中国5月份氧化铝出口21万吨，同比增104.6%；1-5月氧化铝出口117万吨，同比增79.3%。5月份未锻轧铝及铝材进口35万吨，同比增14.7%；1-5月未锻轧铝及铝材进口167万吨，同比降6.9%。5月份钢材进口48万吨，同比降24.5%；1-5月钢材进口255万吨，同比降16.1%。5月份铝矿砂及其精矿进口1751万吨，同比增29.4%；1-5月铝矿砂及其精矿进口8518万吨，同比增33.1%。

Group 1: Aluminum Exports and Imports - In May, China's alumina exports reached 210,000 tons, a year-on-year increase of 104.6% [1] - From January to May, alumina exports totaled 1.17 million tons, reflecting a year-on-year increase of 79.3% [1] Group 2: Aluminum and Aluminum Products Imports - In May, imports of unwrought aluminum and aluminum products amounted to 350,000 tons, a year-on-year increase of 14.7% [1] - From January to May, unwrought aluminum and aluminum products imports totaled 1.67 million tons, showing a year-on-year decrease of 6.9% [1] Group 3: Steel Imports - In May, steel imports were recorded at 480,000 tons, representing a year-on-year decrease of 24.5% [1] - From January to May, total steel imports reached 2.55 million tons, indicating a year-on-year decrease of 16.1% [1] Group 4: Bauxite and Its Concentrates Imports - In May, imports of bauxite and its concentrates were 17.51 million tons, a year-on-year increase of 29.4% [1] - From January to May, bauxite and its concentrates imports totaled 85.18 million tons, reflecting a year-on-year increase of 33.1% [1]