Talk:Calcination

Calcination Calcination is tha thermal treatment of an

Bad application definitions

I disagree with the second two bullet points of the applications calcination. Calcination is primarily thermal decomposition. Oxidation of sulfides, for instance, is a roasting process. Smelting is certainly not a calcination process. I'm going to try and take care of these definitions under the more general topic Pyrometallurgy. BSMet94 20:33, 5 January 2007 (UTC) My observation over my 76 years has been that definitions of words change at least a bit as you move from one discipline to an other , one manufacture to an other and over the centuries. Likely this is also true of calcination. Explaining even poor definitions can be helpful, if they are in common use.Ccpoodle (talk) 21:29, 15 December 2008 (UTC)

You may be right. However the reference that was there to calcining 'sulfates' is surely wrong. I have altered this to sulfides. Peterkingiron 17:05, 13 January 2007 (UTC)

No, no. Driving off sulfur dioxide from sulfides is not calcination. That's a roasting process: MeS + O2 = MeO + SO2. Roasting is distinguished from calcining by there being a gas-solid reaction. Some sulfates can in theory be thermally decomposed: MeSO4 = MeO + SO2 + 0.5 O2. However, you are right to flag it (however misguidedly), because it really shouldn't be mentioned at all, since it's not practiced industrially.BSMet94 03:28, 14 January 2007 (UTC)

I bow to your superior knowledge. However, I think that there is a case for a separate article on Roasting (metallurgy). Peterkingiron 15:51, 14 January 2007 (UTC)

I have now provided a brief article and cross-referenced to the section in pyrometallurgy. However, that section is currently better than the my new article. I would invite you to expand what I have started. Peterkingiron 16:08, 14 January 2007 (UTC)

Oh, absolutely! That's what I sort of originally intended, to have a general pyrometallurgy article, and more specific topic articles on drying, calcining, smelting, and pyro-refining. This is turning out to be a good collaboration! I hope some others start contributing as well.BSMet94 21:55, 14 January 2007 (UTC)

Heh, and I was wondering how to handle Roasting, when there was already an article having to do with cooking, and something to do with the planet Jupiter. I see you've taken care of that too! BSMet94 21:57, 14 January 2007 (UTC)

iron

Now, I'm completely unaware of iron carbonate calciners. Where is this done. Most iron ore, to my knowledge is hematite, magnetite, taconite, etc. Where's the siderite coming from?BSMet94 03:33, 14 January 2007 (UTC)

A major source of ore for the British iron industry until perhaps the 1850s was nodules of ironstone which occur in seams in various coalfields. The ore was calcined before being charged to the blast furnace. I suspect that this also applies to the industry in certain parts of Europe, such as the Ruhr, but am not certain. Peterkingiron 15:51, 14 January 2007 (UTC)

more revisions

I'm making a general revision. I removed some information, but most of it will get put back in another form soon. I got into the chemistry a bit more, and I'm about to add a whole list of examples (with references, never fear).BSMet94 20:33, 31 January 2007 (UTC)

When you discuss calcination of sulfates, be sure you clarify the formation potential of SO3 vs. that of SO2 + O2. Calcination of sulfates is unique in that the presence of O2 in the calcination environment affects the calcination temperature as well as the relative amount of the product gases.Thermbal 03:57, 11 November 2007 (UTC)

Calcination of china clay

There is no mention of this and it is large area of study.

Any objections to the addition?

Raelth42 (talk) 22:23, 4 August 2009 (UTC)

If you know about the subject and can add material citing reliable sources, please add this. I would suggest making it a new item under "industrial processes". Peterkingiron (talk) 22:39, 6 August 2009 (UTC)

Wordsworth disagrees

According to Wordsworth (dictionary of science and technology) calcination is used in the field of chemistry and in mining, with slightly different meanings. In chemistry it is any (!) prolonged treatment by heat, be it with or without air. In mining it is (according to ww) used almost interchangably with roasting. Getting the sulfur out is called sweet roasting, getting CO2 out is called dry roasting. In both fields the absence of oxygen is not implied.

The exact definition as given here without qualification is almost certainly wrong, encyclopedically speaking.

Rotating calciners?

There is a very specific definition of a calciner in the top section, including that it is vertical, made of steel, and rotates. I have no doubt that this is one way of doing it, but the vast majority of calciners (i.e. lime kilns) are either non-moving (e.g. shaft kilns, parallel flow regenerative kilns) or are near-horizontal rotary kilns. Indeed, the Industrial processes section has a diagram showing a non-moving shaft kiln, made of bricks.

So I'd remove that sentence altogether, as it's incorrect and should have been in the industrial processes section anyway! Tomphills (talk) 20:13, 4 July 2023 (UTC)