To demonstrate the effect of mechanochemical processing on solid-state recrystallization, four inorganic salts of NaCl, KCl, NaBr and KBr were selected on the basis of a literature survey and crystallographic data, and their binary mixtures were ground with a planetary ball mill. X-ray powder diffraction patterns of the ground particles were analyzed, showing either formation of solid solutions and exchange reactions as well as no changes occurring due to grinding. The binary systems of NaCl NaBr and KCl-KBr resulted in the formation of complete solid solutions, while the NaBr-KCl system exhibited the exchange reaction so that the final XRD patterns were exactly the same as those of NaCl-KBr. Additional experiments with salt mixtures containing NaBr and KCl showed the occurrence of the exchange reactions and simultaneous formation of solid solutions. From these observations, mechanochemical processing was found to be effective to cause several types of solid-state recrystallization at the atomic level.