SHANGHAI, Jul. 20 (SMM) -- Traded prices of spot aluminum in Shanghai on July 20 were between RMB 17,760-17,790/mt, with premiums of positive RMB 60-90/mt over SHFE current-month aluminum prices. Low iron aluminum was traded between RMB 17,780-17,820/mt. Traded prices of spot aluminum in Wuxi were RMB 17,750-17,780/mt. After opening higher, SHFE aluminum prices fell due to strong short selling and spot aluminum prices met resistance at RMB 17,800/mt as a result. Goods holders increased supplies but kept premiums firm, and market transactions were rarely reported due to weak consumption.