* Pinera most unpopular leader since Pinochet rule
* Chile economy seen growing 6.6 pct in 2011
By Fabian Cambero and Alexandra Ulmer
SANTIAGO, Aug 24 (Reuters) - Protesters barricaded roads and burned tires in parts of Chile's capital on Wednesday as a two-day national strike began against unpopular President Sebastian Pinera, but mining in the world's top copper producer was not disrupted.
The strike, called by Chile's main umbrella labor union CUT and coming on the heels of huge demonstrations by students demanding free education, got off to a slow start.
Public transportation was running and banks were open. While some miners said they supported the strike, operations at some of the world's biggest copper mines were not affected.
Protester demands went beyond educational change, ranging from a new constitution to a revamped tax system.
While previous governments have faced one-day national strikes, it was the first 48-hour national strike since the 1973-1990 Augusto Pinochet dictatorship.
Government spokesman Andres Chadwick said police defused some protests earlier on Wednesday, and that beyond traffic disruptions, the situation was "normal."
"We're all worried about the social climate," said Finance Minister Felipe Larrain, calling the strike illegal and a threat to the economy. He said the government would not tolerate roadblocks.
"We want to be able to push ahead with our programs. ... Government programs are not created in the street but at the polls." Larrain estimated the strike would cost Chile about $200 million a day.
Protesters clashed with police in recent weeks as hundreds of thousands of people took to the streets to rail against the conservative Pinera, who, according to a recent poll, is the least popular leader in the two decades since the end of Pinochet's rule.
Workers at some of the world's biggest copper mines have stage strikes of their own. Workers at BHP Billiton's (BHP.AX) (BLT.L) Escondida, the world's No.1 copper mine, halted a two-week strike earlier this month that stoked global supply fears. [ID:nN1E77400A]
While Latin America's model economy is seen expanding 6.6 percent this year and is an investor magnet thanks to prudent fiscal and monetary policies, many ordinary Chileans feel they are not sharing in an economic miracle fueled by high copper prices.
Pinera, who took power a year and a half ago and appointed a Cabinet filled with technocrats, has alienated many Chileans with his policies. He is less than halfway through his four-year term.
A major Cabinet reshuffle last month, the second since Pinera took power, failed to quell unrest. [ID:nN1E76H180]
The slump in Pinera's support is seen hindering him in Congress, and delaying the passage of capital market reforms aimed at turning Chile into a financial hub to rival Brazil. (Editing by Simon Gardner and Peter Cooney)