Wikipedia - [1]
Kanthal heaters for limestone production - [2]
Calcium oxide is quicklime [3]
Quicklime is $120/metric ton (MT) in 2015 [4]
280MMT are produced per year [5], or about 33B market
4MJ/kg of quicklime produced for shaft kiln. The theoretical heat requirement for dissociation of CaCO3 is about 3,15 MJ

per kg of lime. The rotary kiln consumes about 8 MJ per kg of lime. [6]

Lime Production (Calcination and More)

Parts

Kanthal heater tubes - [7] - radiant heaters are already protected from chemical and thermal shock
Alumina tubes - with kanthal heater wire outside? [8]
Graphite tube - $500 for 3' of 2" ID - [9]. This should work as calcium carbide is formed only at much higher temperatures compared to lime production.