Producing Uniform Laboratory Scale Mixtures Using a Mortar Grinder

Table of Contents

Filled Pastes Production
Test with Mortar Grinder and Agate Grinding Set
About Fritsch


One of the most difficult tasks in the production of uniform mixtures is the fine distribution of pure liquid mercury in an amalgam of fine solid metal powders. In this article a reference case is studied: the addition of a metallic powder to a high-viscosity synthetic resin. Large amalgamated grains (up to 3 mm in size) were produced by manual mixing. The solution was then added to the Mortar Grinder PULVERISETTE 2 using an agate grinding set and special adjustments were done in order to minimize the application of energy.

Filled Pastes Production

In the field of liquid-solid mixtures, filled pastes production needs a special mention. It is generally quite difficult to add solid materials to the high viscosity organic phase. For instance, it is not trivial adding ceramic or inorganic powders to organic binders such as synthetic resin or varnish. Note also that in solid-liquid mixtures, the contamination of ceramic powders with very little amounts of solid in liquid substances can occur.

High viscosity pastes are often formed. Experts talk about filled composite materials. An increase in the degree of the solid content in the paste would therefore be ideal.

Here, a reference case is presented: the addition of a metallic powder to a high-viscosity synthetic resin. The Mortar Grinder PULVERISETTE 2 was utilised, equipped with a grinding set of hardened steel (Fig. 1). The processing time was 30 minutes. The powder was added, while the heat produced by the comminution process favoured the homogeneous mixing of the solid (up to 80% of the mass percentage).

Figure 1. The Mortar Grinder PULVERISETTE 2 with an agate grinding set.

Test with Mortar Grinder and Agate Grinding Set

For the test, the Mortar Grinder PULVERISETTE 2 with an agate grinding set was utilised. The iron nitrate solution was chosen as a model-solution since it is colored and therefore its homogeneity could be evaluated visually. While the mill was grinding, approximately 1 ml of liquid in 50 g powder was instilled. Further homogenization followed.

Figure 2. Sample after 5 minutes grinding in the Mortar Grinder PULVERISETTE 2.

After 5 minutes a visually homogeneous paste was created (Fig. 2).

About Fritsch

Fritsch is one of the internationally leading manufacturers of application-oriented laboratory instruments for sample preparation and particle sizing.

Here a short view of the Fritsch instrument ranges:

  • Mills for crushing, micro-milling, mixing, homogenising of hard-brittle, fibrous, elastic and/or soft materials dry or in suspension.
  • Instruments for particle size determination by laser diffraction, dynamic light scattering and sieving.
  • Laboratory Instruments for representative dividing of dry and wet samples, controlled sample feeding and ultrasonic cleaning.

This information has been sourced, reviewed and adapted from materials provided by Fritsch.

For more information on this source, please visit Fritsch.

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