Power Thesaurus. 1969. pedometer thesaurus http://www.powerthesaurus.org/pedometer/synonyms (accessed August 31, 2017). Harvard. Power Thesaurus 1969, pedometer thesaurus, Power Thesaurus, viewed 31 August, 2017, <http://www.powerthesaurus.org/pedometer/synonyms>.
We would like to Buy Columbite with Nb2O5 45-55% min,Ta2O5 approx 5%, U3O8+ThO2 0.5% max. Niobium metal ingots 99.95%min.
This confusion arose because tantalum and niobium are similar metals, are always found together and are very difficult to isolate. Niobium was rediscovered and renamed by Heinrich Rose in 1844 when he produced two new acids, niobic acid and pelopic acid, from samples of columbite and tantalite.