How is ammonia manufactured industrially?

Ammonia is prepared on a large-scale by the Haber’s process.N2(g)+3H2(g)  2NH3(g)              ΙH°=-46.1 kJ/molThe optimum conditions for manufacturing ammonia are:(i) Pressure (around 200 ×105 Pa)(ii) Temperature (4700 K)(iii) Catalyst such as iron oxide with small amounts of  Al2O3 and K2O