TWI614348B - Aluminum slag stabilizer - Google Patents

Description

Aluminum slag stabilizer

The invention relates to an aluminum slag stabilizer and an aluminum slag stability resource method, which converts aluminum slag waste into stable waste which does not produce ammonia odor after water, so as to be buried or further resourced.

Aluminum slag is scum produced by reverberating furnace and furnace smelting when aluminum scrap is recycled or aluminum is cast. Since aluminum is a relatively active metal, it is easy to oxidize with oxygen in the air to form alumina; a small part reacts with nitrogen to form aluminum nitride; or with fuel gas and organic impurities to form aluminum carbide, and The unreacted aluminum metal component also remains in the aluminum slag, making the composition of the aluminum slag very complicated and uneven.

In the reclaimed aluminum plant, the scum for cooling is initially screened and recovered in the factory. The slag material is firstly crushed by a hammer mill or a ball mill, and then sieved. The content of metal aluminum is higher than that of the sieved large particles. High, can be sent to the rotary furnace for remelting treatment. Typical products are larger than 1/4 inch in size and typically have a metal aluminum content of up to 60 to 70% and can be sent directly to a rotary kiln. For the intermediate particle size, the metal aluminum content is usually between 30 and 45%. After ball milling (dry) equipment, it can be further enriched and processed to improve the grade and then remelted and recovered. The aluminum slag having a particle size of 20 mesh or less is generally not disposed of and is discarded or used as a fill.

The technology and development of domestic aluminum slag recycling and resource treatment have been carried out for many years, but looking at the various aluminum slag stabilization technologies, TW455514 is treated with wet acid and acid such as sulfuric acid and phosphoric acid, and TW233312 is treated by ball milling and agitating machinery, TW123458 An aluminum slag stabilization method, which utilizes calcium oxide-containing substances (such as desulfurization slag waste produced by a steelmaking plant) as a stabilizer for the use of aluminum slag waste, etc., cannot achieve the purpose of complete stabilization of the aluminum slag, and some technologies Need to use expensive disposal costs, or stabilize During the process, it was explained that the odorous ammonia gas and the combustible gas methane were treated in a very complicated and inefficient manner. Therefore, there is no commercial operation of the domestic aluminum slag resource, and the aluminum slag waste is still mainly buried in sanitary.

However, before entering the sanitary burial, the problem of odor and odor emission during the temporary storage and transportation of aluminum slag remains to be solved. The inventor proposed a cost-effective aluminum slag stabilizer and aluminum slag stability resource treatment process, which can effectively inhibit aluminum slag. The odor and harmful substances are discharged, so that the aluminum slag can be stabilized, easy to enter the sanitary landfill or further resourced, and avoid the problem of people's feelings.

The invention relates to an aluminum slag stabilizer and a method for restoring resources, which uses a substance containing ferrous chloride, sweet potato leaves, banana leaves and garlic as a stabilizer for aluminum slag waste, and the acid after hydrolysis by ferrous chloride The environment promotes the stability of the aluminum slag. When the heating and cooking promotes the reaction and evaporates the water, the remaining aluminum slag has no odor. After the treated aluminum slag touches the water, it will not produce an odor such as ammonia odor. The purpose of the aluminum slag stabilization treatment.

Among the components of the aluminum slag, in addition to the main alumina component, aluminum nitride and aluminum carbide will continue to explain the odorous ammonia and flammable gas methane when exposed to water in a humid environment, causing environmental damage. Serious pollution. Therefore, when the aluminum slag is disposed of or reused, it must be carefully considered how to avoid and solve the aforementioned environmental pollution problems.

The aluminum metal, aluminum nitride, aluminum carbide and the like remaining in the aluminum slag are reactive, and when reacted with water, a hydrolysis reaction occurs, and the chemical reaction formulas are as follows:

(1) Metallic aluminum Al _(s) +3H ₂ O ₍₁₎ → Al(OH) _3(s) +3/2H _2(g) , △H=-99.8kcal/mol

(2) Aluminum carbide Al ₄ C _3(s) +12H ₂ O ₍₁₎ → 4Al(OH) _3(s) +3CH _4(g) , △H=-422.5kcal/mol

(3) Aluminum nitride AlN _(s) +3H ₂ O ₍₁₎ → Al(OH) _3(s) +NH _3(g) , △H=-53.2kcal/mol

It is shown by the above reaction formula that after the components such as aluminum metal, aluminum nitride, aluminum carbide and the like remaining in the aluminum slag are hydrolyzed with water, the main products are all aluminum hydroxide, and both are exothermic. Although the composition of the aluminum slag may be different depending on the source of the recycled raw material of the recycled aluminum plant, in the high temperature process of smelting, gold Aluminium is more active and oxygen than other elements, so the high aluminum content characteristics of the scum remain unchanged.

At least 2,000 metric tons of aluminum slag waste is produced annually from the reclaimed aluminum plant and the aluminum smelting industry. Although aluminum slag belongs to general business waste, unlike hazardous waste, it is subject to strict regulations, but the composition of aluminum slag is very Uneven, containing metal aluminum, aluminum nitride, aluminum carbide and other components, if not properly stabilized, in contact with water, will continue to explain the odor of ammonia and flammable gas methane, The environment causes serious pollution. However, in general, when the aluminum slag is subjected to the stabilization treatment, since part of the aluminum nitride component is coated on the inner layer of the aluminum slag particles, the main product of the hydrolysis reaction which is generally stabilized is aluminum hydroxide, which is a colloidal state. The product, which is in the outer layer of the aluminum slag particles, hinders the infiltration of water molecules, making the hydrolysis reaction of aluminum nitride inside the aluminum slag particles very slow and difficult. That is to say, in the process of burying and storing aluminum slag, the release of ammonia odor often lasts for several years, and the present invention improves and overcomes the aforementioned problems.

In view of the shortcomings of the conventional aluminum slag technology, the object of the present invention is to provide an aluminum slag stabilizer and an aluminum slag stability resource treatment process, mainly by using a specific proportion of aluminum slag, ferrous chloride, and sweet potato leaves. , a combination of several kinds of substances such as banana leaves and garlic, and then add appropriate amount of water, and continue to fully stir and heat the steps, so that the harmful substances such as aluminum nitride, aluminum carbide, metal aluminum and the like are rapidly hydrolyzed and leave the aluminum residue, and finally The obtained aluminum slag powder has no odor and odor, and even when it is in contact with water, it does not emit odor and harmful substances, effectively solves the problem that the aluminum slag is not stable enough, and achieves the ultimate stability of aluminum slag disposal and resource recovery.

The aluminum slag stabilizer of the present invention is mainly composed of a combination of four substances including ferrous chloride, sweet potato leaves, banana leaves and garlic. The aluminum slag stabilizer may be selected from the group consisting of 15% to 45% by weight of ferrous chloride, 12% to 25% by weight of sweet potato leaves, 12% to 25% by weight of banana leaves and 61%~ 5% by weight of the composition of the garlic.

The aluminum slag stabilizer of the invention has the effects of high efficiency reduction and elimination of the odor of the aluminum slag, and the mechanism for avoiding the odor of the aluminum slag and reducing the odor of the aluminum slag is the stability of the aluminum slag stabilizer. Chloride ion (Cl ^- ) reacts with ammonia gas (NH ₃ ) produced by aluminum slag to form ammonium chloride, and ferrous ion (Fe ⁺² ) of aluminum slag stabilizer reacts with hydrogen sulfide (H ₂ S) produced by aluminum slag The formation of ferrous sulfide makes the aluminum residue stable. Its main chemical reaction formula is as follows:

(4) NH ₃ +Cl ^- +H ₂ O → NH ₄ Cl+OH ^-

(5) Fe ²⁺ + H ₂ S → 2H ⁺ + FeS

(6)H ⁺ +OH ^- → H ₂ O

The sweet potato leaf, banana leaf and garlic head contained in the stabilizer composition of the present invention cannot be analyzed for the detailed chemical reaction mechanism between the sweet potato leaf and the aluminum residue to be treated because of the compound component, but the inventors have found through many experiments that although The use of a kind of ferrous chloride alone and a certain degree of inhibition of odor and odor, but the combination of melon leaves, banana leaves and garlic and ferrous chloride, has the effect of eliminating the odor of the aluminum residue (extra) and efficient, The aluminum slag stabilizer of the invention has higher efficiency than the ferrous chloride alone. The aluminum slag powder obtained after the treatment has no odor and even emits odor and harmful substances even when it is in contact with water. The invention solves the problem that the stability of the aluminum slag is not complete, and achieves the ultimate stability of the aluminum slag and the recovery of the resources, and fully demonstrates that the aluminum slag stabilizer of the invention has novelty and progress.

The aluminum slag stability resource treatment process of the present invention is as shown in the first figure, and the steps thereof include: (a) placing the aluminum slag in a pulverizer for pulverization for 1 to 60 minutes to obtain an aluminum slag powder having an average particle diameter of less than 600 μm; b) taking the aluminum slag powder obtained in the step (a) and placing it in the mixing and stirring tank, and adding an appropriate amount of the aluminum slag stabilizer and the water to form a mixture, wherein the aluminum slag stabilizer is added in an amount of 1% to 20% by weight of the aluminum slag powder. %, the water directly added in this step is 150%~300% of the weight of the aluminum slag powder; (c) the mixture obtained in the step (b) is stirred for 1 to 120 minutes to make a mixture which is uniformly mixed; (d) The mixture obtained in the step (c) is heated and cooked until the water is completely evaporated, and the dried powder is left to obtain the stabilized aluminum residue.

The gas discharged from the above blending, mixing and heating and cooking is introduced into the exhaust gas treatment system by the exhaust gas collection system, and the treated purified gas complies with air pollution control. Discharge after the regulations.

10‧‧‧Aluminum slag

20‧‧‧Aluminum slag stabilizer

30‧‧‧ water

40‧‧‧Smash

50‧‧‧ blending

60‧‧‧ stirring

70‧‧‧heat cooking

80‧‧‧Reinforced aluminum slag

The first picture Aluminium slag stability resource processing process (1)

The second picture of aluminum slag stability resource processing process (2)

The technical features and advantages of the present invention, as well as the description of the first and second figures, and the test results of several preferred embodiments, will be apparent to those of ordinary skill in the art.

The aluminum slag stability resource treatment process of the present invention (please refer to the first figure), the steps thereof include: (a) placing the aluminum slag (10) in a pulverizer for pulverization (40) for 1 to 60 minutes, so that the average granule is obtained. The aluminum slag powder having a diameter of less than 600 μm; (b) the aluminum slag powder obtained in the step (a) is placed in a mixing and stirring tank, and then an appropriate amount of aluminum slag stabilizer (20) and moisture (30) are added to form a mixture, wherein the aluminum slag The stabilizer is added in an amount of 1% to 20% by weight of the aluminum slag powder, and the water directly added in this step is 150% to 300% by weight of the aluminum slag powder; (c) the mixture obtained in the step (b) is stirred (60) ) 1~120 minutes, to make a mixture of evenly mixed; (d) Finally, the homogeneous mixture obtained in the step (c) is heated and cooked (70) and heated to evaporate until the water is evaporated, and the dried powder is left to obtain the stabilized aluminum residue. (80).

If the particle size distribution of the aluminum slag is already subtle, the pulverization process of the step (a) of the first process flow can be skipped and directly enters the step (b), so another aspect of the present invention can process the process of the first figure. Can be simplified to the processing flow of the second figure.

Above the first and second figures, in the blending, mixing and heating and steaming The exhausted gas is introduced into the exhaust gas treatment system by the exhaust gas collection system, and the treated purified gas is discharged after complying with the air pollution control regulations (this exhaust gas collection and treatment portion is not shown in the drawing).

The aluminum slag samples used in the embodiments of the present specification are all taken from a secondary aluminum slag temporary storage field in China. The particle size analysis results of the aluminum slag show that the particle size ranges from 63 to 500 μm, and more than 90% of the particle diameters are less than 500 μm. A sample of aluminum slag that has not been processed, indicated by the code X.

Example 1: Aluminum slag stabilizer blending and production

To make 120kg of aluminum slag stabilizer, first take 40kg of ferrous chloride, 20kg of sweet potato leaves, 20kg of banana leaves and 40kg of garlic, put them in the pulverizer, and then pulverize for 1~60 minutes to make the average granules A composition having a diameter of less than 1,000 μm and a uniform composition, that is, a sample having an aluminum residue stabilizer (indicated by code A).

Example 2: Aluminium slag stability and resource treatment

Take a mixed stirring tank of heating system, add 1,000kg of aluminum slag sample (X), 120kg of aluminum slag stabilizer sample (A) and 2,500kg of water together into the mixing and agitation tank, first mix and stir for 30 minutes, stir it. Uniform, then start heating until the liquid in the mixing tank is boiled, and then continue to heat and cook until the water is completely evaporated, leaving the dry powder, which is stabilized aluminum slag (indicated by the code Y).

The pH of the aluminum slag (X) before treatment was 10.5, and the detection value of ammonia nitrogen was 1,190 mg/L. The pH of the stabilized aluminum slag (Y) treated by the present invention was 8.4, and the detection value of ammonia nitrogen was 13.2. Mg/L, detailed Table 1, fully shows that the stabilized aluminum slag (Y) treated by the invention has no strong alkali and odor, even if it is added with water to the stabilized aluminum slag (Y), it will not escape. Disgusting odor.

The stabilized aluminum slag treated by the invention is tested by the toxic characteristic dissolution program (TCLP) of the business waste: pH value is 7.50, total copper is 1.06 mg/L, total enthalpy is 1.04 mg/L, and total arsenic is 0.002. The total selenium is 0.006mg/L, the remaining hexavalent chromium, total chromium, total cadmium, total lead and total mercury are all ND. The test results of each test item are in compliance with the control standards, as shown in Table 2. Therefore, it is fully shown that the stabilized aluminum slag (Y) treated by the present invention is not a hazardous business waste, and can be directly sent to a sanitary landfill for disposal, and can be directly used for subsequent reuse or as a raw material for resource utilization, such as Sand and stone replace materials, bricks, ceramics, cement materials, etc.

While the present invention has been described above by way of a preferred embodiment, it is not intended to limit the scope of the present invention, and the scope of the present invention can be modified and retouched without departing from the spirit and scope of the invention. The person defined in the scope of the patent application shall prevail.

In summary, the present invention can be utilized in the industry, and the relevant aluminum slag stabilizer and aluminum slag stability resource treatment process disclosed in the present invention are not found in the publication or have been publicly used before being examined. In the innovative technology in the field of aluminum slag waste treatment, and after the specific implementation of the present invention, it is possible to surely prevent the aluminum slag from escaping the odor in the future, and at the same time, the aluminum slag stabilized by the present invention is subjected to a commercial waste toxicity characteristic dissolution program (TCLP). The results are in line with regulatory standards and can indeed achieve the goal of resource recycling. Those of ordinary skill in the art can easily complete the prior art according to the application, fully demonstrating the novelty and progress of the present invention; Ming's aluminum slag stabilizer and aluminum slag stability resource treatment process can help solve the domestic environmental problems of aluminum slag waste burial and achieve the ultimate goal of recycling and reuse of aluminum slag resources, increase industrial competitiveness, and expect you to grant patents as soon as possible. Benefiting domestic related industries.

10‧‧‧Aluminum slag

20‧‧‧Aluminum slag stabilizer

30‧‧‧ water

40‧‧‧Smash

50‧‧‧ blending

60‧‧‧ stirring

70‧‧‧heat cooking

80‧‧‧Reinforced aluminum slag

Claims (1)

An aluminum slag stabilizer, which is a composition composed of ferrous chloride, sweet potato leaves, banana leaves, and garlic; and in the composition, the content of ferrous chloride is 25% by weight to 40% by weight; The content of sweet potato leaves is 12% by weight to 25% by weight; the content of banana leaves is 12% by weight to 25% by weight, and the rest is garlic.