By Kirstin Ridley LONDON (Reuters) -Anglo-Australian mining giant BHP has lost an appeal in a London court seeking to block a 5 billion pound-plus ($6 billion-plus) lawsuit by 200,000 Brazilians over a dam failure that triggered Brazil’s worst environmental disaster. The Court of Appeal ruled on Friday that the group lawsuit, which is seeking damages for the 2015 disaster and is one of the largest in English legal history, can proceed in English courts. Senior judges said they had dismissed each application to halt the case. BHP is now expected to take its appeal to the Supreme Court. The coll…