Pilot plant for testing efficient ore digestion - DFG large-scale "grinding circuit test rig with roller mill"

The system is a complete grinding/classifying circuit. The main components are a roller mill (LM 3.6/3w) from Loesche designed for wet grinding and a vibrating circular screen (VRS 1500/3) from Allgaier. In addition to the main components, several hydrocyclones and a decanter (centrifuge) are also installed in the system.

This means that both wet and dry grinding can be realised. Different operating modes are also available in wet grinding mode. This means that system products with a particle size of less than 45 µm are also possible. Both cylindrical and conical rollers are available for the mill. The surface pressure of the roller mill can be infinitely varied between 530 kN/m² and 1400 kN/m². Depending on the feed material and the grinding parameters, plant throughputs of up to 500 kg/h with a maximum grinding throughput of 5000 kg/h are possible.

Company partnerContact person
  • Prof. Dr.-Ing H. Lieberwirth
  • Dr.-Ing Th. Zinke
  • M. Sc. O. Schindler (PhD student)

Motivation and project objectives

In the future, the total demand for raw materials is expected to continue to increase. For this reason alone, it is not sufficient to work with the raw materials already in the cycle. Primary raw material processing will therefore always be necessary in the future. The crushing of ore is particularly energy-intensive. This alone accounts for approx. 6...7 % of the global energy requirement caused by the tumbling mills used to date. For this reason, there are many endeavours to reduce the energy required for grinding ores. A number of alternatives for dry processing are already known and some have been trialled. However, dry processing is not practical in some cases due to process engineering and climatic conditions. In addition, depending on the ambient conditions, dry grinding requires a considerable amount of energy to dry the ore.

Nass- und Trockenmahlanlage 1
Nass- und Trockenmahlanlage 2
Nass- und Trockenmahlanlage 3

Tasks of the IART

In the past, the project planning, assembly and commissioning were supported.

The plant is currently still being tested. This includes tests with the substitute material granodiorite. Different aggregates have been tested individually so far. The first dry grinding tests with recirculation were successful. In the future, testing of the wet grinding circuit will begin.

Optional funding information

***German Research Foundation (DFG) - Project: 361116310***