Let's overlook this a little bit from a technical standpoint, instead of experience.
Antracite is a very hard coal, low in volatile contents, thus gas and water based combution agents are greatly missing, usually more oil based agents are present, making it very difficult to burn.
The next difficult coal was coke, because it was nearly pure carbon.
Very easy to burn was soft coal, we in Germany call it brown coal, it's close to peat moss, and contains many water and water based combustion agents, but it's very fine and if you burn it, it will quickly decay into small glowing pieces.
A steam engine has allways problems with combustion, as there is no additional air supply and all air for combustion is drawn into the firebed by the blastpipe and the draught generated by it. Coal with low gas based volatile components need more air to burn, that those having high gas volatile components.
Antracite burns with a small bright flame, usually like coke with nearly white flames and it the draught is missing, it will get to small little blue flames - and usually the coal tends to melt and flow, producing huge 'cakes' of cinder on the grate.
Coal high in volatile gas components burns with long orange yellow flames, and if draught is missing, the flames remain orange with a yellow heart, the coal doesn't melt, it usually expands like into huge cauliflower like burning things, which break down to little particles and produce high amount of ashes.
Soft coal, high in water and water based volatile components burns with an orange flame if drought is missing, flames up in draught into bright yellow very short long flames and produces high amount of ashes and glowing sparks are all around the fire...
So all is associated with air... for coal low in gas you need a better draught and more air, than for coal with high volatile gas parts... So a standard firebox was usually build for coal with medium or high volatile gas components. Belpaire Fireboxes were usually for coals with a lower volatile gas components, so called bad coals.
In germany soft coal was fired onto a special grid with very small air ventilation openings and a special smokebox design, to hold back the sparks drawn thru the flues on strong working engines... the german democratic republic railways usually filled the common grid of standard fireboxes with stones, or gravel. And here they fired briquettes made of soft coal rich in water... so the draught was not reduced, it was split by the multiple channels and splits in the gravel, so the softcoal was not to high raised from the firebed and sparks were reduced, as the small glowing ashes traveled slowly down the stones and burned completely - it was a cheap and good alternative.... but still to much of the water based volatile combustion agents were drawn as thick yellow brown smoke out of the chimney, resulting in very bad locomotive performance and power output.
On the other side, antracite was tested, but it needed more air than common ejectors generated and even the multi cone Kylchap blastpipe didn't solved this problem... a more special grid was needed to suport free air flow thru the fire and a better draught by improvised blastpipes were needed... but this experiementation was abandoned, as such coal was delievered to local stationary power plants, were this coal was grinded to dust and fired into air flow burners... Again the german democratic republic experiements with coal dust firings, but only made this working for soft coal, not for anthracite ... but it was close... but it never came into working, as electric and diesel locos took over... and all other remaining steamers fired gas coals...
So to fire anthracite you'll need a firebox with supports the high demand of air... and now see and discus, it the wootten firebox might be able to solve this problem
Allways keep two-thrid level in gauge and a well set fire, that's how the engineer likes a fireman