To start with, GRAPHENE IS NOT MINED!!!!! Graphite is. Graphene can be MANUFACTURED from natural graphite (that has been mined) or agricultural waste (typically corn cobs ref ShengQan Group).
Re the "How many bags?" question: I reckon at least 200. Minimum.
Meanwhile back on planet earth.....
CRL Price at posting:
2.5¢ Sentiment: Buy Disclosure: Held