Mechanical process technology

In the field of mechanical process technology, VDZ’s diverse services range from characterisation of solids in powder form to conduction of complex grinding trials and classification testing to optimisation of industrial plants. Our laboratory staff and technicians have many years of experience with the sometimes highly sensitive measurement procedures employed in mechanical process engineering. The key measurement procedures are accredited and subject to regular round robin tests and internal quality checks.

Our experts regularly perform optimisation projects for industrial grinding plants in the cement sector and other sectors of industry and know the requirements of everyday operations inside and out. In the completion of research commissions and conduction of publicly funded research projects, we systematically improve our understanding of process engineering and continuously advance our methods.

We can support you as a reliable and independent partner even in complex and interdisciplinary projects. We will be more than happy to advise you and help you find the ideally tailored solution for your problem.

Characterisation of solids in powder form

Characterisation of solids is of significance not only for the cement industry. VDZ offers a multitude of physical analyses for characterisation of finely dispersoid solids systems.

Grindability acc. to Bond
Grindability acc. to Zeisel
Grindability acc. to Schiller
Grindability (HGI) acc. to HardgroveDIN 51742
Specific surface acc. to BlaineDIN EN 196-6, ASTM C204
Specific surface acc. to BET DIN ISO 9277
Determination of true density
Determination of the bulk density
Determination of bulk density/litre-weight
Determination of particle size distribution by sieve analysis (vibratory sieve shaker)DIN 66165, DIN ISO 3310, DIN 196-6 section 3
Determination of particle size particle size distribution by sieve analysis (air jet sieve)DIN 196-6 section 5
Wet screening
Determination of particle size distribution by laser granulometry
Determination of the separation characteristics of air separators (Tromp) DIN 66142
Determination of moisture in drying cabinetDIN EN 1097-5, DIN 51718 – method B, DIN EN 15414, DIN 51904

Typical substances for analysis: cement, clinker, limestone, marl, clay, (granulated) blast furnace slag, pozzolanas, fly ash, trass, shale, quartz sand, iron oxide, coal, petcoke, fine particles, bypass dust, baghouse dust, silica, microsilica, crushed cement sand.

Treatment and sample preparation

Analysing alternative fuels and solids systems requires highly complex treatment of the samples, which are difficult to reduce in size. Of key significance here are homogeneity and representativity of the sample as well as the requirement to keep treatment from affecting the sample's chemical composition (e.g. in the case of highly volatile constituents). Our range of services includes the following treatment and sample preparation measures:

We will be more than happy to provide individual advice on issues from sampling to treatment and subsequent chemical analyses. Get in touch with us.

Research commissions, comminution and separation tests, grinding commissions

Kugelmühle im Mühlen-Technikum des VDZ

The VDZ’s pilot mill centre possesses numerous semi-industrial grinding plants, classifiers and screen apparatuses for testing under near-industrial conditions and for pursuing research and development projects. They include both continuous-operation plants and plants for intermittent operation.

The comprehensive capacities for substance characterisation and further analysis available on site allow us to act as your single source for planning and execution of your research projects, including those of extensive complexity.

Grinding Plants

  • Continuous grinding plant with heated ball mill
  • Closed-circuit grinding plant with heated ball mill and caged-rotor classifier
  • Batch grinding in batch ball mills (some heated and with gassing capacity)
  • Continuous vertical roller mill with caged-rotor classifier
  • Intermittent, rapid-rotation horizontal agitated media mill for dry milling down to finest particle sizes


  • Alpine laboratory classifier (lab scale)
  • High-efficiency classifier (industrial size)
  • Continuous tumble screener
  • Perflux screen
  • Filter/separator system

With our many years of experience, we are capable of supporting research and development projects from the first project sketch to execution to scientific interpretation. We can perform grinding commissions even for small material quantities (target variables: sieve residue, particle size distribution (including for specific distribution range scopes), Blaine specific surface).

We will be more than happy to advise you on solutions matching your individual requirements.

Optimisation of grinding plants and classifiers

VDZ offers auditing and manufacturer-independent optimisation of industrial grinding plants, including all subsystems. VDZ’s experts draw from a wealth of experience and the findings from a multitude of national and international projects to assess and optimise grinding plants for cement grinding, raw meal grinding, coal grinding and other dry grinding processes in further industry sectors.

Our expertise is thus not limited solely to process engineering. We are capable of offering you comprehensive solutions that incorporate the chemistry and mineralogy of raw materials and products.

We supply tailored solutions to match the issue at hand. Our range includes optimisation services focusing on the following:

  • Reduction of specific energy demand/improvement of energy efficiency
  • Raising capacities
  • Changing fineness/particle size distribution
  • Targeted modification of cement properties
  • Use of grinding aids
  • Reduction of wear/extension of service life
  • Planning mechanical and process-technology maintenance
  • Holistic examination of grinding and product portfolio
  • Bottleneck analysis
  • Impartial cost estimates
  • Supporting investment projects

We will be more than happy to advise you on solutions matching your individual requirements.

Information on how a typical optimisation project proceeds is available here.

Additional information about technical reviews/technical audits of cement-industry production plants is available here.


Dr. Stefan Seemann

Dr Stefan Seemann

+49-211-45 78-254

+49-211-45 78-400

Service offer

VDZ Technical reviews

Technical reviews: energy efficiency – environmental services – product and process optimisation

Quality standards

The management system of VDZ gGmbH is certified by DQS in accordance with ISO 9001.

VDZ gGmbH is accredited by the Germany's National Accreditation Body according to DIN EN ISO/IEC 17025.

Quality standards

The management system of VDZ gGmbH is certified by DQS in accordance with ISO 9001.

VDZ gGmbH is accredited by the Germany's National Accreditation Body according to DIN EN ISO/IEC 17025.