420
K. Vaupel et al.
Fig. 7 Immission 50 mm
above the reservoir at 6.6 s −1
sieving frequency
Fig. 8 Immission 50 mm
above the reservoir at
10.0 s −1 sieving frequency
2.4 Cooperation with Project A6: Grinding Aids
In cooperation with project A6 maintained by the Technische Universität Braunschweig influences of grinding aids on product dustiness were investigated. Durcal40
limestone supplied by Omya AG, Switzerland was milled for 80 min in a GSM 06
(Siebtechnik GmbH, Germany) vibrating mill, with the addition of 0.1 mass percent
of grinding aid. Purpose of the grinding was to produce limestone paticles with particle sizes in the lower micrometer range, since they have a wide industrial application.
As grinding aids pure substances Triethanolamin (TEA) (C 6 H 15 NO 3 ), Diethylenglycol (DEG) (C 4 H 10 O 3 ) and heptanonic acid (C 7 H 14 O 2 ) with purities >96% were
added.
The milling process took place in a hermetically sealed steel container with a
volume of 1 L, which was filled to 30% with 6 mm diameter steel balls as grinding
body. Sample size of Durcal40 was 198.1 g [5]. As a reference Durcal40 was milled
without addition of a grinding aid, too. In preparation of the experiments, the limestone was dried for 20 h at 80 °C. In this way, four limestone powders were milled
K. Vaupel et al.
Fig. 7 Immission 50 mm
above the reservoir at 6.6 s −1
sieving frequency
Fig. 8 Immission 50 mm
above the reservoir at
10.0 s −1 sieving frequency
2.4 Cooperation with Project A6: Grinding Aids
In cooperation with project A6 maintained by the Technische Universität Braunschweig influences of grinding aids on product dustiness were investigated. Durcal40
limestone supplied by Omya AG, Switzerland was milled for 80 min in a GSM 06
(Siebtechnik GmbH, Germany) vibrating mill, with the addition of 0.1 mass percent
of grinding aid. Purpose of the grinding was to produce limestone paticles with particle sizes in the lower micrometer range, since they have a wide industrial application.
As grinding aids pure substances Triethanolamin (TEA) (C 6 H 15 NO 3 ), Diethylenglycol (DEG) (C 4 H 10 O 3 ) and heptanonic acid (C 7 H 14 O 2 ) with purities >96% were
added.
The milling process took place in a hermetically sealed steel container with a
volume of 1 L, which was filled to 30% with 6 mm diameter steel balls as grinding
body. Sample size of Durcal40 was 198.1 g [5]. As a reference Durcal40 was milled
without addition of a grinding aid, too. In preparation of the experiments, the limestone was dried for 20 h at 80 °C. In this way, four limestone powders were milled