The paper presents the research on the quality of thirteen-component granular mixture. The changes in the quality of the mixture after reduction the mixing time from a standard time of 30 minutes to: 25 minutes, 20 minutes and 15 minutes have been analyzed. The research has been conducted in industrial conditions where a vertical mixer with worm agitator with the charge of two tons was used. Research results were presented graphically as changes in concentration of components shares in the mixing time of 30, 25, 20 and 15 minutes and the obtained results were compared. Quality assessment of a thirteen-component mixture with the use of residual sum of squares for four mixing times was carried out.