In this embodiment, the sulfur in the petroleum sulfide mainly includes elemental sulfur, organic sulfur and inorganic sulfur, wherein the organic sulfur includes one or more of sulfide, mercaptan and thiophenol, and the inorganic sulfur includes one or more of hydrogen sulfide and sodium sulfide.

[0033] In this embodiment, during the coal washing process, the sulfur in the petroleum sulfide reacts with the washing water and trivalent arsenic in the coal to convert the trivalent arsenic into pentavalent arsenic, which is easily adsorbed by the adsorbent, thereby improving the arsenic removal rate.

[0034] In one embodiment, the iron oxide in the Fe-Mn composite oxide described in the present disclosure includes Fe 2 O 3 , FeO and Fe 3 O 4 One or more of the following, manganese oxides include MnO and / or MnO 2 .

[0035] In a preferred embodiment, the Fe-Mn composite oxide described in the present disclosure is composed of ferric oxide and manganese oxide. In this embodiment, based on the total weight of the Fe-Mn composite oxide, the content of ferric oxide is 35-55% by weight, preferably 40-45% by weight; the content of manganese oxide is 45-65% by weight, preferably 55-60% by weight.

[0036] In this embodiment, the sulfur formed by the reaction of sulfur in petroleum sulfide with arsenic can react with Fe and Mn elements in Fe-Mn composite oxide to form compounds such as iron sulfide, ferrous sulfide and manganese sulfide, thereby preventing sulfur from entering the washing water and causing environmental pollution.

[0037] In one embodiment, the method for preparing the Fe-Mn composite oxide disclosed in the present invention is a conventional choice in the art and is not specifically required by the present application.

[0038] In one embodiment, the method for preparing the Fe-Mn composite oxide comprises: 3+ Solution and Mn 2+ A stabilizer is added to the solution mixture, and a weak alkaline ammonia solution is added to adjust the pH value to 7.5-8.0, and finally the solution is drained and calcined to obtain the product.

[0039] In another embodiment, the method for preparing the Fe-Mn composite oxide comprises: In KMnO 4 Add an appropriate amount of NaOH solution to the solution to make the solution alkaline during the entire reaction process; 4 Add the above KMnO 4 The solution is stirred, drained and calcined in sequence to obtain the Fe-Mn composite oxide.

[0040] In one embodiment, the catalyst comprises slaked lime and / or quicklime, preferably slaked lime. In this embodiment, adding a catalyst to the solid arsenic composition can promote the effect of arsenic conversion treatment and further improve the removal efficiency of arsenic.

[0041] In one embodiment, the dispersant includes a phosphate ester type polymer; the polymer includes one or more of an aromatic phosphate ester polymer, a fatty alcohol polyoxyethylene ether phosphate ester polymer and an alkyl alcohol amide phosphate ester polymer.

[0042] In a preferred embodiment, the phosphate ester salt type polymer comprises a combination of an aromatic phosphate ester salt polymer, a fatty alcohol polyoxyethylene ether phosphate ester salt polymer and an alkyl alcohol amide phosphate ester salt polymer.

[0043] In a further preferred embodiment, the aromatic phosphate ester polymer comprises behenylamide dimethyl hydroxypropyl ammonium chloride; the fatty alcohol polyoxyethylene ether phosphate ester polymer comprises fatty alcohol polyoxyethylene ether phosphate potassium salt; and the alkyl alcohol amide phosphate ester polymer comprises alkyl alcohol amide phosphate potassium salt.

[0044] In this embodiment, the potassium salt of fatty alcohol polyoxyethylene ether phosphate is obtained by sequentially subjecting fatty alcohol polyoxyethylene ether AEO-3 to esterification, hydrolysis and neutralization. The potassium salt of alkyl alcohol amide phosphate is prepared from alkyl alcohol amide phosphate.

[0045] In one embodiment, based on the total weight of the phosphate-type polymer, the content of the aryl phosphate polymer is 40-70% by weight, the content of the fatty alcohol polyoxyethylene ether phosphate polymer is 15-25% by weight, and the content of the combination of alkyl alcohol amide phosphate polymer is 15-25% by weight.

[0046] In a preferred embodiment, based on the total weight of the phosphate-type polymer, the content of the aryl phosphate polymer is 45-60% by weight, the content of the fatty alcohol polyoxyethylene ether phosphate polymer is 20-23% by weight, and the content of the combination of alkyl alcohol amide phosphate polymer is 20-22% by weight.

[0047] In this embodiment, adding a dispersant to the solid arsenic composition can make the solid arsenic composition evenly dispersed in the washing water, and improve the dispersion efficiency, thereby improving the efficiency of arsenic removal. Using a phosphate ester type polymer including a composition of an aromatic phosphate ester polymer, a fatty alcohol polyoxyethylene ether phosphate ester polymer and an alkyl alcohol amide phosphate ester polymer as a dispersant can further improve the dispersion efficiency, thereby further improving the efficiency of arsenic removal.

[0048] In the above embodiment, the mixture of surfactant and modified dolomite powder, auxiliary absorbent, catalyst and dispersant is fully compatible in water, and the aqueous solution of the mixture is a homogeneous system. When the mixture of surfactant and modified dolomite powder, auxiliary absorbent, catalyst and dispersant is fully dissolved in water during full mixing, it begins to separate into two layers, one layer mainly containing surfactant, and the other layer mainly containing the mixture of modified dolomite powder, auxiliary absorbent, catalyst and dispersant. Due to the repulsion of the same charge, the diffuse double layers of the surfactant and the combined mixture coil maintain a mutually repulsive zone, becoming a thermodynamically stable solution. When fully mixed, due to the compression of the double layer, the surfactants approach each other, the double layers overlap, the polymer coils tend to curl up, the repulsive zone between the surfactant and the combined mixture molecules decreases, and a dense two-dimensional separation trend begins to occur; and when the electrolyte concentration increases to a certain value, it separates into two obvious phases.

[0049] In a preferred embodiment, based on the total weight of the solid arsenic composition, the content of dolomite powder is 50-60% by weight, the content of surfactant is 4-7% by weight, the content of auxiliary absorbent is 20-28% by weight, the content of catalyst is 20-25% by weight, and the content of dispersant is 3-7% by weight.

[0050] In this embodiment, when the content of each component in the solid arsenic composition is at a very suitable content, it can exhibit a good synergistic effect, so that the arsenic in the product of the coal washing process is adsorbed after conversion, which can further reduce the arsenic content in the product of the coal washing process and improve the removal efficiency of the arsenic element.

[0051] In one embodiment, the weight ratio of the petroleum sulfide to the Fe-Mn composite oxide is (1.5-4.0):1.

[0052] In a preferred embodiment, the weight ratio of the petroleum sulfide to the Fe-Mn composite oxide is (2.0-3.0):1.

[0053] In this embodiment, by adding petroleum sulfide and the Fe-Mn composite oxide in a suitable weight ratio, not only can the sulfur element after the reaction be completely absorbed by the Fe-Mn composite oxide, but also the sulfur element in the washing water can be completely absorbed by the Fe-Mn composite oxide, thereby reducing the sulfur content in the coal washing process product and further reducing the pollution of sulfur to the environment.

[0054] In one embodiment, the weight ratio of the dolomite powder to the auxiliary absorbent is (1.5~3.5):1.

[0055] In a preferred embodiment, the weight ratio of the dolomite powder to the auxiliary absorbent may be in the range of any one of 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2 and 3.4 or any two thereof.

[0056] The second aspect of the present disclosure provides a method for using the solid arsenic composition described in the first aspect, the method comprising allowing the solid arsenic composition and coal to enter a coal washing device for coal washing treatment; the weight ratio of the solid arsenic composition to the coal is (0.2~0.3):1.

[0057] In this embodiment, the solid arsenic composition is added to the washing water, and the dispersant can promote the dispersion of each component to various locations, reduce the arsenic content in the product of the coal washing process, and improve the removal efficiency of arsenic.

[0058] In one embodiment, the coal described in the present disclosure is obtained from the Qipanjing coal production area in Wuhai, Inner Mongolia. In this embodiment, the content of arsenic in the coal is 20-100 ug / g.

[0059] The present disclosure is further illustrated by examples below, but the present disclosure is not limited thereto. Unless otherwise specified, the chemicals used in the following examples and comparative examples are all commercially available products with a purity of more than 99% by weight, wherein the chemicals include polydimethylsiloxane-b-polymethacrylic acid, polydimethylsiloxane-b-polymethyl methacrylate and alkanolamide polyoxyethylene ether. The petroleum sulfide described in the present disclosure is the oil obtained from the gasoline etherification device; the coal described in the present disclosure comes from the coal obtained from the Qipanjing production area in Wuhai, Inner Mongolia, and the content of arsenic in the coal is 65ug / g.

[0060] Preparation Example The method for preparing Fe-Mn composite oxide comprises: In KMnO 4 An appropriate amount of NaOH solution was added to the solution so that the pH value of the solution was 12 during the entire reaction process; Under stirring conditions, FeSO4 Add the above KMnO 4 The solution is then stirred for 60 minutes; and finally, the Fe-Mn composite oxide is obtained by draining and calcining.

[0061] Example 1 The method for preparing the solid arsenic composition S1 comprises: 50 g of dolomite powder, 5 g of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306), 15 g of petroleum sulfide with a sulfur content of 5.0 ppm and 5 g of a composition of Fe-Mn composite oxide, 20 g of slaked lime and 5 g of alkyl alcohol amide phosphate potassium salt were uniformly mixed to obtain a solid arsenic composition S1; Based on the total weight of the solid arsenic composition, the content of dolomite powder is 50 weight %, the content of surfactant is 5 weight %, the content of auxiliary absorbent is 20 weight %, the content of catalyst is 20 weight %, and the content of dispersant is 5 weight %.

[0062] Example 2 The method for preparing the solid arsenic composition S2 comprises: 60 g of dolomite powder, 5.5 g of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306), 10 g of petroleum sulfide with a sulfur content of 5.0 ppm and 4.5 g of a composition of Fe-Mn composite oxide, 15 g of slaked lime and 5 g of potassium salt of alkyl alcohol amide phosphate are uniformly mixed to obtain a solid arsenic composition S2; Based on the total weight of the solid arsenic composition, the content of dolomite powder is 60 weight %, the content of surfactant is 5.5 weight %, the content of auxiliary absorbent is 14.5 weight %, the content of catalyst is 15 weight %, and the content of dispersant is 5 weight %.

[0063] Example 3 The method for preparing the solid arsenic composition S3 comprises: 53 g of dolomite powder, 7 g of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306), 18 g of petroleum sulfide with a sulfur content of 5.0 ppm, 7 g of a composition of Fe-Mn composite oxide, 10 g of slaked lime and 5 g of alkyl alcohol amide phosphate potassium salt were uniformly mixed to obtain a solid arsenic composition S3; Based on the total weight of the solid arsenic composition, the content of dolomite powder is 53 weight %, the content of surfactant is 7 weight %, the content of auxiliary absorbent is 25 weight %, the content of catalyst is 10 weight %, and the content of dispersant is 5 weight %.

[0064] Example 4 The method for preparing the solid arsenic composition S4 comprises: 55 g of dolomite powder, 10 g of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306), 10 g of petroleum sulfide with a sulfur content of 5.0 ppm and 5 g of a composition of Fe-Mn composite oxide, 10 g of slaked lime and 10 g of alkyl alcohol amide phosphate potassium salt are uniformly mixed to obtain a solid arsenic composition S4; Based on the total weight of the solid arsenic composition, the content of dolomite powder is 55 weight %, the content of surfactant is 10 weight %, the content of auxiliary absorbent is 15 weight %, the content of catalyst is 10 weight %, and the content of dispersant is 10 weight %.

[0065] Example 5 The method for preparing the solid arsenic composition S5 comprises: 70 g of dolomite powder, 5 g of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306), 7 g of petroleum sulfide with a sulfur content of 5.0 ppm, 3 g of a composition of Fe-Mn composite oxide, 10 g of slaked lime and 5 g of alkyl alcohol amide phosphate potassium salt were uniformly mixed to obtain a solid arsenic composition S5; Based on the total weight of the solid arsenic composition, the content of dolomite powder is 70 weight %, the content of surfactant is 5 weight %, the content of auxiliary absorbent is 10 weight %, the content of catalyst is 10 weight %, and the content of dispersant is 5 weight %.

[0066] Example 6 The method for preparing the solid arsenic composition S6 is the same as that in Example 1, except that the weight ratio of the petroleum sulfide to the Fe-Mn composite oxide is 1:1.

[0067] Example 7 The method for preparing the solid arsenic composition S7 is the same as that in Example 1, except that the weight ratio of the dolomite powder to the auxiliary absorbent is 1.33:1.

[0068] Example 8 The method for preparing the solid arsenic composition S8 is the same as that in Example 1, except that the particle size of the dolomite powder is 100-110 mesh.

[0069] Example 9 The method for preparing the solid arsenic composition S9 is the same as that of Example 1, except that the sulfur content in the petroleum sulfide is 4.0 ppm.

[0070] Example 10 The method for preparing the solid arsenic composition S10 is the same as that in Example 1, except that the surfactant is composed of 55 wt % of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306) and 45 wt % of polydimethylsiloxane-b-polymethyl methacrylate (molecular weight 306).

[0071] Embodiment 11 The method for preparing the solid arsenic composition S11 is the same as that of Example 1, except that the dispersant is composed of 50 wt % of behenylamide dimethyl hydroxypropyl ammonium chloride, 25 wt % of fatty alcohol polyoxyethylene ether phosphate potassium salt, and 25 wt % of alkyl alcohol amide phosphate potassium salt.

[0072] Comparative Example 1 The method for preparing the solid arsenic composition D1 is the same as that of Example 1, except that the auxiliary absorbent is replaced by an equal weight of dolomite powder.

[0073] Comparative Example 2 The method for preparing the solid arsenic composition D2 is the same as that of Example 1, except that the auxiliary absorbent is composed only of petroleum sulfide with a sulfur content of 5.0 ppm.

[0074] Comparative Example 3 The method for preparing the solid arsenic composition D3 comprises: 75 g of dolomite powder, 5 g of polydimethylsiloxane-b-polymethacrylic acid (molecular weight 306), 3.75 g of petroleum sulfide (sulfur content 8.0 ppm), 1.25 g of a composition of Fe-Mn composite oxide, 8 g of slaked lime and 7 g of alkyl alcohol amide phosphate potassium salt were uniformly mixed to obtain a solid arsenic composition S1; Based on the total weight of the solid arsenic composition, the content of dolomite powder is 75 weight %, the content of surfactant is 5 weight %, the content of auxiliary absorbent is 5 weight %, the content of catalyst is 8 weight %, and the content of dispersant is 7 weight %.

[0075] Test Case Test Example 1 25 g / min of a solid arsenic composition and 100 g / min of coal are introduced into a coal washing device for coal washing treatment; wherein the solid arsenic composition is S1-S11 obtained in Examples 1-11, D1-D3 obtained in Comparative Examples 1-3, and an arsenic-fixing agent in the prior art; wherein the arsenic-fixing agent in the prior art is purchased from Dow Chemical Company, and its main components and ingredients include: 50-60 wt % of diatomaceous earth, 20-30 wt % of a dispersant, and 20-30 wt % of a surfactant.

[0076] GB / T 3058 “Determination of arsenic in coal” and / or GB / T 20475.3 “Grading of harmful elements in coal Part 3: Arsenic” were used to determine the arsenic content in coal before and after arsenic fixation. The specific data are shown in Table 1 below.

[0077] Test Example 2 The method of coal washing is the same as that of Test Example 1, except that 15 g / min of solid arsenic composition S1 and 100 g / min of coal are fed into the coal washing device for coal washing. Specific data are shown in Table 2 below.

[0078] Table 1 Test data in embodiments and comparative examples

[0079] Table 2 Test data in the test case

[0080] Among them, arsenic removal efficiency = [(arsenic content of original coal sample - arsenic content after arsenic fixation) / arsenic content of original coal sample] × 100%.

[0081] As shown in Table 1, according to the comparison of the data in Examples 1 to 11 and Comparative Examples 1 to 4, it can be seen that the dolomite powder, the auxiliary absorbent and the catalyst in the solid arsenic composition of the present invention have a good synergistic effect, so that the arsenic in the product of the coal washing process is adsorbed after conversion, which can reduce the arsenic content in the product of the coal washing process and improve the removal efficiency of the arsenic element. In addition, the use of dolomite powder with low price, low preparation cost and wide raw materials as the main adsorbent can not only reduce the environmental pollution problems in the traditional coal washing process, improve the environmental protection performance of the coal washing process, but also improve the economic effect of the solid arsenic composition. According to the comparison of the data in Example 1 and Example 6, when the weight ratio of the petroleum sulfide to the Fe-Mn composite oxide is (1.5~4.0):1, the removal efficiency of the arsenic element can be improved. According to the comparison of the data in Example 1 and Example 7, when the weight ratio of the dolomite powder to the auxiliary absorbent is (1.5~3.5):1, the removal efficiency of the arsenic element can be improved. According to the comparison of the data in Example 1 and Example 8, when the particle size of the dolomite powder is less than 100 mesh, the removal efficiency of arsenic can be improved. According to the comparison of the data in Example 1 and Example 9, when the sulfur content in the petroleum sulfide is 5.0~10.0ppm, the removal efficiency of arsenic can be improved. According to the comparison of the data in Example 1 and Example 10, when the composition and content of the surfactant are appropriate, the removal efficiency of arsenic can be improved. According to the comparison of the data in Example 1 and Example 11, when the composition and content of the dispersant are appropriate, the removal efficiency of arsenic can be improved. As shown in Table 2, according to the comparison of the data in Test Example 1 and Test Example 2, when the weight ratio of the solid arsenic composition to the coal is (0.2~0.3):1, the removal efficiency of arsenic can be improved.

[0082] The preferred embodiments of the present disclosure are described in detail above; 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.

[0083] 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.

[0084] 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 solid arsenic composition for use in a coal washing process, characterized in that: The solid arsenic composition comprises dolomite powder, a surfactant, an auxiliary absorbent, a catalyst and a dispersant; The auxiliary absorbent includes a composition of petroleum sulfide and Fe-Mn composite oxide; Based on the total weight of the solid arsenic composition, the content of the dolomite powder is 40-70% by weight, the content of the surfactant is 1-10% by weight, the content of the auxiliary absorbent is 10-30% by weight, the content of the catalyst is 10-30% by weight, and the content of the dispersant is 1-10% by weight.

2. The solid arsenic composition according to claim 1, characterized in that Based on the total weight of the solid arsenic composition, the content of the dolomite powder is 50-60% by weight, the content of the surfactant is 4-7% by weight, the content of the auxiliary absorbent is 20-28% by weight, the content of the catalyst is 20-25% by weight, and the content of the dispersant is 3-7% by weight.

3. The solid arsenic composition according to claim 1, characterized in that: The particle size of the dolomite powder is less than 100 mesh; The sulfur content in the petroleum sulfide is 5.0-10.0 ppm; The iron oxide in the Fe-Mn composite oxide includes one or more of Fe2O3, FeO and Fe3O4, and the manganese oxide includes MnO.

4. The solid arsenic composition according to claim 1, characterized in that The surfactant includes a copolymer of polysiloxane and acrylic acid and / or a copolymer of polysiloxane and acrylate; The molecular weight of the copolymer in the surfactant is 300-400.

5. The solid arsenic composition according to claim 4, characterized in that: The surfactant includes polydimethylsiloxane-b-polymethacrylic acid and polydimethylsiloxane-b-polymethyl methacrylate; Based on the total weight of the surfactant, the content of the polydimethylsiloxane-b-polymethacrylic acid is 50-60% by weight, and the content of the polydimethylsiloxane-b-polymethyl methacrylate is 40-50% by weight.

6. The solid arsenic composition according to claim 1, characterized in that: The weight ratio of the petroleum sulfide to the Fe-Mn composite oxide is (1.5-4.0):

1.

7. The solid arsenic composition according to claim 1, characterized in that: The catalyst includes slaked lime.

8. The solid arsenic composition according to claim 7, characterized in that: The dispersant is selected from a phosphate ester salt type polymer; The phosphate ester salt type polymer includes a composition of an aromatic phosphate ester salt polymer, a fatty alcohol polyoxyethylene ether phosphate ester salt polymer and an alkyl alcohol amide phosphate ester salt polymer; Based on the total weight of the phosphate-type polymer, the content of the aryl phosphate polymer is 40-70% by weight, the content of the fatty alcohol polyoxyethylene ether phosphate polymer is 15-25% by weight, and the content of the combination of alkyl alcohol amide phosphate polymer is 15-25% by weight.

9. The solid arsenic composition according to claim 8, characterized in that: The weight ratio of the dolomite powder to the auxiliary absorbent is (1.5-3.5):

1.

10. A method for using the solid arsenic composition according to any one of claims 1 to 9, characterized in that: The use method comprises the steps of allowing the solid arsenic composition and coal to enter a coal washing device for coal washing treatment; the weight ratio of the solid arsenic composition to the coal is (0.2-0.3):1.

Images