November 21, 2011   Weak feed demand weighs on China sulphate prices   An eFeedLink Exclusive     Prices were stable to lower.   Transacted prices of sulphate feed additives in China Variety Price as of Oct 31 (RMB/tonne) Price as of  Nov 20 (RMB/tonne) Price change (RMB/tonne) Cupric sulphate 16,100-16,400 15,950-16,4 ...