CTernary　carbonate　(K2CO3-Li2CO3-Na2CO3,　4:4:2　mass　ratio)　can　be　used　as　a　high-temperature　heat　transfer　and　thermal　storage　medium　in　concentrated　solar　power　systems.　Ternary　carbonate　nanofluids　with　1.0　wt%　SiO2　nanoparticles　were　prepared　by　mechanical　mixing　at　high　temperatures　in　order　to　enhance　the　specific　heat　capacity　and　the　thermal　conductivity.　The　effects　of　stirring　rate　(500　rpm,　750　rpm,　and　1000　rpm)　and　stirring　time　(15　min,　30　min,　and　60　min)　on　the　thermal　properties　of　the　as-prepared　nanofluids　were　analyzed.　The　results　showed　that　the　dispersion　homogeneity　of　the　nanoparticles　in　the　nanofluids　varied　with　the　stirring　rate　and　the　mixing　time,　thereby　affecting　the　formation　of　special　nanostructures.　The　maximum　enhancements　in　specific　heat　capacity　and　thermal　conductivity　at　a　temperature　of　540　degrees　C,　stirring　rate　of　750　rpm　and　stirring　time　of　30　min　were　38.5%　and　50%,　respectively.　The　specific　heat　capacity　of　the　optimal　nanofluids　had　no　significant　deterioration　after　the　thermostatic　(at　600　degrees　C　for　150　h)　and　thermal　shock　(50　cycles)　experiments　were　conducted.