A carbon emission accounting method for high-zinc lead liquid slag integrated smelting process

Abstract

This application relates to the fields of environmental science, industrial ecology, and carbon emission management, specifically disclosing a carbon emission accounting method for an integrated high-zinc-lead molten slag smelting process. This invention divides the integrated high-zinc-lead molten slag smelting process from "cradle" to "gate" into stages such as raw material mining and transportation, lead-zinc smelting, energy production, and waste heat utilization. By quantifying the energy consumption and carbon emissions at each stage of the high-zinc-lead slag raw material to crude lead product lifecycle, it achieves carbon footprint accounting for crude lead products, solving the problems of missing carbon emission accounting methods and ambiguous accounting boundaries in the integrated high-zinc-lead molten slag smelting process. Simultaneously, this invention provides a solution to the problem of allocating energy intensity and carbon emission intensity for the co-production of crude lead and crude zinc in the integrated high-zinc-lead molten slag smelting process by introducing a product allocation method.

Description

Technical Field

[0001] This application belongs to the fields of environmental science, industrial ecology and carbon emission management technology, and specifically relates to a carbon emission accounting method for an integrated smelting process of high zinc lead liquid slag. Background Technology

[0002] Against the backdrop of global climate change and carbon neutrality goals, the quantification of the carbon footprint of industrial products is receiving increasing attention. Lead, as a crucial basic industrial raw material, undergoes a pyrometallurgical process involving high energy consumption and complex chemical reactions, resulting in significant carbon emissions. Existing carbon emission accounting methods, when applied to complex industrial processes such as lead smelting, often face challenges such as data uncertainty, dynamism, and the coupling of multiple products, making accurate and reliable carbon footprint assessments difficult. Particularly in the cradle-to-gate lifecycle stage, how to systematically integrate carbon emissions from raw material acquisition, transportation, and processing, and how to rationally allocate carbon emissions from various products and byproducts in complex production lines, are pressing technological challenges that need to be addressed. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art; to this end, this invention provides a life cycle carbon emission accounting method for the integrated smelting process of high zinc lead liquid slag from "cradle" to "gate", which is used to solve the problem of carbon emission accounting for crude lead products at different stages in the prior art, thereby achieving accurate quantification of crude lead products.

[0004] The specific steps include: Step 1, determining the carbon emission accounting boundary: dividing the entire process into raw material mining and transportation, lead-zinc smelting, energy production, and waste heat utilization; Step 2, identifying various energy sources and energy-consuming media within the accounting boundary: analyzing carbon emission sources and identifying their types based on life cycle assessment; Step 3, collecting activity data: collecting activity data on the consumption of various energy sources and energy-consuming media, and carbon emission sources in each process segment within the selected time period of the accounting boundary, while also collecting the corresponding standard coal equivalent coefficient and carbon emissions. Factors; Step 4, Construct an energy consumption calculation model: Based on the input-output method and energy conservation, construct a calculation model for the comprehensive energy consumption of energy-related materials and the comprehensive energy consumption of energy-consuming working fluids, and then obtain the comprehensive energy consumption; Step 5, Construct a carbon emission accounting formula: Based on the input-output method and material balance method, analyze the carbon content in raw materials, intermediate products, final products and final residues, and construct a formula for calculating the total carbon emissions; Step 6, Product energy consumption and carbon emission allocation: Based on the output of crude lead and crude zinc products, use the output percentage allocation method or coefficient lookup method to allocate product energy consumption and carbon emissions.

[0005] Preferably, the determination of the accounting boundary in step 1 covers the entire life cycle from cradle to gate, including carbon emissions generated during the raw material mining process, carbon emissions from transporting raw materials from the mine to the smelting enterprise, carbon emissions from each process in the lead-zinc smelting process, carbon emissions generated from the combustion of fossil fuels, carbon emissions generated from the production process of purchased electricity and purchased heat, and carbon emissions generated from the utilization of waste heat devices.

[0006] Preferably, the application of life cycle assessment in step 2 includes: tracking the energy flow and material transformation path within the entire process system based on the input-output method, analyzing the carbon content distribution in various components such as raw materials, intermediate products, final products and final slag in the lead smelting process through the material balance method, and determining the existence form and migration and transformation law of carbon elements in the entire smelting process.

[0007] Preferably, the scope of activity data collection in step 3 includes: raw material consumption, energy consumption, final slag production, crude lead product production, crude zinc product production, standard coal equivalent coefficients for various energy sources, standard coal equivalent coefficients for various energy-consuming working fluids, and emission factors for various carbon emission sources. Among them, the activity data for fossil fuels includes lower heating value, consumption, carbon content per unit calorific value, and carbon oxidation rate.

[0008] The preferred formula for calculating the comprehensive energy consumption of energy categories is as follows: ; In the formula, AC i k represents the actual consumption of the i-th type of energy in production. i This represents the standard coal equivalent coefficient for the i-th energy source.

[0009] The preferred formula for calculating the comprehensive energy consumption of the energy-consuming working medium is: ; In the formula, AC j k represents the actual consumption of the j-th energy-consuming working fluid in production. j This represents the standard coal equivalent coefficient of the j-th energy-consuming working medium.

[0010] The preferred formula for calculating comprehensive energy consumption is: .

[0011] Preferably, the carbon emission accounting formula is constructed based on the input-output method and the material balance method as follows: ; In the formula, CE mine This indicates the carbon emissions during the extraction of various raw and auxiliary materials, CE transport This indicates the carbon emissions from transporting various raw and auxiliary materials from the mine to the smelting plant, CE. raw Indicates the total carbon content in raw materials and auxiliary materials, CEfuel CE represents the carbon emissions from burning various fossil fuels. process This indicates the carbon emissions generated by the thermal decomposition of carbonate substances during lead smelting, CE. power This indicates the carbon emissions generated from the net purchase of electricity and heat involved in the lead smelting production process, CE. device This indicates the carbon emissions generated by the net output of electricity and heat from the waste heat treatment unit in the lead smelting production process, CE. slag This indicates the total amount of carbon in the final residue.

[0012] Preferably, the carbon emissions CeP from fossil fuel combustion are... fuel The calculation formula is: ; Among them, CE fuel NCV represents the total carbon emissions produced by burning fossil fuels. j FC represents the lower heating value of the j-th fossil fuel. j CC represents the consumption of the j-th type of fossil fuel. j OF represents the carbon content per unit calorific value of the j-th fossil fuel. j denoted by , which represents the carbon oxidation rate of the j-th fossil fuel, and 44 / 12 represents the ratio of the relative molecular masses of carbon dioxide to carbon.

[0013] Preferably, the carbon emissions (CE) generated by the thermal decomposition of carbonate substances during lead smelting are low. process The calculation formula is: ; In the formula, AD j EF represents the activity data of the j-th carbonate. j The carbon dioxide emission factor of the j-th carbonate, PUR j This indicates the purity of the j-th carbonate.

[0014] Preferably, in step 6, the allocation of product energy consumption and carbon emissions adopts two allocation methods based on the proportion of crude zinc product output: when the proportion of crude zinc product output is less than the preset output proportion threshold, the output percentage allocation method is adopted, and the total comprehensive energy consumption and carbon emissions are directly allocated according to the output ratio of crude lead and crude zinc to obtain the unit comprehensive energy consumption and carbon emission intensity of crude lead product; when the proportion of crude zinc product output is greater than or equal to the preset output proportion threshold, the coefficient lookup method is adopted, and the unit comprehensive energy consumption of crude zinc ingot process and the carbon emission factor of crude zinc ingot pyrometallurgical smelting process are obtained by looking up the standard, the comprehensive energy consumption and carbon emission contribution value of crude zinc are calculated, and then the energy consumption and carbon emission of crude lead product are obtained by the difference method.

[0015] Preferably, the comprehensive energy consumption per unit of crude lead product in the percentage-based production allocation method and carbon emission intensity The calculation formula is: ; ; In the formula, E represents total energy consumption, CE represents total carbon emissions, and m Zn m Pb These represent the qualified product output of crude zinc and crude lead respectively during the accounting period.

[0016] Preferably, the coefficient lookup method is used to determine the unit comprehensive energy consumption of crude lead products. and carbon emission intensity The calculation formula is: ; ; In the formula, E represents total energy consumption, CE represents total carbon emissions, and e Zn This indicates the comprehensive energy consumption per unit product in the crude zinc ingot process (Level 1), ef Zn This indicates the carbon emission factor of crude zinc in the pyrometallurgical process of crude zinc ingots.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Strong full life cycle coverage: By defining a complete accounting boundary from cradle to gate, this invention systematically integrates carbon emission data from all stages of the entire process, including raw material mining and transportation, lead and zinc smelting, energy production and waste heat utilization, and constructs a carbon emission accounting system covering the entire life cycle of raw material acquisition, transportation and production processing, breaking through the limitations of existing technologies that only focus on a single process or some stages.

[0018] 2. Improved accounting model: This invention constructs an energy consumption calculation model and carbon emission accounting formula based on the input-output method and material balance method. By analyzing the carbon content distribution and carbon existence form in raw materials, intermediate products, final products and final slag, it realizes the accurate quantification of carbon emissions, and provides a scientific and reliable accounting method for the integrated smelting process of high zinc lead liquid slag.

[0019] 3. Rational allocation of multiple products: In view of the characteristics of the co-production process of crude lead and crude zinc, this invention designs a dual-mode product energy consumption and carbon emission allocation mechanism that can be flexibly selected according to the proportion of crude zinc production. By combining the production percentage allocation method and the coefficient lookup method, the problem of multi-product coupling allocation in complex production lines is solved, and the rational allocation of carbon emissions of co-production products is achieved.

[0020] This invention provides a carbon emission accounting system for the integrated smelting process of high zinc-lead liquid slag. By comprehensively collecting activity data from the entire process of the integrated smelting process of high zinc-lead liquid slag, a carbon emission accounting model and a product energy consumption and carbon emission intensity allocation model are constructed from the "cradle" to the "gate". The system fully considers the energy consumption and carbon emissions generated in the process within the entire accounting boundary, providing an accounting method for the integrated smelting process of high zinc-lead liquid slag. Attached Figure Description

[0021] Figure 1 This is a system boundary diagram of the present invention; Figure 2 The emission types are classified according to the present invention; Figure 3 The carbon emission structure of the entire life cycle of the integrated smelting process of high zinc and lead liquid slag. Detailed Implementation

[0022] Example 1: This invention provides a carbon emission accounting method for an integrated smelting process of high-zinc lead liquid slag, the method comprising the following specific steps: In the carbon emission accounting method described above, step 1 is to determine the carbon emission accounting boundary from cradle to gate.

[0023] This step constitutes the top-level design framework of the entire carbon emission accounting system, the core of which lies in clarifying the spatial and temporal scope of the accounting object.

[0024] In terms of spatial scope, the entire high-zinc lead liquid slag integrated smelting process system is divided into several stages based on selected boundaries, including raw material mining and transportation, lead-zinc smelting, energy production, and waste heat utilization. The raw material mining and transportation stage encompasses mining operations, ore beneficiation operations, ore crushing and grinding operations, ore pre-drying operations, and transportation of ore from the mine to the smelting plant. The lead-zinc smelting process includes sintering, granulation, reduction smelting, refining, and flue gas treatment. Energy production includes fossil fuel mining and processing, the production and transmission of purchased electricity, and the production and transmission of purchased heat. Waste heat utilization includes waste heat recovery from waste heat boilers, power output from waste heat power generation devices, and the utilization of waste heat steam.

[0025] In terms of time frame, the accounting boundary covers the entire lifecycle from the commencement of raw material mining activities to the departure of crude lead and zinc products from the smelter. Step 1, defining the accounting boundary, encompasses the entire lifecycle from cradle to gate, including carbon emissions from raw material mining, transportation carbon emissions from raw materials from the mine to the smelter, carbon emissions from each stage of the lead-zinc smelting process, carbon emissions from fossil fuel combustion, carbon emissions from the production of purchased electricity and heat, and carbon emissions from the utilization of waste heat treatment facilities. The output of this step is a complete list of accounting boundaries, clearly outlining all processes and their boundary points within the accounting scope.

[0026] In the above carbon emission accounting method, step 2 is to identify various energy sources and energy-consuming working media within the accounting boundary.

[0027] This step is based on the life cycle assessment method to identify carbon emission sources within the accounting boundary and to sort out the types of carbon emission sources.

[0028] Specifically, based on the input-output method, the energy flow path and material transformation path within the entire process system are tracked. The carbon content distribution in raw materials, intermediate products, final products and final slag in the lead smelting process is analyzed by the material balance method to determine the existence form and migration and transformation law of carbon element in the entire smelting process.

[0029] The scope of energy type identification includes, but is not limited to: primary energy sources such as raw coal, washed coal, crude oil, natural gas, shale gas, and biomass energy; secondary energy sources such as coke, coal gas, heavy oil, diesel, gasoline, fuel oil, liquefied petroleum gas, steam, and hot water; and electrical energy sources such as purchased electricity, self-generated electricity, and waste heat power generation. The scope of energy-consuming working fluid identification includes, but is not limited to: compressed air, oxygen, nitrogen, argon, cooling water, circulating water, and demineralized water. The results of the carbon emission source classification will form a detailed carbon emission source list, categorized and archived according to direct and indirect emission sources. Direct emission sources mainly include carbon dioxide emissions from the combustion of fossil fuels in smelting processes, carbon dioxide emissions from the thermal decomposition of carbonates, and emissions from carbon oxidation in materials; indirect emission sources mainly include carbon dioxide emissions from the production of purchased electricity, carbon dioxide emissions from the production of purchased heat, and carbon dioxide emissions from the mining and transportation of raw materials.

[0030] In the carbon emission accounting method described above, step 3 is to collect activity data.

[0031] This step uses the energy-carrying materials and carbon emission sources identified in step 2 to collect activity data on the consumption of various energy sources and energy-consuming working materials and carbon emission sources in each process link within the selected time period of the accounting boundary. At the same time, it collects the corresponding standard coal equivalent coefficient and carbon emission factor of carbon emission sources.

[0032] The collected activity data can be categorized as follows: The first category is raw material data, including consumption of lead-zinc ore, carbonaceous reducing agents, limestone, quartz, coke, iron filings, and other auxiliary materials; the second category is energy consumption data, including consumption of various fossil fuels, electricity, heat, and energy-consuming working fluids; the third category is product output data, including the output of qualified crude lead and zinc products, final slag output, and by-product output; the fourth category is material composition data, including chemical composition analysis data of raw materials, intermediate products, final products, and final slag. The collected standard coal equivalent coefficients include those for various energy sources and energy-consuming working fluids, sourced from the national standard "General Rules for Comprehensive Energy Consumption Calculation" and industry standards. The collected carbon emission factors include carbon dioxide emission factors from fossil fuels, carbon dioxide emission factors from carbonates, carbon dioxide emission factors from electricity consumption, and carbon dioxide emission factors from heat consumption. Among them, the emission factor data for fossil fuels includes parameters such as lower heating value, carbon content per unit calorific value, and carbon oxidation rate. The data sources are the "Guidelines for Greenhouse Gas Emission Accounting", the IPCC emission factor database, and the China Product Life Cycle Greenhouse Gas Emissions Database (CPCD).

[0033] In the above carbon emission accounting method, step 4 involves constructing an energy consumption calculation model. This step, based on the input-output method and the law of conservation of energy, analyzes the energy flow within the entire carbon accounting system and constructs calculation models for the comprehensive energy consumption E1 (energy-related) and the comprehensive energy consumption E2 (energy-consuming working fluid), thereby obtaining the comprehensive energy consumption E. The calculation model for the comprehensive energy consumption E1 is shown in the formula: ; In the formula, AC i k represents the actual consumption of the i-th type of energy in production. i denoted by , i represents the standard coal equivalent coefficient of the i-th energy source, and n represents the total number of energy types included in the calculation.

[0034] The calculation model for the comprehensive energy consumption E2 of the energy-consuming working fluid is as follows: ; In the formula, AC j k represents the actual consumption of the j-th energy-consuming working fluid in production. j Represents the standard coal equivalent coefficient of the j-th energy-consuming working medium; E2 is equal to the sum of the products of the actual consumption of each energy-consuming working substance and the corresponding standard coal equivalent coefficient.

[0035] The total energy consumption E is the arithmetic sum of the total energy consumption of energy-related products E1 and the total energy consumption of energy-consuming working fluids E2, that is, E equals the sum of E1 and E2.

[0036] The application of the input-output method in this model is reflected in: Using each process step as a node and the flow direction of energy and energy-consuming working fluid as edges, a process energy flow network diagram is constructed. By analyzing the energy input-output relationship of each node, the law of conservation of energy is ensured to be strictly followed throughout the entire accounting system. Step 4, the construction process of the energy consumption calculation model, includes the following sub-steps: First, establish the energy flow topology of the process and draw a complete energy flow path diagram from the input of raw materials and auxiliary materials to the output of products. Second, determine the energy form conversion relationship on each energy flow path and clarify the conversion efficiency between different energy forms such as fuel combustion heat energy, raw material reaction heat energy, waste heat recovery heat energy, and power consumption. Third, establish the energy balance equation for each process step based on the law of conservation of energy. Fourth, solve the energy balance equations of each process step simultaneously to obtain the quantitative relationship between the consumption of each energy source and energy-consuming working medium and the overall energy consumption.

[0037] In the aforementioned carbon emission accounting method, step 5 involves constructing the carbon emission accounting formula. This step, based on the input-output method and material balance method, analyzes the carbon content in various components of the lead smelting process, including raw materials, intermediate products, final products, and final slag, determines the forms in which carbon exists, and then constructs a formula for calculating the total carbon emissions (CE) from cradle to gate for the integrated high-zinc lead liquid slag smelting process. The calculation of total carbon emissions (CE) covers the following eight sub-items: CE mine This represents the carbon emissions during the extraction of various raw and auxiliary materials. The data is obtained by multiplying the corresponding emission factor by the consumption of raw and auxiliary materials; CE transport This represents the carbon emissions from transporting various raw and auxiliary materials from mines to smelting enterprises. The data is obtained by multiplying the emission factors corresponding to the transport distance and mode of transport by the volume of raw and auxiliary materials transported; CE raw This represents the total carbon content of carbon-containing components in raw and auxiliary materials. The data is obtained through phase analysis to determine the presence of carbon-containing components in the raw and auxiliary materials. If carbon-containing components are present, carbon emissions are calculated and included based on the carbon content analysis results; otherwise, the value is 0. CE fuel This represents the carbon emissions produced by burning various fossil fuels; the calculation methods are explained in detail in subsequent paragraphs. process This represents the carbon emissions generated by the thermal decomposition of carbonate substances during lead smelting; the calculation method is explained in detail in subsequent paragraphs; CE power This represents the carbon emissions generated from the net purchased electricity and heat involved in the lead smelting production process. The data is obtained by subtracting the emissions corresponding to the replacement of electricity and heat by waste heat recovery from the product of electricity and heat consumption and their corresponding emission factors; CEdevice This represents the carbon emissions generated by the net output of electricity and heat from the waste heat treatment system in the lead smelting process. The data is obtained by multiplying the waste heat power generation and waste heat steam utilization by the corresponding emission factors; CE slag This represents the total carbon content of the carbon-containing components in the final slag. The data is obtained through phase analysis to determine the presence of carbon-containing components in the final slag. If carbon-containing components are present, the carbon emissions are calculated and included based on the carbon content analysis results; otherwise, the value is 0. The application of the material balance method in this step is reflected in: taking carbon as the research object, tracing the complete material balance path of carbon from raw material input, smelting process transformation to product and waste output, and establishing an input-output balance equation for carbon to ensure the completeness and accuracy of the carbon emission accounting results.

[0038] Regarding carbon emissions from the combustion of fossil fuels (CE) fuel Based on the accounting methods described in the IPCC methodology and considering the actual situation of the integrated smelting process of high-zinc lead liquid slag, two calculation models were constructed. The first calculation model is applicable to fossil fuels with known carbon content parameters, and its calculation formula is as follows: ; In the formula, NCV j FC represents the lower heating value of the j-th fossil fuel. j CC represents the consumption of the j-th type of fossil fuel. j OF represents the carbon content per unit calorific value of the j-th fossil fuel. j denoted by , where 44 / 12 represents the carbon oxidation rate of the j-th fossil fuel, 44 / 12 represents the ratio of the relative molecular masses of carbon dioxide to carbon, and n represents the total number of fossil fuel types included in the calculation.

[0039] The second calculation method is applicable to fuels with partially unknown carbon content parameters, and its calculation formula is as follows: ; CE fuel 'Indicates the carbon emissions of fuels with unknown carbon content, AD' jf EF represents the activity data for the j-th type of fossil fuel. jf The carbon dioxide emission factor of the jth fossil fuel.

[0040] The process of constructing a carbon emission calculation model for fossil fuel combustion includes the following sub-steps: First, based on the activity data collected in step 3, determine the types and quantities of various fossil fuels consumed; second, consult the corresponding standard emission factor parameters according to the fuel type, including lower heating value, carbon content per unit calorific value, and carbon oxidation rate; third, for fuels for which detailed parameters cannot be obtained, use the comprehensive emission factor method for simplified calculation; fourth, summarize the carbon emissions of various fuels to obtain the total carbon emissions generated by fossil fuel combustion.

[0041] Regarding the carbon emissions (CE) generated by the thermal decomposition of carbonate substances during lead smelting... process The calculation formula is as follows: ; AD j EF represents the activity data of the j-th carbonate. j The carbon dioxide emission factor of the j-th carbonate, PUR j This indicates the purity of the j-th carbonate.

[0042] The construction process of the carbon emission calculation model for carbonate thermal decomposition includes the following sub-steps: First, the chemical composition of carbonate-containing materials is determined through phase analysis to identify the types of various carbonates; second, the mass percentage or volume percentage of various carbonates in carbonate-containing materials is quantitatively analyzed; third, the amount of carbon dioxide produced by the complete decomposition of various carbonates is calculated based on the chemical equations of carbonate decomposition reactions; fourth, the amount of carbon dioxide produced by the decomposition of various carbonates is summarized to obtain the total carbon emissions generated by carbonate thermal decomposition.

[0043] In the above carbon emission accounting method, step 6 is the allocation of product energy consumption and carbon emissions. This step uses two different allocation methods to allocate product energy consumption and carbon emissions based on the production volume of crude lead and crude zinc products.

[0044] When the proportion of crude zinc production is less than a preset production threshold (specifically set at 5%), a production percentage allocation method is used to directly allocate the combined energy consumption and carbon emissions of the two products according to the production ratio of crude lead and crude zinc. The theoretical basis for this allocation method is that when the proportion of crude zinc production is low, the contribution of crude zinc as a co-product to the overall energy consumption and carbon emissions of the smelting system is small. Therefore, it can be approximated that the unit energy consumption and unit carbon emissions of crude zinc are equivalent to those of crude lead. In this case, the unit comprehensive energy consumption of crude lead is... The calculation formula is: ; Carbon intensity of crude lead products E Pb The calculation formula is: In the formula, E represents the overall energy consumption, CE represents the total carbon emissions of the process, and m Zn m Pb These represent the qualified product output of crude zinc and crude lead respectively during the accounting period.

[0045] When the proportion of crude zinc product output is greater than or equal to the preset output proportion threshold, the coefficient lookup method is used to obtain the comprehensive energy consumption e of the first-level unit product of the crude zinc ingot process by referring to the standard "Energy Consumption Limits for Unit Products of Non-ferrous Heavy Metal Smelting Enterprises". Zn The carbon emission factor ef of crude zinc in the pyrometallurgical smelting process of crude zinc ingots was obtained by consulting relevant emission factor databases. Zn Then, the comprehensive energy consumption and carbon emission contribution of crude zinc are calculated.

[0046] The theoretical basis for this allocation method is as follows: When the proportion of crude zinc production is high, crude zinc, as one of the main products, makes a significant contribution to the energy consumption and carbon emissions of the entire smelting system. In this case, the energy consumption and carbon emissions of crude zinc should be determined first, and then the energy consumption and carbon emissions of crude lead should be obtained by the difference method. The formula for calculating the unit comprehensive energy consumption e of crude lead is as follows: ; Crude lead products carbon emission intensity (CE) Pb The calculation formula is: ; In the formula, E represents the total energy consumption, e Zn This indicates the comprehensive energy consumption per unit product in the crude zinc ingot process (Level 1), EF. Zn This indicates the carbon emission factor of crude zinc in the pyrometallurgical process of crude zinc ingots.

[0047] Example 2: As Figures 1-3 As shown, this invention proposes a carbon emission accounting method for an integrated smelting process of high-zinc lead liquid slag. The invention will be further described in detail below with reference to specific embodiments.

[0048] Step 1: Determine the carbon emission accounting boundary for the integrated high-zinc lead liquid slag smelting process. See [link to specific carbon emission accounting boundary details]. Figure 1 As shown.

[0049] Step 2: Identify various energy sources, energy-consuming media, and carbon emission sources within the accounting boundary; collect data on production activities, energy-carrying materials converted to standard coal equivalent, carbon emission factors, etc.; carbon emission sources are classified as follows: Figure 2 .

[0050] Step 3: Construct a unit product energy consumption and carbon emission intensity model for the integrated smelting process of high zinc lead liquid slag.

[0051] Step 4: Substitute the activity data and quantify the results. Based on the product output, allocate the energy consumption and carbon emission contribution values.

[0052] This embodiment uses production data from the pilot production of 1 ton of crude lead using a high-zinc lead liquid slag integrated smelting process as an example.

[0053] 1. Identify various energy sources, energy-consuming media, and carbon emission sources, and collect data. Based on step 2 and Figure 1 The data results for identifying non-fossil energy materials within the accounting boundary are shown in Table 1.

[0054] Table 1 Non-fossil energy data Note 1. Raw materials and auxiliary materials are not used during the mining and transportation stages and are not included in the unit comprehensive energy consumption calculation; 2. XRD analysis determined that neither the mixed raw material nor the final residue contained carbonates, thus confirming that neither was a carbon-containing material and that the carbon emissions were both zero. 3. The Pb content in the mixed raw materials was found to be 32.5%, and the limestone purity was 83.7%. 4. The electricity output from the waste heat recovery device has been included in the net purchased electricity.

[0055] The results of the fossil fuel energy data are shown in Table 2.

[0056] Table 2 Fossil Fuel Energy Data Table 2. Energy consumption and carbon emission calculations 1) Overall energy consumption: ; The comprehensive energy consumption during the accounting period is calculated using the above formula: E = 225.89 kgce.

[0057] 2) According to the explanation in the formula and examples of this invention, the mixed raw materials, crude lead product, and final slag do not contain carbon. The formula is as follows: , Simplified to the following formula: .

[0058] The mining and transportation of raw materials are combined, thus reducing carbon emissions (CE). mine +CE transport =1479.6kgCO2e.

[0059] because Therefore, CE fuel =565.9kgCO2e.

[0060] The emissions generated during lead-zinc smelting are from the thermal decomposition of limestone, therefore CE process =58.9kgCO2e.

[0061] For waste heat recovery devices, there is the issue of electricity and steam being transmitted externally, and the waste heat device consuming demineralized water. This means demineralized water contributes positively to carbon emissions, while steam contributes negatively. The transmitted electricity offsets the purchased electricity, resulting in a net purchased electricity emission. Net purchased electricity emissions: CE power =63.3kgCO2e, net output steam CE device =180.6kgCO2e (after deducting carbon emissions from desalination). The total carbon emissions of the products during the accounting period are CE = 1987.6 kg CO2e.

[0062] 3. Product allocation, quantifying unit energy consumption and carbon emission intensity. Since the ratio of crude zinc product to total product is 2.91% during the accounting period, method ① is chosen in this example to calculate the energy consumption and carbon emission intensity allocation of crude lead. The unit comprehensive energy consumption and carbon emission intensity of crude lead product are as follows: Unit comprehensive energy consumption of crude lead products: ; Carbon emission intensity of crude lead products: ; According to calculations, in this embodiment, the comprehensive recovery rate of crude lead is 95%, and the unit comprehensive energy consumption is 219.3 kgce / t crude lead. The carbon emission intensity allocated by the integrated smelting process of high zinc lead liquid slag is 493.2 kgCO2e / t crude lead.

[0063] 4. Comparison with existing "three-furnace" process Table 3 Comparison of Process Indicators Based on the above comparison, the integrated smelting process of high zinc and lead liquid slag has lower unit comprehensive energy consumption and process carbon emission intensity than the "three-furnace" process.

Claims

1. A method for carbon emission accounting of an integrated smelting process of high-zinc lead liquid slag, characterized in that, Includes the following steps: Determine the carbon emission accounting boundary and divide the entire process into raw material mining and transportation, lead and zinc smelting, energy production, and waste heat utilization processes. Identify various energy sources and energy-consuming media within the carbon emission accounting boundary, and analyze and sort out the types of carbon emission sources based on the life cycle assessment method; Collect activity data on the consumption of various energy sources and energy-consuming media and carbon emission sources in each process link within the selected time period of the carbon emission accounting boundary, as well as the corresponding standard coal equivalent coefficient and carbon emission factor; Based on the input-output method and the law of conservation of energy, a calculation model for the comprehensive energy consumption of energy-related components and the comprehensive energy consumption of energy-consuming working fluids is constructed, thereby obtaining the comprehensive energy consumption. Based on the input-output method and the material balance method, the carbon content in raw materials, intermediate products, final products and final residues is analyzed, and a formula for calculating total carbon emissions is constructed. Based on the production volume of crude lead and crude zinc products, the energy consumption and carbon emissions of the products are allocated using either the production percentage allocation method or the coefficient lookup method.

2. The carbon emission accounting method for an integrated high-zinc lead molten slag smelting process according to claim 1, characterized in that, The formula for calculating the comprehensive energy consumption of energy categories is as follows: ； In the formula, AC i k represents the actual consumption of the i-th type of energy in production. i This represents the standard coal equivalent coefficient for the i-th energy source.

3. The carbon emission accounting method for the integrated smelting process of high-zinc lead liquid slag as described in claim 1, characterized in that, The formula for calculating the comprehensive energy consumption of energy-consuming working fluid is: ； In the formula, AC j k represents the actual consumption of the j-th energy-consuming working fluid in production. j This represents the standard coal equivalent coefficient of the j-th energy-consuming working medium.

4. The carbon emission accounting method for an integrated high-zinc lead liquid slag smelting process according to claim 3, characterized in that, The formula for calculating comprehensive energy consumption is: 。 5. The carbon emission accounting method for an integrated high-zinc lead molten slag smelting process according to claim 1, characterized in that, The formula for calculating total carbon emissions is constructed based on the input-output method and the material balance method as follows: ； In the formula, CE mine This indicates the carbon emissions during the extraction of various raw and auxiliary materials, CE transport This indicates the carbon emissions from transporting various raw and auxiliary materials from the mine to the smelting plant, CE. raw Indicates the total carbon content in raw materials and auxiliary materials, CE fuel CE represents the carbon emissions from burning various fossil fuels. process This indicates the carbon emissions generated by the thermal decomposition of carbonate substances during lead smelting, CE. power This indicates the carbon emissions generated from the net purchase of electricity and heat involved in the lead smelting production process, CE. device This indicates the carbon emissions generated by the net output of electricity and heat from the waste heat treatment unit in the lead smelting production process, CE. slag This indicates the total amount of carbon in the final residue.

6. The carbon emission accounting method for an integrated high-zinc lead molten slag smelting process according to claim 5, characterized in that, The formula for calculating carbon emissions from fossil fuel combustion is: ； Among them, CE fuel NCV represents the total carbon emissions produced by burning fossil fuels. j FC represents the lower heating value of the j-th fossil fuel. j CC represents the consumption of the j-th type of fossil fuel. j OF represents the carbon content per unit calorific value of the j-th fossil fuel. j denoted by , which represents the carbon oxidation rate of the j-th fossil fuel, and 44 / 12 represents the ratio of the relative molecular masses of carbon dioxide to carbon.

7. The carbon emission accounting method for an integrated high-zinc lead molten slag smelting process according to claim 6, characterized in that, The formula for calculating carbon emissions from the thermal decomposition of carbonates during lead smelting is as follows: ； In the formula, AD j EF represents the activity data of the j-th carbonate. j The carbon dioxide emission factor of the j-th carbonate, PUR j This indicates the purity of the j-th carbonate.

8. The carbon emission accounting method for the integrated smelting process of high zinc lead liquid slag as described in claim 1, characterized in that: In the allocation of product energy consumption and carbon emissions, when the output of crude zinc products accounts for less than 5%, the production percentage allocation method is adopted, and the comprehensive energy consumption and carbon emissions of the two products are allocated according to the production percentage of crude lead and crude zinc. In the allocation of product energy consumption and carbon emissions, when the output of crude zinc accounts for more than or equal to 5%, the coefficient lookup method is used to calculate the comprehensive energy consumption and carbon emission contribution value of crude zinc, and then the difference is used to obtain the energy consumption and carbon emission of crude lead.

9. The carbon emission accounting method for an integrated high-zinc lead liquid slag smelting process according to claim 8, characterized in that, When using the production percentage allocation method, the formulas for calculating the unit comprehensive energy consumption and carbon emission intensity of crude lead products are as follows: ； ； In the formula, E represents total energy consumption, CE represents total carbon emissions, and m Zn m Pb These represent the qualified product output of crude zinc and crude lead respectively during the accounting period.

10. The carbon emission accounting method for an integrated high-zinc lead molten slag smelting process according to claim 8, characterized in that, When using the coefficient lookup method, the formulas for calculating the unit comprehensive energy consumption and carbon emission intensity of crude lead products are as follows: ； ； In the formula, E represents total energy consumption, CE represents total carbon emissions, and e Zn This indicates the comprehensive energy consumption per unit product in the crude zinc ingot process (Level 1), ef Zn This indicates the carbon emission factor of crude zinc in the pyrometallurgical process of crude zinc ingots.

Images