Dec 29 (Reuters) - China's top copper smelters kept floor treatment and refining charges (TC/RCs) for copper concentrate in the first quarter of 2022 flat from the previous quarter, two people with knowledge of the matter said on Wednesday.

The rates were set at $70 per tonne and 7 cents per pound during a meeting of the China Smelters Purchase Team (CSPT) held online on Wednesday, the sources said.

The new rates are 32% higher than the $53 per tonne and 5.3 cents per pound set during the same period a year earlier.

Miners pay TC/RCs to smelters to process copper concentrate into refined metal, offsetting the cost of the ore. The charges fall when supply tightens and rise when more concentrate is available.

Jiangxi Copper, Tongling Nonferrous, China Copper and other members of the CSPT in top copper consumer China are meant to adhere to the floor price when agreeing spot processing deals for imported concentrate.

The first-quarter floor is higher than a recent settlement between U.S.-based miner Freeport-McMoRan Inc and Chinese smelters of $65 per tonne and 6.5 cents per pound for term supply of copper concentrate next year.

That settlement is set to be the annual benchmark for 2022, which will be referenced in concentrate supply contracts worldwide. It represents a 9.2% increase on this year's benchmark and is the first time the smelters have managed to secure better annual terms since 2015.

"The Q4 rate is a reaction to the current market situation," said one of the sources, who declined to be identified as he was not authorized to speak to the media.

Analysts expect the tight copper mine supply seen in recent years to ease in 2022, although it remains uncertain whether the Las Bambas mine in Peru, which produces around 2% of the world's copper, will be able to resume and sustain operations after a month-long transport blockade.

Spot treatment charges in China , as assessed by Asian Metal, dipped to $59.50 a tonne this week, having held steady at $60.50 since early September, indicating a tighter concentrate market. The charges had been languishing at decade lows of around $30 a tonne in April. (Reporting by Emily Chow and Tom Daly; Editing by Christian Schmollinger and Devika Syamnath)