翻訳と辞書 |
taconite
Taconite is a variety of iron formation, an iron-bearing (> 15% iron) sedimentary rock, in which the iron minerals are interlayered with quartz, chert, or carbonate. Newton Horace Winchell, the Minnesota State Geologist, coined the term during his pioneering investigations of the Precambrian Biwabik Iron Formation of northeastern Minnesota. He noted the rock had a superficial resemblance to iron-bearing rocks from the Taconic Mountains of New York. The iron content of taconite, commonly present as finely dispersed magnetite, is generally 25 to 30%. ==History== In the late 19th and early 20th centuries, the United States was mining such an abundance of iron ore of high quality that taconite was considered an uneconomic waste product. By the end of World War II, however, much of the high-grade iron ore in the United States had been exhausted. Taconite became valued as a new source of the metal.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「taconite」の詳細全文を読む
スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|