GS Paper 3
Syllabus: Science and Technology, Environment Conservation
Context: Coal India Ltd (CIL) has envisaged processing the fragmented rock (known as Overburden Rocks (OB) for sand production in mines.
- OB material contains about 60% sandstone by volume which is harnessed through crushing and processing of Overburden.
What is M Sand?
M sand is a form of artificial sand, manufactured by crushing large hard stones, mainly rocks or granite, into fine particles, which are then washed and finely graded. It is widely used as a substitute for river sand for construction purposes, mostly in the production of concrete and mortar mix.
Need for M Sand
- Due to high demand, regulated supply and a complete ban on sand mining during monsoon to protect the river ecosystem, finding an alternative to river sand became necessary.
- The Supreme Court banned illegal mining on riverbeds in 2017
- Sand Mining Framework (2018) prepared by the Ministry of Mines envisages alternative sources of sand in the form of Manufactured Sand (M-Sand) from crushed rock fines (crusher dust), and sand from Overburden (OB) of coal mines.
Why Coal India Ltd?
During Opencast mining of Coal India, the overlying soil and rocks are removed as waste to extract coal and the fragmented rock (Overburden or OB) is heaped in dumps. Most of the waste is disposed of at the surface which occupies a considerable land area and requires extensive planning and control to minimize the environmental impact of mining.
Difference between M Sand and Natural River sand
Process of extraction of M-Sand:
Benefits of Manufactured Sand (M-Sand):
- Cost-effectiveness: As it can be produced in large quantities at a lower cost.
- Consistency: in grain size and shape, which can be beneficial for construction projects that require a specific type of sand.
- Environmental benefits: Helps reduce the need for mining natural sand, which can have negative environmental impacts.
- Additionally, using the overburden from coal mines can help to repurpose materials that would otherwise be considered waste.
- Lesser Sand extraction from the river will reduce erosion of channel beds & banks and protect the water habitat
- Help maintain the water table
- Reduced water consumption: This helps reduce the amount of water required for construction projects, as it does not require washing before use.
- Better workability: Since it’s more angular and has a rougher surface, which makes it more workable for construction projects.
Concerns regarding M Sand:
- Due to its smooth and angular textures, it leads to more water and cement requirements to achieve the expected workability, thereby increase in overall costs.
- If the M Sand contains a large number of micro fine particles, it can affect the strength and workability of concrete.
Sand is a mixture of small grains of rock and granular materials which is mainly defined by size, being finer than gravel and coarser than silt.
- Sand is classified as a “minor mineral”, under The Mines and Minerals (Development and Regulations) Act, 1957 (MMDR Act)
- Administrative control over minor minerals vests with the State Governments
Q. Is sand mining illegal in India? Discuss the impacts of sand mining and suggest the way forward. (250 words)