The use of various mineral additives in the production of cements and concretes is one of the urgent tasks of building materials science, as it reduces the consumption of Portland cement clinker, the production of which is accompanied by a large consumption of electricity and the release of CO2 during its production. The use of mixed cements reduces not only the cost of building materials, but also solves the environmental safety of the environment. The work is devoted to the development of composite cements using mineral additives - dunite of one of the widespread magnesia rocks in Central Aldan (Yakutia). Dunit composes inagli Massif and is located in the industrially developed area of Central Aldan. Petrographic and thermographic studies became the basis for the preliminary preparation of the charge. Pre-annealing, fine joint grinding and additional mechanical activation of the charge are applied. Selected resource-saving, optimal mode of autoclave synthesis of composite binder. It is shown that the autoclave synthesis was able to obtain a high-strength cement stone twice the strength of the cement stone from Portland cement PC 500. It is found that increasing the mechanical strength of the products curing at autoclave composite binders the synthesis achieved by the introduction of a system of micro - silicates of magnesium (serpentinization of dunite). At the same time, finely ground and pre-annealed magnesium silicates perform the role of a micro-filler in the system, contributing to an increase in the density of the formed stone, and the active component involved in the formation of a strong crystallization structure.