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Metallurgy refers to the process and process of extracting metals or metal compounds from minerals and making metals into metal materials with certain properties by various processing methods. Metallurgy has a long history of development, from the Stone Age to the subsequent Bronze Age, and then to the large-scale development of modern steel smelting. The history of human development is fused with the history of metallurgy.

Hvac is an integral part of the building, including: heating, ventilation, air conditioning three aspects. Engaged in the field of building environment control, building energy conservation and intelligent technology of building facilities, with air-conditioning, heating, ventilation, building water supply and drainage, gas supply and other public facilities system, building heat supply system and building energy conservation design, construction, commissioning, operation management capabilities and building automation department.