Nansha Trough located in the southwestern South China Sea (SCS) is a promising area of gas hydrate resources in China, in which authigenic gypsum and pyrite assemblages in surface sediments are widely distributed.

Moreover,based on the analysis of these methods,a concept of contribution and the stiffness coefficient contributionβ, which views the contribution of rib beam towards gypsum combination mode as a kind stiffness of the structure,is proposed to calculate the reinforced concrete ribbed plaster mold combination of flat-slab system much more accurately.

This paper describes the developing tendency of mineral concentration for complex iron ore introduces the technological flow sheet of weak magnetic separation-intense magnetic separation-flotation (gravity separation) dealing with complex iron ore of magnetic-hematite and concentrating technology and flotation agents.