was "buying coal"

[Glenn]

Coal, bituminous, anthracite, etc, is not one coal, but a type of coal.  Each coal seam is what used to be part of a swamp that over much time turned into coal.  The swamps were huge and extended over several states, and the coal formed was dependent of that vegetation grew in that particular swamp, and that particular part of the individual swamp.

[ThomasPowers]

If you are using a hand crank blower then Bituminous coal doesn't go out while you are hammering at the anvil.  Anthracite coal can, of course you can hire a person to crank the blower while you work.   While I do not have electricity in my shop, I can't afford to hire help on my erratic forging schedule.

Bituminous coal is easier to light too.

Bituminous coal cokes, allowing a smith to make a cave fire---very handy when forge welding a pattern welded billet.

It's rather like gasoline and diesel;  gasoline is a lot cleaner than diesel; yet people still persist in using diesel for some tasks.

Good Bituminous blacksmithing coal is low in sulfur and cokes well.

[George N. M.]

The grade of coal is closely connected to the conditions under which it has been subjected since its burial.  Generally, the deeper it has been buried and the greater the pressure and heat it has been subjected to over the millennia the "higher" grade it will be.  The "grades" of coal are pretty much assigned on the basis of the number of BTUs per ton.  So, anthracite is higher grade than bituminous which is higher than sub-bituminous which is higher than lignite which is higher than peat.  Other characteristics besides heat content per weight which make coal good for blacksmithing purposes such as coking (agglomeration) and sulfur content are pretty much independent of grade.  However, the best coking coals are bituminous grade.  Anthracite and western sub-bituminous coal is seldom a good coking coal.  Some of the best coking coals are pretty high in sulfur.

So, what is the best coal for a blacksmith is a balance of qualities.  Often, we are restricted by what is available to us and what we are willing/able to pay.

"By hammer and hand all arts do stand."

[arkie]

Another coal grading "tool" often used is "vitrinite reflectance"....you'll have to google it....too much trouble to explain it here, sorry. (In simple terms, the shiny-er it is, the more mature, or harder it is.)  No, "shiny-er, is NOT a technical term....LOL

[ThomasPowers]

I think my old Mineralogy Prof might have used "shiny-er"---his definition of a rock was "anything that when you drop it on your foot, your foot hurts".  I can still reel off his exact definition of a mineral though "A Naturally Occurring Inorganic Crystalline Solid"  So coal and Amber are not minerals!  (However naturally occurring ice is a mineral, artificial is not!)

(Kern Jackson author of Jackson's "Lithology")

[Frazer]

So diamonds aren't minerals? If not, what are they?

 

...wait. diamonds are inorganic. Apologies.

Edited October 5, 2021 by Frazer
Answered my own question...

[ThomasPowers]

You are welcome to discuss various exceptions with Dr Jackson; although the services of a medium are required, (D 2008).

Besides the definition I remember to always say Magnetite  when asked for a mineral in an igneous sample...

[Frazer]

No exception here. Diamonds fall under the definition provided above.

[mcostello]

I would like to see one big enough to hurt a foot when dropped.

[JHCC]

On 10/5/2021 at 1:47 PM, Frazer said:

diamonds are inorganic. Apologies.

To clarify, organic substances are those that contain carbon-hydrogen bonds (not simply substances that contain carbon or that are formed by living organisms); this excludes not only diamonds, but other allotropes of carbon such as graphite and fullerenes.

[ThomasPowers]

The Cullinan at about a pound and a third might qualify depending on the height of the drop; of course it's been cut up; but you might try asking Queen Elizabeth II  if you could crazy glue the pieces together and try the experiment. I'm sure you will end up on somebody's "watch list" if you do so.

[JHCC]

This also assumes adult human feet. 

[Frosty]

Even a small diamond falling a couple hundred feet on Luna would smart though maybe not through a suit boot. 

A teacher in high school once claimed there was no such thing as terminal velocity in vacuum. Then one of the really smart kids asked if the speed of light didn't count.

Frosty The Lucky.

[SLAG]

Mr. Frosty,

A great comment with a brilliant observation and counter example.

SLAG.

[JHCC]

Teacher: "Different languages handle the double negative differently. In some, a double negative is REALLY negative, while in others, a double negative is a positive. However, there is no language in which a double positive makes a negative."

Student: "Yeah, right."

[ThomasPowers]

Or as one of my Physics Profs once said "You pays your dime and picks your frame of reference."    I must admit I'm much happier working in a Newtonian system; though I remember the limerick:

There was a young lady named Bright

Whose speed was far faster than light

She set off one day in a relative way

and returned the previous night.

Or the graffiti in a University Physics Building bathroom: "String Cheese not Theories!"

[Frosty]

I only wish it were my observation Slag. I was living in a sci fi novel world and FTL was the norm. IIRC the student who made the observation had a measured IQ over 200 a few semesters later but wasn't terribly well adjusted.  He just lived on a whole different level than regular folk. 

I only read about physics until my brain spin stabilizes then quit.

Frosty The Lucky.

[George N. M.]

Frosty, not to belabor the obvious but the terminal velocity observation would only be true in a perfect vacuum.  Outer space has dust and random thing like hydrogen atoms which would slow down an object.  Also, any object would reach a gravity well soon enough that it would not achieve a significant portion of c.  If this were happening there would be intergalactic objects "falling" towards a galaxy traveling at near light speeds.  In theory, probably true, in the real universe not so much.

"By hammer and hand all arts do stand."

[ThomasPowers]

Of course the definition of Terminal Velocity assumes the item is falling through a "fluid", aether need not apply!

Gravitational force drops way off fast---that pesky distance squared factor in the denominator.

Anyway assuming being in a pure vacuum counts, and that there is only one gravitational source, no other forces acting on it, and you are allowing nearly infinite time, it could get pretty frisky!  However acceleration will diminish as you get to relativistic speeds

[Frosty]

Correct George space is not a vacuum. Here's a thought, CAN a vacuum actually exist? 

Your last point Thomas raises another question. E=mc2 says an object can NOT reach C because the energy required is the square of all the energy represented by that mass. It also says that mass increases as the sq. of the velocity.

And as Newton so ably described what we feel as gravity is two objects attracting each other, any of us and Earth attract each other at 1g. Approximately 1g isn't a real constant it varies everywhere on the planet.

The counter to your last point is as follows. An object falls through space towards a black hole. Velocities around singularities are being measured as close to C as can be measured. The falling object's mass increases as it falls to near infinity as it approaches C. The singularity MUST react in equal but opposite movement so it's mass increases.

With increased mass time dilates and slows to near infinity/eternity? but that's only an observation that can be made after the objects return to the same relative velocity as the observer. 

Frisky is matter not being appreciably slowed by relativistic  collisions with dust, random molecules, whatever and radiating the impact energy as Gamma or higher energy radiation.

See why I don't spend a lot of time thinking about physics? If I want to simplify physics I read a little about quantum sciences. I stop if it starts making sense though.

Everything CAN be made to work.

Frosty The Lucky.

[JHCC]

13 hours ago, Frosty said:

CAN a vacuum actually exist? 

I certainly hope so. If not, what's that thing working as a blower in my coal forge?

[anvil]

Talk about black holes,,, this topic has done a major spatial shift,,, from a bag of coal to black holes!

Back on topic for a moment, I'd like to stress the primary difference between met coal(coking bituminous) and anthracite for we blacksmiths is its ability to coke. For all practical purpose, coke is pure carbon. Most importantly, again for our purposes as blacksmiths, no matter how dirty or low grade your met coal, the coke it makes is far cleaner than the best anthracite.  

[George N. M.]

I began buying and forging with coke years ago to minimize the smoke and smell to avoid neighbor problems.  I only use a bit of green coal to start the coke.  Now that I live in a semi-rural area I could easily go back to straight coal but I've gotten used to coke and will probably continue to use it.  It is a bit fussier in that it will go out if you don't keep some air flow to it but it is a lot cleaner.  It does still make clinkers, though.  The coking process does not remove the impurities that form clinkers.

"By hammer and hand all arts do stand."

[anvil]

Lol, thats why i hedged my bet,, for all practical purposes. I havent used commercial coke in a long time, and I've never used a commercial bituminous coke, so I'll limit my statement to what I know by experience, And thats comparing anthracite to bituminous met coal. As I remember, the coking process removes sulfur, fines and other trace minerals which are in all coals to varying degrees. Sulfur is the main culprit and the sulfur in the anthracite is the problem. Thanks for pointing that out.

I'm facing that choice right now. coke from Utah vs a poor but doable blacksmith coal 30 miles down the road that I've used for a long time.

[ThomasPowers]

Removes coal tars too; the massive steel making of the Industrial Revolution drove a *lot* of coking that produced lots of coal tar as a waste product, that became a wonderful playground for Chemists that accelerated the rise of "modern chemistry".

Strange to think that Gasoline was once a waste product of making Kerosene for lighting...Must be a Friday!