Aluminium prices rose in London on Friday on concerns that supply disruptions from major exporter of the feed material Guinea would further tighten the market for alumina, the main ingredient in making aluminium.

Emirates Global Aluminium said on Friday the exports of alumina raw material bauxite from its subsidiary Guinea Alumina Corporation were suspended by customs and it was seeking clarity from customs on the reason.

Three-month aluminium on the London Metal Exchange (LME) rose 2.5% to $2,650 per metric ton by 1025 GMT. Alumina prices on the Shanghai Futures Exchange (SHFE) jumped to a record high.

"With China being the largest delivery point for bauxite in the world, it is not surprising to see this latest disruption causing prices to surge on the SHFE for alumina," said StoneX analyst Natalie Scott-Gray.

Alumina supply has been challenged this year with disruptions in China and Australia, while Guinea is the world's largest exporter of bauxite, accounting for 70% of global seaborne exports, she added.

Bauxite exports from Guinea are up 23% so far this year, largely due to higher supplies from Guinea Alumina Corporation, according to StoneX. The company exported 14 million tons of bauxite last year.

Meanwhile, copper prices rose in London on Friday but were set for the biggest weekly decline in five weeks as a recent price rally hurt physical demand while inventories in top consumer China rose.

LME copper rose 0.2% to $9,746 a ton, supported by the 21-day moving average at $9,724. The contract was down 2% for the week so far.

China's stimulus announcements on Tuesday failed market expectations and lacked detail; however, the focus is now on further details on Chinese stimulus, scheduled for Saturday.

LME nickel edged up 1.6% to $17,820, zinc increased 1.0% to $3,118.50, lead rose 1.0% to $2,086.50 and tin climbed 1.1% to $33,085.

(Reporting by Polina Devitt in London; additional reporting by Mai Nguyen in Hanoi; Editing by Vijay Kishore)