Chemical Forums
Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: Amitaabh on September 29, 2012, 09:41:29 PM
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In the process of glass blowing , glass pipes are colored by adding small quantities of different metal oxides to the raw materials before melting them. Iron or nickel, in common sand, make the glass green. Other metals are added to create different colors. Cobalt oxide makes blue. Manganese oxide makes purple. Gold or cadmium and selenium make red.
About what is the lowest temperature that a metal oxide will off gas? Obviously a lighter wont heat the whole pipe anywhere past 100C (is it possible to heat a small part of the pipe more than the rest? Im guessing the whole pipe has to be heated equally the flame is 1977C but it cools when it touches the pipe(?) (I dont know if the flame cools but for whatever reason the pipe will take a long time to get considerably hot.) ) so we can use that as the temperature to check if the metal oxides off gas (the metal oxides should not off gas at least less than or equal to 100C). My intuition says that metals off gas at pretty high temperatures so this soundnt be a concern but I would love to check this against the facts.
Is it true that metals and metal oxides off gas at temperatures higher than 100C? What about other coloring agents.
(List of Coloring Agents: cobalt oxide
blue
magnesium oxide
violet
gold or selenium
red
uranium, iron, or silver oxides
yellow
cerric oxide
brown
iridium oxide
black
copper or chromium oxides
green
calcium fluoride or stannic oxide
white or opal )
On a side note why doesn't a lighter blow up when held upside down (shouldnt the flame go into the nozzle and ignite the butane) I often light incense what if a hot piece of incense or ash falls onto the lighter nozzle will it blow up?
There are quite a few questions here. I look forward to learning the answers to these questions. Thank you!
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The metal oxides, by definition, aren't volatile. A little work, on your part, will let you know of the temperatures involved in making glass. They are very far away from "lighter temperature."