CN108975367B - Method for efficiently utilizing high-aluminum coal gangue - Google Patents
Method for efficiently utilizing high-aluminum coal gangue Download PDFInfo
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Abstract
The invention discloses a method for efficiently utilizing high-alumina coal gangue, belonging to the technical field of resource utilization of industrial solid wastes; adding acid into coal gangue or cinder, solidifying, acidifying, dissolving out, filtering and washing to obtain sulfate solution mainly containing aluminum sulfate and cinder containing rich silicon and impurity, wherein the sulfate solution is used for preparing aluminum hydroxide or aluminum oxide and polymeric aluminum ferric sulfate products, and the cinder is calcined to produce white carbon black; the method has reasonable resource utilization, no new solid waste discharge and large product market constant, and can provide a feasible method for resource utilization of the high-aluminum coal gangue.
Description
Technical Field
The invention discloses a method for efficiently utilizing high-aluminum coal gangue, belonging to the technical field of resource utilization and comprehensive resource utilization of industrial solid wastes.
Background
Currently, coal gangue is a black rock associated with a coal seam in a coal-forming process, and is a waste generated in a coal selection and mining process. The annual output of coal gangue in China reaches 15% -20% of the total coal mining amount and 40% of the total industrial waste generation amount in China, but the total utilization rate is not high, and the utilization rate of the coal gangue reaches 70% as far as 2015, which is far away from the target that the resource utilization rate of the coal gangue reaches 80%, and the pressure is very great. The accumulation of a large amount of coal gangue not only occupies a large amount of land, but also pollutes the surrounding ecological environment and causes resource waste. In order to solve the problems, the innovation and the popularization of the traditional technology are enhanced, other process technologies which are reasonable in resource utilization and environment-friendly are required to be explored, and the resource utilization of the coal gangue is enhanced in multiple channels and ways.
Extracting valuable elements from coal gangue to produce related chemical products is a hot spot for efficiently utilizing the coal gangue at present; china's coal gangue mostly contains clay and most of the coal gangue contains aluminum elements, so that extraction of alumina from the aluminous rock coal gangue is a research hotspot in recent years. At present, the method for extracting the alumina from the coal gangue mainly comprises an acid method, an alkaline method and a sintering method, wherein the alkaline method has the defects of large alkali consumption, low aluminum recovery rate, large residue amount, secondary pollution and unreasonable resource utilization, and the sintering method has high energy consumption and is a technical process which is not suitable for national regulations, so the suitable method for comprehensively recovering valuable elements from the coal gangue is the acid method.
CN201310315648.3 discloses a method for efficiently extracting iron, aluminum and titanium from coal gangue, which comprises the steps of drying and crushing the coal gangue, performing acid leaching by a neutralization dry method, drying acid sludge obtained by filtering acid leaching liquid, adding acid for mixing, performing acid leaching, dissolving, filtering, washing, drying, repeating the steps, and improving the dissolution rate of iron, aluminum and titanium in the coal gangue; the method has the advantages that most of carbonate in the raw materials is removed by using the acid solution, the materials are purified, and the utilization rate of the acid is improved; the leaching rate after acid leaching is high, which is beneficial to the subsequent utilization of acid sludge.
CN201610545655.6 provides a method for improving the leaching rate of aluminum in coal gangue, NaOH strong alkali liquor is used for efficiently decomposing the coal gangue at normal pressure and low temperature, and the leaching rate of aluminum element is improved; the invention has the advantages that: the method does not need high-temperature dehydration roasting, and has low reaction temperature and short reaction time; compared with the traditional process, the method has the advantages of mild operation conditions, greatly reduced reaction temperature and reaction pressure, simple operation, greenness, high efficiency, low energy consumption, small environmental pollution and high dissolution rate of the aluminum element up to more than 60%.
CN200510048215.1 relates to a method for producing alumina by using coal gangue as raw material, which comprises the steps of roasting the crushed coal gangue at high temperature, leaching the coal gangue with sodium hydroxide solution, filtering the residue, introducing CO into the filtrate2Gas of Al (OH)3Precipitating, vacuum filtering, and dehydrating at high temperature to obtain Al2O3And (5) producing the product. The invention has the advantages that the production process adopts a roasting salt-leaching combined method, the reaction condition is mild, the production process is easy to control, the waste water generated by the process can be recycled, the waste residue generated after extraction can be used as the filler of rubber products, the environment is protected, and the extraction rate of the aluminum oxide is high.
CN201010266645.1 relates to a coal gangue fuelThe method for extracting alumina, silicon oxide and ferric oxide from burned ash residue comprises pretreating coal gangue, blending coal according to calorific value, activating the coal gangue while calcining to generate electricity, and supplying generated electricity and steam to a system; extracting aluminum oxide from ash by an acid method, extracting silicon oxide by an alkaline method, and extracting ferric oxide by comprehensive utilization of byproducts; acid, alkali, lime, extracting agent and CO required by each process link2Circulating in the system. The energy and chemical composition in the coal gangue are fully utilized, the discharge amount of greenhouse gases and waste residues is greatly reduced, the economic benefit of a system is improved, the coal gangue is a novel coal gangue green and high-added-value utilization technology, and the competitive advantage is obvious.
CN201310315648.3 discloses a method for efficiently extracting aluminum, iron and titanium from coal gangue, which belongs to the technical field of resource utilization of coal-series solid wastes, wherein the coal gangue is dried and ground and then is used for neutralizing solution of dry-method acid leaching clinker, and the acid concentration or pH value at the neutralization end point is determined according to the content of titanium oxide in acid leaching solution; the neutralization filtrate after neutralization reaction and filtration is used for separating aluminum and iron or aluminum, iron and titanium, the neutralization filter residue is not washed, acid is directly added and mixed after drying, acid leaching reaction is carried out in a box-type resistance furnace, after the reaction is finished, dissolution, filtration and washing are carried out, the filtrate is neutralized by fresh coal gangue, and the operation is circularly repeated.
Cheng Xiang Qin and the like research influence factors of extracting the alumina from the coal gangue, and the result shows that the acid leaching time has the greatest influence on the dissolution of the alumina. The optimal dissolution conditions are acid leaching time of 3h, calcination temperature of 650 ℃, hydrochloric acid amount of 225mL (according to the molar ratio of the reaction of the alumina and the hydrochloric acid in the coal gangue of 1: 6), solid-liquid ratio of 1: 3.
in conclusion, researchers do a lot of work on the aspect of efficient dissolution of coal gangue, particularly on the aspect of efficient extraction of aluminum elements in the coal gangue and the aspect of preparation of related chemical products; however, no report is found on the method for producing polymeric aluminum ferric sulfate, aluminum hydroxide (or further calcining to produce alumina) and white carbon black by using coal gangue through reasonable process optimization and product design.
Disclosure of Invention
The invention aims to provide a method for efficiently utilizing high-alumina coal gangue, which takes the high-alumina coal gangue as a raw material, directly uses the high-alumina coal gangue according to self heat productivity or uses the high-alumina coal gangue as a valuable element raw material after recovering heat through a circulating fluidized bed, adds industrial sulfuric acid with the mass concentration of 98 percent to be firstly solidified, then supplements residual acid according to chemical composition, extracts acid soluble substances such as aluminum, iron and the like through acidification reaction and dissolution process, and directly roasts acid slag to produce white carbon black; preparing polymeric aluminum ferric sulfate and aluminum hydroxide (or aluminum oxide) products by acid-soluble substances, recovering sulfuric acid from tail gas generated by calcining the acid-soluble substances for recycling, producing aluminum hydroxide or aluminum oxide by using a Bayer process for calcined substances, and using alkaline residues for a polymeric aluminum sulfate pH value regulator; the method provides a new idea and a new technology for the efficient utilization of the high-aluminum coal gangue, the recovery rate of each element in the coal gangue is high, no new solid waste is generated in the process, and the method is bound to become one of the most effective ways for the resource utilization of the high-aluminum coal gangue in the future.
The high-aluminum coal gangue is calculated by the mass of ash, and the mass ratio of each component is Al2O3＞30%，Fe2O3＜15%，CaO＜2%，MgO＜2%。
The method of the invention achieves the purpose of efficiently utilizing the high-alumina coal gangue, and comprises the following specific steps:
(1) taking the coal gangue meeting the requirements, and recovering heat by using a circulating fluidized bed to obtain cinder when the low-level calorific value of the coal gangue is more than or equal to 800 cal/kg; if the lower calorific value is less than 800cal/kg, the heat-resistant material is directly used, the grinding granularity is determined according to whether the heat is recovered, when the heat is recovered, the grinding granularity is less than 10 percent of the sieve residue of 80 meshes, and when the heat is not recovered, the sieve residue of 120 meshes is less than 5 percent;
(2) adding industrial sulfuric acid into high-alumina coal gangue or burnt slag thereof according to the mass ratio of the industrial sulfuric acid with the mass concentration of 98% to the raw material of 1.1-1.2, reacting at normal temperature-50 ℃, transferring into a vertical acidification kiln after the industrial sulfuric acid is solidified, supplementing 98% of the industrial sulfuric acid according to the mass ratio of the industrial sulfuric acid to the raw material of 0.1-0.2, and carrying out acidification reaction for 2-3 h, wherein the inlet heat source temperature of the acidification kiln is 180-190 ℃;
(3) and after the acidification is finished, transferring the acidification material into a reaction tank with stirring, wherein the mass ratio of the acidification material to the dissolving solution is 1: adding a dissolving solution in a ratio of 2-3, stirring and dissolving for 1-1.5 h at 60-80 ℃, filtering to obtain a sulfate solution, and washing filter residues until the pH of a washing solution is greater than 3 to obtain acid residues;
(4) spray drying and calcining part of the sulfate solution in the step (3) to obtain an alumina primary product, recovering sulfuric acid from tail gas for system recycling, producing aluminum hydroxide from the alumina primary product by using a Bayer process, or further calcining the aluminum hydroxide to produce aluminum oxide, concentrating the recovered alkali for system recycling, and using the alkaline residue as a pH regulator for producing polymeric aluminum ferric sulfate and simultaneously supplementing an iron source; oxidizing the residual sulfate solution, adjusting the pH value and producing polymeric aluminum ferric sulfate;
(5) and calcining the acid sludge at 900-1000 ℃ to obtain the white carbon black product meeting the E-type requirement of HG/T3068-2008 standard.
And (3) the dissolving solution in the step (3) is clear water or the first washing liquid for washing the filter residue in the step (1).
The calcining temperature of the sulfate after spray drying in the step (4) is 900-1000 ℃, and the calcining time is 2-3 h; the polymerization reaction temperature of the aluminum ferric sulfate is 60-80 ℃, the polymerization time is 4-6 h, and the preparation method is a conventional preparation process.
The principle of the invention is as follows:
in order to dissolve acid in the coal gangue as much as possible and realize silicon-rich impurity removal of acid slag, the mass ratio of the coal gangue or cinder to sulfuric acid is generally required to be 1.2-1.4, but the sulfuric acid is added once, so that the subsequent acidification reaction materials are difficult to transfer, and the air permeability of an acidification kiln is poor, therefore, the invention adopts the method that at the normal temperature-50 ℃, the mixture is reacted with the sulfuric acid to generate sulfate through easily-reactive substances such as carbonate and part of kaolin or amorphous alumina with high reaction activity in the coal gangue, and then the characteristic that the sulfate carries crystal water at the curing temperature is utilized to realize the mixture from a slurry state to a solid state within 24h, so that the material has fluidity and air permeability in the acidification kiln; in order to improve the dissolution rate of acid soluble matters in the coal gangue, only acid for solidification cannot meet the requirement, therefore, the invention adopts an acid spraying mode in the process of transferring the solidified matters to supplement the residual sulfuric acid so as to ensure that the using amount of the acid meets the process requirement. The acidification reaction is an exothermic reaction, the reaction can be maintained only by properly supplementing a certain heat source, the temperature of the heat source at the inlet is properly increased in order to control the amount of free acid in the final dissolved acidification substance, the free acid is condensed on the surface of a cold-state condensate after being evaporated and vaporized, and then participates in the reaction, so that the utilization rate of the acid is increased. The acidification realizes the conversion of acid solution in the coal gangue to sulfate, and silicic acid obtained by the reaction of silicon oxide is finally dehydrated to form amorphous oxidation, so that the silicic acid can be separated from the sulfate in the subsequent dissolution process, and conditions are created for producing white carbon black by roasting acid sludge. Part of acid-soluble substances are spray-dried to obtain a mixture mainly containing anhydrous aluminum sulfate, an amorphous product mainly containing aluminum oxide can be obtained after calcination, the amorphous product is converted into sodium metaaluminate after alkali dissolution, namely, the aluminum hydroxide can be prepared by using a traditional process seed precipitation method, the aluminum hydroxide can be calcined to produce aluminum oxide, insoluble substances in the alkali dissolution process are mainly oxides or alkali of iron, calcium, magnesium and the like, the insoluble substances are used for a pH value regulator of an acid-soluble substance solution to prepare polymeric aluminum ferric sulfate, and through reasonable arrangement of the yields of the polymeric aluminum ferric sulfate and the aluminum hydroxide or the aluminum oxide product, on one hand, new solid wastes generated in the resource utilization process of coal gangue can be eliminated, and on the other hand, the iron content in the polymeric aluminum ferric sulfate can also be improved; the content of amorphous silica (without ash content) in the acid sludge is more than 96 percent, and the residual carbon and the ignition loss are removed by roasting, thus obtaining the white carbon black product.
Compared with the prior art, the invention has the following advantages:
(1) the problems of material transfer and acidification reaction operation under high acid-gangue ratio are solved by a coal gangue curing mode;
(2) the valuable element extraction product in the coal gangue is reasonable in arrangement, the added value is high, and no new solid waste is generated in the process;
(3) the acid amount required by the reaction of acid soluble matters in the coal gangue is ensured by a secondary acid supplement mode, and the free acid amount of acid compounds is reduced by controlling the temperature of an inlet heat source;
(4) the alkaline residue is used as the pH value regulator prepared from the polymeric aluminum ferric sulfate, so that the components in the alkaline residue are fully utilized, and the problem of environmental pollution caused by the alkaline residue is solved;
(5) the extraction process of the valuable elements of the coal gangue is simple, and the technology is mature.
Drawings
FIG. 1 is a schematic process flow diagram of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the following examples, but the scope of the present invention is not limited to the above-mentioned descriptions.
Example 1
(1) As shown in figure 1, the analysis results of the coal gangue raw material and ash are shown in table 1.1, and the coal gangue has higher calorific value, and the utilization of slag is carried out after the heat is recovered;
TABLE 1.1 analysis of coal gangue raw materials and ash content
(2) Drying and crushing the coal gangue, grinding the coal gangue until the balance of the coal gangue is 9.98 percent after passing through a 80-mesh sieve, and recovering heat by adopting a circulating fluidized bed to obtain cinder;
(3) adding 98% industrial sulfuric acid into the coal gangue burned slag obtained in the step (2) according to the mass ratio of acid gangue to 1:1.2, and curing at 50 ℃;
(4) taking out the coal gangue cured material obtained in the step (3) according to the mass ratio of the industrial sulfuric acid to the cinder of 0.2, adding 98% of industrial sulfuric acid in a spraying mode, transferring the coal gangue cured material into a vertical acidification kiln for acidification reaction, wherein the heating temperature of the inlet of the vertical acidification kiln is 180 ℃, and the retention time is 2.5 hours;
(5) and after the acidification is finished, transferring the acidified materials into a reaction tank with stirring, wherein the mass ratio of the acidified materials to the dissolved solution is 1: 2, adding clear water according to the proportion, stirring for 1.5 hours at 60 ℃, filtering dissolved substances to obtain a sulfate solution, washing filter residues to pH >3 by using the clear water, using a first washing solution as a dissolving solution of an acidification substance in the next process, using a second washing solution as a first washing solution of the filter residues in the next process, using a third washing solution as a second washing solution of the filter residues in the next process, and so on, and finally washing the filter residues to obtain the clear water; table 1.2 shows the acid sludge chemical composition;
TABLE 1.2 compositional analysis (wt%) of the acid sludge
(6) Directly spray-drying and calcining part of the sulfate solution in the step (5) (at 900 ℃ for 3 h) to obtain an alumina primary product, dissolving the alumina primary product in alkali to obtain sodium metaaluminate, preparing aluminum hydroxide by a seed precipitation method, or further calcining the aluminum hydroxide to produce aluminum oxide, wherein the alkali residue is used as a pH regulator for producing polymeric aluminum ferric sulfate; oxidizing the residual sulfate solution by using hydrogen peroxide, adjusting the pH value to 3 by using alkali slag, and reacting at 60 ℃ for 6 hours to prepare polymeric aluminum ferric sulfate by a conventional method;
(7) calcining the acid sludge obtained in the step (5) at 900 ℃ to obtain a white carbon black product, and analyzing to obtain SiO297.48wt%, oil absorption number of 2.5, specific surface area of 83m2/g。
Example 2
(1) The analysis results of the coal gangue raw materials and ash are shown in the table 2.1, and the table shows that the low-level calorific value of the coal gangue is 820cla/kg, the heat recovery requirement is met, and the slag is utilized after the heat is recovered;
TABLE 2.1 analysis of coal gangue raw materials and ash content
(2) Drying and crushing the coal gangue, grinding the coal gangue until the balance of the coal gangue is 6.23 percent after passing through a 80-mesh sieve, and recovering heat by adopting a circulating fluidized bed to obtain cinder;
(3) adding 98% industrial sulfuric acid into the coal gangue burned slag obtained in the step (2) according to the mass ratio of acid gangue of 1:1.1, and curing at normal temperature;
(4) taking out the coal gangue cured material obtained in the step (3) according to the mass ratio of the industrial sulfuric acid to the cinder of 0.1, adding 98% of industrial sulfuric acid in a spraying mode, transferring the coal gangue cured material into a vertical acidification kiln for acidification reaction, wherein the heating temperature of an inlet of the vertical acidification kiln is 190 ℃, and the retention time is 3 hours;
(5) and after the acidification is finished, transferring the acidified materials into a reaction tank with stirring, wherein the mass ratio of the acidified materials to the dissolved solution is 1: 2.5, adding the first washing liquid in the example 1, stirring at 80 ℃ for 1h, filtering dissolved matters to obtain a sulfate solution, circularly washing filter residues (sequentially using the second washing liquid in the step (5) in the example 1 as a first washing liquid, using the third washing liquid as a second washing liquid and clear water) until the pH value is more than 3, wherein the first washing liquid is used as a dissolving liquid of an acidification substance in the next process, the second washing liquid is used as a first washing liquid of filter residues in the next process, and the clear water washing liquid is used as a second washing liquid of the filter residues in the next process; table 2.2 shows the acid sludge chemical composition;
TABLE 2.2 compositional analysis (wt%) of the acid sludge
(6) Directly spray-drying and calcining part of the sulfate solution in the step (5) for 2 hours at 1000 ℃ to obtain an alumina primary product, dissolving the alumina primary product in alkali to obtain sodium metaaluminate, preparing aluminum hydroxide by a seed precipitation method, or further calcining the aluminum hydroxide to produce aluminum oxide, wherein the alkali residue is used as a pH regulator for producing polymeric aluminum ferric sulfate; oxidizing the residual sulfate solution with hydrogen peroxide, adjusting the pH value to 4 by using alkali slag, and reacting at 70 ℃ for 5 hours to prepare polymeric aluminum ferric sulfate by a conventional method;
(7) calcining the acid sludge obtained in the step (5) at 1000 ℃ to obtain a white carbon black product, and analyzing to obtain SiO296.09wt%, an oil absorption value of 2.3 and a specific surface area of 81m2/g。
Example 3
(1) The analysis results of the coal gangue raw material and ash are shown in the table 3.1, and the table shows that the low-level calorific value of the coal gangue is 452cla/kg, the coal gangue does not have the requirement of heat recovery, and the coal gangue is directly used after being dried, crushed and ground;
TABLE 3.1 analysis of coal gangue raw materials and ash content
(2) Grinding the coal gangue obtained in the step (1) until the coal gangue is sieved by a 100-mesh sieve, and the balance being 4.56%;
(3) adding 98% industrial sulfuric acid into the coal gangue burned slag obtained in the step (2) according to the mass ratio of acid gangue to 1:1.2, and curing at 35 ℃;
(4) taking out the coal gangue cured material obtained in the step (3) according to the mass ratio of the industrial sulfuric acid to the cinder of 0.15, adding 98% of industrial sulfuric acid in a spraying mode, transferring the coal gangue cured material into a vertical acidification kiln for acidification reaction, wherein the heating temperature of an inlet of the vertical acidification kiln is 185 ℃, and the retention time is 2.5 hours;
(5) and after the acidification is finished, transferring the acidified materials into a reaction tank with stirring, wherein the mass ratio of the acidified materials to the dissolved solution is 1: 3, adding the first washing liquid in the embodiment 2 in proportion, stirring for 1.2 hours at 70 ℃, filtering dissolved matters to obtain a sulfate solution, circularly washing filter residues (sequentially using the second washing liquid as a first washing liquid and the third washing liquid as a second washing liquid and clear water in the step (5) in the embodiment 2) until the pH value is more than 3, wherein the first washing liquid is used as a dissolving liquid of an acidification substance in the next process, the second washing liquid is used as a first washing liquid of the filter residues in the next process, and the clear water washing liquid is used as a second washing liquid of the filter residues in the next process; table 3.2 shows the acid sludge chemical composition;
TABLE 3.2 compositional analysis (wt%) of the acid sludge
(6) Directly spray-drying and calcining part of the sulfate solution in the step (5) (at 950 ℃ for 2 h) to obtain an alumina primary product, carrying out alkali dissolution on the alumina primary product to obtain sodium metaaluminate, preparing aluminum hydroxide by a seed precipitation method, or further calcining the aluminum hydroxide to produce aluminum oxide, wherein the caustic sludge is used as a pH regulator for producing polymeric aluminum ferric sulfate; oxidizing the residual sulfate solution by using hydrogen peroxide, adjusting the pH value to 3 by using alkali slag, and reacting at 80 ℃ for 4 hours to prepare polymeric aluminum ferric sulfate by a conventional method;
(7) calcining the acid sludge obtained in the step (5) at 1000 ℃ to obtain a white carbon black product, and analyzing to obtain SiO297.02wt%, oil absorption number of 2.0, specific surface area of 75m2/g。
Example 4
(1) The analysis results of the coal gangue raw material and ash are shown in the table 4.1, and the table shows that the low-level calorific value of the coal gangue is 639cla/kg, the coal gangue does not have the requirement of heat recovery, and the coal gangue is directly used after being dried, crushed and ground;
TABLE 4.1 analysis of coal gangue raw materials and ash content
(2) Grinding the coal gangue obtained in the step (1) until the coal gangue is sieved by a 100-mesh sieve, and the balance being 5.27%;
(3) adding 98% industrial sulfuric acid into the coal gangue burned slag obtained in the step (2) according to the mass ratio of acid gangue to 1:1.1, and curing at 40 ℃;
(4) taking out the coal gangue cured material obtained in the step (3) according to the mass ratio of the industrial sulfuric acid to the cinder of 0.2, adding 98% of industrial sulfuric acid in a spraying mode, transferring the coal gangue cured material into a vertical acidification kiln for acidification reaction, wherein the heating temperature of the inlet of the vertical acidification kiln is 180 ℃, and the retention time is 3 hours;
(5) and after the acidification is finished, transferring the acidified materials into a reaction tank with stirring, wherein the mass ratio of the acidified materials to the dissolved solution is 1: 2.5, adding the first washing liquid in the embodiment 3, stirring at 75 ℃ for 1h, filtering the dissolved substance to obtain a sulfate solution, circularly washing the filter residue (sequentially using the second washing liquid in the step (5) in the embodiment 3 as a first washing liquid, using the third washing liquid as a second washing liquid and clear water) until the pH value is more than 3, wherein the first washing liquid is used as a dissolving liquid of an acidification substance in the next process, the second washing liquid is used as a first washing liquid of the filter residue in the next process, and the clear washing liquid is used as a second washing liquid of the filter residue in the next process; table 4.2 is the acid sludge chemistry;
TABLE 4.2 compositional analysis (wt%) of the acid sludge
(6) Directly spray-drying and calcining part of the sulfate solution in the step (5) for 2 hours at 1000 ℃ to obtain an alumina primary product, dissolving the alumina primary product in alkali to obtain sodium metaaluminate, preparing aluminum hydroxide by a seed precipitation method, or further calcining the aluminum hydroxide to produce aluminum oxide, wherein the alkali residue is used as a pH regulator for producing polymeric aluminum ferric sulfate; oxidizing the residual sulfate solution by using hydrogen peroxide, adjusting the pH value to 4 by using alkali slag, and reacting at 65 ℃ for 5 hours to prepare polymeric aluminum ferric sulfate by a conventional method;
(7) calcining the acid sludge obtained in the step (5) at 900 ℃ to obtain a white carbon black product, and analyzing to obtain SiO297.42wt%, oil absorption value of 2.4, specific surface area of 81m2/g。
Claims (6)
1. A method for efficiently utilizing high-aluminum coal gangue is characterized by comprising the following steps: adding industrial concentrated sulfuric acid with the mass concentration of 98% into high-alumina coal gangue or cinder thereof, solidifying, acidifying, dissolving out, filtering and washing to obtain sulfate solution and acid sludge; part of sulfate solution is subjected to spray drying and calcination to prepare aluminum hydroxide by a Bayer process, or the aluminum hydroxide is further calcined to prepare aluminum oxide, and the rest of sulfate solution is used for producing polymeric aluminum ferric sulfate; calcining the acid sludge to produce white carbon black;
the method comprises the following specific steps:
(1) adding industrial sulfuric acid into high-alumina coal gangue or burnt slag thereof according to the mass ratio of the industrial sulfuric acid with the mass concentration of 98% to the raw material of 1.1-1.2, reacting at normal temperature-50 ℃, transferring into a vertical acidification kiln after the industrial sulfuric acid is solidified, supplementing 98% of the industrial sulfuric acid according to the mass ratio of the industrial sulfuric acid to the raw material of 0.1-0.2, and carrying out acidification reaction for 2-3 h, wherein the inlet heat source temperature of the acidification kiln is 180-190 ℃; and after the acidification is finished, transferring the acidification material into a reaction tank with stirring, wherein the mass ratio of the acidification material to the dissolving solution is 1: adding a dissolving solution in a ratio of 2-3, stirring and dissolving for 1-1.5 h at 60-80 ℃, filtering to obtain a sulfate solution, and washing filter residues until the pH of a washing solution is greater than 3 to obtain acid residues;
(2) part of sulfate solution is spray-dried and calcined to obtain alumina primary product, tail gas is recovered to prepare sulfuric acid for recycling, and the alumina primary product is used for producing aluminum hydroxide by Bayer process or the aluminum hydroxide is further calcined to produce aluminum oxide; oxidizing the residual sulfate solution, and adjusting the pH value to 3-4 to produce polymeric aluminum ferric sulfate;
(3) calcining the acid sludge to produce white carbon black;
when the low-grade calorific value of the high-alumina coal gangue is less than 800cal/kg, the high-alumina coal gangue is directly used without recovering heat; when the low-grade heating value of the high-alumina coal gangue is more than or equal to 800cal/kg, the circulating fluidized bed is adopted to recover heat to obtain cinder.
2. The method for efficiently utilizing high-alumina coal gangue as claimed in claim 1, wherein the method comprises the following steps: when the heat is not recovered from the high-aluminum coal gangue, the grinding granularity is less than 5 percent of the sieve residue of 120 meshes, and when the heat is recovered, the grinding granularity is less than 10 percent of the sieve residue of 80 meshes.
3. The method for efficiently utilizing high-alumina coal gangue as claimed in claim 1, wherein the method comprises the following steps: the dissolving solution in the step (1) is clear water or a first washing solution for washing filter residue in the step (1).
4. The method for efficiently utilizing high-alumina coal gangue as claimed in claim 1, wherein the method comprises the following steps: calcining the sulfate after spray drying in the step (2) at the temperature of 900-1000 ℃ for 2-3 h; the polymerization temperature of the aluminum ferric sulfate is 60-80 ℃, and the polymerization time is 4-6 h.
5. The method for efficiently utilizing high-alumina coal gangue as claimed in claim 1, wherein the method comprises the following steps: the alkaline residue in the Bayer process for producing aluminum hydroxide is used as a pH regulator for producing polymeric aluminum ferric sulfate and is used for supplementing an iron source.
6. The method for efficiently utilizing high-alumina coal gangue as claimed in claim 1, wherein the method comprises the following steps: calcining the acid sludge at 900-1000 ℃ to obtain the white carbon black product.
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| CN109835930A (en) * | 2019-02-19 | 2019-06-04 | 昆明理工大学 | A kind of production method of aluminium oxide |
| CN109824074A (en) * | 2019-02-19 | 2019-05-31 | 昆明理工大学 | A kind of production method of aluminium oxide |
| CN112607742A (en) * | 2020-12-24 | 2021-04-06 | 神华准能资源综合开发有限公司 | Method for preparing white carbon black by using high-silicon tailings |
| CN112915990B (en) * | 2021-01-26 | 2022-02-15 | 中国矿业大学(北京) | Coal gangue in-situ carbon activation material and preparation method and application thereof |
| CN113336253A (en) * | 2021-05-24 | 2021-09-03 | 昆明理工大学 | Method for extracting aluminum oxide from high-aluminum coal gangue by using high-concentration SO2 |
| CN113413741B (en) * | 2021-05-28 | 2023-06-30 | 昆明理工大学 | Gangue and method for desulfurizing tail gas by using activated slag of gangue |
| CN115340424A (en) * | 2022-08-15 | 2022-11-15 | 昌晖自动化科技(济南)有限公司 | Coal gangue magnetized soil conditioner and preparation method thereof |
| CN116253343A (en) * | 2023-05-12 | 2023-06-13 | 中科镁基（北京）科技有限公司 | Utilization method of black talcum |
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