The Metals Refinery is a building exclusive to India and is unlocked at the beginning of your colony. It processes 10 units of waste rock per shift, or 30 per sol if you leave it working around the clock. At this rate, you could process 3,000 units of waste rock in 100 sols with one Metals Refinery. Remember, though, that it will take you some time to get the first one up and running, and that unit will occasionally be down for lack of supply, lack of power, drone shortages, maintenance, etc. Either build a second Metals Refinery or research Waste Rock Liquefaction (engineering) and build a Waste Rock Processor to get you all the way there.
There's a good chance your extractors won't create enough waste rock to keep your processors running. If they stop, simply undertake some landscaping projects, like flattening an area or putting in a ramp.
You can keep track of your progress toward the first 1,000 of the 3,000 by checking your Mission Goals. I don't know of any way to track it the rest of the way, but you'll get a pretty good idea of how well you're doing by how quickly you reach the first 1,000.
I had two metal processors running most of the time, with a maximum of three, but they were often running only two shifts per day because I didn't have enough supply. I reached the 1,000 mark at around Sol 40 and unlocked the achievement at Sol 87.