Economic evaluation and purchase decision-making method of waste aluminum for 6-series aluminum alloy smelting

Abstract

The invention discloses an economic evaluation and purchase decision-making method of waste aluminum for 6-series aluminum alloy smelting, which comprises the following steps of: firstly, acquiring target alloy components, waste aluminum components and theoretical maximum additive amount W of the target alloy components and the waste aluminum components, and calculating W by considering iron increment delta Fe and titanium increment delta Ti introduced by smelting; then, based on the W and the market price, the reference cost C1 of not using the waste aluminum and the scheme cost C2 of using the waste aluminum are calculated respectively, and the raw material amount of elements contained in the waste aluminum needs to be deducted in C2 calculation; and finally, calculating the cost reduction amount per ton according to a formula: delta C = (C1-C2) / Q * 1000, and if the delta C is greater than the sum of the waste aluminum treatment cost S and the profit buffer P, procurement is judged to have economic feasibility. According to the invention, a process technology and cost accounting are combined, accurate purchase decision-making driven by data is realized, and the resource utilization efficiency and the cost control capability are improved.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal metallurgy technology, and in particular to a method for accurately calculating the cost and economics of scrap aluminum raw materials during the smelting process of 6-series aluminum alloy round ingots, in order to support procurement decisions. Background Technology

[0002] In the casting production of 6-series aluminum alloy round ingots, manufacturers often seek to use scrap aluminum as a partial raw material to reduce raw material costs. However, the core pain point of the current recycled aluminum market lies in the wide range of scrap aluminum sources and the complex and variable composition, which leads to significant challenges in procurement decisions.

[0003] Currently, when selecting scrap aluminum, procurement personnel primarily rely on market price information, failing to quickly and accurately correlate the specific composition data of the scrap aluminum with the actual amount that can be added at the smelting and casting site and the final raw material cost. This disconnect between technical feasibility and economic decision-making leads to two common dilemmas: first, purchasing scrap aluminum that appears cheap but has severely excessive levels of certain elements, resulting in extremely low (or even unusable) actual additive quantities, ultimately leading to higher overall costs; second, missing out on high-quality scrap aluminum with slightly higher unit prices but excellent compositional matching, allowing for large-scale addition and significant overall cost reduction.

[0004] Current technologies lack a method to combine smelting process parameters (such as the maximum amount that can be added based on elements) with real-time market data for accurate and rapid cost simulation and economic benefit assessment. This makes procurement decisions highly dependent on personal experience, introduces uncertainty, and makes it difficult to achieve optimal resource allocation and effective cost control.

[0005] Therefore, there is an urgent need in this field for an economic evaluation method that integrates and quantitatively correlates the composition of scrap aluminum, the requirements for target alloy composition, the maximum allowable amount, and the final raw material cost, so as to provide reliable data support for the procurement of scrap aluminum. Summary of the Invention

[0006] The purpose of this invention is to provide an economic evaluation and procurement decision-making method for scrap aluminum used in the smelting of 6-series aluminum alloys.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] An economic evaluation and procurement decision-making method for scrap aluminum used in smelting 6-series aluminum alloys includes:

[0009] S1. Obtain prerequisite technical parameters:

[0010] The compositional requirements range of the target 6-series aluminum alloy, the actual composition of the scrap aluminum, and the calculated theoretical maximum allowable addition amount W of the scrap aluminum in the total smelting output Q are obtained to preliminarily determine whether it is suitable for addition. The theoretical maximum allowable addition amount W is a constraint value calculated based on the compositional requirements of each alloying element and the actual composition of the scrap aluminum, taking into account the fixed iron increment ΔFe introduced by the smelting process and the fixed titanium increment ΔTi introduced by the grain refiner.

[0011] S2. Calculate the baseline cost and the proposed cost:

[0012] Based on the required composition range of the target 6-series aluminum alloy, the theoretical maximum allowable addition amount W, the actual composition of the scrap aluminum, and the current market price, the following calculations are performed:

[0013] The first raw material cost C1 when smelting the total output Q of 6-series aluminum alloys without using scrap aluminum;

[0014] The second raw material cost C2 when smelting the total output Q of 6-series aluminum alloys using the theoretically maximum addable amount W of scrap aluminum;

[0015] Among them, the calculation of the second raw material cost C2 needs to deduct the amount of raw materials corresponding to the alloy elements contained in the scrap aluminum W;

[0016] S3. Economic Feasibility Assessment: Calculate the cost reduction per ton ΔC = (C1-C2) / Q × 1000;

[0017] If ΔC>(S+P), then purchasing and using the scrap aluminum is deemed economically feasible.

[0018] Where S is the cost of other treatment per ton of the waste aluminum, and P is a preset profit buffer value.

[0019] In the above scheme, if the theoretical maximum addable amount W / total output Q > 5%, it is judged that it is suitable to add; if the theoretical maximum addable amount W / total output Q ≤ 5%, it is judged that it is not suitable to add.

[0020] In a further technical solution, S2, the calculation of the first raw material cost C1 and the second raw material cost C2 both need to be based on the calculated composition value of the target 6-series aluminum alloy, and the supplementary addition amounts of aluminum-silicon master alloy, aluminum-copper master alloy, magnesium ingot, manganese agent, chromium agent, aluminum-titanium-boron wire, titanium agent and pure aluminum ingot are determined respectively, and the calculation is based on the current market price of each raw material.

[0021] In a further technical solution, the calculation of the supplementary addition amount includes, in advance, the titanium content ΔTi introduced by the fixed addition of aluminum titanium boron wire.

[0022] In a further technical solution, the fixed iron increment ΔFe is 0.1%±0.02%, and the fixed titanium increment ΔTi is 0.01%.

[0023] In a further technical solution, the profit buffer value P is 50-200 yuan / ton. Preferably, the profit buffer value P is 100 yuan / ton.

[0024] In a further technical solution, the theoretical maximum amount W to be added is also constrained by a preset upper limit for process addition. The upper limit for process addition is less than or equal to 90% of the total output Q, and the lower limit for process addition is greater than 5% of the total output Q. When the amount of scrap aluminum added is lower than this lower limit, its use value in smelting production is low and it has no practical application significance.

[0025] A further technical solution involves completing all calculations using an Excel spreadsheet with pre-defined formulas.

[0026] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0027] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing this case.

[0028] The working principle and advantages of this invention are as follows:

[0029] This invention innovatively constructs a cost assessment model that couples smelting process parameters (maximum allowable addition amount W) with market economic data. This approach yields the following significant effects:

[0030] 1. It achieves precise and data-driven procurement decisions: By quantitatively calculating the cost difference before and after using scrap aluminum, and taking technical feasibility (W) as the core input, it provides procurement personnel with an intuitive and objective basis for decision-making, avoiding the blindness and risks of making decisions based on experience.

[0031] 2. Improved resource utilization efficiency and cost control capabilities: It can quickly identify scrap aluminum with real economic value. Even when the unit price is not advantageous but the composition is highly matched, it can discover its cost reduction potential through accurate cost accounting, thereby minimizing the overall cost.

[0032] 3. Promoted synergy between technology management and supply chain management: It opened up the data flow from casting process technology to procurement operations, forming an economic optimization closed loop under technological constraints, and improving the enterprise's refined management and intelligent decision-making level. Detailed Implementation

[0033] The present case will be clearly described in detail below. Any person skilled in the art who understands the embodiments of the present case can make changes and modifications based on the technology taught in the present case without departing from the spirit and scope of the present case.

[0034] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms. Example 1 is as follows:

[0035] Target 6061 aluminum alloy (customized composition): Si: 0.57%-0.6%, Fe: ≤0.18%, Cu: 0.21%-0.23%, Mn: 0.05%-0.07%, Mg: 0.89%-0.93%, Cr: 0.1%-0.12%, Zn: ≤0.05%, Ti: ≥0.04%; Scrap aluminum composition to be evaluated: Si: 0.82%, Fe: 0.345%, Cu: 0.15%, Mn: 0.32%, Mg: 0.11%, Cr: 0.13%, Zn: 0.17%, Ti: 0.02%; Scrap aluminum price The cost is 18.22 yuan / kg, other processing costs S = 200 yuan / ton, the profit buffer P is taken as 100 yuan / ton based on actual cost requirements, and the planned total smelting output Q = 25000 kg; the current market prices of relevant raw materials are: 99.8 aluminum ingot 20.78 yuan / kg, AlSi2O 17.94 yuan / kg, AlCu2O 28.97 yuan / kg, 75% manganese agent 14.79 yuan / kg, 99.9% magnesium ingot 20.26 yuan / kg, 75% chromium agent 47.32 yuan / kg, AlTi5B 27.59 yuan / kg, 75% titanium agent 29.59 yuan / kg. The process for determining whether it is usable and suitable for purchase is as follows:

[0036] Step 1: Brief assessment of compatibility with scrap aluminum

[0037] Based on the target alloy composition requirements and the composition of the scrap aluminum, the calculated values ​​of each element in this 6061 aluminum alloy are as follows: Si: 0.585%; Fe: 0.18%; Cu: 0.22%; Mn: 0.06%; Mg: 0.91%; Cr: 0.105%; Zn: 0.05%; Ti: The customer-required Ti value is ≥0.04%, and the Ti content in the scrap aluminum is 0.02%. Considering an increment of ΔTi = 0.01%, 0.02% + 0.01% = 0.03% < 0.04%, therefore the calculated Ti value is 0.04%.

[0038] Based on the calculated composition values ​​and the content of each element in the scrap aluminum, the estimated amount of scrap aluminum that can be added according to each element is as follows: Si 17835.37 kg, Cu 25000 kg, Mn 4687.5 kg, Mg 25000 kg, Cr 20192.3 kg, Zn 7352.9 kg, Ti 25000 kg, and Fe: The Fe content in the scrap aluminum is 0.345%, and the calculated value of Fe is 0.18%. 0.345% + 0.1% = 0.445% > 0.18%. Considering the increment of ΔFe of 0.1%, the estimated amount of scrap aluminum that can be added is 25000 × (0.18% - 0.1%) / (0.345% - 0.1%) = 8163.27 kg. Based on the calculation results for each element, the minimum amount added is taken as the theoretical maximum amount of scrap aluminum that can be added, which is 4687.5 kg.

[0039] Preliminary assessment of whether the scrap aluminum is suitable for addition:

[0040] The theoretical maximum allowable addition amount W / total smelting amount Q=4687.5kg / 25000kg=18.75%>5%, this waste aluminum is suitable for addition.

[0041] Step 2: Calculate the cost reduction potential of casting.

[0042] (1) Calculate the cost of 6061 aluminum alloy material required by the customer without using scrap aluminum for casting:

[0043] 1. Determine the prices of various intermediate alloys, elemental solvents, pure aluminum ingots, and other raw materials:

[0044] The prices of AlSi20 raw materials are RMB 17.94 / kg, AlCu20 raw materials are RMB 28.97 / kg, 75% manganese is RMB 14.79 / kg, 99.9% magnesium ingots are RMB 20.26 / kg, 75% chromium is RMB 47.32 / kg, AlTi5B is RMB 27.59 / kg, 75% titanium is RMB 29.59 / kg, and 99.8% aluminum ingots are RMB 20.78 / kg.

[0045] Calculate the weight of the added raw materials:

[0046] AlSi20 addition amount = Q × customer's calculated value / 20% = 25000kg × 0.585% / 20% = 731.25kg;

[0047] AlCu20 addition amount = Q × customer's calculated value / 20% = 25000kg × 0.22% / 20% = 275kg;

[0048] Magnesium ingot addition amount = Q × customer's calculated value / 99.9% = 25000kg × 0.91% / 99.9% = 227.73kg;

[0049] 75% manganese additive dosage = Q × customer's calculated value / 75% = 25000kg × 0.06% / 75% = 20kg;

[0050] 75% chromium additive dosage = Q × customer's calculated value / 75% = 25000kg × 0.105% / 75% = 35kg;

[0051] AlTi5B addition amount = Q × 0.01% / 5% = 25000kg × 0.01% / 5% = 50kg;

[0052] 75% titanium additive addition amount = (Q × customer's calculated value - Q × 0.01%) / 75% = (25000kg × 0.04% - 25000kg × 0.01%) / 75% = 10kg;

[0053] 99.8% Aluminum Ingot Addition Amount = (Q - AlSi2O Addition Amount - AlCu2O Addition Amount - Magnesium Ingot Addition Amount × 99.9% - 75% Manganese Agent Addition Amount × 75% - 75% Cr Agent Addition Amount × 75% - Aluminum-Titanium-Boron Wire Addition Amount × 99% - 75% Titanium Agent Addition Amount × 75%) / 99.8% = (25000kg - 731.25kg - 275kg - 227.73kg × 99.9% - 20kg × 75% - 35kg × 75% - 50kg × 99% - 10kg × 75%) / 99.8% = 23715.43kg;

[0054] Total cost without using scrap aluminum = (AlSi20 price × AlSi20 addition amount + AlCu20 price × AlCu20 addition amount + Magnesium ingot price × Magnesium ingot addition amount + 75% manganese agent price × 75% manganese agent addition amount + 75% Cr agent price × 75% Cr agent addition amount + Aluminum-titanium-boron wire price × Aluminum-titanium-boron wire addition amount + 75% titanium agent price × 75% titanium agent addition amount + 99.8% aluminum ingot price × 99.8% aluminum ingot addition amount) Quantity) = (17.94 yuan / kg × 731.25kg + 28.97 yuan / kg × 275kg + 20.26 yuan / kg × 227.73kg + 14.79 yuan / kg × 20kg + 47.32 yuan / kg × 35kg + 27.59 yuan / kg × 50kg + 29.59 yuan / kg × 10kg + 20.78 yuan / kg × 23715.43kg) = 522291.22 yuan;

[0055] Calculations show that the total cost of producing the 6061 alloy required by the customer without using scrap aluminum is 522,291.22 yuan.

[0056] (2) Based on the determined amount of scrap aluminum that can be added, which is 4687.5 kg, calculate the material cost required for smelting and casting using scrap aluminum:

[0057] 1. Determine the prices of various intermediate alloys, elemental solvents, pure aluminum ingots, and other raw materials:

[0058] The prices of AlSi20 raw materials are RMB 17.94 / kg, AlCu20 raw materials are RMB 28.97 / kg, 75% manganese is RMB 14.79 / kg, 99.9% magnesium ingots are RMB 20.26 / kg, 75% chromium is RMB 47.32 / kg, AlTi5B is RMB 27.59 / kg, 75% titanium is RMB 29.59 / kg, 99.8% aluminum ingots are RMB 20.78 / kg, and scrap aluminum is RMB 18.22 / kg.

[0059] 2. Determine the usage of other raw materials besides scrap aluminum:

[0060] AlSi20 addition amount = (Q × customer's calculated value - weight of Si in scrap aluminum) / 20% = (25000kg × 0.585% - 4687.5kg × 0.82%) / 20% = 539.06kg;

[0061] AlCu20 addition amount = (Q × customer's calculated value - Cu weight in scrap aluminum) / 20% = (25000kg × 0.22% - 4687.5kg × 0.15%) / 20% = 239.84kg;

[0062] Magnesium ingot addition amount = (Q × customer's calculated value - weight of Mg in scrap aluminum) / 99.9% = (25000kg × 0.91% - 4687.5kg × 0.11%) / 99.9% = 222.57kg;

[0063] 75% manganese additive addition = (Q × customer's calculated value - weight of Mn in scrap aluminum) / 75% = (25000kg × 0.06% - 4687.5kg × 0.32%) / 75% = 0kg;

[0064] 75% chromium additive addition amount = (Q × customer's calculated value - weight of Cr in scrap aluminum) / 75% = (25000kg × 0.105% - 4687.5kg × 0.13%) / 75% = 26.88kg;

[0065] AlTi5B addition amount = Q × 0.01% / 5% = 25000kg × 0.01% / 5% = 50kg;

[0066] 75% titanium additive addition = (Q × customer's calculated value - weight of Ti in scrap aluminum - Q × 0.01% / 75% = (25000kg × 0.04% - 4687.5kg × 0.02% - 25000kg × 0.01%) / 75% = 8.75kg;

[0067] 99.8% Aluminum Ingot Addition Amount = (Q - Waste Aluminum Addition Amount - AlSi2O Addition Amount - AlCu2O Addition Amount - Magnesium Ingot Addition Amount × 99.9% - 75% Manganese Addition Amount × 75% - 75% Chromium Addition Amount × 75% - Aluminum-Titanium-Boron Wire Addition Amount × 99% - 75% Titanium Addition Amount × 75%) / 99.8% = (25000kg - 4687.5kg - 539.06kg - 239.84kg - 222.57kg × 99.9% - 0kg × 75% - 26.88kg × 75% - 50kg × 99% - 8.75kg × 75%) / 99.8% = 20891.67kg;

[0068] Total cost of using scrap aluminum = (Scrap aluminum price × Scrap aluminum addition amount + AlSi2O price × AlSi2O addition amount + AlCu2O price × AlCu2O addition amount + Magnesium ingot price × Magnesium ingot addition amount + 75% manganese agent price × 75% manganese agent addition amount + 75% chromium agent price × 75% chromium agent addition amount + Aluminum-titanium-boron wire price × Aluminum-titanium-boron wire addition amount + 75% titanium agent price × 75% titanium agent addition amount + 99.8% aluminum ingot price × 99.8% aluminum ingot addition amount) = (18.22 yuan / (kg×4687.5kg+17.94 yuan / kg×539.06kg+28.97 yuan / kg×239.84kg+20.26 yuan / kg×222.57kg+14.79 yuan / kg×0kg+47.32 yuan / kg×26.88kg+27.59 yuan / kg×50kg+29.59 yuan / kg×8.75kg+20.78 yuan / kg×20891.67kg)=509949.60 yuan;

[0069] Calculations show that the total cost of producing the 6061 alloy required by the customer using this scrap aluminum is 509,949.60 yuan.

[0070] Step 3: Economic Feasibility Assessment

[0071] The cost reduction per ton is ΔC = (C1 - C2) / Q × 1000 = (522291.22 yuan - 509949.60 yuan) / 25000kg × 1000 = 487.34 yuan / ton.

[0072] Other processing costs per ton S + buffer costs P = 200 yuan / ton + 100 yuan / ton = 300 yuan / ton.

[0073] The cost reduction per ton is greater than the other processing cost per ton (S) plus the buffer cost (P), so the scrap aluminum is ultimately deemed suitable for purchase. Example 2 is as follows:

[0074] Target 6061 aluminum alloy (customized composition): Si: 0.57%-0.6%, Fe: ≤0.18%, Cu: 0.21%-0.23%, Mn: 0.05%-0.07%, Mg: 0.89%-0.93%, Cr: 0.1%-0.12%, Zn: ≤0.05%, Ti: ≥0.04%; Scrap aluminum composition to be evaluated: Si: 0.82%, Fe: 0.345%, Cu: 0.15%, Mn: 0.32%, Mg: 0.11%, Cr: 0.13%, Zn: 1.05%, Ti: 0.02%, Scrap aluminum price. The cost is 17.39 yuan / kg, other processing costs S = 200 yuan / ton, profit buffer P is taken as 100 yuan / ton based on actual cost requirements, and the planned total smelting output Q = 25000 kg; the current market prices of relevant raw materials are: 99.8 aluminum ingot 20.78 yuan / kg, AlSi2O 17.94 yuan / kg, AlCu2O 28.97 yuan / kg, 75% manganese agent 14.79 yuan / kg, 99.9% magnesium ingot 20.26 yuan / kg, 75% chromium agent 47.32 yuan / kg, AlTi5B 27.59 yuan / kg, 75% titanium agent 29.59 yuan / kg. The process for determining whether it is usable and suitable for purchase is as follows:

[0075] Step 1: Brief assessment of compatibility with scrap aluminum

[0076] Based on the target alloy composition requirements and the composition of the scrap aluminum, the calculated values ​​of each element in this 6061 aluminum alloy are as follows: Si: 0.585%; Fe: 0.18%; Cu: 0.22%; Mn: 0.06%; Mg: 0.91%; Cr: 0.105%; Zn: 0.05%; Ti: The customer-required Ti value is ≥0.04%, and the Ti content in the scrap aluminum is 0.02%. Considering an increment of ΔTi = 0.01%, 0.02% + 0.01% = 0.03% < 0.04%, therefore the calculated Ti value is 0.04%.

[0077] Based on the calculated composition values ​​and the content of each element in the scrap aluminum, the estimated amount of scrap aluminum that can be added according to each element is as follows: Si 17835.37 kg, Cu 25000 kg, Mn 4687.5 kg, Mg 25000 kg, Cr 20192.3 kg, Zn 1190.48 kg, Ti 25000 kg, Fe: The Fe content in the scrap aluminum is 0.345%, and the calculated value of Fe is 0.18%. 0.345% + 0.1% = 0.445% > 0.18%. Considering the increment of ΔFe of 0.1%, the estimated amount of scrap aluminum that can be added is 25000 × (0.18% - 0.1%) / (0.345% - 0.1%) = 8163.27 kg. Based on the calculation results of each element, the minimum amount added is taken as the theoretical maximum amount of scrap aluminum that can be added, W, which is 1190.48 kg.

[0078] Determining whether the scrap aluminum is suitable for addition: The theoretical maximum amount that can be added is W / total smelting amount Q = 1190.48 kg / 25000 kg = 4.76% < 5%, which does not reach the lower limit of the process addition. Therefore, the scrap aluminum is not suitable for addition.

[0079] Step 2: Cost Calculation and Economic Feasibility Assessment

[0080] Since the amount of scrap aluminum added does not meet the process constraints, its use value is extremely low. There is no need to conduct subsequent cost accounting. It is directly determined that the scrap aluminum has no economic value for purchase and is not suitable for purchase. Example 3 is as follows:

[0081] Target 6061 aluminum alloy (customized composition): Si: 0.57%-0.6%, Fe: ≤0.18%, Cu: 0.21%-0.23%, Mn: 0.05%-0.07%, Mg: 0.89%-0.93%, Cr: 0.1%-0.12%, Zn: no requirement, Ti: ≥0.04%, other single elements: ≤0.05%; Scrap aluminum composition to be evaluated: Si: 0.82%, Fe: 0.345%, Cu: 0.15%, Mn: 0.32%, Mg: 0.67%, Cr: 0.13%, Zn: 0.17%, Ti: 0.02%, Pb: 0.1%; Scrap aluminum price is 19.36 yuan / kg, other processing costs S = 200 yuan / ton, profit buffer P is taken as 100 yuan / ton based on actual cost requirements, planned total smelting output Q = 25000kg; Current market prices of relevant raw materials are: 99.8 aluminum ingot 20.78 yuan / kg, AlSi2O 17.94 yuan / kg, AlCu2O 28.97 yuan / kg, 75% manganese agent 14.79 yuan / kg, 99.9% magnesium ingot 20.26 yuan / kg, 75% chromium agent 47.32 yuan / kg, AlTi5B 27.59 yuan / kg, 75% titanium agent 29.59 yuan / kg. The customer has no oxidation requirement. The process for determining its usability and suitability for purchase is as follows:

[0082] Step 1: Brief assessment of compatibility with scrap aluminum

[0083] Based on the target alloy customer's composition requirements, national standard requirements, scrap aluminum composition, and the customer's requirement for no oxidation, the calculated values ​​of each element in this 6061 aluminum alloy are as follows: Si: 0.585%; Fe: 0.18%; Cu: 0.22%; Mn: 0.06%; Mg: 0.91%; Cr: 0.105%; Zn: 0.17%; Ti: The customer requires Ti to be ≥0.04%, and the Ti content in the scrap aluminum is 0.02%. Considering the increment of ΔTi=0.01%, 0.02%+0.01%=0.03%<0.04%, therefore the calculated value of Ti is 0.04%; Pb: Pb is not a major element of 6061 as specified in the national standard. The content of Pb in the scrap aluminum is >0.05%, so it is listed separately and also needs to be calculated. The calculated value of non-major alloying elements is uniformly fixed at 0.02%.

[0084] Based on the calculated composition values ​​and the content of each element in the scrap aluminum, the estimated amount of scrap aluminum that can be added according to each element is as follows: Si 17835.37 kg, Cu 25000 kg, Mn 4687.5 kg, Mg 25000 kg, Cr 20192.3 kg, Zn 25000 kg, Ti 25000 kg, Pb 5000 kg, Fe: The Fe content in the scrap aluminum is 0.345%, and the calculated value of Fe is 0.18%. 0.345% + 0.1% = 0.445% > 0.18%. Considering the increment of ΔFe of 0.1%, the estimated amount of scrap aluminum that can be added is 25000 × (0.18% - 0.1%) / (0.345% - 0.1%) = 8163.27 kg. Based on the calculation results for each element, the minimum amount added is taken as the theoretical maximum amount of scrap aluminum that can be added, which is 4687.5 kg.

[0085] Determining whether the scrap aluminum is suitable for addition: The theoretical maximum amount that can be added is W / total smelting amount Q = 4687.5kg / 25000kg = 18.75% > 5%, therefore the scrap aluminum is suitable for addition.

[0086] Step 2: Calculate the cost reduction potential of casting.

[0087] Calculate the cost of 6061 aluminum alloy material required by the customer without using scrap aluminum for casting:

[0088] 1. Determine the prices of various intermediate alloys, elemental solvents, pure aluminum ingots, and other raw materials:

[0089] The prices of AlSi20 raw materials are RMB 17.94 / kg, AlCu20 raw materials are RMB 28.97 / kg, 75% manganese is RMB 14.79 / kg, 99.9% magnesium ingots are RMB 20.26 / kg, 75% chromium is RMB 47.32 / kg, AlTi5B is RMB 27.59 / kg, 75% titanium is RMB 29.59 / kg, and 99.8% aluminum ingots are RMB 20.78 / kg.

[0090] Calculate the weight of the added raw materials:

[0091] AlSi20 addition amount = Q × customer's calculated value / 20% = 25000kg × 0.585% / 20% = 731.25kg;

[0092] AlCu20 addition amount = Q × customer's calculated value / 20% = 25000kg × 0.22% / 20% = 275kg;

[0093] Magnesium ingot addition amount = Q × customer's calculated value / 99.9% = 25000kg × 0.91% / 99.9% = 227.73kg;

[0094] 75% manganese additive dosage = Q × customer's calculated value / 75% = 25000kg × 0.06% / 75% = 20kg;

[0095] 75% chromium additive dosage = Q × customer's calculated value / 75% = 25000kg × 0.105% / 75% = 35kg;

[0096] AlTi5B addition amount = Q × 0.01% = 25000kg × 0.01% / 5% = 50kg;

[0097] 75% titanium additive addition amount = (Q × customer's calculated value - Q × 0.01%) / 75% = (25000kg × 0.04% - 25000kg × 0.01%) / 75% = 10kg;

[0098] 99.8% Aluminum Ingot Addition Amount = (Q - AlSi2O Addition Amount - AlCu2O Addition Amount - Magnesium Ingot Addition Amount × 99.9% - 75% Manganese Agent Addition Amount × 75% - 75% Cr Agent Addition Amount × 75% - Aluminum-Titanium-Boron Wire Addition Amount × 99% - 75% Titanium Agent Addition Amount × 75%) / 99.8% = (25000kg - 731.25kg - 275kg - 227.73kg × 99.9% - 20kg × 75% - 35kg × 75% - 50kg × 99% - 10kg × 75%) / 99.8% = 23715.43kg;

[0099] Total cost without using scrap aluminum = (AlSi20 price × AlSi20 addition amount + AlCu20 price × AlCu20 addition amount + Magnesium ingot price × Magnesium ingot addition amount + 75% manganese agent price × 75% manganese agent addition amount + 75% Cr agent price × 75% Cr agent addition amount + Aluminum-titanium-boron wire price × Aluminum-titanium-boron wire addition amount + 75% titanium agent price × 75% titanium agent addition amount + 99.8% aluminum ingot price × 99.8% aluminum ingot addition amount) Quantity) = (17.94 yuan / kg × 731.25kg + 28.97 yuan / kg × 275kg + 20.26 yuan / kg × 227.73kg + 14.79 yuan / kg × 20kg + 47.32 yuan / kg × 35kg + 27.59 yuan / kg × 50kg + 29.59 yuan / kg × 10kg + 20.78 yuan / kg × 23715.43kg) = 522291.22 yuan;

[0100] Calculations show that the cost of producing the 6061 alloy required by the customer without using scrap aluminum is 522,291.22 yuan.

[0101] (2) Based on the determined amount of scrap aluminum that can be added, which is 4687.5 kg, calculate the material cost required for smelting and casting using scrap aluminum:

[0102] 1. Determine the prices of various intermediate alloys, elemental solvents, pure aluminum ingots, and other raw materials:

[0103] The prices of AlSi20 raw materials are RMB 17.94 / kg, AlCu20 raw materials are RMB 28.97 / kg, 75% manganese agent is RMB 14.79 / kg, 99.9% magnesium ingot is RMB 20.26 / kg, 75% chromium agent is RMB 47.32 / kg, AlTi5B is RMB 27.59 / kg, 75% titanium agent is RMB 29.59 / kg, 99.8% aluminum ingot is RMB 20.78 / kg, and scrap aluminum is RMB 19.36 / kg.

[0104] 2. Determine the usage of other raw materials besides scrap aluminum:

[0105] The AlSi20 addition amount = (Q × customer's calculated value - weight of Si in scrap aluminum) / 20% = (25000kg × 0.585% - 4687.5kg × 0.82%) / 20% = 539.06kg;

[0106] AlCu20 addition amount = (Q × customer's calculated value - Cu weight in scrap aluminum) / 20% = (25000kg × 0.22% - 4687.5kg × 0.15%) / 20% = 239.84kg;

[0107] Magnesium ingot addition amount = (Q × customer's calculated value - weight of Mg in scrap aluminum) / 99.9% = (25000kg × 0.91% - 4687.5kg × 0.11%) / 99.9% = 222.57kg;

[0108] 75% manganese additive addition = (Q × customer's calculated value - weight of Mn in scrap aluminum) / 75% = (25000kg × 0.06% - 4687.5kg × 0.32%) / 75% = 0kg;

[0109] 75% chromium additive addition amount = (Q × customer's calculated value - weight of Cr in scrap aluminum) / 75% = (25000kg × 0.105% - 4687.5kg × 0.13%) / 75% = 26.88kg;

[0110] AlTi5B addition amount = Q × 0.01% / 5% = 25000kg × 0.01% / 5% = 50kg;

[0111] 75% titanium additive addition = (Q × customer's calculated value - weight of Ti in scrap aluminum - Q × 0.01%) / 75% = (25000kg × 0.04% - 4687.5kg × 0.02% - 25000kg × 0.01%) / 75% = 7.5kg;

[0112] 99.8% Aluminum Ingot Addition Amount = (Q - Waste Aluminum Addition Amount - AlSi2O Addition Amount - AlCu2O Addition Amount - Magnesium Ingot Addition Amount × 99.9% - 75% Manganese Addition Amount × 75% - 75% Chromium Addition Amount × 75% - Aluminum-Titanium-Boron Wire Addition Amount × 99% - 75% Titanium Addition Amount × 75%) / 99.8% = (25000kg - 4687.5kg - 539.06kg - 239.84kg - 222.57kg × 99.9% - 0kg × 75% - 26.88kg × 75% - 50kg × 99% - 7.5kg × 75%) / 99.8% = 20891.67kg;

[0113] Total cost of using scrap aluminum = (Scrap aluminum price × Scrap aluminum addition amount + AlSi2O price × AlSi2O addition amount + AlCu2O price × AlCu2O addition amount + Magnesium ingot price × Magnesium ingot addition amount + 75% manganese agent price × 75% manganese agent addition amount + 75% chromium agent price × 75% chromium agent addition amount + Aluminum-titanium-boron wire price × Aluminum-titanium-boron wire addition amount + 75% titanium agent price × 75% titanium agent addition amount + 99.8% aluminum ingot price × 99.8% aluminum ingot addition amount) = (19.36 yuan / (kg×4687.5kg+17.94 yuan / kg×539.06kg+28.97 yuan / kg×239.84kg+20.26 yuan / kg×222.57kg+14.79 yuan / kg×0kg+47.32 yuan / kg×26.88kg+27.59 yuan / kg×50kg+29.59 yuan / kg×7.5kg+20.78 yuan / kg×20891.67kg)=515293.35 yuan;

[0114] Calculations show that the cost of producing the 6061 alloy required by the customer using scrap aluminum is 515,293.35 yuan.

[0115] Step 3: Economic Feasibility Assessment

[0116] The cost reduction per ton is ΔC = (C1 - C2) / Q × 1000 = (522,291.22 yuan - 515,293.35 yuan) / 25,000 kg × 1000 = 273.59 yuan / ton.

[0117] Other processing costs per ton S + buffer costs P = 200 yuan / ton + 100 yuan / ton = 300 yuan / ton.

[0118] If the cost reduction per ton is less than the other processing cost per ton (S) plus the buffer cost (P), it is ultimately determined that the scrap aluminum has no economic value for purchase and is not suitable for procurement. Example 4 is as follows:

[0119] Target 6063 aluminum alloy (customized composition): Si: 0.44%-0.5%, Fe: ≤0.25%, Cu: ≤0.10%, Mn: ≤0.10%, Mg: 0.54%-0.6%, Cr: ≤0.10%, Zn: ≤0.05%, Ti: ≤0.05%; Scrap aluminum composition to be evaluated: Si: 0.49%, Fe: 0.13%, Cu: 0.09%, Mn: 0.10%, Mg: 0.61%, Cr: 0.08%, Zn: 0.03%, Ti: 0.02%; Scrap aluminum price: 20.13 yuan / kJ g, other processing costs S = 200 yuan / ton, profit buffer P is taken as 100 yuan / ton based on actual cost requirements, planned total smelting output Q = 25000 kg; current market prices of relevant raw materials are: 99.8 aluminum ingot 20.78 yuan / kg, AlSi2O 17.94 yuan / kg, AlCu2O 28.97 yuan / kg, 75% manganese agent 14.79 yuan / kg, 99.9% magnesium ingot 20.26 yuan / kg, 75% chromium agent 47.32 yuan / kg, AlTi5B 27.59 yuan / kg, 75% titanium agent 29.59 yuan / kg. The customer has oxidation requirements; the process for determining its availability and suitability for purchase is as follows:

[0120] Step 1: Brief assessment of compatibility with scrap aluminum

[0121] Based on the target alloy composition requirements, the composition of the scrap aluminum, and the customer's oxidation requirements, the calculated values ​​of each element in the 6063 aluminum alloy are as follows: Si: 0.47%; Fe: The customer's required Fe value is ≤0.25%, and the Fe content in the scrap aluminum is 0.13%. Considering an increment of ΔFe of 0.1%, 0.13% + 0.1% = 0.23% < 0.25%, therefore the calculated Fe value = 0.23%; Cu: 0.09%; Mn: 0.10%; Mg: 0.575%; Cr: 0.08%; Zn: 0.03%; Ti: The customer's required Ti value is ≤0.05%, and the Ti content in the scrap aluminum is 0.02%. Considering an increment of ΔTi = 0.01%, 0.02% + 0.01% = 0.03% < 0.05%, therefore the calculated Ti value = 0.03%.

[0122] Based on the calculated composition values ​​and the content of each element in the waste aluminum, the allowable amounts of waste aluminum to be added according to each element are as follows: Si 23979.59 kg, Cu 25000 kg, Fe 25000 kg, Mn 25000 kg, Mg 23565.57 kg, Cr 25000 kg, Zn 25000 kg, and Ti 25000 kg. According to the calculation results of each element, the theoretical minimum addition amount is 23565.57 kg (accounting for 94.26%). Since it exceeds the 90% process addition limit, the theoretical maximum allowable addition amount of this waste aluminum is Q×90%=22500 kg.

[0123] Determining whether the scrap aluminum is suitable for addition: The theoretical maximum addable amount W / total smelting amount Q = 22500kg / 25000kg = 90%, which is within the 5%-90% process constraint range, so the scrap aluminum is suitable for addition.

[0124] Step 2: Calculate the cost reduction potential of casting.

[0125] Calculate the cost of 6063 aluminum alloy material required by the customer without using scrap aluminum for casting:

[0126] 1. Determine the prices of various intermediate alloys, elemental solvents, pure aluminum ingots, and other raw materials:

[0127] The prices of AlSi20 raw materials are RMB 17.94 / kg, AlCu20 raw materials are RMB 28.97 / kg, 75% manganese is RMB 14.79 / kg, 99.9% magnesium ingots are RMB 20.26 / kg, 75% chromium is RMB 47.32 / kg, AlTi5B is RMB 27.59 / kg, 75% titanium is RMB 29.59 / kg, and 99.8% aluminum ingots are RMB 20.78 / kg.

[0128] Calculate the weight of the added raw materials:

[0129] AlSi20 addition amount = Q × customer's calculated value / 20% = 25000kg × 0.47% / 20% = 587.5kg;

[0130] AlCu20 addition amount = Q × customer's calculated value / 20% = 25000kg × 0.09% / 20% = 112.5kg;

[0131] Magnesium ingot addition amount = Q × customer's calculated value / 99.9% = 25000kg × 0.575% / 99.9% = 143.89kg;

[0132] 75% manganese additive dosage = Q × customer's calculated value / 75% = 25000kg × 0.10% / 75% = 33.33kg;

[0133] 75% chromium additive dosage = Q × customer's calculated value / 75% = 25000kg × 0.08% / 75% = 26.67kg;

[0134] AlTi5B addition amount = Q × 0.01% = 25000kg × 0.01% / 5% = 50kg;

[0135] 75% titanium additive dosage = (Q × customer's calculated value - Q × 0.01%) / 75% = (25000kg × 0.03% - 25000kg × 0.01%) / 75% = 6.67kg;

[0136] 99.8% Aluminum Ingot Addition Amount = (Q - AlSi2O Addition Amount - AlCu2O Addition Amount - Magnesium Ingot Addition Amount × 99.9% - 75% Manganese Agent Addition Amount × 75% - 75% Cr Agent Addition Amount × 75% - Aluminum-Titanium-Boron Wire Addition Amount × 99% - 75% Titanium Agent Addition Amount × 75%) / 99.8% = (25000kg - 587.5kg - 112.5kg - 143.89kg × 99.9% - 33.33kg × 75% - 26.67kg × 75% - 50kg × 99% - 6.67kg × 75%) / 99.8% = 24104.96kg;

[0137] Total cost without using scrap aluminum = (AlSi20 price × AlSi20 addition amount + AlCu20 price × AlCu20 addition amount + Magnesium ingot price × Magnesium ingot addition amount + 75% manganese agent price × 75% manganese agent addition amount + 75% Cr agent price × 75% Cr agent addition amount + Aluminum-titanium-boron wire price × Aluminum-titanium-boron wire addition amount + 75% titanium agent price × 75% titanium agent addition amount + 99.8% aluminum ingot price × 99.8% aluminum ingot addition amount) = (1 (7.94 yuan / kg × 587.5kg + 28.97 yuan / kg × 112.5kg + 20.26 yuan / kg × 143.89kg + 14.79 yuan / kg × 33.33kg + 47.32 yuan / kg × 26.67kg + 27.59 yuan / kg × 50kg + 29.59 yuan / kg × 6.67kg + 20.78 yuan / kg × 24104.96kg) = 520946.87 yuan;

[0138] Calculations show that the cost of producing the 6063 alloy required by the customer without using scrap aluminum is 520,946.87 yuan.

[0139] (2) Based on the determined amount of scrap aluminum that can be added, which is 22,500 kg, calculate the material cost required for smelting and casting using scrap aluminum:

[0140] 1. Determine the prices of various intermediate alloys, elemental solvents, pure aluminum ingots, and other raw materials:

[0141] The prices of AlSi20 raw materials are RMB 17.94 / kg, AlCu20 raw materials are RMB 28.97 / kg, 75% manganese agent is RMB 14.79 / kg, 99.9% magnesium ingot is RMB 20.26 / kg, 75% chromium agent is RMB 47.32 / kg, AlTi5B is RMB 27.59 / kg, 75% titanium agent is RMB 29.59 / kg, 99.8% aluminum ingot is RMB 20.78 / kg, and scrap aluminum is RMB 20.13 / kg.

[0142] 2. Determine the usage of other raw materials besides scrap aluminum:

[0143] The AlSi20 addition amount = (Q × customer's calculated value - weight of Si in scrap aluminum) / 20% = (25000kg × 0.47% - 22500kg × 0.49%) / 20% = 36.25kg;

[0144] AlCu20 addition amount = (Q × customer's calculated value - Cu weight in scrap aluminum) / 20% = (25000kg × 0.09% - 22500kg × 0.09%) / 20% = 11.25kg;

[0145] Magnesium ingot addition amount = (Q × customer's calculated value - weight of Mg in scrap aluminum) / 99.9% = (25000kg × 0.575% - 22500kg × 0.61%) / 0.999 = 6.51kg;

[0146] 75% manganese additive addition = (Q × customer's calculated value - weight of Mn in scrap aluminum) / 75% = (25000kg × 0.1% - 22500kg × 0.1%) / 75% = 3.33kg;

[0147] 75% chromium additive addition amount = (Q × customer's calculated value - weight of Cr in scrap aluminum) / 75% = (25000kg × 0.08% - 22500kg × 0.08%) / 75% = 2.67kg;

[0148] AlTi5B addition amount = Q × 0.01% / 5% = 25000kg × 0.01% / 5% = 50kg;

[0149] 75% titanium additive addition = (Q × customer's calculated value - weight of Ti in scrap aluminum - Q × 0.01%) / 75% = (25000kg × 0.03% - 22500kg × 0.02% - 25000kg × 0.01%) / 75% = 0.67kg;

[0150] 99.8% Aluminum Ingot Addition Amount = (Q - Waste Aluminum Addition Amount - AlSi2O Addition Amount - AlCu2O Addition Amount - Magnesium Ingot Addition Amount × 99.9% - 75% Manganese Addition Amount × 75% - 75% Chromium Addition Amount × 75% - Aluminum-Titanium-Boron Wire Addition Amount × 99% - 75% Titanium Addition Amount × 75%) / 99.8% = (25000kg - 22500kg - 36.25kg - 11.25kg - 6.51kg × 99.9% - 3.33kg × 75% - 2.67kg × 75% - 50kg × 99% - 0.67kg × 75%) / 99.8% = 2396.79kg;

[0151] Total cost of using scrap aluminum = (Scrap aluminum price × Scrap aluminum addition amount + AlSi2O price × AlSi2O addition amount + AlCu2O price × AlCu2O addition amount + Magnesium ingot price × Magnesium ingot addition amount + 75% manganese agent price × 75% manganese agent addition amount + 75% chromium agent price × 75% chromium agent addition amount + Aluminum-titanium-boron wire price × Aluminum-titanium-boron wire addition amount + 75% titanium agent price × 75% titanium agent addition amount + 99.8% aluminum ingot price × 99.8% aluminum ingot addition amount) = (20.13) (yuan / kg × 22500kg + 17.94 yuan / kg × 36.25kg + 28.97 yuan / kg × 11.25kg + 20.26 yuan / kg × 6.51kg + 14.79 yuan / kg × 3.33kg + 47.32 yuan / kg × 2.67kg + 27.59 yuan / kg × 50kg + 29.59 yuan / kg × 0.67kg + 20.78 yuan / kg × 2396.79kg) = 505413.14 yuan;

[0152] Calculations show that the cost of producing the 6063 alloy required by the customer using scrap aluminum is 505,413.14 yuan.

[0153] Step 3: Economic Feasibility Assessment

[0154] The cost reduction per ton is ΔC = (C1 - C2) / Q × 1000 = (520,946.87 yuan - 505,413.14 yuan) / 25,000 kg × 1000 = 621.35 yuan / ton.

[0155] Other processing costs per ton S + buffer costs P = 200 yuan / ton + 100 yuan / ton = 300 yuan / ton.

[0156] The cost reduction per ton is greater than the other processing cost per ton (S) plus the buffer cost (P), so the scrap aluminum is ultimately deemed suitable for purchase.

[0157] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys, characterized in that: include: S1. Obtain prerequisite technical parameters: Obtain the required range of the target 6-series aluminum alloy composition, the actual composition of the scrap aluminum, and the calculated theoretical maximum amount W that the scrap aluminum can be added to in the total smelting output Q; wherein, the theoretical maximum amount W is a constraint value calculated based on the composition requirements of each alloying element and the actual composition of the scrap aluminum, and taking into account the fixed iron increment ΔFe introduced by the smelting process and the fixed titanium increment ΔTi introduced by the grain refiner. S2. Calculate the baseline cost and the proposed cost: Based on the required composition range of the target 6-series aluminum alloy, the theoretical maximum allowable addition amount W, the actual composition of the scrap aluminum, and the current market price, the following calculations are performed: The first raw material cost C1 when smelting the total output Q of 6-series aluminum alloys without using scrap aluminum; The second raw material cost C2 when smelting the total output Q of 6-series aluminum alloys using the theoretically maximum addable amount W of scrap aluminum; Among them, the calculation of the second raw material cost C2 needs to deduct the amount of raw materials corresponding to the alloy elements contained in the scrap aluminum W; S3. Economic Feasibility Assessment: Calculate the cost reduction per ton ΔC = (C1-C2) / Q × 1000; If ΔC>(S+P), then purchasing and using the scrap aluminum is deemed economically feasible. Where S is the cost of other treatment per ton of the waste aluminum, and P is a preset profit buffer value.

2. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 1, characterized in that: In S2, the calculation of the first raw material cost C1 and the second raw material cost C2 both need to be based on the calculated composition value of the target 6-series aluminum alloy, and the supplementary addition amounts of aluminum-silicon master alloy, aluminum-copper master alloy, magnesium ingot, manganese agent, chromium agent, aluminum-titanium-boron wire, titanium agent and pure aluminum ingot are determined respectively, and the calculation is based on the current market price of each raw material.

3. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 2, characterized in that: In the calculation of the supplementary addition amount, the titanium content ΔTi introduced by the fixed addition of aluminum titanium boron wire is pre-calculated for titanium element.

4. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 1, characterized in that: The fixed iron increment ΔFe is 0.1% ± 0.02%, and the fixed titanium increment ΔTi is 0.01%.

5. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 1, characterized in that: The profit buffer value P is 50-200 yuan / ton.

6. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 5, characterized in that: The profit buffer value P is 100 yuan / ton.

7. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 1, characterized in that: The theoretical maximum amount W to be added is also constrained by a preset upper limit for process addition, which is less than or equal to 90% of the total output Q, and the lower limit for process addition is greater than 5% of the total output Q.

8. The method for economic evaluation and procurement decision-making of scrap aluminum for smelting 6-series aluminum alloys according to claim 1, characterized in that: All calculations are performed using an Excel spreadsheet with pre-defined formulas.