The company - which is listed in both New York and Toronto - produced 81,000 tonnes of zinc in the fourth quarter, which was down 12% year-on-year. The full-year production was 320,000t, which fell into the guidance range of 310,000-342,000t, according to preliminary and unaudited results released on February 3. 

Nexa's copper production for the quarter was 7,000t, dropping from 15,000t a year earlier, which took 2021 production to 30,000t. That sat just above the top of the 26,000-29,000t guidance. 

Lead production rose 2% year-on-year to 13,000t in the December quarter, taking 2021 production to 46,000t compared with guidance of 42,000-49,000t. 

Silver production rose 8% year-on-year to 2,311 ounces in the three-month period. For 2021, silver production of 8,808oz hit the guidance of 8,531-9,317oz, the company said. 

Nexa's treated ore volumes in the fourth quarter stood at 3.12 million tonnes, down 1% from a year earlier, while 2021 volumes were 12.33Mt, having risen 14% year-on-year. 

"In 2021, we were able to safely operate and overcome operational setbacks, as well as the ongoing challenges imposed by COVID-19 and inflationary cost pressures across our supply chain," Nexa's CEO Ignacio Rosado said. 

Rosado noted that the pandemic was expected to continue to present challenges, but he was confident in the company's ability to navigate its way through it. 

BMO Capital Markets analyst Jackie Przybylowski said that Nexa's fourth-quarter production was in line with consensus estimates. 

Nexa announced on January 12 that heavy rainfall in the Brazilian state of Minas Gerais had caused its Vazante underground operation to reduce its daily production to 60% of its capacity. The company provided an update on the situation on February 3, saying that monthly production is under review. 

Typically, Nexa releases a three-year outlook with the fourth quarter results, but that has been delayed due to the weather issues and is now scheduled to be provided on February 15. 

"Given that we are now expecting a more prolonged impact to Vazante, we are reducing our estimate to 3,000tpd in Q1/22 (from 4,176tpd)," Przybylowski said.

"We expect that the flood will only impact the current quarter, and we have not adjusted our Q2 or future expectations," she added. 

Nexa traded on the Toronto Stock Exchange at C$8.21/share on February 6, a rise of 1% day-on-day. The stock had a 52-week high/low range of C$12.86/C$6.50. 

Nexa's market capitalisation was C$1,087 million.