Research Article
Economic and Environmental Evaluation and Optimal Ratio of Natural and Recycled Aggregate Production
Table 2
Symbols used in this study for modeling.
| | Symbol | Description |
| | Quantity of natural aggregate (ton) | | Quantity of recycled aggregate (ton) | | (%) | Natural/recycled aggregate ratio percent | | Apparatus | | Production capacity of plant (ton/h) | | Number of activated days in a year (day) | | Number of activated hours in a day (hour) | | Number of items required for apparatus | | Number of apparatus in step 1 | | Number of apparatus in step 2 | | Useful life of plant (year) | | Price of crude oil (used/kg) | | FED | Final energy consumption = final energy demand (KW h/ton) | | PED | Primary specific energy demand (kgoe/ton) | | COE | Specific CO2eq emission (kg CO2eq/ton) | | Final to primary energy factor | | CO2 emission factor | | Power of apparatus | | Total cost (USD/ton) | | Energy cost | | Investment (ownership) cost (USD/ton) | | Equipment holding (maintenance) cost of step (USD/ton) | | Human resource cost of step (USD/ton) | | Unit price of apparatus (USD) |
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