Model Answer
0 min readIntroduction
Neyveli Lignite Corporation India Limited (NLCIL), now known as NLC India Limited, operates one of the largest open-cast lignite mines in India, located in Neyveli, Tamil Nadu. Lignite, a low-grade coal, is a crucial energy source for power generation in the southern region. Established in 1956, Neyveli Lignite Mine has played a pivotal role in India’s energy security. The mine’s operations have evolved over the years, incorporating advanced mining techniques and machinery to enhance efficiency and productivity. This answer will detail the mining methodology employed at Neyveli, along with the machinery utilized, supported by illustrative sketches.
Overview of Neyveli Lignite Mine
The Neyveli Lignite Mine comprises multiple mines – Mine I, Mine II, Mine III, and Mine IV. Initially, mining was exclusively open-cast. However, with increasing depth, underground mining methods were also adopted. The lignite seams are found at varying depths, necessitating a combination of both techniques.
Mining Methodology
1. Open Cast Mining
Open cast mining is the predominant method used at Neyveli. It involves removing the overburden (soil and rock layers above the lignite seam) to expose the lignite. The process can be broken down into the following stages:
- Exploration & Planning: Geological surveys and drilling are conducted to delineate the lignite seams and plan the mining operations.
- Overburden Removal: This is the most significant stage, involving the use of heavy machinery to remove the overburden.
- Lignite Extraction: Once the lignite seam is exposed, it is extracted using excavators and loaders.
- Transportation: The extracted lignite is transported to the power plant or beneficiation plant using dump trucks and conveyors.
Sketch: Open Cast Mining - Showing overburden removal, lignite extraction, and transportation.
2. Underground Mining
Underground mining is employed when the lignite seam is too deep to be economically extracted using open-cast methods. The process involves creating underground tunnels and chambers to access the lignite. Key stages include:
- Shaft Sinking: Vertical shafts are sunk to access the lignite seam.
- Tunnel Development: Horizontal tunnels (galleries) are driven from the shaft to reach the lignite seam.
- Lignite Extraction: Lignite is extracted using continuous miners or conventional methods (drilling and blasting).
- Transportation: The extracted lignite is transported to the surface using conveyors and elevators.
Sketch: Underground Mining - Showing shaft sinking, tunnel development, and lignite extraction.
Machinery Under Use
Open Cast Mining Machinery
| Machinery | Function |
|---|---|
| Draglines | Removing overburden in large quantities. |
| Bucket Wheel Excavators (BWE) | Continuous removal of overburden. |
| Rope Shovels | Excavating lignite and loading it onto dump trucks. |
| Dump Trucks | Transporting lignite and overburden. |
| Conveyors | Continuous transportation of lignite to the power plant. |
| Drills & Blasters | Breaking hard rock formations during overburden removal. |
Underground Mining Machinery
| Machinery | Function |
|---|---|
| Continuous Miners | Cutting and extracting lignite continuously. |
| Drill Rigs | Drilling holes for blasting. |
| Explosives | Breaking lignite seams. |
| Conveyors | Transporting lignite from the working face to the surface. |
| Elevators/Hoists | Raising lignite from underground to the surface. |
| Ventilation Fans | Maintaining air quality underground. |
Conclusion
The Neyveli Lignite Mine remains a critical component of India’s energy infrastructure, providing a reliable source of lignite for power generation. The mine’s continued success relies on the efficient application of both open-cast and underground mining techniques, coupled with the utilization of advanced machinery. Future developments may focus on enhancing beneficiation processes, improving environmental sustainability, and exploring the potential for coal bed methane extraction from the lignite seams.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.