A method for resourceful disposal of high-crystalline-water-content aluminum ammonium alum residue

Abstract

The application discloses a high-crystalline-water-content aluminum ammonium alum slag resourceful treatment method, which comprises the following steps: putting aluminum ammonium alum slag and silicon dioxide powder into a microwave reactor, wherein the aluminum ammonium alum slag is produced in a beryllium oxide smelting process, the main component of the aluminum ammonium alum slag is NH4Al(SO4)2·12H2O, and the water content of the aluminum ammonium alum slag is 40%-50%, and then performing microwave heating to obtain dried aluminum ammonium alum slag; and then performing high-temperature calcination to obtain a calcined sample which can be applied to the preparation of refractory materials. The method can realize efficient dehydration of the aluminum ammonium alum slag, effectively solve the problem of material puffing in the heating process and affect the treatment efficiency, greatly reduce the Be content of the leaching toxicity of the calcined product, has the advantages of good drying effect, short treatment process, full-component resource utilization, and meets the requirements of safe, efficient and green treatment of the aluminum ammonium alum slag.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solid waste treatment, and particularly relates to a resourceful disposal method of aluminum ammonium alum slag with high content of crystal water. BACKGROUND

[0002] The production raw material of industrial beryllium oxide is green beryl, and the chemical composition is 3BeO.Al2O3.6SiO2, and the beryllium content is 2.5-3.6%. Because the beryllium content is low, a large amount of beryllium-containing waste slag is generated in the production process. According to the different production slag links, there are mainly four types of beryllium-containing environmental protection slag, silicon slag, iron slag and aluminum ammonium alum slag. Among them, the aluminum ammonium alum slag is an aluminum-containing waste slag crystal generated in the aluminum removal process by ammonium sulfate evaporation crystallization, and the main component is dodecahydrate aluminum ammonium sulfate [NH4Al(SO4)2.12H2O]. The content of crystal water is high, and the beryllium content is 0.036-0.072%. Because beryllium is a toxic element, the aluminum ammonium alum slag is currently stored and managed strictly in accordance with the hazardous waste list HW20, and the safe disposal of beryllium-containing waste slag is an important means to ensure the green and sustainable development of the beryllium industry.

[0003] The aluminum ammonium alum slag mainly includes aluminum, sulfur, ammonia nitrogen and other components, and can be used for preparing refractory materials after pretreatment. However, the detoxification effect of the aluminum ammonium alum slag directly high-temperature roasting is poor, and the slag sample is easy to expand, which greatly reduces the treatment efficiency, and therefore needs to be dried first. Because the content of crystal water in the aluminum ammonium alum slag is high, the regular drying often presents the phenomenon of "dry outside and wet inside". Because a large amount of crystal water is dissociated in the drying process, the surface of the solid aluminum ammonium alum slag is liquefied, and the sample is easy to stick together into a block, so the drying effect is poor. SUMMARY

[0004] In order to overcome the problems in the prior art, the application provides a resourceful disposal method of aluminum ammonium alum slag with high content of crystal water, which adopts the process of additive mixing-microwave drying-conventional roasting combined treatment, so that the dehydration rate of the aluminum ammonium alum slag is more than 95%, the swelling degree of the aluminum ammonium alum slag in the heating process is reduced, the content of the leaching toxicity Be is greatly reduced by high-temperature roasting, the roasting sample for preparing refractory materials is prepared, and the resourceful disposal of the aluminum ammonium alum slag is realized.

[0005] To solve the above technical problems, the technical scheme provided by the application is as follows:

[0006] The application provides a resourceful disposal method of aluminum ammonium alum slag with high content of crystal water, which comprises the following steps:

[0007] S1, the beryllium-containing aluminum ammonium alum slag with the main component of NH4Al(SO4)2.12H2O and the content of crystal water of 40-50% is uniformly mixed with silica powder, and then microwave heating is performed to obtain a dried aluminum ammonium alum slag and silica powder mixture, and the water content of the dried mixture is 0-2%;

[0008] S2, high-temperature calcining the dried mixture obtained in step S1 to obtain a calcined sample applicable to preparation of a refractory material.

[0009] Since the aluminum ammonium alum slag contains 40-50% of crystal water which is difficult to dry, and the main component is NH4Al(SO4)2•12H2O, because of the high content of crystal water, the conventional drying presents the phenomenon of "dry outside and wet inside", and the sample is easy to stick together into a block due to the large amount of crystal water dissociation in the drying process, and the drying effect is poor, therefore, in the present application, the method of adding additive-microwave drying is adopted firstly to reduce the water content of the aluminum ammonium alum slag to about 1%, and the phenomenon of sticking together into a block does not occur, and the heating product is in a dry and loose state, avoiding the problem of easy swelling during calcining. The addition of the additive on the one hand alleviates the swelling degree of the aluminum ammonium alum slag during the heating and drying process by utilizing the water absorption, and on the other hand, the additive has the effect of fixing beryllium, which provides conditions for the subsequent high-temperature calcining detoxification. During calcining, the beryllium sulfate decomposes to form beryllium silicate with the silicon dioxide in the slag and the added silicon dioxide to realize the stabilization of the beryllium component, and sulfur and ammonia nitrogen are effectively removed, and by virtue of the high aluminum content in the aluminum ammonium alum slag, the calcined product can be used to prepare a refractory material.

[0010] In the present application, the water content of the aluminum ammonium alum slag dried sample prepared after microwave drying is below 2%, and the dehydration rate is above 95%, effectively solving the problems of high energy consumption, serious swelling, low processing efficiency, easy sticking together into a block and poor detoxification effect in the direct high-temperature calcining dehydration process of the aluminum ammonium alum slag, and realizing the high-temperature calcining efficient preparation of a refractory material product and other resource utilization of the aluminum ammonium alum slag.

[0011] As an optional embodiment, in the method provided by the present application, the beryllium-containing aluminum ammonium alum slag is a product formed by combining ammonium sulfate with aluminum sulfate during the removal of aluminum from the leaching solution after the beryllium ore smelting sample is leached with concentrated sulfuric acid in the production process of beryllium oxide.

[0012] As an optional embodiment, in the method provided by the present application, the beryllium-containing aluminum ammonium alum slag is aluminum ammonium alum slag with Be content ≤0.08%, S content ≤15%, NH3-N content ≤4.50% and Al content ≥5% by weight.

[0013] In the present application, Be is determined by ICP alkali fusion method, S is determined by high-frequency infrared absorption method, NH3-N is determined by distillation-neutralization titration method, and Al is determined by inductively coupled plasma emission spectrometry.

[0014] As an optional embodiment, in the method provided by the present application, in step S1, the beryllium-containing aluminum ammonium alum slag and the silicon dioxide powder mixture are placed in an alumina material container, and then placed in a microwave reactor for microwave heating.

[0015] As an optional implementation, in the method provided by the application, in step S1, the amount of silica powder added is 0.5-1% by weight of the beryllium-containing alunite residue.

[0016] Preferably, the amount is 0.5-0.8%, more preferably 0.6-0.8%.

[0017] The silica powder additive in the application mainly plays a role in relieving the swelling of the alunite residue during heating and drying and strengthening the effect of beryllium fixation during high-temperature calcination. When the amount is less than 0.5%, the swelling inhibition effect is not obvious; when the amount is greater than 1%, the silica is excessive in the beryllium fixation reaction, resulting in waste of raw materials.

[0018] As an optional implementation, in the method provided by the application, in step S1, the thickness of the mixture of the alunite residue and the silica powder during drying is controlled to be 1-3 cm.

[0019] Preferably, the thickness is 1-2.5 cm, more preferably 1.5-2 cm.

[0020] Different layer thicknesses affect the dehydration effect, and in the application, the thickness of the material is set to 1-3 cm, which is the most reasonable. If the layer is too thick, the drying is not sufficient; if the layer is too thin, the drying efficiency is affected.

[0021] As an optional implementation, in the method provided by the application, in step S1, the microwave drying temperature is 100-130°C, and the drying time is 10-30 min.

[0022] Preferably, the drying temperature is 110-120°C, and the drying time is preferably 15-25 min, more preferably 15-20 min.

[0023] The microwave heating in the application is an optimized heating method, which strengthens the drying degree and improves the dehydration efficiency. If the drying temperature is lower than 100°C, the dehydration is not complete, and the dehydration effect is poor; if the drying temperature is higher than 130°C, energy is wasted. If the drying time is less than 10 min, the drying is not complete; if the drying time is greater than 30 min, excessive unnecessary energy consumption is generated.

[0024] As an optional implementation, in the method provided by the application, in step S2, the high-temperature calcination temperature is 1100-1200°C, and the calcination time is 40-60 min.

[0025] In the application, if the calcination temperature of the mixture after microwave drying is lower than 1100°C or the time is less than 40 min, the reaction is not complete, the calcined sample is partially caked, and the beryllium fixation effect is not ideal; if the calcination temperature is higher than 1200°C or the time is longer than 60 min, unnecessary energy consumption is wasted.

[0026] As an optional implementation, in the method provided by the application, in step S2, the high-temperature roasting temperature is 1120-1180°C, and the roasting time is 45-55 min.

[0027] As an optional implementation, in the method provided by the application, in step S2, the content of leaching toxicity Be in the roasting sample is ≤0.02 mg / l.

[0028] After roasting, the content of leaching toxicity Be in the aluminum ammonium alum residue roasting sample is less than 0.02 mg / l, and the basic phase composition of beryllium is beryllium silicate, beryl and beryllium sulfate, mainly beryllium silicate. It is used for preparing refractory materials with a mixing ratio of 60%.

[0029] Compared with the prior art, the application has the following beneficial effects:

[0030] (1) In the application, the aluminum ammonium alum residue has a high content of crystal water. With the selective and integral heating characteristics of microwave, the silica powder is mixed to have the effects of water absorption, swelling relief and beryllium fixation. The water content of the aluminum ammonium alum residue is greatly reduced to about 1% in a short time, the phenomenon of sticking together due to high internal water content is avoided, and the subsequent beryllium fixation effect is poor. The microwave heating product is slightly swollen and dry and loose, which provides a favorable basis for the subsequent efficient high-temperature roasting and beryllium fixation. Secondly, more than 90% of beryllium in the aluminum ammonium alum residue exists in the form of beryllium sulfate. Under high-temperature roasting conditions, beryllium sulfate is decomposed to form beryllium silicate with the silica in the residue and the added silica, so as to realize the stabilization of beryllium component. At the same time, sulfur and ammonia nitrogen are effectively removed. With the high aluminum content in the aluminum ammonium alum residue, the roasting product can be used to prepare refractory materials.

[0031] (2) In the application, the method of adding additives, microwave drying and high-temperature roasting is used to realize efficient dewatering of the aluminum ammonium alum residue, effectively solve the problems of easy swelling and low treatment efficiency of the aluminum ammonium alum residue during direct high-temperature roasting, and greatly reduce the content of leaching toxicity Be in the roasting product to ≤0.02 mg / l, which meets the standard requirements. The application has the advantages of good drying effect, short treatment process and full-component resource utilization, and meets the requirements of safe, efficient and green treatment of aluminum ammonium alum residue. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the application, the application will be described more fully below with reference to the specification and preferred embodiments. However, the scope of protection of the application is not limited to the following specific embodiments.

[0033] Unless otherwise defined, all the professional terms used below have the same meaning as generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the application.

[0034] Unless otherwise specifically indicated, all materials, reagents, and equipment used in the present application are commercially available or are prepared by known methods.

[0035] Example 1

[0036] A method for resourceful disposal of aluminum ammonium alum slag with high crystallization water content, comprising the following steps:

[0037] A. Microwave drying

[0038] The aluminum ammonium alum slag is analyzed, and the chemical composition is aluminum ammonium alum slag with Be 0.048%, S 14.77%, Al 5.87%, and NH3-N 3.98% by weight. The water content of the aluminum ammonium alum slag is 45.08%.

[0039] The aluminum ammonium alum slag raw material sample is mixed with 0.8% by weight of silica powder, and then uniformly loaded into an aluminum oxide material special tray. The thickness of the mixed material layer is controlled to be 2.5 cm. The tray loaded with the aluminum ammonium alum slag and the silica powder is placed in a microwave reactor for microwave heating. The mixture is dehydrated at 115°C for 17 min, and after the incubation is over, it is cooled to room temperature. The obtained dry mixed product is loose, slightly puffed, and has a water content of 1.28%.

[0040] B. Roasting

[0041] The dry mixed product obtained in step A is placed in a muffle furnace and roasted at 1150°C for 45 min. The obtained roasted sample product has a leaching toxicity Be content of 0.0048 mg / l. The leaching toxicity Be is below 0.02 mg / l, and its beryllium basic phase composition is beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the prepared aluminum ammonium alum slag roasted sample are shown in Table 1.

[0042] Table 1: Beryllium phase analysis table of aluminum ammonium alum slag roasted sample

[0043]

[0044] The prepared aluminum ammonium alum slag roasted sample is used to prepare refractory materials with a mixing ratio of 60%. The chemical composition of the refractory materials is shown in Table 2, and the product performance test analysis results are shown in Table 3.

[0045] Table 2: Chemical composition table of aluminum ammonium alum slag roasted sample for preparing refractory materials / %

[0046]

[0047] Table 3: Performance table of aluminum ammonium alum slag roasted sample for refractory materials

[0048]

[0049] Example 2

[0050] A method for resourceful disposal of aluminum ammonium alum residue with high crystallization water content, comprising the following steps:

[0051] A. Microwave drying

[0052] The aluminum ammonium alum residue is analyzed, and the chemical composition is aluminum ammonium alum residue with 0.052% of Be, 14.65% of S, 5.72% of Al and 3.93% of NH3-N by weight, and the moisture content of the aluminum ammonium alum residue is 42.79%.

[0053] The aluminum ammonium alum residue raw material sample is mixed with 1.0% of silica powder by weight, and is uniformly loaded into an aluminum oxide material special tray, the thickness of the mixed material layer is controlled to be 1.5 cm, and the tray loaded with the aluminum ammonium alum residue and the silica powder is placed into a microwave reactor for microwave heating. The mixture is dehydrated at 112°C for 12 min, and after the heat preservation is completed, it is cooled to room temperature, and the obtained dried mixed product is loose, slightly puffed, and the moisture content is 1.92%.

[0054] B. Roasting

[0055] The dried mixed product obtained in step A is placed into a muffle furnace, and is roasted at 1150°C for 60 min, and the obtained roasting sample product has a leaching toxicity Be content of 0.0045 mg / l. The leaching toxicity Be is below 0.02 mg / l, and the basic phase composition of beryllium is beryllium silicate, beryl and beryllium sulfate. The beryllium phase analysis results of the prepared aluminum ammonium alum residue roasting sample are shown in Table 4.

[0056] Table 4: Beryllium phase analysis table of aluminum ammonium alum residue roasting sample

[0057]

[0058] The prepared aluminum ammonium alum residue roasting sample is used for preparing refractory materials with a mixing ratio of 60%, the chemical composition of the refractory materials is shown in Table 5, and the product performance detection analysis results are shown in Table 6.

[0059] Table 5: Chemical composition table of aluminum ammonium alum residue roasting sample for preparing refractory materials / %

[0060]

[0061] Table 6: Performance table of aluminum ammonium alum residue roasting sample for refractory materials

[0062]

[0063] Example 3

[0064] A method for resourceful disposal of aluminum ammonium alum residue with high crystallization water content, comprising the following steps:

[0065] A, microwave drying

[0066] The aluminum ammonium alum residue is analyzed, and its chemical composition is aluminum ammonium alum residue with Be 0.045%, S 14.71%, Al 5.90%, and NH3-N 3.88% by weight, and the water content of the aluminum ammonium alum residue is 45.65%.

[0067] The aluminum ammonium alum residue raw material sample is mixed with 0.6% by weight of silica powder, and the mixture is uniformly loaded into an aluminum oxide material special tray, the thickness of the mixture layer is controlled to be 1.5 cm, and the tray loaded with the aluminum ammonium alum residue and the silica powder is placed in a microwave reactor for microwave heating. The mixture is dehydrated at 118°C for 19 min, and after the holding is finished, it is cooled to room temperature, and the dried mixed product obtained is loose, slightly puffed, and has a water content of 0.87%.

[0068] B, calcination

[0069] The dried mixed product obtained in step A is placed in a muffle furnace and calcined at 1100°C for 45 min, and the leaching toxicity of the obtained calcined sample is 0.012 mg / l. The leaching toxicity of Be is below 0.02 mg / l, and its beryllium phase composition is beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the prepared aluminum ammonium alum residue calcined sample are shown in Table 7.

[0070] Table 7: Beryllium phase analysis table of aluminum ammonium alum residue calcined sample

[0071]

[0072] The prepared aluminum ammonium alum residue calcined sample is used to prepare refractory materials with a mixing ratio of 60%, and the chemical composition of the refractory materials is shown in Table 8, and the product performance test analysis results are shown in Table 9.

[0073] Table 8: Chemical composition table of aluminum ammonium alum residue calcined sample for preparing refractory materials / %

[0074]

[0075] Table 9: Performance table of aluminum ammonium alum residue calcined sample for refractory materials

[0076]

[0077] Example 4

[0078] A method for resource disposal of aluminum ammonium alum residue with high crystallization water content, comprising the following steps:

[0079] A, microwave drying

[0080] The aluminum ammonium alum slag is analyzed, and the chemical composition is aluminum ammonium alum slag with Be 0.055%, S 14.63%, Al 5.82% and NH3-N 3.83% by weight, and the water content of the aluminum ammonium alum slag is 43.86%.

[0081] The aluminum ammonium alum slag raw material sample is mixed with 0.5% by weight of silica powder, and the mixture is uniformly loaded into an aluminum oxide material special tray, the thickness of the mixture layer is controlled to be 1.5 cm, and the tray loaded with the aluminum ammonium alum slag and the silica powder is placed in a microwave reactor for microwave heating. The mixture is dehydrated at 108°C for 15 min, and after the holding is finished, it is cooled to room temperature, and the dried mixed product obtained is loose, slightly puffed, and the water content is 1.86%.

[0082] B, calcination

[0083] The dried mixed product obtained in step A is placed in a muffle furnace and calcined at 1100°C for 60 min, and the calcined sample product obtained has a leaching toxicity Be content of 0.015 mg / l. The leaching toxicity Be is below 0.02 mg / l, and its beryllium basic phase composition is beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the aluminum ammonium alum slag calcined sample prepared are shown in Table 10.

[0084] Table 10: Beryllium phase analysis table of aluminum ammonium alum slag calcined sample

[0085]

[0086] The aluminum ammonium alum slag calcined sample is prepared, which is used as a refractory material with a mixing ratio of 60%, and the chemical composition of the refractory material is shown in Table 11, and the product performance test analysis results are shown in Table 12.

[0087] Table 11: Chemical composition table of aluminum ammonium alum slag calcined sample for preparing refractory materials / %

[0088]

[0089] Table 12: Performance table of aluminum ammonium alum slag calcined sample as refractory material

[0090]

[0091] Example 5

[0092] A method for resource disposal of aluminum ammonium alum slag with high crystallization water content, comprising the following steps:

[0093] A, microwave drying

[0094] The aluminum ammonium alum slag is analyzed, and the chemical composition is aluminum ammonium alum slag with Be 0.043%, S 14.83%, Al 5.71% and NH3-N 3.95% by weight, and the water content of the aluminum ammonium alum slag is 44.86%.

[0095] The aluminum ammonium alum slag raw material sample is mixed with 1.0% by weight of silica powder, and the mixture is uniformly loaded into an aluminum oxide material special tray, the thickness of the mixture layer is controlled to be 1.5 cm, and the tray loaded with the aluminum ammonium alum slag and the silica powder is placed in a microwave reactor for microwave heating. The mixture is dehydrated at 120°C for 20 min, and after the holding is finished, it is cooled to room temperature, and the obtained dry mixed product is loose, slightly puffed, and the water content is 0.61%.

[0096] B, calcination

[0097] The dry mixed product obtained in step A is placed in a muffle furnace and calcined at 1180°C for 45 min, and the obtained calcined sample product has a leaching toxicity Be content of 0.0035 mg / l. The leaching toxicity Be is below 0.02 mg / l, and the basic phase composition of beryllium is beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the prepared aluminum ammonium alum slag calcined sample are shown in Table 13.

[0098] Table 13: Beryllium phase analysis table of aluminum ammonium alum slag calcined sample

[0099]

[0100] The prepared aluminum ammonium alum slag calcined sample is used as a refractory material with a mixing ratio of 60%, and the chemical composition of the refractory material is shown in Table 14, and the product performance test analysis results are shown in Table 15.

[0101] Table 14: Chemical composition table of aluminum ammonium alum slag calcined sample for preparing refractory materials / %

[0102]

[0103] Table 15: Performance table of aluminum ammonium alum slag calcined sample as refractory material

[0104]

[0105] Example 6

[0106] A method for resource disposal of aluminum ammonium alum slag with high crystallization water content, comprising the following steps:

[0107] A, microwave drying

[0108] The aluminum ammonium alum slag of Example 1 is used.

[0109] The aluminum ammonium alum slag raw material sample was mixed with 0.8% by weight of silica powder, and was uniformly loaded into an aluminum oxide special tray, the thickness of the mixture layer was controlled to be 2.5 cm, and the tray loaded with the aluminum ammonium alum slag and the silica powder was placed into a microwave reactor for microwave heating. The mixture was dehydrated at 115°C for 17 min, and after the end of the incubation, it was cooled to room temperature, and the dried mixture product obtained was loose, slightly puffed, and the water content was 1.28%.

[0110] B, calcination

[0111] The dried mixture product obtained in step A was placed into a muffle furnace, and was calcined at 1050°C for 45 min, and the calcined sample product obtained had a leaching toxicity Be content of 0.35 mg / l. The leaching toxicity Be was above 0.02 mg / l, and the basic phase composition of beryllium thereof was beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the aluminum ammonium alum slag calcined sample obtained are shown in Table 16.

[0112] In Example 6, the method of normal microwave combined with low-temperature calcination was used, and the calcined sample product obtained had a relatively large leaching toxicity Be content.

[0113] Table 16: Beryllium phase analysis table of aluminum ammonium alum slag calcined sample

[0114]

[0115] Example 7

[0116] A method for resource disposal of aluminum ammonium alum slag with high crystallization water content, comprising the following steps:

[0117] A, microwave drying

[0118] The aluminum ammonium alum slag of Example 1 was used.

[0119] The aluminum ammonium alum slag raw material sample was mixed with 0.8% by weight of silica powder, and was uniformly loaded into an aluminum oxide special tray, the thickness of the mixture layer was controlled to be 2.5 cm, and the tray loaded with the aluminum ammonium alum slag and the silica powder was placed into a microwave reactor for microwave heating. The mixture was dehydrated at 90°C for 17 min, and after the end of the incubation, it was cooled to room temperature, and the dried mixture product obtained was relatively loose, and the water content was 11.38%.

[0120] B, calcination

[0121] The dried mixture product obtained in step A was placed into a muffle furnace, and was calcined at 1150°C for 45 min, and the calcined sample product obtained had a leaching toxicity Be content of 0.12 mg / l. The leaching toxicity Be was above 0.02 mg / l, and the basic phase composition of beryllium thereof was beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the aluminum ammonium alum slag calcined sample obtained are shown in Table 17.

[0122] The roasting sample product obtained by the method of low-temperature microwave combined roasting in Example 7 has a high Be content in leaching toxicity.

[0123] Table 17: Beryllium phase analysis table of aluminum ammonium alum slag roasting sample

[0124]

[0125] Comparative Example 1

[0126] A method for resource disposal of aluminum ammonium alum slag with high crystallization water content includes the following steps:

[0127] A, microwave drying

[0128] The aluminum ammonium alum slag of Example 1 is used.

[0129] The aluminum ammonium alum slag raw material sample and 0.8% by weight of silica powder are loaded into an aluminum oxide material special tray, the thickness of the mixture is controlled to be 2.5 cm, and the tray loaded with the aluminum ammonium alum slag and silica powder is placed in an electric heating air drying oven reactor for conventional heating. The mixture is dehydrated at 115°C for 17 min, and after the end of the heat preservation, it is cooled to room temperature, and the obtained product is bonded into a block with a water content of 39.21%.

[0130] B, roasting

[0131] The dried mixture product obtained in step A is placed in a muffle furnace and roasted at 1150°C for 45 min. The product swells seriously during roasting, and the roasting sample product obtained has a Be content of 0.20 mg / l in leaching toxicity. The Be leaching toxicity is above 0.02 mg / l, and the basic phase composition of beryllium is beryllium silicate, beryl, and beryllium sulfate. The beryllium phase analysis results of the aluminum ammonium alum slag roasting sample prepared are shown in Table 18.

[0132] In Comparative Example 1, the method of conventional heating dehydration is used, the dehydration temperature and time are the same as in Example 1, but the dehydration rate is poor, and the Be content in leaching toxicity of the product after normal roasting is high.

[0133] Table 18: Beryllium phase analysis table of aluminum ammonium alum slag roasting sample

[0134]

[0135] Comparative Example 2

[0136] A method for resource disposal of aluminum ammonium alum slag with high crystallization water content includes the following steps:

[0137] A, microwave drying

[0138] The aluminum ammonium alum slag of Example 2 is used.

[0139] The aluminum ammonium alum residue sample was mixed with 1.0% by weight of the silica powder, and was uniformly loaded into an aluminum oxide special tray, the thickness of the mixed material layer was controlled to be 1.5 cm, and the tray loaded with the aluminum ammonium alum residue and the silica powder was placed into an electric heating air drying oven reactor for conventional heating. The aluminum ammonium alum residue was dehydrated at 112°C for 12 min, and after the heat preservation was completed, it was cooled to room temperature, and the obtained product was bonded into a block, and the water content was 38.53%.

[0140] B, calcination

[0141] The dried mixed product obtained in step A was placed into a muffle furnace, and was calcined at 950°C for 45 min, the product was seriously puffed during the calcination process, and a lump appeared in the center of the product, the leaching toxicity of Be in the obtained calcined sample was 0.26 mg / l. The leaching toxicity of Be was more than 0.02 mg / l, and the basic phase composition of beryllium was beryllium silicate, beryl and beryllium sulfate. The beryllium phase analysis results of the prepared aluminum ammonium alum residue calcined sample are shown in Table 19.

[0142] In the comparative example 2, the conventional dehydration method was used, the dehydration temperature and time were the same as those in the example 2, but the dehydration rate was poor, and the leaching toxicity of Be in the product after low-temperature calcination was high.

[0143] Table 19: Beryllium phase analysis table of aluminum ammonium alum residue calcined sample

[0144]

[0145] Comparative example 3

[0146] A method for resource disposal of aluminum ammonium alum residue with high crystallization water content, comprising the following steps:

[0147] A, microwave drying

[0148] The aluminum ammonium alum residue of example 3 was used.

[0149] The aluminum ammonium alum residue sample was mixed with 0.6% by weight of the silica powder, and was uniformly loaded into an aluminum oxide special tray, the thickness of the mixed material layer was controlled to be 1.5 cm, and the tray loaded with the aluminum ammonium alum residue and the silica powder was placed into an electric heating air drying oven reactor for conventional heating. The mixture was dehydrated at 118°C for 19 min, and after the heat preservation was completed, it was cooled to room temperature, and the obtained product was bonded into a block, and the water content was 37.16%.

[0150] B, calcination

[0151] The dried mixture obtained in step A was placed in a muffle furnace and calcined at 1050°C for 60 min. The calcined product was severely puffed. The leaching toxicity of Be in the calcined product was 0.13 mg / l. The leaching toxicity of Be was more than 0.02 mg / l. The basic phase composition of beryllium was beryllium silicate, beryl and beryllium sulfate. The beryllium phase analysis results of the calcined product of the alunite residue are shown in Table 20.

[0152] In the comparative example 3, the conventional dehydration method was used. The dehydration temperature and time were the same as those in example 3, but the dehydration rate was poor. The leaching toxicity of Be in the product after calcination at low temperature was high.

[0153] Table 20: Beryllium phase analysis table of calcined product of alunite residue

[0154]

[0155] Comparative example 4

[0156] A method for resource disposal of alunite residue with high crystallization water content, comprising the following steps:

[0157] A, microwave drying

[0158] The alunite residue of example 1 was used.

[0159] The alunite residue sample was loaded into an aluminum oxide special tray, and the thickness of the alunite residue layer was controlled to be 2.5 cm. The tray loaded with the alunite residue was placed in a microwave reactor for microwave heating. The alunite residue was dehydrated at 115°C for 17 min, and then cooled to room temperature. The obtained alunite residue drying product was loose and puffed, and the water content was 1.31%.

[0160] B, calcination

[0161] The dried alunite residue obtained in step A was placed in a muffle furnace and calcined at 1150°C for 45 min. The leaching toxicity of Be in the calcined product was 0.0193 mg / l. The leaching toxicity of Be was less than 0.02 mg / l. The basic phase composition of beryllium was beryllium silicate, beryl and beryllium sulfate. The beryllium phase analysis results of the calcined product of the alunite residue are shown in Table 21.

[0162] Table 21: Beryllium phase analysis table of calcined product of alunite residue

[0163]

[0164] The method of dehydration by microwave heating in Comparative Example 4 has the same dehydration temperature and time as in Example 1, and no silica powder is added during the dehydration process. Although the dehydration effect is not much different from that in Example 1, the swelling degree of the dehydration product is more serious than that in Example 1. After normal calcination, the leaching toxicity Be content of the product is also relatively higher.

[0165] The above is a further detailed description of the present application in combination with specific preferred embodiments, and cannot be deemed to limit the specific implementation of the present application to these descriptions. For those skilled in the art to which the present application belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present application, and all of them shall be deemed to fall within the protection scope of the present application.

Claims

1. A method for resourceful disposal of high crystalline water content aluminum ammonium alum residue, characterized in that, The method comprises the following steps: S1, mixing beryllium-containing aluminum ammonium alum slag with a main component of NH4Al(SO4)2·12H2O and a crystallization water content of 40-50% with silica powder to obtain a dry mixture of aluminum ammonium alum slag and silica powder after microwave heating, wherein the water content of the dry mixture is 0-2%, and the silica powder is mixed in an amount of 0.5-1% of the beryllium-containing aluminum ammonium alum slag by weight; S2, high-temperature calcining the dry mixture obtained in step S1 to obtain a calcined sample applicable to the preparation of refractory materials.

2. The high-crystalline water content alunite slag resourceful disposal method according to claim 1, characterized in that, The beryllium-containing aluminum ammonium alum slag is a product formed by the combination of ammonium sulfate and aluminum sulfate when aluminum is removed from the leaching solution after beryllium ore smelting samples are leached by concentrated sulfuric acid in the production process of beryllium oxide.

3. The high-crystalline water content alunite slag resourceful disposal method according to claim 1, characterized in that, The beryllium-containing aluminum ammonium alum slag is aluminum ammonium alum slag with a Be content of ≤0.08% by weight, an S content of ≤15%, an NH3-N content of ≤4.50%, and an Al content of ≥5%.

4. The high-crystalline-water-content alunite-flue-dust resourceful disposal method according to claim 1, characterized in that, In step S1, the mixture of beryllium-containing aluminum ammonium alum slag and silica powder is placed in an alumina container and then placed in a microwave reactor for microwave heating.

5. The high-crystalline-water-content alunite-flue-dust resourceful disposal method according to claim 1, characterized in that, In step S1, the thickness of the mixture of aluminum ammonium alum slag and silica powder is controlled to be 1-3 cm during the drying process.

6. The high-crystalline-water-content alunite-flue-dust resourceful disposal method according to claim 1, characterized in that, In step S1, the microwave drying temperature is 100-130°C, and the drying time is 10-30 min.

7. The high-crystalline-water-content alunite-flue-dust resourceful disposal method according to claim 1, characterized in that, In step S2, the high-temperature calcining temperature is 1100-1200°C, and the high-temperature calcining time is 40-60 min.

8. The high-crystalline-water-content alunite slag resourceful disposal method according to claim 1, characterized in that, In step S2, the high-temperature calcining temperature is 1120-1180°C, and the high-temperature calcining time is 45-55 min.

9. The high-crystalline-water-content alunite-flue-dust resourceful disposal method according to claim 1, characterized in that, In step S2, the leaching toxicity Be content in the calcined sample is ≤0.02 mg / L.

Images