Why Nickel Prices are increase last two Weaks

Nickel are largely produced by Russia, Indonesia, Philippines, Canada, Australia, Brazil and China, the 50%  production held by Asia, most of country demand in nickel is China.
The production ban in Indonesia has create problem and increase nickel rate day by day, as report of brokerage firm nickel rate should be increase in coming days more than Rs.1000.
Commodity calls for Monday :
buy gold 30150 target 30250,30300,30350 stop loss 30000
buy silver 46200 target 46450, 46600,46900 stop loss 45800
buy copper 422 target 425,427,435 stop loss 418
buy nickel 935 target 938,942,947 stop loss 928