15,600 tpd. Reserves stand at 7.2

million ounces grading 5 700 000 000 nanogram per tonne gold (DoM., 2005). What is the gold grade in;
i) grams per tonne (g/t)? (2mks)
ii) parts per million (ppm)? (2mk

1 answer

To convert the gold grade from nanograms per tonne to grams per tonne and parts per million, let's follow these calculations step by step.

i) Convert to grams per tonne (g/t)

  1. We have the gold grade as 5,700,000,000 nanograms per tonne.
  2. To convert nanograms to grams, we use the fact that \( 1 , \text{gram} = 1,000,000,000 , \text{nanograms} \).
  3. Therefore, we can convert the gold grade as follows:

\[ \text{Gold grade in g/t} = \frac{5,700,000,000 , \text{nanograms}}{1,000,000,000 , \text{nanograms/gram}} = 5.7 , \text{g/t} \]

ii) Convert to parts per million (ppm)

  1. The definition of parts per million (ppm) is the same as grams per tonne (g/t) when dealing with solids, as there are 1,000,000 grams in a tonne.
  2. Because of this, the gold grade in g/t will also be the same numeric value in ppm.

Thus, the gold grade is:

\[ \text{Gold grade in ppm} = 5.7 , \text{ppm} \]

Summary:

  • Gold Grade in grams per tonne (g/t): 5.7 g/t
  • Gold Grade in parts per million (ppm): 5.7 ppm