The Finn struggled for straightline speed in the race. He faced a tough battle getting past the Mercedes of Michael Schumacher, which had high tyre wear but was faster on the straights.
"We did not have much speed. Considering how difficult the handling was and how tricky the car was to drive I am very happy to finish third," Raikkonen said.
"I wasn't expecting a very easy race and it turned out to be very difficult.
"The first few laps on new tyres were good and then I started sliding. We had a bit more high downforce to get more grip which meant we struggled in a straight line."
Raikkonen ultimately overtook Schumacher with a very bold outside-line pass into Eau Rouge.
"Michael passed me once and then he got me back," said Raikkonen.
"Even with DRS I could not pass him, so I had to take a chance to overtake him with KERS into Eau Rouge and he still almost got me back."
He regarded his third place as damage limitation.
"It is better to finish third than not to finish," Raikkonen said.
"We didn't win but we didn't have the speed to win so we didn't deserve to win.
"The last two races we had the speed but in races that you could not overtake. Here we did not have the speed."