cost[mine]

Yearly royalties payable on each mine kept open

extract_ub[mine]

Upper bound on amount of ore extracted from each mine in a year

quality[mine]

Quality of ore from each mine

quality_required[year]

Required quality of blended ore per year

max_num_worked_per_year

Maximum number of mines worked per year

revenue_per_ton

Revenue per ton of blended ore

discount_rate

Annual discount rate for future years

Extract[mine,year].ub

Upper bound on Extract[mine,year]

quality_sol[year]

Quality of blended ore per year