i need help designing a coal furnace to reach tempuratures over 1300 celcius

hello, after remembering my trip to sovereighn hill when i was 10,
and remembering learning how gold bars were made during the gold rush,
seeing that a small wood / coal powerd furnace( 1 Metre high 0.7 metres wide) made from clay , was capable of melting gold (melting point 1060 celcius),
and having long discusions with my friend as to what method we were to take , in building a sodium furnace,
i sugested we build a furnace and make our sodium metal using the deville process involving boiling sodium carbonate and carbon together then passing the metal and monoxide gas through oil.
and we agreed on this as we could smelt metals with it also, make grinding media ect, and it would be cheaper than using propane.

now that i have decided to make this furnace, based on what i saw when i was 10, i need help designing it correctly, so that it acheives tempuratures in exess of 1300C, the one at sovereigh hill i was told could reach 1500C.

at the moment, my idea is that i can build the furnace 1M high and 50cm wide (roughly ), out of bricks and mortar, then fuel it with coal, eventually after being pre ignited by wood.
at the base, i plan on having a small vent which i will pump air into using a small inflatable matress inflator, to supp,y the furnace with air.
at the top it will have a small round hole in which i will insert things to smelt, which lie inside a ceramic pot .in the case of making sodium via deville proccess, it would have a steel pipe sealed off at the base, reduced at the top running nto a deep cooled oil bath
also at the top, there would be two small vents to allow air flow as there air must go somewhere being pumped in.

what i need to know, is if htis will work, and if i need to place my ceramic pot right inside the furnace, or just partially in it, as in the diagram of my design.

i am asking all this as i have no idea if it will work at this small size, and because i have little experience or knowledge of the potential tempuratures that can be acheived.

Picture of i need help designing a coal furnace to reach tempuratures over 1300 celcius