News tagged with cobalt
Cobalt ( /ˈkoʊbɒlt/ or /ˈkoʊbɔːlt/) is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.
Cobalt-based blue pigments have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought by alchemists to be due to the known metal bismuth. Miners had long used the name kobold ore (German for goblin ore) for some of the blue-pigment producing minerals; they were named because they were poor in known metals and gave poisonous arsenic-containing fumes upon smelting. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold.
Nowadays, some cobalt is produced specifically from various metallic-lustered ores, for example cobaltite (CoAsS), but the main source of the element is as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo and Zambia yields most of the cobalt metal mined worldwide.
Cobalt is used in the preparation of magnetic, wear-resistant and high-strength alloys. Cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give a distinctive deep blue color to glass, smalt, ceramics, inks, paints and varnishes. Cobalt occurs naturally as only one stable isotope, cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and in the production of gamma rays.
Cobalt is the active center of coenzymes called cobalamin or vitamin B12, and is an essential trace element for all animals. Cobalt is also an active nutrient for bacteria, algae and fungi.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
(HealthDay)—Serum metal levels of cobalt and chromium are elevated at all postoperative time points up to 36 months following metal-on-metal lumbar disc replacement, according to research published in the ...
Other Dec 22, 2012 | 4 / 5 (1) | 0
The Blackberry vs. iPhone battle has been ongoing since Apple's 2007 phone debut, with no end in sight. That is until today. According to a study being presented at the Annual Scientific Meeting of the American College of ...
Health Nov 09, 2012 | 2 / 5 (2) | 0
Hundreds of thousands of people have been fitted with replacement hips whose flawed design may be exposing them to toxic metal, according to a probe by the BBC and the British Medical Journal (BMJ) unveiled Tuesday.
Health Feb 28, 2012 | 5 / 5 (1) | 1