hard ore मीनिंग इन हिंदी

A cone crusher is suitable for crushing a variety of mid-hard and above mid-hard ores and rocks.
Vein gold needed crushing, and they probably used crushing or stamp mills worked by water-wheels to comminute the hard ore before washing.
It is highly likely that they also developed water-powered stamp mills to crush hard ore, which could be washed to collect the heavy gold dust.