Micronization of the pesticide chlorothalonil with different ball types

Abstract

To achieve micronization in micro and nanoparticle agitator mills are often used. Also used are balls for the grinding step, which are: glass balls, zirconium silicate balls and zirconium oxide balls. A suspension with the active ingredient chlorothalonil at 700 g/L was prepared, being 2 liters for each type of balls. For this, a 1 liter grinding chamber with 0.7 liters of balls was used. The rotation of the mill was set at 2000 rpm and the rotation of the feed pump at 250 rpm. In addition, the temperature of the product, before grinding, was 26°C.  The micronization with the glass balls during the process presented the lowest temperature 30°C, but with the lowest flow rate 0.09 L/min and the longest grinding time with 32 minutes. With zirconium silicate balls, the temperature reached was 38°C, the flow rate was 0.15 L/min and the grinding time was 20 minutes. The best result obtained was with the zirconium oxide balls, but with the highest temperature 42°C, but with the highest flow rate 0.19 L/min, and the shortest grinding time with 16 minutes, respectively. When determining the price of kWh consumed by the equipment when using the different types of balls, it was found that, with the zirconium oxide balls, a savings of up to 50% of the electricity consumption is achieved, compared to the use of glass balls. Comparing zirconium silicate balls with glass balls, a 37% savings in consumption is achieved. Finally, with zirconium oxide balls being compared to zirconium silicate, a 25% savings in electricity consumption was obtained.