SHANGHAI, Mar 16 (SMM) - The prices of primary aluminium trended lower, while the scrap prices were firm, narrowing the spread between the two. In south China, the spread between primary aluminium and aluminium scrap shrank greatly due to the price growth of the latter. For example, for extrusion and shredded tense in the Foshan market, the spread narrowed from 3,918 yuan/mt at the beginning of the month to 2,842 yuan/mt at the end of the month and from 3,645 yuan/mt to 2,350 yuan/mt respectively. However, the spread in east China remained stable. For instance, for extrusion and mechanical tense in Shanghai, the spread only shrank by 82 yuan/mt and 191 yuan/mt respectively.