Quartz surface contamination due to its processing in the Magstream model 100

The processing of quartz in the Magstream, a piece of equipment used to separate minerals according to their specific gravities, leads to the formation of colloidal magnetite and iron ligninsulphonate precipitates on its surface. These precipitates activate quartz for flotation with amine, especially in pH ranges less than 9.0 and over 10.5. These results indicate a restriction of the use of Magstream to separate minerals when further studies involve surface properties.