In this process, high-purity tin tetrachloride is produced from metallic tin and chlorine in a single reaction chamber. This is done by dissolving gaseous or liquid chlorine in circulating liquid tin tetrachloride. This solution is then passed into the bottom of a vertical tubular reactor containing loosely packed granulated tin. About half-way up the granulated-tin column, the tin tetrachloride is taken out of the reactor in order to increase the chlorine concentration and recycle it into the reactor. At the same time, the heat of reaction contained in the liquid tin tetrachloride can be extracted using a heat exchanger.