Sajjad Afraei

Sajjad Afraei

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Sajjad Afraei

Amirkabir University of Technology

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 April 2023 in Resources Policy
Verified
Journal Article
Closed access
NBNaser Badakhshan
Naser Badakhshan
KSKourosh Shahriar
Kourosh Shahriar
SASajjad Afraei
Sajjad Afraei
EBEzzeddin Bakhtavar
Ezzeddin Bakhtavar

17 June 2024 in Resources Policy
Verified
Journal Article
Closed access
NBNaser Badakhshan
Naser Badakhshan
KSKourosh Shahriar
Kourosh Shahriar
SASajjad Afraei
Sajjad Afraei
EBEzzeddin Bakhtavar
Ezzeddin Bakhtavar

19 May 2025 in Expert Systems with Applications
Verified
Journal Article
Open access
NBNaser Badakhshan
Naser Badakhshan
EBEzzeddin Bakhtavar
Ezzeddin Bakhtavar
KSKourosh Shahriar
Kourosh Shahriar
HKHassan Khosravi
Hassan Khosravi
SASajjad Afraei
Sajjad Afraei
Eugene Ben-AwuahEugene Ben-Awuah
Eugene Ben-Awuah

13 March 2026 in International Journal of Mining, Reclamation and Environment
Verified
Journal Article
Closed access
NBNaser Badakhshan
Naser Badakhshan
EBEzzeddin Bakhtavar
Ezzeddin Bakhtavar
KSKourosh Shahriar
Kourosh Shahriar
HKHassan Khosravi
Hassan Khosravi
SASajjad Afraei
Sajjad Afraei
Eugene Ben-AwuahEugene Ben-Awuah
Eugene Ben-Awuah

1 January 2026 in International Journal of Engineering
Verified
Journal Article
Open access
PDF file
MHM. M. Hajiabedi
M. M. Hajiabedi
SAS. Afraei
S. Afraei
Strategic mine planning is essential for attracting investment and ensuring efficient resource utilization. Long-term production scheduling determines the sequence of ore and waste block extraction to maximize economic returns while satisfying operational constraints. In addition to estimating the Net Present Value (NPV), it provides a foundation for medium- and short-term planning.This study presents a Mixed-Integer Linear Programming (MILP) model for determining the ultimate pit limit and performing long-term production scheduling under two scenarios: with and without the use of a stockpile. The model aims to maximize project NPV while incorporating seven key constraints—four geometric (block precedence, pit floor width, block extraction continuity, and non-repetition of block selection) and three demand-based (extraction capacity, ore block requirement, and minimum feed grade per period). The model was implemented in GAMS and tested on a hypothetical 5×7 block dataset to evaluate its feasibility and performance. Sensitivity analysis showed that increasing the pit floor width from one to four blocks resulted in a 44.8% reduction in the objective function value. A demand sensitivity analysis (1–3 blocks per period) under the non-stockpile scenario revealed that a 3-block demand was infeasible, while the best result was achieved at 1 block. To address infeasibility, stockpile inventory and shortage variables were introduced. The updated model identified 2 blocks per period as the optimal plant capacity, balancing stockpile holding costs and shortage penalties. If demand exceeds production, a penalty is applied to the objective function; if production exceeds demand, the surplus is added to the stockpile for future use. This mechanism enhances scheduling flexibility and supports more robust decision-making under real-world constraints.

1 January 2022 in SSRN Electronic Journal
Verified
Preprint
Open access
PDF file
NBNaser Badakhshan
Naser Badakhshan
KSKourosh Shahriar
Kourosh Shahriar
SASajjad Afraei
Sajjad Afraei
EBEzzeddin Bakhtavar
Ezzeddin Bakhtavar
One of the most urgent costs imposed on mine owners is the environmental costs of preventing, reducing, or compensating for adverse environmental impacts of mining activities. These costs sometimes increase to the point that mining becomes uneconomical. In the meantime, the most significant issue for mine owner’s inaccurate economic evaluation and less uncertainty is to include these costs in feasibility studies and evaluations. The most critical issue here is to quantify the environmental costs (per Ton of extracted ore), which have not reported to be focused. This study provided a framework-based methodology to solve this challenge. The methodology considers the most critical factors influencing the environmental costs in the life cycle of a mine. This method was implemented using Songun copper mine dataset for open-pit and block-caving sections. Results indicated that the environmental cost per Ton of the extracted materials was $0.0306 and $0.0224 for open-pit and block-caving sections, respectively. Since the environmental impacts of open-pit activities are higher than block-caving activities, higher costs are needed to prevent, reduce, and compensate the environmental impacts of open pit than block caving. The main superiority of this method is the possibility of its simple application for any mine located in any country.