Abstract: An iron ore enterprise in central Shandong is a refractory iron ore mine. Superimposing the early market environment factors，the project forecast is difficult to be profitable，and it has not been built for many years. In order to achieve efficient and intensive development of this mineral resource，according to the characteristics of this type of magnetite-based raw ore and the product particle size requirements of the existing sand and gravel market，the iron ore processing and sand and gravel preparation processes are deeply integrated to form a set of processes with two market products. The mixed processing process solves the problems of many equipment，many factories，large land occupation，and many operators in traditional process. While reducing investment and cost，it brings huge economic benefits to the enterprise，and further promotes energy conservation and emission reduction work，which is in line with the national "double carbon" policy.

Key words: iron ore processing, sand preparation, mixed use, double carbon