Mining of bauxite and limestone (valid until September 2031); road transportation (general cargo, limited to Guangxi and Guizhou branch operations); production and sales of aluminum and magnesium ore products, smelting products, and processed products; production and sales of autoclaved fly ash bricks and related services; production and sales of carbon products and related non-ferrous metal products, industrial water, electricity and steam, and industrial oxygen and nitrogen; engaged in survey and design, construction and installation; mechanical equipment