Mining colossus Rio Tinto has announced a clutch of fixed rate bond issues with a weighted average maturity of 11.6 years.The offering comprises $500 million of three-year, $500 million of five-year, $1 billion of 10-year and $500 million of 30-year debt securities, making $2.5bn in total.Coupons are as follows: Three-year = 12.125%; Five-year = 2.0%; 10-year = 3.5%; 30-year = 4.75%.jh