SHANGHAI, Sept. 18 (SMM) – Spot aluminum was mainly traded between RMB 15540-15550/mt in Shanghai on Tuesday, with discounts between RMB 120-110/mt. Low-iron aluminum was traded near 15610/mt. The current-month 1210 contract gapped lower in morning session and struggled at the 5-day moving average. In response, spot aluminum prices edged down, with spot discounts above RMB 100/mt. Cargo holders held back goods, holding quotations firm at RMB 15,540/mt. Downstream buying interest was low, leaving overall trading light.