A method for resource utilization of aluminum ash slag in cooperation with copper slag

Abstract

The application discloses a waste copper slag treatment method for treating waste with waste, in particular to a resource utilization method for cooperatively treating copper slag with aluminum ash, and belongs to the technical field of solid waste. The specific principle is that the main component AlN in the aluminum ash reacts with water easily to generate ammonia gas, and the ammonia gas has strong reducing property and can displace copper in the copper slag under the condition of high-temperature roasting, so that the copper slag can be recycled and reused. The method has the advantages of simple operation, low cost, no secondary pollution and the like, and has good economic benefits.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology for copper slag and aluminum ash slag, and specifically to a resource utilization method for the co-processing of copper slag with aluminum ash slag. Background Technology

[0002] Aluminum ash is mainly generated in all aluminum melting processes, such as aluminum electrolysis and aluminum (including recycled aluminum) processing. It primarily adsorbs impurities like alumina from the molten aluminum. Therefore, aluminum ash must be periodically removed from the furnace during smelting, becoming industrial waste. The main phases of aluminum ash are metallic aluminum, alumina, aluminum nitride, and magnesium aluminum spinel, with aluminum nitride content ranging from 10% to 40%, alumina from 15% to 30%, and elemental aluminum from 5% to 20%. Statistics show that approximately 150 to 290 kg of aluminum ash is generated for every ton of aluminum produced and cast. Using aluminum ash to treat copper slag, a waste product, offers a new approach, turning waste into a valuable resource, which is of great significance for improving environmental and social benefits.

[0003] Copper is an essential non-ferrous metal indispensable in fields such as electrical engineering, light industry, machinery manufacturing, construction, and national defense. In my country, approximately 97% of copper is obtained through pyrometallurgical smelting of copper concentrate. Copper smelting slag commonly contains metallic elements such as Cu, Fe, Zn, Au, and Ag. How to better utilize copper slag as a resource is a pressing issue for the copper smelting industry. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a resource utilization method for the co-processing of copper slag with aluminum ash slag.

[0005] The technical solution of the present invention is as follows: a resource utilization method for the co-processing of copper slag with aluminum ash slag, comprising the following steps:

[0006] S1: Dry the copper slag and aluminum ash slag, then crush and grind them into powder;

[0007] S2: Mix copper slag and aluminum ash slag powder evenly in a certain proportion and then calcine it under a steam atmosphere;

[0008] S3: The roasting product from step S2 is crushed and then floated to recover elemental copper.

[0009] S4: Alumina recovery is performed on the residue after flotation.

[0010] Preferably, in step S1, the copper slag and aluminum ash slag are dried and then crushed and ground to below 200 mesh.

[0011] Preferably, in step S1, the mass ratio of copper slag to aluminum ash slag is (2-4):1.

[0012] Preferably, in step S2, the roasting is carried out by directly introducing steam into a tube furnace.

[0013] Preferably, in step S2, the roasting is specifically carried out in a tube furnace with ferrous sulfate heptahydrate added and roasted in a steam atmosphere.

[0014] Preferably, in step S2, the calcination temperature is 500–800°C, and the heating rate is 5–10°C / min.

[0015] Preferably, in step S2, the roasting and heat preservation time is 1 to 2 hours.

[0016] Preferably, in step S4, NaOH solution is added to the residue after flotation to obtain NaAlO2; or Al(OH)3 precipitate is obtained under acidic conditions.

[0017] The beneficial effects of this invention are:

[0018] (1) This invention adopts the concept of treating waste with waste to achieve the co-processing of copper slag and aluminum ash slag, making full use of the waste slag resources in the smelting industry.

[0019] (2) The process of this invention is simple, highly operable, produces no polluting products, and uses inexpensive and widely available raw materials. Attached Figure Description

[0020] Figure 1 This is a flowchart of the direct steam roasting process in a method for the co-processing and resource utilization of copper slag and aluminum ash slag according to the present invention.

[0021] Figure 2 This is a flowchart of the process of adding ferrous sulfate heptahydrate and calcining in a method for the co-processing and resource utilization of copper slag and aluminum ash slag according to the present invention.

[0022] Figure 3 These are XPS plots of Example 1(b) and Comparative Example 1(a). Detailed Implementation

[0023] A method for the resource utilization of copper slag involves drying, crushing, and grinding aluminum ash slag and copper slag, mixing them, and then calcining them at a temperature of 500–800°C in a steam atmosphere. The calcined product is crushed and then floated to recover metallic copper. NaOH solution is added to the residue to obtain NaAlO2, and Al(OH)3 precipitate is obtained under acidic conditions and can be used in other processes.

[0024] The main principle of this invention lies in the fact that the main component of aluminum ash is aluminum nitride, which undergoes a hydrolysis reaction at high temperatures to generate NH3. Ammonia gas has strong reducing properties and displaces copper at high temperatures. The specific chemical equation is as follows:

[0025] 2AlN + 3H₂O → Al₂O₃ + 2NH₃

[0026] 3CuS + 2NH3 → 3Cu + N2 + 3H2S;

[0027] In the preferred embodiment, in step S1, the copper slag and aluminum ash slag are dried and then crushed and ground to below 200 mesh.

[0028] In the preferred embodiment, in step S1, the mass ratio of copper slag to aluminum ash slag is (2-4):1.

[0029] In the preferred embodiment, in step S2, steam can be directly introduced into the tube furnace for roasting, or ferrous sulfate heptahydrate can be added and mixed and roasted in a steam atmosphere.

[0030] In the preferred embodiment, in step S2, the calcination temperature is 500–800°C and the heating rate is 5–10°C / min.

[0031] In the preferred embodiment, the roasting and heat preservation time in step S2 is 1 to 2 hours.

[0032] The following detailed description of a method for the co-processing and resource utilization of copper slag and aluminum ash slag provided by the present invention, with reference to specific embodiments, is not intended to limit the scope of protection of the present invention.

[0033] It should be noted that the copper slag used in this invention comes from Daye Mine in Hubei Province. After crushing the copper slag and aluminum ash slag, they were placed in an oven and dried at 100℃ for 3 days. The dried slag was then ground to below 200 mesh. The composition and content of the copper slag and aluminum ash slag were determined and are shown in Tables 1 and 2, respectively.

[0034] Table 1. Elemental types and contents in copper slag

[0035]

[0036] Table 2 Composition and content of aluminum ash slag

[0037]

[0038] Example 1

[0039] A method for the co-processing and resource utilization of copper and aluminum ash slag, referenced Figure 1 The specific steps are as follows: Take 1.5g of crushed and dried aluminum ash powder and 4.5g of crushed and dried copper slag powder, mix them evenly, and put them into a tube furnace. After vacuuming, steam is introduced at a flow rate of 100ml / min for calcination. The heating rate is set to 10℃ / min, the target temperature is 500℃, and the calcination time lasts for 2 hours.

[0040] Example 2

[0041] A method for the co-processing and resource utilization of copper slag and aluminum ash slag, referenced Figure 2The specific steps are as follows: Take 1.5g of crushed and dried aluminum ash powder and 3.5g of crushed and dried copper slag powder, add 1.0g of FeSO4·7H2O and mix evenly. Then put it into a tube furnace, evacuate the vacuum, and introduce steam at a flow rate of 100ml / min for calcination. The heating rate is set to 10℃ / min, the target temperature is 500℃, and the calcination time lasts for 2 hours.

[0042] Comparative Example 1

[0043] A method for the co-processing and resource utilization of copper slag and aluminum ash slag, the specific steps of which are as follows: 1.5g of crushed and dried aluminum ash slag powder and 4.5g of crushed and dried copper slag powder are mixed evenly and placed in a tube furnace. After vacuuming, argon gas is introduced at a flow rate of 100ml / min for roasting. The heating rate is set to 10℃ / min, the target temperature is 500℃, and the roasting time lasts for 2 hours.

[0044] Example 3

[0045] A method for the co-processing and resource utilization of copper slag and aluminum ash slag, referenced Figure 1 The specific steps are as follows: Take 1.5g of crushed and dried aluminum ash powder and 3g of crushed and dried copper slag powder, mix them evenly, and put them into a tube furnace. After vacuuming, steam is introduced at a flow rate of 100ml / min for calcination. The heating rate is set to 10℃ / min, the target temperature is 500℃, and the calcination time lasts for 2 hours.

[0046] Example 4

[0047] A method for the co-processing and resource utilization of copper slag and aluminum ash slag, referenced Figure 1 The specific steps are as follows: Take 1.5g of crushed and dried aluminum ash powder and 4.5g of crushed and dried copper slag powder, mix them evenly, and put them into a tube furnace. After vacuuming, steam is introduced at a flow rate of 100ml / min for calcination. The heating rate is set to 10℃ / min, the target temperature is 500℃, and the calcination time lasts for 1 hour.

[0048] Example 5

[0049] A method for the co-processing and resource utilization of copper slag and aluminum ash slag, referenced Figure 1 The specific steps are as follows: Take 1.5g of crushed and dried aluminum ash powder and 4.5g of crushed and dried copper slag powder, mix them evenly, and put them into a tube furnace. After vacuuming, steam is introduced at a flow rate of 100ml / min for calcination. The heating rate is set to 10℃ / min, the target temperature is 700℃, and the calcination time lasts for 2 hours.

[0050] The products obtained by flotation after calcination with steam (Example 1) and Comparative Example 1 were characterized by XPS analysis, as shown in the figure. Figure 3 ,from Figure 3 It can be seen from this that Figure 3 Elemental copper was indeed formed in b; however, XPS analysis of the product roasted with argon gas (Comparative Example 1) did not reveal a copper peak in the 0-valence state. Figure 3 a) Simultaneously, sodium hydroxide was added to the residue after flotation in Examples 1-5, and carbon dioxide was passed through to generate a white precipitate. Both hydrochloric acid and sodium hydroxide dissolved in the white precipitate, further proving that the white precipitate was aluminum hydroxide.

[0051] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of the present invention.

Claims

1. A method for the resource utilization of copper slag through the co-processing of aluminum ash slag, characterized in that, Includes the following steps: S1: Dry the copper slag and aluminum ash slag, then crush and grind them into powder; S2: Mix copper slag and aluminum ash slag powder evenly in a certain proportion and then calcine it under a steam atmosphere; In step S2, the roasting is specifically carried out in a tube furnace with ferrous sulfate heptahydrate added and roasted under a steam atmosphere. The roasting temperature is 500-800℃ and the heating rate is 5-10℃ / min. S3: The roasting product from step S2 is crushed and then floated to recover elemental copper. S4: Alumina recovery is carried out on the residue after flotation; in step S1, the copper slag and aluminum ash slag are dried and crushed and ground to below 200 mesh; in step S1, the mass ratio of copper slag and aluminum ash slag is (2~4):1; in step S2, the roasting is carried out by directly introducing steam into a tube furnace; the roasting holding time in step S2 is 1~2 hours. In step S4, NaOH solution is added to the residue after flotation to obtain NaAlO2; or Al(OH)3 precipitate is obtained under acidic conditions.

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