▎ 摘　　要

NOVELTY - A system (10) comprises a catalyst, a reactor (16) comprising a reaction chamber (20) in fluid communication with a hydrocarbon feed gas supply (12), a carbon separator configured to separate the nanocarbon mixture from the product gas, and a nanosilica-based suspension stabilizer configured for mixing with 5-21 %mass nanocarbon mixture, and a surfactant configured for mixing with 2-9 %mass nanocarbon mixture of the mass of the admixture. The catalyst and the reactor configured to produce a nanocarbon mixture and a product gas by catalytic decomposition of a hydrocarbon feed gas. The nanocarbon particles are chosen from carbon nanotube particles, carbon nanofiber particles, graphene particles, graphite particles, carbon black, paracrystalline carbon particles, polycrystalline carbon particles, nanodiamonds, single-layer fullerene particles, and multilayer fullerene particles. USE - System used for preparing admixture in the form of liquid for forming concrete. ADVANTAGE - The system improves the long term stability of the nanocarbon particles in the admixture and surfactant which facilitates dispersion of the nanocarbon particles in the admixture. DETAILED DESCRIPTION - A system (10) comprises a catalyst, a reactor (16) comprising a reaction chamber (20) in fluid communication with a hydrocarbon feed gas supply (12), a carbon separator configured to separate the nanocarbon mixture from the product gas, and a nanosilica-based suspension stabilizer configured for mixing with 5-21 %mass nanocarbon mixture and a surfactant configured for mixing with 2-9 %mass nanocarbon mixture of the mass of the admixture. The catalyst and the reactor configured to produce a nanocarbon mixture and a product gas by catalytic decomposition of a hydrocarbon feed gas. The nanocarbon mixture comprises at least two different types of nanocarbon particles. The nanocarbon particles are chosen from carbon nanotube particles, carbon nanofiber particles, graphene particles, graphite particles, carbon black, paracrystalline carbon particles, polycrystalline carbon particles, nanodiamonds, single-layer fullerene particles, and multilayer fullerene particles. The admixture comprises 0.4-1.9 %mass nanocarbon particles. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the system for producing the nanocarbon mixture. System (10) Hydrocarbon feed gas supply (12) Hydrocarbon feed gas (14) Reactor (16) Reaction chamber (20)