IND AS 116 Leases

hi to all, i have a company, which main activity is coal mining.Entity had hired a machine,which was specifically designed for this company only, for the coal crushing. the consideration was based on the per ton of coal crushed during the month, which has contingency but the average tons crushed per annum was given at 10lacs tons. the obligation was not compulsory to met for consideration. there is no minimum fixed consideration in this contract, if machine has not done any work during a month. in this context, can i consider this as a lease under IND AS 116? if it so, what is my fixed payment to that machine?