Method for producing deoxygenated aluminum, aluminum powder and zinc oxide in single batch process

Abstract

The present disclosure relates to a method for producing deoxygenated aluminum, aluminum powder and zinc oxide in a single batch process. The method includes feeding the aluminized zinc dross into an induction furnace to melt the aluminized zinc dross. The method comprises the step of extracting zinc oxide powder, deoxidized aluminum and aluminum powder from molten aluminized zinc dross.

Description

Technical Field

[0001] The present disclosure relates to the field of treating galvalume dross formed during the process of galvanizing steel. In particular, but not exclusively, the present disclosure relates to a method of producing deoxidized aluminum (aluminum deox), aluminum powder and zinc oxide from galvalume dross in a single batch process. Background Art

[0002] Galvanizing dross is a byproduct of the process of galvanizing steel. Steel products are galvanized to improve the corrosion resistance of steel. Galvanizing is widely used to produce coatings on steel, wherein the process of galvanizing is carried out by immersing the steel product in a bath of molten zinc and aluminum. In the process of galvanizing, fresh zinc and aluminum are added at regular intervals because a large amount of zinc and aluminum are lost in the form of galvanizing dross. Galvanizing dross is a combination of free zinc and Zn-Fe-Al intermetallic compounds, which is formed by multiple reactions between zinc, aluminum and dissolved iron from the immersed steel product. Galvanizing dross is a valuable byproduct because it contains high levels of zinc and aluminum. However, due to the lack of technology and initiatives to extract zinc and aluminum from galvanizing dross, zinc and aluminum resources are often wasted. In addition, the long-term storage of galvanizing dross creates long-term environmental problems.

[0003] Traditionally, a variety of technologies have been studied to recover zinc and aluminum from galvanized dross in different extraction processes, wherein these technologies include but are not limited to distillation, electrolytic refining, leaching, ultra-gravity technology, etc. However, this conventional technology extracts each of zinc, aluminum, silicon, iron, etc. from raw materials such as galvanized dross by using a separate independent process for each type of extraction. Therefore, manufacturers do produce deoxidized aluminum / powder and zinc oxide; but they are made in two independent processes, in two different batches, and from two different raw materials. They each independently produce aluminum products from aluminum-containing raw materials and similarly produce zinc products from zinc-containing raw materials, and have no relationship with each other. This conventional technology consumes a lot of time and cost for the infrastructure for extracting aluminum powder, zinc oxide, etc. Therefore, there is a need for a method for preparing deoxidized aluminum / powder and zinc oxide from one raw material, i.e., galvanized dross, in a single batch process.

[0004] The present disclosure is intended to overcome one or more of the limitations set forth above, as well as any other limitations associated with the prior art. Summary of the invention

[0005] The present disclosure provides a method for producing deoxidized aluminum, aluminum powder and zinc oxide from galvanized dross in a single batch process. The method includes feeding the galvanized dross into an induction furnace to melt the galvanized dross, wherein the galvanized dross is received as a by-product. The received galvanized dross is classified into one of top galvanized dross, bottom galvanized dross and galvanized dross of a limited size, wherein the top galvanized dross and the bottom galvanized dross are classified based on the iron content of the received galvanized dross. The method also includes the steps of transferring the molten galvanized dross to a silicon carbide crucible furnace for heating the molten galvanized dross to a predetermined temperature, wherein zinc vapor evaporates from the top of the molten galvanized dross when the molten galvanized dross is heated. The method includes collecting zinc vapor into an oxidation chamber to produce zinc oxide powder and adding pure aluminum to the residual molten metal based on the determination of the quality test of the molten metal, wherein the residual molten metal is the residual content when the zinc vapor is evaporated from the molten galvanized dross. The method also includes casting the molten metal through a casting machine to produce deoxidized aluminum or aluminum powder.

[0006] The foregoing summary is illustrative only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The novel features and characteristics of the present disclosure are set forth in the appended claims. However, the disclosure itself, as well as the preferred mode of use, further objects and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings. One or more embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0008] Figure 1 A flow chart showing a method of producing deoxidized aluminum, aluminum powder, and zinc oxide from galvanized dross in a single batch process is shown according to an embodiment of the present disclosure;

[0009] Figure 2A A flow chart showing steps for processing received galvalume dross is shown according to an embodiment of the present disclosure;

[0010] Figure 2B A flow chart showing the steps of producing zinc oxide powder from received galvanizing dross according to an embodiment of the present disclosure is shown;

[0011] Figure 3A A flow chart showing the steps of processing the remaining molten metal after extracting the zinc vapor is shown according to an embodiment of the present disclosure; and

[0012] Figure 3B A flow chart showing steps for producing aluminum powder from residual molten metal is shown according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] In this document, the word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment or implementation of the present subject matter described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0014] Although the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the accompanying drawings and will be described in detail below. However, it should be understood that it is not intended to limit the present disclosure to the disclosed form, but on the contrary, the present disclosure will cover all modifications, equivalents and alternatives falling within the spirit and scope of the present disclosure.

[0015] The terms "comprises," "includes," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a setup, apparatus, or process that includes a list of components or steps includes not only those components or steps, but may include other components or steps not expressly listed or inherent to such setup, apparatus, or process. In other words, one or more elements in a system or device preceded by "comprising ..." does not preclude the presence of other or additional elements in the system or device, without more constraints.

[0016] Embodiments of the present disclosure provide a method for producing deoxidized aluminum, aluminum powder, and zinc oxide from galvanized dross in a single batch process. The method includes feeding the galvanized dross into an induction furnace to melt the galvanized dross, wherein the galvanized dross is received as a by-product. Prior to feeding into the induction furnace, the received galvanized dross is classified into one of top galvanized dross, bottom galvanized dross, and galvanized dross of a limited size, wherein the top galvanized dross and the bottom galvanized dross are classified based on the iron content of the received galvanized dross. The method also includes the steps of transferring the molten galvanized dross to a silicon carbide crucible furnace for heating the molten galvanized dross to a predetermined temperature, wherein zinc vapor evaporates from the top of the molten galvanized dross when the molten galvanized dross is heated. The method includes collecting zinc vapor into an oxidation chamber to produce zinc oxide powder and adding pure aluminum to the residual molten metal based on the determination of the quality test of the molten metal, wherein the residual molten metal is the residual content when the zinc vapor is evaporated from the molten galvanized dross. The method also includes casting the molten metal through a casting machine to produce deoxidized aluminum or aluminum powder.

[0017] The following paragraphs refer to Figure 1 and Figure 3B Describe the present disclosure. In the accompanying drawings, Figure 1 is an exemplary method of the present disclosure and illustrates the various steps of a method (100) for producing deoxidized aluminum, aluminum powder, and zinc oxide in a single batch process. The method (100) enables manufacturers to produce deoxidized aluminum, aluminum powder, and zinc oxide from galvanized dross, which is a waste byproduct of the process of galvanizing metal products in a single batch process. Therefore, the method (100) eliminates the requirement of using two separate processes, two different batches, and two different raw materials to produce deoxidized aluminum / powder and zinc oxide from galvanized dross. In one embodiment, the method (100) according to the present disclosure facilitates the separation of galvanized dross into recycled aluminum and zinc independently in a single batch process. Therefore, the method (100) enables manufacturers to recycle galvanized dross with the most efficient technology. In addition, the method (100) only requires one set of machines to simultaneously produce recycled aluminum and zinc oxide. Therefore, compared with traditional methods for producing recycled aluminum and zinc, the present invention saves cost, time, fuel, energy, floor space, and manpower.

[0018] However, it should be understood by those skilled in the art that the size and configuration of a set of required machines for completing the method (100) may vary according to the requirements of different types of installation environments. Any such changes / modifications should be construed as being within the scope of the present disclosure.

[0019] like Figure 1 As shown in , the method (100) includes one or more blocks to be performed to produce deoxidized aluminum, aluminum powder, and zinc oxide in a single batch process. The order in which the method (100) is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the subject matter described herein.

[0020] At box (102), the galvalume dross is fed into an induction furnace for melting. In one embodiment, the galvalume dross is received as a by-product and the galvalume dross may be obtained in the form of large chunks, wherein each chunk weighs in the range of 50 kg to 1,500 kg, depending on the dross handling practices at the source,

[0021] That is, the mill that produces such dross. When the galvalume dross is received, the galvalume dross is classified into one of top-grade galvalume dross, bottom-grade galvalume dross, and galvalume dross of a limited size. The top-grade galvalume dross and the bottom-grade galvalume dross are classified based on the iron content of the received galvalume dross. In one example, the top-grade galvalume dross may contain a chemical composition of aluminum, zinc, iron, silicon, and copper, the ratios of which are shown in Table 1.

[0022]

[0023] Table 1

[0024] In another example, the bottom level galvalume dross may include a chemical composition of aluminum, zinc, iron, silicon, and copper in the proportions shown in Table 2.

[0025]

[0026] Table 2

[0027] In addition, the galvalume dross is fed into the induction furnace for melting. In one embodiment, in the case of top-grade galvalume dross, the galvalume dross is fed directly into the induction furnace for melting. In the case of bottom-grade galvalume dross, the galvalume dross is cut into smaller pieces each having a size of 21 inches or less, wherein such small pieces of bottom-grade galvalume dross are directly transferred to the silicon carbide crucible furnace for processing. The top-grade galvalume dross is placed into the induction furnace by using an overhead crane, wherein a crane of suitable capacity is used to safely transfer the top-grade galvalume to the induction furnace. A set of iron hooks attached to the top-grade galvalume dross pieces are removed as early as possible to prevent any iron from accumulating in the metal bath.

[0028] An induction furnace is an electric furnace in which heat is applied by induction heating of the galvanized dross. Induction furnace capacities range from less than one kilogram to one hundred tons and are used to melt iron and steel, copper, aluminum and precious metals. Induction furnaces offer a clean, energy-efficient and well-controlled melting process compared to most other metal melting methods. Induction furnaces work on the principle of induction heating, where an electrically conductive material is heated in a non-contact manner. Thus, induction furnaces eliminate the need to burn fuel or other external heat sources.

[0029] Therefore, the received galvanized dross is melted in the induction furnace. Figure 2A The steps shown in perform a process of melting the received galvanizing dross.

[0030] At box (202), a flux additive is added to the molten galvalume dross. In one embodiment, a flux additive in a mixture of covering flux (1.5% of the induction furnace batch weight) and sodium cryolite (0.5% of the induction furnace batch weight) is added to the bath, i.e., the molten galvalume dross. Thus, the top surface of the molten galvalume dross is covered with flux to minimize oxidation of the metal.

[0031] At block (204), slag is removed from the molten galvanized dross. In one embodiment, slag is produced when the galvanized dross is melted and is a composite solution of silicates and oxides that solidifies upon cooling. Slag is removed from the molten galvanized dross to help remove impurities and protect the induction furnace refractory lining from excessive wear.

[0032] After removing the slag from the top of the molten galvanized dross, as Figure 1 The slag-free molten galvanizing dross is further processed as shown in FIG.

[0033] At box (104), the slag-free molten galvalume dross is transferred to a silicon carbide crucible furnace. In one embodiment, the slag-free molten galvalume dross is transferred to a silicon carbide crucible furnace for processing the galvalume dross at high temperatures. Silicon carbide crucible furnaces are designed to provide precise high temperature uniformity and efficient indirect heating of non-ferrous metals. Silicon carbide is a ceramic material with relatively high electrical conductivity when compared to other ceramics.

[0034] In the process of transferring the molten galvalume dross without slag into the silicon carbide crucible furnace, the induction furnace is tilted 90 degrees, where the molten galvalume dross flows through the ladle and is filled into the ladle. In addition, the molten galvalume dross is transferred from the ladle to the silicon carbide crucible furnace. In the case of bottom galvalume dross, the solid bottom galvalume dross is directly inserted into the silicon carbide crucible furnace for melting.

[0035] Therefore, the top galvanized dross is first added to the induction furnace for melting, and then the molten metal of the galvanized dross is transferred to the silicon carbide crucible furnace. The induction furnace is a furnace that is larger in size than the silicon carbide crucible furnace. Therefore, the induction furnace can accommodate larger sized galvanized dross blocks, and can melt larger sized galvanized dross blocks without cutting into blocks with reduced size. In addition, the use of the induction furnace results in lower fuel costs compared to the silicon carbide crucible furnace, and also saves time for the silicon carbide crucible furnace, thereby increasing the output of zinc and recycled aluminum. However, if necessary, the top galvanized dross can also be melted directly in the silicon carbide crucible furnace in the case where, for example, the induction furnace is occupied by other ongoing materials or is under maintenance, or the volume of galvanized dross required by multiple silicon carbide crucible furnaces is larger than the volume that can be transferred by the induction furnace.

[0036] At box (106), the molten galvanized dross is heated to a predetermined temperature to evaporate zinc vapor. In one embodiment, the molten galvanized dross is further heated in a silicon carbide crucible furnace. The molten galvanized dross is heated to a predetermined temperature range of 1300°C to 1400°C to boil the metal of the molten galvanized dross. When the molten galvanized dross is heated, zinc vapor evaporates from the top of the molten galvanized dross. Zinc is converted into a gaseous form because the boiling point of zinc is 907°C, where the boiling points of other metals in the galvanized dross, namely aluminum (Al), silicon (Si), iron (Fe) and copper (Cu), are 2470°C, 2355°C, 2862°C and 2560°C, respectively. Since the boiling point of zinc is lower than the boiling points of other metal elements present in the galvanized dross, namely Al, Si, Fe and Cu, only zinc evaporates to form zinc vapor, while the other metals remain in the crucible in a molten form.

[0037] At box (108), the zinc vapor is collected in an oxidation chamber to produce zinc oxide powder. In one embodiment, the zinc vapor is collected in an oxidation chamber where the zinc vapor reacts with oxygen from the air and produces zinc oxide vapor. Figure 2B The process of collecting zinc oxide vapor is carried out according to the steps shown in FIG.

[0038] At box (212), the zinc oxide vapor is sent through a long tube for cooling. In one embodiment, the zinc oxide vapor is sent through a four hundred foot long tube for cooling to form a fine white solid powder, namely zinc oxide powder.

[0039] At box (214), the zinc oxide powder is collected in a pulse jet baghouse. In one embodiment, the zinc oxide in solid powder form is evacuated from the pulse jet baghouse. A pulse jet baghouse or pulse jet dust collector is a self-cleaning dry filtration system. A pulse jet dust collector cleaning system utilizes bursts of compressed air to remove particulate matter and dust from the surface of an internal filter media. Pulse jet dust collectors are used because of their ease of operation, low energy usage, and minimal maintenance requirements.

[0040] At block (216), the zinc oxide powder is passed through a mixer. In one embodiment, after pulse jet filtering of the zinc oxide powder is completed, the zinc oxide powder is passed through a mixer to increase the bulk density of the zinc oxide powder.

[0041] At box (218), the quality of the zinc oxide powder is determined. In one embodiment, the quality of the zinc oxide is checked multiple times regularly in the same furnace by the corresponding quality assurance team in the laboratory by following standard quality procedures. After the quality is determined, the zinc oxide is weighed and packed into 25 kg HDPE bags.

[0042] In one example, zinc oxide produced from galvanizing dross was assessed to have a purity within the range shown in Table 3.

[0043] element ZnO purity Minimum value (%) 85.0 Maximum value (%) 99.3

[0044] Table 3

[0045] Therefore, zinc oxide white sealing grade is produced as a finished product and is used in the manufacture of ceramics, rubber and paints.

[0046] When the evaporation of zinc from the top of the molten galvanizing dross is complete, Figure 1 The remaining molten metal is further processed as shown in FIG.

[0047] At box (110), pure aluminum is added to the remaining molten metal based on the mass of the molten metal. In one embodiment, by Figure 3AThe steps shown in carry out the process of adding pure aluminum to the remaining molten metal.

[0048] At box (302), a flux additive is added to the residual molten metal. In one embodiment, after zinc evaporation is complete, a flux additive pink coating flux is added to the residual molten metal and the mixture is stirred. The residual molten metal is the contents residue after zinc vapor evaporates from molten galvanizing dross, wherein the residue contents are secondary aluminum with other elements Si, Fe and Cu present in small amounts.

[0049] Typically, secondary aluminum is made from recycled aluminum scrap from various aluminum products and profiles, such as aluminum chips, aluminum sheets, aluminum scraps, aluminum radiators, cast aluminum, extrusions, painted siding, aluminum dross, etc. Typically, secondary aluminum has a higher tolerance to alloying elements such as iron, magnesium, and silicon.

[0050] At block (304), slag is removed from the remaining molten metal. In one embodiment, slag is removed from the remaining molten metal by using a manual or power tool.

[0051] At block (306), the chemical composition of the slag-free residual molten metal is evaluated. In one embodiment, the chemical composition of the sample of the residual molten metal is evaluated by a quality assurance team through laboratory quality equipment such as an optical emission spectrophotometer (OES).

[0052] OES is used to understand the immediate chemical composition of finished products and raw materials. OES is a well-established and widely used analytical instrument for determining the elemental composition of a wide range of metals. Sample types tested using OES include samples from melts in primary and secondary metal production, as well as tubes, bolts, bars, wires, plates, etc. in the metalworking industry. OES can analyze a wide range of elements from hydrogen to uranium in solid metal samples covering a wide range of concentrations, providing very high accuracy, high precision and low detection limits.

[0053] Quality testing helps determine if the chemical composition of the remaining molten metal matches customer requirements.

[0054] At box (308), pure aluminum is added to the residual molten metal based on the evaluation. In one embodiment, when it is determined that there is no match with the customer requirements, pure aluminum is then added to the silicon carbide crucible furnace to achieve the desired composition of the residual molten metal. A sample of the residual molten metal is again extracted and then evaluated in an OES to verify that the chemical properties of the metal melt meet the customer requirements. In the event that the quality received is not as good as expected, an aluminum ingot or aluminum scrap with a purity of 99.5% is added to the residual molten metal and the mixture is homogenized by stirring. After the addition of pure aluminum, a sample of the residual molten metal is again extracted and the chemical properties are checked by using an OES.

[0055] Therefore, the quality of recycled aluminum can be improved by adding pure aluminum to the residual molten metal.

[0056] After completing the quality test and finally determining the quality of the recycled aluminum required, such as Figure 1 The remaining molten metal is further processed as shown in FIG.

[0057] At box (112), deoxidized aluminum / aluminum powder is produced by casting or atomizing the remaining molten metal.

[0058] In one embodiment, upon finalizing the quality of the recycled aluminum, the residual molten metal is cast into a mold of the desired shape to obtain deoxidized aluminum of the desired shape. In the case of shapes such as pellets to be made, the molten metal is then transferred to a pellet casting machine such as a homemade chakari, wherein the molten metal is passed through the holes of a tray, which solidifies upon cooling to form droplets called pellets or granules. In the case of aluminum ingots, cubes or hemispheres, the molten metal is poured onto a customized mold having a corresponding shape and size as per customer requirements. Further, the deoxidized aluminum is packaged into 50kg HDPE woven bags or 1MT jumbo HDPE bags as per customer requirements.

[0059] In one example, deoxidized aluminum produced from top galvanized dross (which has a lower iron content) was evaluated to have a chemical composition in the proportions shown in Table 4.

[0060] element Aluminum (Al) Zinc (Zn) Silicon (Si) Iron (Fe) Minimum value (%) 87.0 1.5 2.0 2.0 Maximum value (%) 93.0 4.5 4.0 5.5

[0061] Table 4

[0062] In one example, deoxidized aluminum produced from bottom galvanized dross (which has a higher iron content) was evaluated to have a chemical composition in the proportions shown in Table 5.

[0063]

[0064]

[0065] Table 5

[0066] Deoxidized aluminum made from galvanized dross is a deoxidizer applied to the deoxidation of molten steel, which improves the quality of the steel. Molten steel contains dissolved oxygen, which is important to remove during the melting stage, otherwise the solid steel contains porosity, which in turn reduces the tensile strength of the steel.

[0067] In another embodiment, the residual molten metal is processed to produce aluminum powder. Figure 3B The steps shown in FIG. 1 are used to carry out a process for producing aluminum powder from residual molten metal.

[0068] At box (312), the remaining molten metal is transferred to a holding furnace. In one embodiment, the holding furnace is used to further process the molten metal. The holding furnace is a heated reservoir to hold the molten metal ready for casting.

[0069] At block (314), the molten aluminum is atomized to form fine aluminum shots. In one embodiment, high pressure air jets are used within a holding furnace to atomize the molten metal into fine molten particles or pellets, which form a solid powder, ie, aluminum powder, upon ambient cooling.

[0070] At box (316), the fine aluminum pellets are collected in a collection chamber. In one embodiment, the fine aluminum pellets are collected in a collection chamber attached to a holding furnace. In one example, atomization is accomplished by bifurcating the molten metal with 10 kg air pressure from a nozzle after the molten metal passes through a ceramic sheet with 4.5 mm holes. The hot air from the chamber is sucked in by a 3HP fan.

[0071] At box (318), the fine aluminum shot is sieved into different sizes. In one embodiment, the aluminum powder in the form of fine aluminum shot is sieved into different sizes and packed in 25Kg HDPE bags. The finer variants of the aluminum powder are collected in a cyclone separator present between the fan and the collection chamber. Aluminum fine shot for different applications.

[0072] In one example, aluminum powder produced from galvanizing dross was evaluated to have a chemical composition in the proportions shown in Table 6.

[0073] element Aluminum (Al) Zinc (Zn) Silicon (Si) Iron (Fe) Minimum value (%) 89.0 1.0 1.0 1.0 Maximum value (%) 95.0 3.8 3.3 4.0

[0074] Table 6

[0075] Aluminum powder formed by atomization is used in different applications, such as making ferroalloys, such as ferromanganese, ferrochrome, etc. During the preparation of ferroalloys, aluminum powder is added to produce a thermite reaction, which is an exothermic reaction that produces the extreme heat required to produce ferroalloys. For the same purpose, aluminum powder can also be used in the firecracker industry. For the above applications, the aluminum powder size varies in the range of -10 mesh to +100 mesh.

[0076] In addition, finer aluminum powder with a mesh size of -200 mesh is used in the manufacture of aluminum phosphide (ALPHOS) as a fumigant. Aluminum powder with a mesh size of 300 mesh is used in the production of AAC blocks (aerated concrete blocks).

[0077] In the experiment, the information related to each process cycle is recorded. In the exemplary description, each process cycle of the silicon carbide crucible furnace, i.e., a batch, is referred to as a heat and is assigned a heat number. Each heat has a weight of 800 kg as an input in the form of melt (in the case of top galvanized dross) or solid (in the case of bottom galvanized dross). The production process of each heat consists of 4 stages, such as charging, oxidation, sampling and casting. During the charging stage, the temperature of the input is increased to make it boil at 1400°C, wherein the time spent in the charging process is in the range of 1 hour when the silicon carbide crucible furnace is fed with molten metal from an induction furnace to 4 hours when the solid dross is directly melted. In addition, the oxidation process takes about 6 hours, wherein the zinc vapor form reacts with oxygen to form zinc oxide. In addition, the sampling process takes about 0.5 hours, and the casting process takes about 1.5 hours. Therefore, the total time for each heating is about 12 hours, wherein when the molten metal is directly transferred to the silicon carbide crucible furnace, the time can be reduced to about 9 hours. Additionally, when aluminum is made into powder, one hour of casting time is saved from the process cycle because the molten metal is immediately transferred to a holding furnace, reducing the total heating time to only about eight hours.

[0078] In another example, it was observed that for an input of 100 kg of top galvalume dross, 98 kg of finished product, i.e. aluminium and zinc, was received as output. In case of using bottom galvalume dross as input, 95 kg of finished product was received. Thus, the yield of top galvalume dross was 98% and the yield of bottom galvalume dross was 95%.

[0079] In yet another example, the slag formed on the molten galvanized dross contains both metallic and non-metallic contents. The slag is placed in a steel container and then transported to a shed by a combination of cranes and rails. The slag is further processed in a vibrating machine that distributes the internal heat of the slag to gather the metallic contents together, thereby converting the metallic contents into liquid form, which is poured from the vibrating machine into a mold to form an ingot. The remaining material is allowed to cool for several hours and further passed through a ball mill and then a pulverizer to further separate any metallic contents left from the non-metallic contents. The metallic contents recovered from the slag are then re-melted in an induction furnace and transferred to a silicon carbide crucible furnace for removal of zinc by oxidation and then casting of the remaining residual aluminum.

[0080] Advantages of the present disclosure:

[0081] The present disclosure provides a method (100) that can enable manufacturers to produce deoxidized aluminum, aluminum powder, and zinc oxide from galvanizing dross, which is a waste byproduct of the process of galvanizing metal products in a single batch process. Thus, the method (100) eliminates the requirement to use two separate processes, two different batches, and two different raw materials to produce deoxidized aluminum / powder and zinc oxide.

[0082] In addition, the method (100) facilitates the separation of galvalume dross into recycled aluminum and zinc independently in a single batch process. Thus, the method (100) forms a new application for galvalume dross. The method (100) also enables manufacturers to recycle galvalume dross in the most efficient and environmentally friendly manner. In addition, the use of galvalume dross results in significantly lower costs compared to the cost of raw materials used to make deoxidized aluminum, aluminum powder, and zinc oxide in separate manufacturing processes.

[0083] The method (100) enables raw material costs to be significantly reduced compared to competing manufacturers, thereby providing the manufacturer with a significant cost advantage. As a result, the manufacturer can sell recycled aluminum and zinc at a lower price than other producers.

[0084] In addition, the method (100) only requires one set of machines to produce both recycled aluminum and zinc oxide. Therefore, compared with the conventional method of producing recycled aluminum and zinc, the present invention saves cost, time, fuel, energy, floor space and manpower.

[0085] In the detailed description of the embodiments of the present disclosure, reference is made to the accompanying drawings that form a part of the present disclosure, and in the accompanying drawings, specific embodiments in which the present disclosure can be practiced are shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure, and it should be understood that other embodiments may be utilized and may be changed without departing from the scope of the present disclosure. Therefore, this description should not be considered to have a limiting meaning.

[0086] Equivalent:

[0087] Regarding the use of substantially any plural and / or singular terms herein, those skilled in the art may appropriately convert the plural to the singular and / or the singular to the plural, depending on the context and / or application. For the sake of clarity, various singular / plural substitutions may be explicitly set forth herein. Those skilled in the art will understand that, in general, the terms used herein, especially the terms used in the appended claims (e.g., the body of the appended claims), are generally intended to be "open" terms (e.g., the term "including" should be interpreted as "including but not limited to", the term "having" should be interpreted as "at least having", the term "including" should be interpreted as "including but not limited to", etc.). Those skilled in the art will further understand that if a specific number of claim narrations is intended to be introduced, such an intention will be explicitly stated in the claim, and in the absence of such a narration, there is no such intention. For example, to aid understanding, the following appended claims may include the use of the introductory phrases "at least one" and "one or more" to introduce claim narrations. However, the use of such phrases should not be interpreted as implying that a claim recitation introduced by the indefinite article "a" or "an" limits any particular claim containing such introduced claim recitation to an invention containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should generally be interpreted as meaning "at least one" or "one or more"); the same is true for the use of definite articles used to introduce claim recitations.

[0088] Furthermore, even if a particular number of an introduced claim recitation is explicitly recited, one skilled in the art will recognize that such recitation should generally be interpreted to mean at least the recited number (e.g., a bare recitation of "two recitations" without other modifiers generally means at least two recitations, or two or more recitations). Furthermore, in those cases where a convention similar to "at least one of A, B, and C, etc." is used, generally such construction is in the sense that one skilled in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those cases where a convention similar to "at least one of A, B, or C, etc." is used, generally such construction is in the sense that one skilled in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Those skilled in the art will further understand that any disjunctive words and / or phrases that actually present two or more alternative terms, whether in the specification, claims or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B".

[0089] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and not limitation, with the true scope and spirit being indicated by the following claims.

Claims

1. A method for recovering aluminum and zinc from galvanized dross in a single batch process, the method comprising: feeding galvalume dross into an induction furnace to melt the galvalume dross, wherein the galvalume dross is received as a by-product; transferring the molten galvalume dross to a silicon carbide crucible furnace for heating the molten galvalume dross to a predetermined temperature, wherein zinc vapor evaporates from a top of the molten galvalume dross while heating the molten galvalume dross; collecting the zinc vapor into an oxidation chamber to produce zinc oxide powder; adding pure aluminum to residual molten metal when determining a quality test of molten metal, wherein the residual molten metal is the residual content when the zinc vapor is evaporated from the molten galvanizing dross; and The molten metal is cast by a casting machine to produce deoxidized aluminum or aluminum powder.

2. The method according to claim 1, wherein the received galvalume dross is classified into one of top-grade galvalume dross, bottom-grade galvalume dross and galvalume dross of a defined size, wherein the top-grade galvalume dross and the bottom-grade galvalume dross are classified based on the iron content of the received galvalume dross.

3. The method according to claim 1, wherein top-grade galvalume dross is directly fed into the induction furnace for melting, and in case of bottom-grade galvalume dross, the bottom-grade galvalume dross is cut into smaller pieces each having a size of 21 inches or less, wherein such small pieces of the bottom-grade galvalume dross are directly transferred to the silicon carbide crucible furnace for processing.

4. The method according to claim 1, wherein melting the received galvanizing dross comprises the following steps: adding a flux additive in a mixture of a covering flux and sodium cryolite to the molten galvalume dross, wherein a top portion of the molten galvalume dross is covered by the flux to minimize oxidation levels; Slag is removed from the top of the molten galvanizing dross.

5. The method of claim 1, wherein transferring the molten galvanized dross to the silicon carbide crucible furnace comprises the following steps: Tilt the induction furnace 90 degrees, wherein the molten galvanized dross flows through a launder and is filled into a ladle; as well as The molten galvanized dross is transferred from the ladle to the silicon carbide crucible furnace.

6. The method of claim 1, wherein the molten galvalume dross is heated to a predetermined temperature range of 1300°C to 1400°C to boil the metal of the molten galvalume dross.

7. The method of claim 1, wherein collecting the zinc vapor in the oxidation chamber comprises the steps of: conveying zinc oxide produced by oxidation of the zinc vapor through a 400-foot long pipe to cool and form a fine white solid zinc oxide powder; collecting the zinc oxide powder in a pulse jet air bag chamber; determining the mass of the zinc oxide powder based on a predetermined standard; as well as The zinc oxide powder is passed through a mixer to increase the bulk density of the zinc oxide powder.

8. The method of claim 1, wherein adding pure aluminum to the residual molten metal comprises the steps of: adding a flux additive to the residual molten metal; removing slag from the top of the residual molten metal; evaluating the chemical composition of a sample of the slag-free residual molten metal by performing a quality test on the sample of the slag-free residual molten metal, and Based on the evaluation of the chemical composition, pure aluminum is added to the residual molten metal to achieve a desired composition of the residual molten metal.

9. The method according to claim 1, wherein the residual molten metal is cast into a mold having a desired shape to obtain the deoxidized aluminum having a desired shape.

10. The method of claim 1, wherein producing aluminum powder from the molten metal comprises the steps of: transferring the molten aluminum to a holding furnace; atomizing the molten aluminum by using a high pressure air jet to form fine aluminum shots; collecting the fine aluminum shot in a collection chamber attached to the holding furnace; as well as The fine aluminum shots were sieved into different sizes.

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