Aluminium prices on Tuesday marginally climbed to Rs 237.65 per kilogram in futures trade as speculators built up fresh positions amid a positive trend in the spot market. On the Multi Commodity Exchange, aluminium contracts for October delivery increased 5 paise or 0.02 per cent to Rs 237.65 per kg in a business turnover of 3,293 lots. Analysts said fresh positions created by traders amid demand from consuming industries supported aluminium prices in the futures market.