* Iron ore prices rise after Brazil mining dam failure
(Updates Jan. 31 story with deal amount in paragraph 2):
LONDON (Reuters) - Global trader Glencore is close to finalizing a deal to make a $500 million payment to the mining arm of Brazil’s Companhia Siderurgica Nacional (CSN) for iron ore cargoes to be delivered over five years, sources familiar with the matter said. One source said Glencore (GLEN.L), which would receive 20 million tonnes of iron ore over the period, would sign the deal no later than the first quarter.