Everyone was in for a big shock when PM Modi announced on November 8 that ₹500 and ₹1000 notes will no longer be legal tender. From the very next morning, people began queuing up outside banks to get their old currency exchanged. 

This move entailed wiping out 86 per cent of cash that was in circulation! Now, that's a huge amount.

But how exactly does our government plan to get rid of the old currency notes?

Source: thewire.in

According to a report by BBC, RBI has a daunting task of destroying around 20 billion expired banknotes ahead of it. But RBI doesn't think that destroying expired notes is that big a challenge. Just a year ago, in 2015-16, Axis Bank had destroyed more than 16 billion notes and a year before that, more than 14 billion notes were destroyed. An RBI official told BBC:

Destroying so much cash is not a challenge because we have enough shredding and briquetting machines with very high capacities. These are automatic machines which shred the cash into the finest of pieces.
Source: sputniknews.com

The shredding rooms have tight security around and people who carry out the shredding process wear surgical masks to cover their noses and mouths to prevent themselves from dust and fungus.

The RBI will shred the notes into smallest of pieces and make briquettes out of them, which will then be dumped in vast landfills. But sometimes, it's also recycled to make calendars, paper weights, tea-coasters, trays and other such items.