TW200815609A - Method for the stabilization and recycling of aluminum dross from secondary metallurgy - Google Patents

Abstract

This invention provides a new process for the treatment to stabilize the aluminum nitride and fine metallic aluminum powder containing solid waste, especially the slag from the secondary aluminum metallurgy. By the reaction of aluminum nitride and metallic aluminum with the humidity in the air, ammonia and hydrogen gas are produced which restrict not only the welfare of the human being but also the safety in the industry. In this invention, the thermal hydro chemical method is used to stabilize the material mentioned above. By adding oxidant and pH-value regulator, aluminum nitride and fine metallic aluminum powder are converted to stable aluminum oxide. The product can be reused as the raw material for cement and brick production. Besides, it can be used to replace sand in the construction engineering.

Description

200815609 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a method for recycling secondary molten aluminum waste, in particular to waste containing aluminum nitride and fine metal aluminum powder, which is depleted. Processing and outputting the oxidized product a that can be reused; thus, the land space required for burying can be avoided, and the exploitation/shock consumption of natural resources can be reduced, thereby improving the use efficiency of waste and enhancing economic value.

[Prior Art] According to i, the _ smelting process is mainly based on the recovered waste slag. After high-temperature smelting, partial smelting, lining and other procedures, the ingot product can be produced. The use of downstream industries such as tools and building materials is an important part of the recycling of resources in Taiwan. As with the general high-temperature smelting process, the second generation of the brain is the main waste. In addition to _, there are other impurities in the money, the main components are listed as follows: Element A1 Si N Cl Content 25-30 15-20 1-5 0.5-1.5 Cut 'Because noodle phase #高' sister shaft and material The main component of the reaction, the reaction formula is as follows·· ”

Mg1.5-3

Ca 〇·2-1·2 people in the _ Guocai County added a large number of sputum and anti-oxidation (first type) 2Al + 1.502->AJ2〇3 5 200815609 A1 + 0.5N2^A1N (second type) Therefore, in the aluminum slag produced, in addition to the aluminum contained in the waste aluminum and the alumina produced after high-temperature oxidation, there is still a nitriding. In addition to the above two compounds, the particle size ranges from the large particles above the public grade to the fine powder below 10μ1η. At present, the hybrid f-source technology is designed for the metal Ming. The process is as shown in the first figure: it is crushed and sieved to take the metal-rich coarse particles for smelting, and the remaining metal aluminum powder is too fine. With the current technology, there is no possibility of recycling, and more is treated with concealment; but because the residue is Thai-like gray edge, its towel still contains metal! g fine powder and nitriding, these two components will be found with the water _ generating gas, the reaction formula is as follows: 2A1N + 3H20 AI2O3 + 2NH3 (third type) 2A1 + 3H20 - Al2 〇 3 + 3H2 (fourth formula) The ammonia and helium produced (ammonia has a pungent odor and is toxic, and hydrogen is flammable) not only causes environmental pollution, but also seriously hinders the reuse of bismuth bismuth slag. In view of this, this The inventors have developed an economic benefit of converting the reactive aluminum metal powder and aluminum nitride into reusable alumina in a wet chemical manner to recycle waste for reuse. SUMMARY OF THE INVENTION * The present invention mainly uses a wet chemical method to convert metal and mouse into oxygen contact in two stages. The work is as follows: 1. The oxidation of the metal is carried out by means of an oxidant and a high temperature aeration. 6 200815609 Oxidation, the reaction formula is as follows: 2Α1+1.5〇2^Α12〇3 (Fifth Formula) This can be used to convert the Jinle into an oxide first, so as to avoid a large amount of acid value adjustment agent. 2. Destruction of Nitridazole · This stage is treated with hydration in the environment of alkaline and aqueous phase. The main reactions are as follows: AIN + OH· + H20 — 2ΝΗ3 + Αι(0ίί)4_ ( The formula 6 is fixed in the solubility of water at a fixed temperature, and the excess is volatilized to the wire towel; the recording of hydrogen and oxygen is combined with other cations to form a hydrate. The output of this counter-county is related to the production and volatility. Therefore, the following two methods can be used to accelerate the reaction. (1) The water solubility of ammonia is quite high, at room temperature 2 (the next liter of water can dissolve about 2 a liter. Atmospheric gas, it is necessary to use high temperature to reduce the solubility in ammonia, so that the equilibrium of the reaction shown in the sixth formula is shifted to the product side, and the purpose of completely destroying the nitriding is achieved. (2) In addition to high temperature, exposure can also be utilized. In the way of air, the ammonia is carried out from the water to achieve the same purpose. In summary, the process flow chart shown in the second figure can be obtained, especially for the waste containing the metal Cui Lu and the nitrite. The resource treatment of the secondary molten aluminum waste residue remaining after the recovery of the metal Ilu is extremely effective. [Embodiment] Using the process technology disclosed in the present invention, the secondary molten aluminum remaining after the recovered metal Ming 200815609 is processed. The slag powder, as shown in the second figure, has the following steps: (1) Dry-mixed aluminum slag powder: the aluminum slag dry powder is stirred to make it fully mixed uniformly, avoiding excessive concentration of metal aluminum and aluminum nitride, causing local reaction. Mass production of gas (ammonia, hydrogen), causing Boiling phenomenon; (2) Slurry aluminum slag powder: Firstly, put 9G °C hot water in the heat preservation reaction tank equipped with a stirrer and aeration device, listen to the starter and aeration equipment, and then dry the aluminum evenly. The slag powder is slowly added to the reaction tank to control the solid-liquid ratio to 1 metric ton / cubic meter; (3) Oxidation reaction: adding hydrogen peroxide or other oxidizing agent, the amount of hydrogen peroxide is about 5 angstroms per gram. Litreat and aeration reaction for 3 minutes; (4) Hydration reaction · Slowly add slaked lime or other _ to improve the pH value, pH is best at η, slaked lime is about 100 kg per ton of slag powder, and exposed The gas reacts for 90 minutes; when the hydration reaction is carried out, the water is evaporated and the amount of hot water is added. (4) The overall rhyme reduction is allowed to be within 10%; (5) After the reaction is finished, it is allowed to stand for at least 20 minutes to precipitate the oxidized product; 6) Solid-liquid separation and cleaning · After extracting the supernatant liquid, wash the sinking material until the odor of the shot is removed; the preferred age is added to the 9 〇t hot water for at least 10 minutes; the washing procedure is preferably repeated. Three times to effectively remove residual ammonia. Oxidation products can be obtained for subsequent reuse, such as 200815609 sandstone replacement materials, cement squaring scales, pinakis, etc. The original smashed powder is detected by elemental analyzer and thermal analysis to contain 3 nitrogen and 2% metal. After the process of this process, the composition of the obtained oxidation products is as follows:

Most of them are in the form of oxidized inscriptions. The conversion rate of metal and nitriding is more than 85%' and more than 90% of chlorine can be removed to facilitate the subsequent reuse of oxidized products.

In summary, the present invention has indeed achieved the intended use and efficacy, and the innovative technology can replace the metal and nitriding _ into a reusable resource-based oxidation product; The second molten aluminum slag powder remaining in private, the case has more progressive effect, and provides substantial economic benefits for industrial use. Therefore, the invention has met the application requirements of the invention patent, and the application for invention patent is filed according to law. For review, and early grant of patents, Real Deze. [Simple description of the diagram] The first figure shows the current process of recovering aluminum from the secondary molten aluminum slag. The second figure shows the process flow chart of the present invention. 9

Claims (1)

200815609 X. Patent application scope ··································································································· : Adding an appropriate amount of hot water to the heat preservation reaction tank and starting: the town secrets the worms and the worms and the worms are added to the tank; (3) the oxidation reaction, the addition of the oxidizing agent's continued to win and aeration Oxidation reaction, at least 30 minutes; • (4) Hydration money: slowly add money _ the whole division is at least u, although _ mixing and aeration to carry out hydration reaction for at least 90 minutes, and timely addition of appropriate amount of hot water during the hydration reaction; (5) Solid-liquid separation: After the reaction is completed, the oxidized product can be obtained after the liquid-repellent separation. 2. The method of claim 2, wherein the step (2) is added to the hot water in the heat preservation reaction tank, and the water temperature is at least 5 Torr. 〇 Above. 3. The method of claim i, wherein the step (2) aeration, na _ simultaneously performs the aeration amount and the swimming speed so as not to cause the woven slurry to form a sink. 4. The method according to claim _, wherein the step (2) has a solid-liquid ratio of 1 mic/m3. 5. The method of claim 1, wherein the oxidizing step of the step (3) is such that the oxidizing agent is hydrogen peroxide, bleach or other oxidizing agent. 6. The method of claim 5, wherein the oxidizing agent is used in an amount of from 1 to 100 liters per gram of slag powder. 7. The method of claim 1, wherein the step (4) hydration reaction station 200815609 uses slaked lime, sodium hydroxide, and a drug. Sodium carbonate or other additives with increased pH, sputum, and fines are used for each pure one, and the sputum can be used alone or in combination. In the line, tearing the branches, shooting _ hydration reaction is appropriate (4) 1 adding hot water, the total volume reduction of the slurry is allowed to be within Na. m The method of the first item, wherein the step (3) solid-liquid separation wooden moon? Set or over (repeated) filtration or centrifugation or decantation techniques. U. The method of claim 10, wherein the time is 5 to 20 minutes. 12. The method of claim 2, wherein the step (5) obtains the oxidized product, then washes and separates the water, and washes it to remove residual ammonia, and then separates it by solid-liquid separation, and has good commercial value. The oxygen is poured. 13. For the party* mentioned in the scope of patent application, in the water washing procedure, hot water above 50 °C is used. 14. The method of claim 12, wherein the solid-liquid separation process is carried out by using a method of self-secreting, adding Wei water or heating the dry material to remove water from the solid. 11