A Chinese-Tajik antimony and gold mining joint venture has once again delayed its start-up because of the coronavirus pandemic and now plans to begin commercial production by October, Tajik state metals firm TALCO said on Monday.

TALCO Gold, jointly owned by TALCO and China's Tibet Huayu Mining Co, planned to start producing antimony, a metal used in batteries and fire retardants, from the Konchoch deposits in western Tajikistan in March.

It initially put off the start-up until the middle of this year as the Central Asian nation closed its borders and suspended the issuance of work permits for foreigners due to the pandemic.

On Monday, Igor Sattarov, head of TALCO's information and public relations department, said the pandemic has significantly changed the project's timeframe.

"Taking into account the current situation, we plan to start it no later than in October," he said in an email.

Tajikistan, which borders China, has confirmed 5,035 COVID-19 cases with 50 deaths.

Sattarov said construction work at the site was 80% complete, but the delivery of equipment produced in Finland has been delayed by coronavirus-related restrictions and it could take another two months to finally get it shipped and running.

At the same time, he said, fresh data has indicated the venture could produce up to 21,000 tonnes of antimony and 2.5 tonnes of gold per year - more than the previous estimate of 16,000 tonnes and 2.2 tonnes respectively.

"According to this data, Tajikistan could have the world's biggest antimony reserves and become the No.3 global producer after Russia and China," he said.

Sattarov said TALCO would review the output targets of its main aluminium business amid the global economic downturn.

However, in the first quarter, he said, the company increased aluminium output by 12% year on year and it has so far maintained the same pace.

(Reporting by Nazarali Pirnazarov,; Writing by Olzhas Auyezov; editing by Emelia Sithole-Matarise)