Puzzle ZQFL 

Workings

Hint
Start by looking at the consonants and vowels (AEIOU).

Answer
65 tonnes.

Vowels (AEIOU) are worth 3 and consonants are worth 5, added together and then multiplied by the number of ingots.

So TIN has 1 vowel (worth 3) and 2 consonants (worth 10).

Added gives 13, then multiplied by 5 ingots = 65.