Fastmarkets MB, page-64

what can you say, people don't like tailings. But when we talk about ~$5 billion dollars worth of recoverable zinc, assuming stable prices, assuming recovery rates are achieved as stated, then that money is real

3% in situ zinc x 0.62 recovery rate = 1.86% x 77mt total resource = 1.43mt Zn x ~AUD$3,400 = $4.85b total revenue + silver credits = a speculation that has good upside. 

Now we just have to define the word Right