This work presents the experimental investigation of the micromixing characteristics of a spinning disk reactor (SDR) by using a system of competitive parallel reactions, particularly the iodide-iodate reaction (Villermaux-Dushman reaction). The objective of this study is to analyze the influence of various operating parameters such as the rotational speed of the disk, the feed location, and the surface structure of the disk on the mixing quality. It is shown that the micromixing efficiency can be particularly controlled by variation of the disk speed. These results are further validated by the investigation of the precipitation reaction of barium sulfate. This synthesis offers fast reaction kinetics with induction times in the range of milliseconds, resulting in a mixing time which lies in the range of this for efficient mixers like microreactors. The use of the spinning disk technology enables one to produce particles continuously with controllable mean sizes down to 27 nm, without the risk of fouling or blocking.