Wikipedia:Reference desk/Archives/Miscellaneous/2017 January 30

= January 30 =

Coal silo


Why would a mine put coal in silos? It's not particularly liable to spoilage if left out in the rain, and nobody's going to be stealing significant quantities if they just pile it up. I understand that you could just gravity-empty the contents for putting in a train, but seeing that they have conveyers to move it from the pile into the silo in the first place, it seems like they have to move it from a pile either way. Nyttend (talk) 01:39, 30 January 2017 (UTC)


 * Just imagine how heavy wet coal would be.--TMCk (talk) 01:43, 30 January 2017 (UTC)
 * Coal can soak up water? All the pieces I remember encountering (whether large ones, sold for fuel, or small ones, found on an old railroad bed) seemed to be non-porous.  Nyttend (talk) 01:49, 30 January 2017 (UTC)
 * Google "porous coal" and you'll find stuff like and . &#40;&#40;&#40;The Quixotic Potato&#41;&#41;&#41; (talk)  03:02, 30 January 2017 (UTC)


 * This attempts to explain the purpose of the coal silo. ←Baseball Bugs What's up, Doc? carrots→ 02:38, 30 January 2017 (UTC)


 * Nowadays the cool kids are using in-situ coal gasification. &#40;&#40;&#40;The Quixotic Potato&#41;&#41;&#41; (talk) 02:40, 30 January 2017 (UTC)


 * According to its metadata, the full title of that picture is "VERY LARGE COAL MINE IN APPALACHIA, VIRGINIA, NEAR KINGSPORT TENNESSEE. THE MINE HAS THREE SILOS TO STORE THE COAL UNTIL IT IS PROCESSED AND READY FOR SHIPMENT". Therefore, I assume that the coal is "processed" before it is dumped into the train's hopper cars. I speculate that processing may include breaking big chunks into smaller chunks, and maybe even washing, but not drying, since the hopper cars are not covered. -Arch dude (talk) 03:02, 30 January 2017 (UTC)


 * Another possible reason for putting coal in silos is if the coal is "dusty" (has a high proportion of fine particles, as is often the case when mechanical mining is used) -- the purpose would be to stop the dust from blowing around and maybe causing an explosion. 2601:646:8E01:7E0B:904E:8E2E:48D1:CC6E (talk) 10:22, 30 January 2017 (UTC)


 * Could it possibly be that silos are efficient means of storing things; less land than a pile... -- Jayron 32 18:55, 30 January 2017 (UTC)
 * Certainly more efficient for transporting, compared with an open pile. ←Baseball Bugs What's up, Doc? carrots→ 21:28, 30 January 2017 (UTC)


 * Mines try to avoid storing coal, as they're not getting paid for it. Where possible, it's sold and shipped out as fast as it's produced. Some needs to be stored, enough to fill a train or the anticipated fleet of trucks, but it's not much in terms of production over time.
 * Silos are used to simplify handling. Coal in a silo can be loaded automatically onto a conveyor at the base of it (not directly beneath as it would be crushed - they're offset by a chute). Coal in piles would be need to be loaded with mechanical shovels. Apart from being costly, that's too slow to allow the rapid loading of a train-sized quantity. Particularly for a merry-go-round train that doesn't even stop.
 * Some silos aren't used to store coal internally, but form a vertical core for a outdoor pile. They're small concrete towers, with lots of windows in the sides. Making a neat pile - one that stores the most coal in the least area and is easiest to shovel up - needs a conveyor to do so, dumping coal from a single point. Small piles can do this with a cantilevered conveyor boom, but concrete towers are simpler for large piles. These are mostly used in places like coal power stations where a large reserve might want to be stored for some time but there isn't the same need for rapid burst loading. Andy Dingley (talk) 22:06, 30 January 2017 (UTC)


 * You can find most answers in those two sources: and .--TMCk (talk) 22:19, 30 January 2017 (UTC)

Fata Morgana of the sun creating bazaar rainbow
I witnessed a rainbow column that that looked like a large hologram 75' away. My son in law saw a Rainbow during a freezing rain mix that was a pattern of fish scale shapes with RB colors mixing & changing. Do you have a source of other strange rainbow?18:50, 30 January 2017 (UTC)18:50, 30 January 2017 (UTC)Roger Llamas (phone number deleted) — Preceding unsigned comment added by 142.254.3.203 (talk)
 * Very strange things happen.  If you go to Victoria Falls when the moon is full and the sky is clear you may see a "moonbow".   This is caused, much like the rainbow, by reflected sunlight being refracted through water in the air (which in this comes from the spray created by the waterfall). 86.134.217.67 (talk) 19:59, 30 January 2017 (UTC)


 * Here are some photographs and discussion/description of strange rainbows  . SemanticMantis (talk) 20:17, 30 January 2017 (UTC)


 * Some examples of these type of rainbows you are describing (each with a slightly different cause) include Halo (optical phenomenon), Corona (optical phenomenon), and Glory (optical phenomenon). -- Jayron 32 15:03, 31 January 2017 (UTC)
 * This site has a wealth of information and photographs about various types of atmospheric optical phenomena: . CodeTalker (talk) 04:46, 1 February 2017 (UTC)