The Kazakhstan–based miner sold 1,130 tonnes of copper cathode in the nine months to September, compared to 511 tonnes in the first six months of the year.
Mining operations also picked up strongly with 357,000 tonnes of ore stacked at the end of the nine months compared to 166,000 tonnes three months earlier.
Revenues for the nine months were US$7.73 mln (US$7.38mln) with a gross profit of US$949,000 ( US$1.73mln), but after a currency charge of US$16.8mln, net losses rose to US$21.6mln from US$5mln.
Frontier has debts of around US$90mln. In March, it agreed the sale of its Naimanjal licence in Kazakhstan to UTM for US$30mln.
This has yet to complete, though regulatory approval for the sale was granted in July.