阅读说明：本技术 一种铝灰加工资源利用的方法 (Method for utilizing aluminum ash processing resources ) 是由 姜晓云 余猛钢 倪慧芳 于 2021-09-16 设计创作，主要内容包括：本发明公开了一种铝灰加工资源利用的方法,属于铝灰处理技术领域,一种铝灰加工资源利用的方法,将待处理的铝灰破碎后投入磁选机中,去除铝灰中的铁元素；对处理后的铝灰进行粉碎筛分,得到铝渣颗粒和二次铝灰,铝渣颗粒经过金属铝提取段处理,得到铝锭和二次铝灰,二次铝灰重新投入磁选机中,二次铝灰进入热处理段,它可以实现经高温脱氮-协同固氟的工艺处理铝灰,处理过程清洁无二次污染,不仅实现了铝灰的绿色高效无害化处理,同时处理后得到的氧化铝基粉料可用于制备化工材料、耐火材料、建筑材料等,社会经济效益显著。(The invention discloses a method for utilizing aluminum ash processing resources, which belongs to the technical field of aluminum ash treatment and comprises the steps of crushing aluminum ash to be treated, putting the crushed aluminum ash into a magnetic separator, and removing iron elements in the aluminum ash; the treated aluminum ash is crushed and screened to obtain aluminum slag particles and secondary aluminum ash, the aluminum slag particles are treated by a metal aluminum extraction section to obtain aluminum ingots and the secondary aluminum ash, the secondary aluminum ash is thrown into a magnetic separator again, and the secondary aluminum ash enters a heat treatment section, so that the aluminum ash can be treated by a high-temperature denitrification-synergistic fluorine fixation process, the treatment process is clean and free of secondary pollution, green and efficient harmless treatment of the aluminum ash is realized, meanwhile, the treated aluminum oxide-based powder can be used for preparing chemical materials, refractory materials, building materials and the like, and the social and economic benefits are remarkable.)

1. A method for utilizing aluminum ash processing resources is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: a cold ash treatment section;

s11: crushing the aluminum ash to be treated, and then putting the crushed aluminum ash into a treatment line to remove iron elements in the aluminum ash;

s12: performing ball milling and screening on the aluminum ash treated in the step S11 to obtain aluminum slag particles and secondary aluminum ash, treating the aluminum slag particles through a metal aluminum extraction section to obtain aluminum ingots and the aluminum ash, and putting the aluminum ash into a treatment line again;

step two: heat treatment stage

S21: putting the secondary aluminum ash in the first step into a denitrifier, adding a certain amount of water, mixing and stirring to convert part of aluminum nitride in the aluminum ash into ammonia gas, and collecting;

s22: conveying the obtained partially denitrified aluminum ash to a rotary kiln, wherein the rotary kiln has a certain inclination and a certain rotating speed, and the secondary aluminum ash moves from a low-temperature end to a high-temperature end under the action of gravity, so that the secondary aluminum ash is heated to evaporate free water and then remove crystal water, and then is subjected to phase change through high-temperature sintering to convert an aluminum oxide crystal phase into an alpha phase, and finally, obtaining clinker, cooling and bagging to obtain an aluminum oxide finished product.

2. The method for utilizing aluminum ash processing resources as claimed in claim 1, wherein the method comprises the following steps: the method also comprises the following third step: the environment-friendly section comprises a flue gas treatment system and a dust removal system; the flue gas treatment system is used for treating nitrogen oxides and ammonia in flue gas; the dust removal system is used for removing dust in the whole aluminum ash processing process.

3. The method for utilizing aluminum ash processing resources as claimed in claim 2, wherein the method comprises the following steps: the flue gas treatment system is mainly used for denitration treatment and ammonia gas collection, and ammonia gas in the S21 step is converted into ammonia water to be sprayed in the heat treatment section process to remove oxynitride in high-temperature flue gas.

4. The method for utilizing aluminum ash processing resources as claimed in claim 2, wherein the method comprises the following steps: the dust removal system comprises two dust removal modes of cyclone dust removal and cloth bag dust removal.

5. The method for utilizing aluminum ash processing resources as claimed in claim 1, wherein the method comprises the following steps: and in the step S12, the crushing and screening of the aluminum ash are finished by a ball mill and a screening machine respectively, wherein the ball mill is a corundum ball mill.

6. The method for utilizing aluminum ash processing resources as claimed in claim 1, wherein the method comprises the following steps: the metallic aluminum extraction section in the step S12 includes the steps of:

firstly, putting aluminum slag particles into a rotary kiln, adding a slag-beating agent, frying and recovering metal aluminum to obtain aluminum liquid and aluminum ash slag, and cooling the aluminum liquid to obtain an aluminum alloy ingot;

and secondly, putting the aluminum ash into a cold ash bucket for cooling to obtain cold aluminum ash again.

7. The method for utilizing aluminum ash processing resources as claimed in claim 6, wherein the method comprises the following steps: the temperature in the rotary kiln is kept at 800-1100 ℃, and the rotary kiln is covered and tightly closed for 20-50min after the slag removing agent is added; the cooling temperature of the ash cooling barrel is 40-60 ℃, and the ash cooling barrel is sprayed by circulating water, so that the barrel body and cooling water exchange heat to realize cooling.

8. The method for utilizing aluminum ash processing resources as claimed in claim 1, wherein the method comprises the following steps: and in the step S22, evaporating free water in the aluminum ash filter residue by adopting a drying mode, wherein the drying temperature is 100-200 ℃.

9. The method for utilizing aluminum ash processing resources as claimed in claim 1, wherein the method comprises the following steps: in the step S22, crystal water in the aluminum ash is removed by adopting a heating mode, wherein the heating temperature is 600-800 ℃.

10. The method for utilizing aluminum ash processing resources as claimed in claim 1, wherein the method comprises the following steps: the phase change temperature in the S22 step is 1200-1300 ℃; the temperature is reduced to 150-200 ℃ by water cooling in the step S22.

Technical Field

The invention relates to the technical field of aluminum ash treatment, in particular to a method for utilizing aluminum ash processing resources.

Background

Aluminum ash is a solid waste produced from aluminum smelting and aluminum processing. Generally, aluminum ash contains a large amount of metallic aluminum, needs to be recycled, has complex components, slightly changes due to different production links, different raw materials of manufacturers and different operating conditions, but generally contains metallic aluminum, aluminum oxide, aluminum nitride, aluminum chloride and other components.

At present, the process technology for recovering metallic aluminum or aluminum oxide from aluminum ash is continuously explored.

For example, patent application No. CN202011108725.4 discloses a method for treating aluminum ash with high efficiency and harmlessness, but in this scheme, firstly, water needs to be added in step 1, stirring is started, slurry mixing is performed, a small amount of ammonia gas is generated, the ammonia gas is discharged and collected through a negative pressure exhaust port, then water needs to be added in step 2, the ammonia gas generated by reaction is discharged and collected through the negative pressure exhaust port, step 3 also needs to be washed with water, and finally step 4 is washed, the water consumption in the whole process is too large, water pollution is serious, additional water pollution disposal cost is needed in actual life, the investment cost is increased to a certain extent, and ammonia gas is generated in step 1 and step 2, but the subsequent ammonia gas is not recycled in the reaction and is treated as waste gas to be treated, the inventor shows that dilute sulfuric acid can be used for absorption to prepare ammonium sulfate for other purposes, in addition, the chloride salt by-product is also produced in large amounts and needs to be disposed of.

For example, patent application No. CN201810062643.7 discloses a resource utilization method of secondary aluminum ash, but this patent requires complex chemical reactions, and during the implementation of specific enterprises, the problem of project land property location is encountered first (the generation of chemical reactions is listed in chemical enterprises, the required land is used for chemical engineering, and it is generally difficult to obtain land use right), the production process is complex, the production line is longer, a complete production line cannot be formed, two or more production lines need to be disconnected to complete production, and more by-products are produced, and the by-products need to be treated, which is very high in cost.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a method for utilizing aluminum ash processing resources, wherein a small amount of water is added during treatment, aluminum nitride is converted into ammonia gas and the ammonia gas is absorbed by the water and converted into ammonia water, and the ammonia water can be used for the subsequent high-temperature denitration step, so that the cyclic utilization of the ammonia is realized; meanwhile, the core technology of denitrification in the scheme is that aluminum ash is treated by a rotary kiln, and compared with the traditional treatment mode, the process flow is simpler.

In order to solve the above problems, the present invention adopts the following technical solutions.

A method for utilizing aluminum ash processing resources comprises the following steps:

the method comprises the following steps: a cold ash treatment section;

s11: crushing the aluminum ash to be treated, and then putting the crushed aluminum ash into a treatment line to remove iron elements in the aluminum ash;

s12: ball-milling and screening the aluminum ash treated in the step S11 to obtain aluminum slag particles and secondary aluminum ash, treating the aluminum slag particles through a metal aluminum extraction section to obtain aluminum ingots and the aluminum ash, and putting the aluminum ash into a treatment line again, specifically a magnetic separator;

step two: heat treatment stage

S21: putting the secondary aluminum ash in the first step into a denitrifier, adding a certain amount of water, mixing and stirring to convert part of aluminum nitride in the aluminum ash into ammonia gas, and collecting;

s22: conveying the obtained partially denitrified aluminum ash to a rotary kiln, wherein the rotary kiln has a certain inclination and a certain rotating speed, and the secondary aluminum ash moves from a low-temperature end to a high-temperature end under the action of gravity, so that the secondary aluminum ash is heated to evaporate free water and then remove crystal water, and then is subjected to phase change through high-temperature sintering to convert an aluminum oxide crystal phase into an alpha phase, and finally, obtaining clinker, cooling and bagging to obtain an aluminum oxide finished product.

Further, the method also comprises the third step of: an environment-friendly section; the environment-friendly section comprises a flue gas treatment system and a dust removal system; the flue gas treatment system is used for treating nitrogen oxides and ammonia in flue gas; the dust removal system is used for removing dust in the whole aluminum ash processing process.

Furthermore, the flue gas treatment system mainly carries out denitration treatment and ammonia gas collection, and the ammonia gas in the step S21 is converted into ammonia water to be sprayed and removed in the heat treatment section process, so that the nitrogen oxide in the high-temperature flue gas is removed, the ammonia gas generated in the step S21 is recycled in the step S22, the generation of byproducts in the ammonia gas treatment is effectively avoided, and the trouble of the byproduct treatment is reduced.

Furthermore, the dust removal system comprises two dust removal modes of cyclone dust removal and cloth bag dust removal, dust in the whole production process is treated, the dust amount in a production workshop is reduced, the health of workers is guaranteed, and meanwhile, the influence of the dust on the quality of produced products is reduced.

Further, the crushing and screening of the aluminum ash in the step S12 are respectively completed by a ball mill and a screening machine. Preferably, the ball mill is a corundum ball mill, and compared with a traditional ball mill, the corundum ball mill is not easy to produce iron pollution.

Further, the metallic aluminum extraction section in the step S12 includes the following steps:

firstly, putting aluminum slag particles into a rotary kiln while the aluminum slag particles are hot, adding a slag-beating agent, frying and recovering metal aluminum to obtain aluminum liquid and aluminum ash slag, and cooling the aluminum liquid to pass through an ingot stacking machine to obtain aluminum alloy ingots;

and secondly, putting the aluminum ash into an aluminum ash cooling barrel for cooling to obtain cold aluminum ash again.

Further, the temperature in the rotary kiln is kept at 1100 ℃ of 800-; the cooling temperature of the ash cooling barrel is 40-60 ℃, and the ash cooling barrel is sprayed by circulating water, so that the barrel body and cooling water exchange heat to realize cooling.

Further, the temperature in the rotary kiln is maintained at 800 ℃.

Further, adding a residue removing agent, covering and tightly sealing for 30min

Further, in the step S22, a drying method is adopted to evaporate free water in the aluminum ash filter residue, wherein the drying temperature is 100 ℃ and 200 ℃, and preferably 120 ℃.

Further, in the step S22, the crystal water in the aluminum ash is removed by heating, and the heating temperature is 600-800 ℃, preferably 600 ℃.

Further, the phase change temperature in the S22 step is 1200-1300 ℃; the temperature in the step S22 is reduced to 150 ℃ and 200 ℃ by water cooling, preferably 200 ℃.

Compared with the prior art, the invention has the advantages that:

the secondary aluminum ash of this scheme adsorbs and stores the ammonia at the denitrogenation machine denitrogenation in-process, and the ammonia high temperature of calling the storage at the in-process of rotary kiln processing sprays, gets rid of the oxynitride that produces among the high temperature heating process for the ammonia can be used at this scheme mesocycle, compares in traditional and collects the ammonia or absorbs with dilute sulphuric acid and change into other uses such as ammonium bisulfate into in addition, and is more convenient and resources are saved.

Two, the aluminium ash of this scheme partial denitrification passes through the rotary kiln and handles, heat earlier the evaporation free water, desorption crystal water again, later through high temperature sintering dephasing, the cooling obtains the finished product, compare in traditional processing mode, process flow is simple, can form a whole assembly line, compare in the patent that the application number is CN202011108725.4, water pollution is less, the ammonia can recycle, can not produce the chlorate accessory substance, and compare in the patent that the application number is CN201810062643.7, the assembly line is shorter, process flow is simple, also can not have the chlorate accessory substance to produce, the pollution greatly reduced.

And thirdly, the corundum ball mill is adopted in the ball milling process, and compared with the traditional ball mill, the corundum ball mill is not easy to pollute by iron.

The scheme is low in investment cost and risk, not only is suitable for investment production of small and medium-sized factories, but also is suitable for large-scale production, and the produced product is high in value.

Drawings

FIG. 1 is a process flow diagram of the present invention;

FIG. 2 is a process flow diagram after adding an environmental protection section.

Detailed Description

Example 1:

referring to fig. 1-2, a method for utilizing aluminum ash processing resources includes the following steps:

the method comprises the following steps: cold ash treatment section

S11: and lifting the aluminum ash to be treated in the storage bin to a magnetic separator through a lifter, and removing iron elements in the aluminum ash to obtain scrap iron. The iron element is a harmful impurity in the aluminum alloy smelting preparation and needs to be removed before smelting. Before being lifted to the magnetic separator, the waste iron can be primarily crushed by a crusher so as to be convenient for extraction of the waste iron. The crushed aluminum materials are subjected to dry magnetic separation, and scrap iron can be separated by a crusher with a magnetic separation roller;

s12: and (4) crushing the aluminum ash treated in the step (S11) into particles through a ball mill, and then lifting the particles to a screening machine through a lifter for screening to obtain aluminum slag particles and secondary aluminum ash. Putting the aluminum slag particles into a rotary kiln while the particles are hot, then adding a slag removing agent, covering and tightly closing for 30 minutes, operating by utilizing heat energy generated by the spontaneous combustion principle of the aluminum slag, and keeping the temperature of the rotary kiln at about 800 ℃ to obtain aluminum ingots and aluminum slag. Generally, the aluminum slag particles contain about 30% of liquid metal aluminum, more than 50% of liquid aluminum in the aluminum slag particles can be separated and recovered through a rotary kiln, and the content of the metal aluminum in the aluminum slag particles can be reduced to below 15% after recovery treatment. The aluminum ingot can be cooled and then is processed by an ingot stacking machine to obtain the aluminum alloy ingot with good quality. . The aluminum ash slag is thrown into an aluminum slag hopper, transported by a forklift, poured from a feed port of the cold ash bucket for cooling treatment, cooled by circulating water spraying and indirect cooling, uniformly distributed over the cooling bucket by a water pump and a spray header, and subjected to heat exchange with the cooling water through the bucket body, so that the hot slag can be rapidly cooled to 40-60 ℃ to obtain secondary aluminum ash. And (3) putting the secondary aluminum ash into a bin again, carrying out lifting magnetic separation, carrying out self-impact grinding and steel ball grinding again, conveying the ground aluminum ash into a screening machine to further separate aluminum and ash in the secondary aluminum ash, returning the separated aluminum slag particles to the rotary kiln to continue frying, and reducing the content of metal aluminum in the treated aluminum ash to be below 2% (simple substance aluminum). And (4) putting the secondary aluminum ash into a transfer bin through a lifter, and waiting for entering a heat treatment section.

Step two: heat treatment stage

S21: putting the secondary aluminum ash into a denitrifier through a lifter, adding a certain amount of water, mixing and stirring to convert part of aluminum nitride in the aluminum ash into ammonia gas, adsorbing and collecting the ammonia gas, and converting the ammonia gas into ammonia water to be stored by using an ammonia gas adsorption tower for high-temperature denitration during subsequent phase change;

s22: conveying the obtained partial denitrified aluminum ash into a rotary kiln, wherein the rotary kiln has a certain inclination and a certain rotating speed, the aluminum ash moves from a cold end to a hot end under the action of gravity, and is heated by a drying zone at the temperature of 120 ℃ to evaporate free water in the aluminum ash filter residue; then, heating the aluminum ash by a preheating zone at the temperature of 700 ℃ to remove crystal water in the aluminum ash; then, finishing the calcination phase change of the aluminum ash through a crystal phase transition zone at the temperature of 1400 ℃ so that the alumina crystal phase is converted into an alpha phase; and finally, cooling to 200 ℃ through secondary air and kiln head air leakage by a cooling zone, and bagging to obtain an aluminum oxide finished product.

The fuel of the rotary kiln is natural gas, natural gas and air are introduced into the burner in the kiln for heating, and the rotation of the kiln body also strengthens the heat transfer process. During the calcining process of the rotary kiln, smoke dust and SO can be generated by the combustion of natural gas₂NxOx; the calcination of the aluminum ash produces NO₂(ii) a Dust is generated during the rotation of the rotary kiln. The waste gas of the rotary kiln is directly discharged into a flue gas treatment system from a kiln tail flue and then discharged through a P3 exhaust funnel. The stored ammonia water can be utilized for spraying in the flue gas treatment system to remove oxynitride in the high-temperature flue gas. The kiln head cooling feeding and discharging process can cause partial dust to escape, the dust is collected by the gas collecting hood and then sent into the dust removal system for treatment and then discharged, most of the dust which is not collected is settled on the ground, and a small amount of the dust is discharged in an unorganized manner.

Test example 1:

100Kg of aluminum ash raw material to be treated is crushed by a crusher and then put into a magnetic separator for magnetic separation for 10min, 1.24Kg of waste iron is separated, the aluminum ash treated by the waste iron is ball-milled by a ball mill for 50min and then is ground into particles, and the particles are sieved by a sieving machine with the particle size of 120 meshes to obtain 45.7Kg of aluminum slag particles and secondary aluminum ash. The aluminum slag particles are put into a rotary furnace while the particles are hot, then a slag-removing agent is added into the rotary furnace, the mixture is tightly closed for 30 minutes, and the temperature of the rotary furnace is kept at about 800-900 ℃, so that 23.3Kg of aluminum ingot and 21Kg of aluminum slag are obtained. And cooling the aluminum ash slag to 40-60 ℃ through a cold ash bucket to obtain 20Kg of aluminum ash, and putting the aluminum ash into the treatment line again.

And (3) putting the secondary aluminum ash into a denitrifier, adding 3kg of water, mixing and stirring for 5min, and adsorbing and collecting the generated ammonia gas for later use. After stirring, the mixture is conveyed into a rotary kiln and cooled to 200 ℃ through a drying zone at 120 ℃, a preheating zone at 700 ℃, a crystal phase transformation zone at 1400 ℃ and a cooling zone, and 65.2kg of alumina mixture is obtained, and the recovery rate is 65.2%.

Test example 2:

100Kg of aluminum ash raw material to be treated is crushed by a crusher and then put into a magnetic separator for magnetic separation for 10min, 0.7Kg of waste iron is separated, the aluminum ash treated by the waste iron is ball-milled by a ball mill for 50min and is milled into particles, and the particles are sieved by a sieving machine with the particle size of 120, so that 23.6Kg of aluminum slag particles and secondary aluminum ash are obtained. The aluminum slag particles are put into a rotary furnace while the particles are hot, then a slag-removing agent is added into the rotary furnace, the mixture is tightly closed for 30 minutes, and the temperature of the rotary furnace is kept at about 800-950 ℃ to obtain 14.2Kg of aluminum ingots and aluminum slag. And cooling the aluminum ash slag to 40-60 ℃ through a cold ash bucket to obtain 5.9Kg of aluminum ash, and putting the aluminum ash into the magnetic separator again.

And (3) putting the secondary aluminum ash into a denitrifier, adding 3kg of water, mixing and stirring for 5min, and adsorbing and collecting the generated ammonia gas for later use. And after stirring, conveying the mixture to a rotary kiln, and drying the mixture at 120 ℃, preheating the mixture at 700 ℃, transforming the crystal phase at 1400 ℃ and cooling the cooled mixture to 200 ℃ to obtain 83.4kg of alumina mixture with the recovery rate of 83.4%.

Test example 3:

100Kg of aluminum ash raw material to be treated is crushed by a crusher and then put into a magnetic separator for magnetic separation for 10min, 8.3Kg of waste iron is separated, the aluminum ash treated by the waste iron is ball-milled by a ball mill for 50min and then is sieved by a sieving machine with the particle size of 60-120 meshes, and 16.7Kg of aluminum slag particles and secondary aluminum ash are obtained. The aluminum slag particles are put into a rotary furnace while the particles are hot, then a slag-removing agent is added into the rotary furnace, the mixture is tightly closed for 30 minutes, and the temperature of the rotary furnace is kept at about 800-950 ℃ to obtain 11.2Kg of aluminum ingots and aluminum slag. And cooling the aluminum ash slag to 40-60 ℃ through a cold ash bucket to obtain 5.1Kg of aluminum ash, and putting the aluminum ash into the magnetic separator again.

And (3) putting the secondary aluminum ash into a denitrifier, adding 3kg of water, mixing and stirring for 5min, and adsorbing and collecting the generated ammonia gas for later use. After stirring, the mixture is conveyed into a rotary kiln and is dried at 120 ℃, preheated at 700 ℃, cooled to 200 ℃ by a crystal phase transition zone and a cooling zone at 1400 ℃, and 78.2kg of alumina is obtained with the recovery rate of 78.2%.