A method for synergic resource utilization of zinc-aluminum alloy welding slag and waste hydrochloric acid for hot galvanizing

Abstract

This invention provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The synergistic resource utilization method includes the following steps: (1) mixing zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid, and performing dissolution and neutralization treatment to obtain a first treatment liquid; (2) extracting the first treatment liquid to obtain an extract and a raffinate; (3) back-extracting the extract to obtain a mixture of zinc chloride and ammonium chloride; and then performing evaporation and crystallization treatment to obtain zinc ammonium chloride; and finally, aging the raffinate to obtain polyaluminum ferric chloride. The synergistic resource utilization method of this invention is simple to operate, has low processing costs, and realizes the synergistic treatment of industrial waste zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid, which has good economic and environmental benefits and is suitable for large-scale promotion and application.

Description

Technical Field

[0001] This invention relates to the field of industrial waste resource utilization technology, and in particular to a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid. Background Technology

[0002] Hot-dip galvanizing, also known as hot-dip zinc plating, is a common method of metal corrosion protection. Hot-dip galvanized products offer advantages such as good corrosion resistance, high cost-effectiveness, long service life, large market capacity, low cost, and 100% recyclability. The principle of hot-dip galvanizing involves cleaning the steel or iron parts, treating them with a solvent, drying them, and then immersing them in molten zinc at approximately 430°C. This process forms a zinc coating on the surface of the workpiece, achieving corrosion resistance.

[0003] The hydrochloric acid used in the hot-dip galvanizing pickling process experiences a decrease in pickling speed and efficiency once its acidity drops to a certain concentration, rendering the acid waste acid that needs to be discharged. Traditional methods for treating waste hydrochloric acid from hot-dip galvanizing typically involve neutralization with liquid alkali, quicklime, hydrated lime, or carbide slag. However, these methods generate large amounts of waste residue, causing secondary pollution. Another method is oxidative roasting, where waste hydrochloric acid is sprayed into a 600°C furnace, where Fe2O3 is discharged from the bottom, and hydrogen chloride gas is absorbed by water to produce hydrochloric acid as a byproduct. However, this method requires significant equipment investment, high energy consumption, and high operating costs, making it unsuitable for widespread use by small and medium-sized enterprises and for the large-scale treatment of waste hydrochloric acid from hot-dip galvanizing.

[0004] CN111018001A discloses a process for treating waste hydrochloric acid from hot-dip galvanizing. The process includes feeding pretreated and reduced-impurity-removed waste hydrochloric acid into a triple-effect evaporation system for evaporation and concentration, followed by cooling, centrifugal filtration, and the extraction of solid ferrous chloride and mother liquor. If the zinc content in the solid ferrous chloride does not exceed the control threshold, it is used to produce ferric chloride, a water treatment agent that meets national standards. Otherwise, it needs to be dissolved in dilute acid water generated from evaporation and concentration, and then recrystallized to obtain solid ferrous chloride with a zinc content meeting the control threshold, thereby producing ferric chloride, a water treatment agent that meets national standards. This technical solution is simple, has a low operational risk factor, and does not generate secondary pollution. It provides a new approach for the resource utilization of waste hydrochloric acid from hot-dip galvanizing, effectively reducing environmental pressure while increasing the economic benefits for enterprises.

[0005] CN113651365A discloses a method for utilizing waste hydrochloric acid solution from hot-dip galvanizing pickling. The method includes removing impurities from the waste hydrochloric acid solution from the hot-dip galvanizing pickling process, adjusting the total oxygen content (TOC), and controlling the Fe content. 3+The method involves the following steps: adsorption, desorption, manganese removal, and preparation of basic zinc carbonate using a chloride-type macroporous anion exchange resin. This method is easy to control and can effectively separate elements such as zinc, iron, and manganese from the waste liquid. The chloride-type macroporous anion exchange resin has high adsorption efficiency for zinc, and the recovered product has high purity. The recovered ferrous chloride and basic zinc carbonate meet industry standards, effectively achieving the goal of resource reuse.

[0006] CN106587478A discloses a method for resource utilization treatment of hot-dip galvanizing waste acid, including the following steps: (1) adding an oxidant to the hot-dip galvanizing waste acid to remove Fe from the waste acid. 2+ Fe ion oxidation 3+ Ions, then adjust the pH of the waste acid to 4.5, Fe 3+ (1) Fe(OH)3 precipitate is generated, solid-liquid separation is performed, the Fe(OH)3 precipitate is recovered, and the filtrate proceeds to the next step; (2) The pH of the filtrate obtained in step (1) is adjusted to 9.5, and heavy metal ions generate corresponding sparingly soluble salt precipitates. After solid-liquid separation, the filtrate proceeds to the next step; (3) The pH of the filtrate obtained in step (2) is adjusted to neutral, and then the filtrate is heated and evaporated. The soluble salts in the filtrate crystallize out and are recovered, and the condensate generated during the evaporation process is reused. The separation of iron and heavy metals and the efficient recovery of iron are achieved, while the heavy metal hazardous waste meets the requirements for volume reduction treatment.

[0007] However, the above methods have high processing costs and complex operation steps. Summary of the Invention

[0008] In view of the problems existing in the prior art, this invention provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The method achieves the separation of zinc ammonium and aluminum iron from the two industrial wastes through dissolution and neutralization treatment and extraction. Subsequently, the extract is subjected to back-extraction and evaporation crystallization treatments to obtain zinc ammonium chloride flux; the raffinate is aged to obtain polyaluminum ferric chloride water purification agent. The method of this invention has low processing cost and low energy consumption, achieving the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] This invention provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid, the method comprising the following steps:

[0011] (1) Mix zinc-aluminum alloy welding slag with hot-dip galvanized waste hydrochloric acid and perform dissolution and neutralization treatment to obtain the first treatment solution;

[0012] (2) Extract the first treatment solution to obtain the extract and the raffinate;

[0013] (3) The extract is back-extracted to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization, zinc ammonium chloride is obtained;

[0014] The raffinate was aged to obtain polyaluminum ferric chloride.

[0015] The present invention describes a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The method involves dissolving and neutralizing the two industrial wastes, dissolving the metal elements in a first treatment solution. Then, an extraction method is used to allow zinc and ammonium to enter the extract, while aluminum and iron enter the raffinate. The extract and raffinate are then treated separately to obtain two products: zinc ammonium chloride and polyaluminum ferric chloride. Zinc ammonium chloride can be used as a flux in zinc-aluminum alloy welding processes, while polyaluminum ferric chloride is utilized as a water purification agent. The method described in this invention is simple to operate, has low processing costs, and yields high-value-added products: a flux and a water purification agent. It achieves the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid, resulting in significant economic and environmental benefits.

[0016] Preferably, the zinc-aluminum alloy welding slag in step (1) includes 5 to 10 wt% ammonium chloride, for example, it can be 5 wt%, 5.5 wt%, 6 wt%, 7 wt%, 7.5 wt%, 8 wt%, 9 wt%, or 10 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Aluminum chloride 8–20 wt%, for example, 8 wt%, 10 wt%, 13 wt%, 15 wt%, 17 wt%, 18 wt%, 19 wt%, or 20 wt%, but not limited to the listed values; other unlisted values ​​within this range also apply.

[0018] Zinc chloride 10-30 wt%, for example, 10 wt%, 13 wt%, 15 wt%, 20 wt%, 25 wt%, 26 wt%, 28 wt%, or 30 wt%, but not limited to the listed values; other unlisted values ​​within this range also apply.

[0019] The hydroxide is 1 to 5 wt%, for example, it can be 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, or 5 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] Preferably, the hydroxide includes zinc hydroxide and aluminum hydroxide.

[0021] Preferably, the hot-dip galvanizing waste hydrochloric acid includes 60-120 g / L of zinc, for example, it can be 60 g / L, 65 g / L, 70 g / L, 80 g / L, 90 g / L, 95 g / L, 100 g / L or 120 g / L, etc., but is not limited to the listed values, other unlisted values ​​within this range are also applicable;

[0022] The iron concentration is 80–120 g / L, for example, it can be 80 g / L, 85 g / L, 90 g / L, 95 g / L, 100 g / L, 105 g / L, 110 g / L or 120 g / L, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] Preferably, the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 5-10%, for example, it can be 5%, 5.5%, 6%, 7%, 7.5%, 8% or 10%, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] Preferably, the solid-liquid ratio of the zinc-aluminum alloy welding slag to the hot-dip galvanized waste hydrochloric acid in step (1) is 1:1 to 1:3 g / mL, for example, it can be 1:1 g / mL, 1:1.5 g / mL, 1:1.8 g / mL, 1:2 g / mL, 1:2.5 g / mL, 1:2.7 g / mL or 1:3 g / mL, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] The present invention preferably uses a solid-liquid ratio of 1:1 to 1:3 g / mL for the zinc-aluminum alloy welding slag and the hot-dip galvanizing waste hydrochloric acid, thereby achieving efficient leaching of ammonium, aluminum, and zinc from the zinc-aluminum alloy welding slag and zinc and iron from the hot-dip galvanizing waste hydrochloric acid. A small solid-liquid ratio between the zinc-aluminum alloy welding slag and the hot-dip galvanizing waste hydrochloric acid leads to low hydrochloric acid utilization and low extraction rate; conversely, a large solid-liquid ratio leads to insufficient dissolution of the welding slag and low zinc and aluminum recovery rates.

[0026] Preferably, the temperature of the dissolution and neutralization treatment in step (1) is 30 to 50°C, for example, it can be 30°C, 35°C, 38°C, 40°C, 46°C, 47°C or 50°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0027] Preferably, the extractant used in step (2) includes P507 extractant, which has the advantages of high selectivity, high recovery rate and low loss.

[0028] Preferably, the extraction temperature is 30 to 50°C, for example, 30°C, 35°C, 38°C, 40°C, 46°C, 47°C or 50°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0029] Preferably, the back-extraction agent used in step (3) includes hydrochloric acid with a concentration of 5 to 20%, for example, it can be 5%, 8%, 10%, 12%, 15%, 18% or 20%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] The preferred back-extraction agent used in this invention includes hydrochloric acid with a concentration of 5-20%, which has the advantages of not introducing impurities and being able to recover chloride salts again.

[0031] Preferably, the back-extraction temperature is 30-60°C, for example, it can be 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Preferably, the temperature of the evaporation crystallization process in step (3) is 90 to 120°C, for example, it can be 90°C, 93°C, 95°C, 100°C, 105°C, 110°C or 120°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] Preferably, the evaporation crystallization process takes 1 to 3 hours, for example, 1 hour, 1.3 hours, 1.5 hours, 1.8 hours, 2 hours, 2.5 hours, 2.7 hours, or 3 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the aging temperature in step (3) is 80 to 105°C, for example, it can be 80°C, 85°C, 90°C, 95°C, 100°C, 103°C or 105°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the aging treatment time is 3 to 8 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 6 hours, 7 hours or 8 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the zinc ammonium chloride described in step (3) is used as a flux in the zinc-aluminum alloy welding section.

[0037] Preferably, the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

[0038] As a preferred technical solution of the present invention, the collaborative resource utilization method includes the following steps:

[0039] (1) Mix zinc-aluminum alloy welding slag with hot-dip galvanized waste hydrochloric acid at a solid-liquid ratio of 1:1 to 1:3 g / mL and dissolve and neutralize it at a temperature of 30 to 50°C to obtain the first treatment solution.

[0040] The zinc-aluminum alloy welding slag comprises: 5-10 wt% ammonium chloride, 8-20 wt% aluminum chloride, 10-30 wt% zinc chloride, and 1-5 wt% hydroxide; the hydroxide comprises zinc hydroxide and aluminum hydroxide; the hot-dip galvanizing waste hydrochloric acid comprises 60-120 g / L zinc and 80-120 g / L iron; the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 5-10%.

[0041] (2) Using P507 extractant, the first treatment liquid was extracted at a temperature of 30-50℃ to obtain extract and raffinate.

[0042] (3) The extract is back-extracted at a temperature of 30-60°C to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization treatment at a temperature of 90-120°C for 1-3 hours, zinc ammonium chloride is obtained; the zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section.

[0043] The back-extraction agent used includes hydrochloric acid with a concentration of 5-20%;

[0044] The raffinate is aged at 80–105°C for 3–8 hours to obtain polyaluminum ferric chloride; the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] The present invention provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The method is simple to operate, has low processing cost and low energy consumption. Based on the properties of the valuable components contained in the two industrial wastes, the method involves sequentially dissolving, neutralizing and extracting them to separate zinc ammonium and aluminum iron. Then, the extract and raffinate are treated separately to obtain zinc ammonium chloride flux and polyaluminum ferric chloride water purification agent. This method has good economic and environmental benefits and is suitable for large-scale promotion and application. Attached Figure Description

[0047] Figure 1 This is a schematic flowchart of a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid provided by the present invention. Detailed Implementation

[0048] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0049] This invention provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid, the process of which is shown in the schematic diagram below. Figure 1 As shown, the collaborative resource utilization method includes the following steps:

[0050] (1) Mix zinc-aluminum alloy welding slag with hot-dip galvanized waste hydrochloric acid and perform dissolution and neutralization treatment to obtain the first treatment solution;

[0051] (2) Extract the first treatment solution to obtain the extract and the raffinate;

[0052] (3) The extract is back-extracted to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization, zinc ammonium chloride is obtained;

[0053] The raffinate was aged to obtain polyaluminum ferric chloride.

[0054] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0055] Example 1

[0056] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The synergistic resource utilization method includes the following steps:

[0057] (1) The zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid were mixed at a solid-liquid ratio of 1:2 g / mL and then dissolved and neutralized at a temperature of 40℃ to obtain the first treatment solution.

[0058] The zinc-aluminum alloy welding slag comprises: 8 wt% ammonium chloride, 10 wt% aluminum chloride, 20 wt% zinc chloride, and 3 wt% hydroxide; the hydroxide is zinc hydroxide and aluminum hydroxide; the hot-dip galvanizing waste hydrochloric acid comprises 100 g / L zinc and 100 g / L iron; the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 7%;

[0059] (2) Using P507 extractant, the first treatment liquid was extracted at a temperature of 40°C to obtain extract and raffinate.

[0060] (3) The extract is back-extracted at 50°C to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization treatment at 100°C for 2 hours, zinc ammonium chloride is obtained; the zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section.

[0061] The back-extraction agent used is 10% hydrochloric acid;

[0062] The raffinate is aged at 90°C for 5 hours to obtain polyaluminum ferric chloride; the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

[0063] Example 2

[0064] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The synergistic resource utilization method includes the following steps:

[0065] (1) The zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid were mixed at a solid-liquid ratio of 1:1.5 g / mL and then dissolved and neutralized at a temperature of 38°C to obtain the first treatment solution.

[0066] The zinc-aluminum alloy welding slag comprises: 7.5 wt% ammonium chloride, 13 wt% aluminum chloride, 22 wt% zinc chloride, and 1.8 wt% hydroxide; the hydroxide is zinc hydroxide and aluminum hydroxide; the hot-dip galvanizing waste hydrochloric acid comprises 90 g / L zinc and 90 g / L iron; the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 6.6%.

[0067] (2) Using P507 extractant, the first treatment liquid was extracted at a temperature of 42°C to obtain extract and raffinate.

[0068] (3) The extract is back-extracted at 55°C to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization treatment at 110°C for 2.5 h, zinc ammonium chloride is obtained; the zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section.

[0069] The back-extraction agent used is 11% hydrochloric acid;

[0070] The raffinate is aged at 85°C for 4.5 hours to obtain polyaluminum ferric chloride; the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

[0071] Example 3

[0072] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The synergistic resource utilization method includes the following steps:

[0073] (1) The zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid were mixed at a solid-liquid ratio of 1:1 g / mL and then dissolved and neutralized at a temperature of 30℃ to obtain the first treatment solution.

[0074] The zinc-aluminum alloy welding slag comprises: 10 wt% ammonium chloride, 8 wt% aluminum chloride, 30 wt% zinc chloride, and 1 wt% hydroxide; the hydroxide is zinc hydroxide and aluminum hydroxide; the hot-dip galvanizing waste hydrochloric acid comprises 120 g / L zinc and 120 g / L iron; the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 5%.

[0075] (2) Using P507 extractant, the first treatment liquid was extracted at a temperature of 30°C to obtain extract and raffinate.

[0076] (3) The extract is back-extracted at 30°C to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization treatment at 120°C for 3 hours, zinc ammonium chloride is obtained; the zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section.

[0077] The back-extraction agent used is 20% hydrochloric acid;

[0078] The raffinate is aged at 80°C for 8 hours to obtain polyaluminum ferric chloride; the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

[0079] Example 4

[0080] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid. The synergistic resource utilization method includes the following steps:

[0081] (1) The zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid were mixed at a solid-liquid ratio of 1:3 g / mL and then dissolved and neutralized at a temperature of 30-50℃ to obtain the first treatment solution.

[0082] The zinc-aluminum alloy welding slag comprises: 5 wt% ammonium chloride, 20 wt% aluminum chloride, 10 wt% zinc chloride, and 5 wt% hydroxide; the hydroxide is zinc hydroxide and aluminum hydroxide; the hot-dip galvanizing waste hydrochloric acid comprises 60 g / L zinc and 80 g / L iron; the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 10%.

[0083] (2) Using P507 extractant, the first treatment liquid was extracted at a temperature of 50°C to obtain extract and raffinate.

[0084] (3) The extract is back-extracted at 60°C to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization treatment at 90°C for 1 hour, zinc ammonium chloride is obtained; the zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section.

[0085] The back-extraction agent used is hydrochloric acid with a concentration of 5-20%;

[0086] The raffinate is aged at 105°C for 3 hours to obtain polyaluminum ferric chloride; the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

[0087] Example 5

[0088] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid. Except for the solid-liquid ratio of zinc-aluminum alloy welding slag to hot-dip galvanized waste hydrochloric acid in step (1) being 1:0.5 g / mL, the synergistic resource utilization method is the same as that in Example 1.

[0089] Example 6

[0090] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid. Except for the solid-liquid ratio of zinc-aluminum alloy welding slag to hot-dip galvanized waste hydrochloric acid in step (1) being 1:5 g / mL, the synergistic resource utilization method is the same as that in Example 1.

[0091] Example 7

[0092] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid. The synergistic resource utilization method is the same as that in Embodiment 1, except that the P507 extractant in step (2) is replaced with N235 extractant.

[0093] Example 8

[0094] This embodiment provides a method for the synergistic resource utilization of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid. Except for replacing the hydrochloric acid stripping agent in step (3) with sulfuric acid, the synergistic resource utilization method is the same as that in embodiment 1.

[0095] The recovery rates of zinc, ammonium, aluminum, and iron in the above examples and comparative examples, as well as the purity of zinc ammonium chloride and polyaluminum ferric chloride, are shown in Table 1.

[0096] Table 1

[0097]

[0098]

[0099] As can be seen from Table 1:

[0100] (1) As can be seen from the comprehensive examples 1 to 4, the synergistic resource utilization method of zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid provided by the present invention separates zinc ammonium and aluminum iron, and obtains flux zinc ammonium chloride with a purity of up to 99% and water purification agent polyaluminum iron chloride with a purity of up to 99%.

[0101] (2) It can be seen from the combined examples 1 and 5-6 that the solid-liquid ratio of the zinc-aluminum alloy welding slag to the hot-dip galvanizing waste hydrochloric acid in example 5 is large, which is 1:0.5 g / mL, resulting in insufficient dissolution of the welding slag and a low zinc and aluminum recovery rate of only 85%; the solid-liquid ratio of the zinc-aluminum alloy welding slag to the hot-dip galvanizing waste hydrochloric acid in example 6 is small, which is 1:5 g / mL, resulting in low hydrochloric acid utilization and low extraction rate, ultimately reducing the recovery rates of zinc, ammonium, aluminum and iron, and consequently reducing the purity of zinc ammonium chloride and polyaluminum ferric chloride.

[0102] (3) It can be seen from the combined results of Example 1 and Example 7 that the N235 extractant used in Example 7 has a poor extraction effect, and the recovery rates of zinc, ammonium, aluminum and iron are reduced, which in turn leads to a decrease in the purity of zinc ammonium chloride and polyaluminum ferric chloride.

[0103] (4) It can be seen from the combined examples 1 and 8 that the stripping agent used in Example 8 is sulfuric acid, which introduces impurities and reduces the recovery rates of zinc, ammonium, aluminum and iron, which in turn reduces the purity of zinc ammonium chloride and polyaluminum ferric chloride.

[0104] In summary, the co-resource utilization method for zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid provided by this invention is simple to operate, has low processing cost and low energy consumption. It rationally utilizes the properties of the valuable components contained in the two industrial wastes to achieve efficient separation of zinc ammonium and aluminum iron, obtaining high-purity flux zinc ammonium chloride and water purification agent polyaluminum ferric chloride, which has good economic and environmental benefits.

[0105] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A synergic resource recovery method of zinc-aluminum alloy welding slag and hot-dip galvanizing waste hydrochloric acid, characterized in that, The collaborative resource utilization method includes the following steps: (1) Mix zinc-aluminum alloy welding slag with hot-dip galvanizing waste hydrochloric acid and perform dissolution and neutralization treatment to obtain the first treatment solution; (2) Extract the first treatment solution to obtain the extract and the raffinate; (3) The extract is back-extracted to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization, zinc ammonium chloride is obtained; The raffinate is aged to obtain polyaluminum ferric chloride; The solid-liquid ratio of the zinc-aluminum alloy welding slag to the hot-dip galvanized waste hydrochloric acid in step (1) is 1:1~1:3 g / mL; The extraction agent used in step (2) includes P507 extractant; The back-extraction agent used in step (3) includes hydrochloric acid with a concentration of 5-20%.

2. The collaborative resource utilization method according to claim 1, characterized in that, The zinc-aluminum alloy welding slag in step (1) includes: 5-10 wt% ammonium chloride, 8-20 wt% aluminum chloride, 10-30 wt% zinc chloride and 1-5 wt% hydroxide.

3. The collaborative resource utilization method according to claim 2, characterized in that, The hydroxides include zinc hydroxide and aluminum hydroxide.

4. The collaborative resource utilization method according to claim 1, characterized in that, The hot-dip galvanizing waste hydrochloric acid includes 60~120g / L of zinc and 80~120g / L of iron.

5. The collaborative resource utilization method according to claim 1, characterized in that, The mass fraction of the hot-dip galvanizing waste hydrochloric acid is 5-10%.

6. The collaborative resource utilization method according to claim 1, characterized in that, The temperature for the dissolution and neutralization process in step (1) is 30~50℃.

7. The collaborative resource utilization method according to claim 1, characterized in that, The extraction temperature is 30~50℃.

8. The collaborative resource utilization method according to claim 1, characterized in that, The back-extraction temperature is 30~60℃.

9. The collaborative resource utilization method according to claim 1, characterized in that, The temperature of the evaporation crystallization process in step (3) is 90~120℃.

10. The collaborative resource utilization method according to claim 1, characterized in that, The evaporation and crystallization process takes 1 to 3 hours.

11. The collaborative resource utilization method according to claim 1, characterized in that, The aging process in step (3) is carried out at a temperature of 80~105℃.

12. The collaborative resource utilization method according to claim 1, characterized in that, The aging process takes 3 to 8 hours.

13. The collaborative resource utilization method according to claim 1, characterized in that, In step (3), zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section.

14. The collaborative resource utilization method according to claim 1, characterized in that, The polyaluminum ferric chloride is used as a water purification agent for resource utilization.

15. The collaborative resource utilization method according to claim 1, characterized in that, The collaborative resource utilization method includes the following steps: (1) The zinc-aluminum alloy welding slag and hot-dip galvanized waste hydrochloric acid were mixed with a solid-liquid ratio of 1:1~1:3 g / mL and then dissolved and neutralized at a temperature of 30~50℃ to obtain the first treatment solution; The zinc-aluminum alloy welding slag comprises: 5-10 wt% ammonium chloride, 8-20 wt% aluminum chloride, 10-30 wt% zinc chloride, and 1-5 wt% hydroxide; the hydroxide comprises zinc hydroxide and aluminum hydroxide; the hot-dip galvanizing waste hydrochloric acid comprises 60-120 g / L zinc and 80-120 g / L iron; the mass fraction of the hot-dip galvanizing waste hydrochloric acid is 5-10%. (2) Using P507 extractant, the first treatment liquid was extracted at a temperature of 30~50℃ to obtain extract and raffinate; (3) The extract is back-extracted at a temperature of 30~60℃ to obtain a mixture of zinc chloride and ammonium chloride; after evaporation and crystallization treatment at a temperature of 90~120℃ for 1~3h, zinc ammonium chloride is obtained; the zinc ammonium chloride is used as a flux in the zinc-aluminum alloy welding section. The back-extraction agent used includes hydrochloric acid with a concentration of 5-20%; The raffinate is aged at 80-105℃ for 3-8 hours to obtain polyaluminum ferric chloride; the polyaluminum ferric chloride is used as a water purification agent for resource utilization.

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