A vibration mill for simultaneous chemical reaction and comminution was developed, which is heatable up to 450 degrees C and resistant to pressures up to 2 MPa. This apparatus will be named ＇＇reaction mill＇＇ to characterize the combination of the two process steps. The possible accelerations exceed up to 65 g and amplitudes of 7 mm are adjustable, The chemical reaction, which takes place in this reaction mill, is the hydrochlorination of metallurgical grade (MG) silicon, where chlorinated silanes of the form SiHxCl4-x are formed; trichlorosilane SiHCl3 and silicontetrachloride SiCl4 are the main products of this reaction, Additionally the by-product FeCl2 is formed by the hydrochlorination of the main impurity iron Fe. This FeCl2 becomes very important, because it is regarded as reaction inhibitor. The examinations of the combined hydrochlorination and comminution have shown, that a reported induction period in the starting phase of the chemical reaction, carried out singularly, can be reduced to a minimum. On the other hand, it could be noticed, that the lower temperature limit, which is necessary to start the reaction, could be lowered essentually, On one hand, this is explained by the enlargement of the reactive surface during comminution and on the other hand, by a mechanical activation of the MG silicon, Furthermore, the mechanical removal of the reaction inhibiting product-layer of FeCl2 could be determined to have a positive effect to the reaction.