If Australian miners are worried about the dramatic decline in iron ore prices, it doesn't show. At an annual gathering of many of the world's biggest and smallest iron ore producers here the mood is upbeat - as if the heftiest one-day fall in ore prices since the global financial crisis never happened. "Iron ore mining isn't tennis, it's a contact sport," said David Flanagan, chairman of Atlas Iron Ltd. "Sometimes it hurts a bit, like you copped it in the stomach. Iron ore for immediate delivery to China slumped 8 percent on Monday after data showed China's trade balance swung into deficit, amplifying concerns about a slowdown in the world's No. 2 economy and the biggest importer of the steel-making ingredient.