The output of Jaw crusher is fed to Secondary crusher i.e. a Cone Crusher. The feed size -150 mm rock is crushed to -40 mm size. Cone crusher consists of two truncated cones with different diameters. Initially these two truncated cones are called Concave and Mantle, which are made of Manganese alloy. Similarly rocks are crushed in between the chamber of Concave and Mantle.
This is the final crushing stage, where the output of Cone Crusher is fed to Vertical Shaft Impactor (VSI) through screens. M-sand is produced from the output of VSI as an end product. The VSI crusher, by means of its unique design and action, produces well-shaped fine aggregate particles.
When the stones are processed through the Vertical Shaft Impact Crusher, not only fine aggregates, but also coarse aggregates, another end product, acquire improved particle shape and reduced surface roughness. Manufactured Sand plants ensure better grading of fine aggregates for better particle size distribution. Few plants are equipped with air filter systems and/or washing facilities, which maintains micro fine sand particles (the ones passing 75 micron) 3% by weight.
Washing provides an added benefit of keeping Manufactured Sand wet or in partially wet conditions. Though this helps reduce the water absorption rate of Manufactured Sand concrete preparation which in turn contribute to the better workability and workability retention.
Technical specifications for M-Sand
The composition of sand is highly variable, depending on the local rock sources. But the most common constituent of sand is silica (silicon dioxide, or SiO2), usually in the form of quartz. VYTGG
Improved and well-functioning M-Sand value chain, adoption of IS standards among all M-Sand manufacturers leading to better quality. Consistency, improved accessibility and adoption among end consumers. But better skills among construction labour to use M-Sand appropriately and finally better policy environment are vital to meet the growing demand. For new constructions and to prevent the natural disasters such as flooding, ecological imbalances created by indiscriminate river sand mining. But the size of the housing deficit in India to the tune of 90 million units by 2022. The huge demand for sand required in construction make a compelling case for a market systems approach to help housing and construction markets be more responsive and ecologically sensitive.
To advance such initiatives, the Terwilliger Center for Innovation in Shelter is looking to support the M-Sand sector stakeholders. With technical knowledge to make the M-Sand value chain more inclusive and sustainable. Manufacturers, distributors and aggregators, professional associations and academics can apply to join the program by sending an expression of interest for a chance to receive financial and technical support, benefiting from Habitat’s expertise and latest findings from on-going research and global best practices.
Fineness Modulus (FM): Aggregate sieve analysis results denoted in Fineness Modulus.
The latest Indian Standard IS: 383- 2016 “Coarse and Fine Aggregates for Concrete- Specification (Third Revision)” covers the requirements for aggregates. Crushed or uncrushed, derived from natural sources. Such as river terraces and river beds, glacial deposits, rocks, boulders and gravels. Manufactured aggregates produced from other than natural sources, for use in the production of concrete. For normal structural purposes including mass concrete works.
M-Sand for concreting- But its granule thickness/sieve size is 150 Microns-4.75 mm and also adheres to IS Code 383:1970
M-Sand for plastering- Whereas Wall plaster and tiling purposes. But its granule thickness/sieve size is 150 Microns-2.36 mm and this adheres to IS Code 1542:1992
M-sand for Brick work- Used in Masonry, block laying and brick work. Although its granule thickness is 150 microns-3.55mm and it adheres to IS Code 2116:1980
Article Source : MasterBuilder