Department of Physical and Physico-chemical Methods of Mineral Processing

Head of the department:Ing. Slavomír Hredzák, PhD.

The research group of the Department of Physical and Physico-chemical Methods of Mineral Processing focuses on three main research areas:

1. MINERAL PROCESSING (contact: Ing. Slavomír Hredzák, PhD.)

• physical properties of raw materials and mineral processing of raw materials,
• mineral liberation influence of separation process,
• intensification of physical separation processes,
• magnetic and electrostatic separation,
• physical separation of raw materials in hydrocyclone,
• study of behavior of fine-grained particles in physical fields,
• preparation of ferrite-based nanomaterials for ferrofluids and magnetic sorbents preparation,
• recovery of metals and critical raw materials from industrial wastes.

2. REMOVAL OF TOXIC SUBSTANCES FROM WATERS AND SOILS (contact: Ing. Miroslava Václavíková, PhD.)
a) Sorption Processes:

• synthesis of sorbents based on metal oxides (Fe, Cu, Al, Mn) by conventional techniques as well as by power ultrasound assisted techniques,
• synthesis of composite materials – fixation of iron nanooxides into the matrices of activated carbon, biomass waste, clays, zeolites, bentonites, silica,
• chemical modification (activation) of sorbents,
• material characterization by advanced physical and chemical analytical techniques, e.g. FTIR, XRD, elemental chemical analysis, surface area analysis, zeta potential measurements, XRF analysis, CHNS analysis, TOC analysis, and magnetic properties measurements,
• sorption characteristics of sorbents towards heavy metal/metalloid cations (Cu, Pb, Zn, Cd, etc.) and anions/oxoanions (As, Cr, Mo, Se etc.) as well as organic pollutants (azo-dyes, pesticides, HCH, PCB, PAH compounds, etc.).

b) Degradation of Organic Pollutants in Waters and Soils:

• extraction of organic compounds from soil matrices (HCH, PCB, PAH compounds),
• degradation of organic pollutants by chemical and biological techniques,
• electro-chemical degradation of organic pollutants from waste waters, soils and model solutions.

c) Engineered Nanoparticles (ENPs) in Environmental Applications:

• synthesis of ENPs for water and soil remediation (Fe-, Cu- oxides, composite materials),
• migration and fate of ENPs in the environment (study of migration routes, ageing, reactivity, adsorption, aggregation, corrosion etc.),
• risk assessment of remediation processes.

3. MICROWAVE TREATMENT OF RAW MATERIALS, INDUSTRIAL WASTES AND BIOMASS (contact: RNDr. Michal Lovás, PhD.)

• microwave-assisted treatment of raw materials, metallurgical wastes, Slovak coal and biomass waste;
  study of dielectric properties of materials,
• microwave-assisted pyrolysis of biomass waste and Slovak coal to obtain bio-oil and utilization of solid carbon residue for the environmental application,
• microwave-assisted extraction of organic substances from Slovak coal and biomass,
• microwave energy application in the metallurgical waste treatment (leaching of the metallurgical wastes and obtaining of valuable components by microwaves),
• microwave-assisted vitrification of hazardous materials with high content of heavy metals,
• toxicity tests, chemical and mechanical stability assessment of vitrificates,
• modification of the magnetic properties of minerals by microwaves,
• desulfurization of coal using microwaves,
• modeling of microwave heating for composite materials.

RESEARCH INFRASTRUCTURE

Analysis

• Quantachrome NOVA 1200e Surface Area & Pore Size Analyzer (Quantachrome Instruments, USA) for surface area measurement (BET) and pore size analysis,
• Elementar Vario Macro Cube (Elementar Analysensysteme, GmbH., Germany) for CHNS analysis,
• Bruker Tensor 27 (Bruker Optik GmbH., Germany) for FTIR analysis,
• Kappabridge KLY-2, Geofyzika Brno for magnetic susceptibility measurements at magnetic field intensity
  300 A.m^-1, homogeneity of magnetic field – 0.2 %, operating frequency – 920 Hz, measuring range  -1 999 x 10^-6 ÷ +650 000 x 10^-6 SI unit,
• Bruker D8 Advance (Bruker ASX GmbH., Karlsruhe, Germany) for X-ray analysis
• UHPLC Dionex Ultimate 3000 (Thermo Fisher Scientific Inc., USA) coupled with mass spectrometer MicroTofQII, (Bruker Daltonik GmbH., Germany) for analysis by liquid chromatography/mass spectrometry
• MP-1 with generator (HM8135 HF Syntesizer 3 GHz) and analyzer (Spectrum Analyzer HM 5530) for measuring of complex dielectric permittivity at room temperature.

 
Physical Separation

• pilot hydrocyclone station – classifying, washing in heavy medium and without heavy medium – so called Water-Only cyclone, max. grain size 5 mm,
• high-intensity magnetic separator – MECHANOBR,
• low-intensity magnetic separator – LAURILA,
• universal laboratory magnetic separator JONES (0.06 ÷ 1.40 T) – polygradient, high-gradient magnetic separation, dry way and wet one,
• magnetohydrostatic separator MHR-1 (separation in ferrofluid) – self-development,
• magnetohydrostatic separator FGS-2 (separation in ferrofluid),
• electrostatic corona separator STURTEVANT – O.H., max. 30 kV.

 
Crushing, Milling and Classifying

• jaw crusher PS D-160, feed max. 80 mm, output 10 – 20 mm,
• roll crusher,
• vibrating jaw grinder VČM-3, feed max. 15 mm, output 0.2 – 3 mm,
• universal laboratory ball and bar mill LP (porcelain, metallic),
• attrition mill,
• laboratory crusher FDV from MRC company (Israel) for biomass,
• vibrating mill VM-1 KSMH-Hranice,
• jewel vibrating pulverisator KM-1,
• air classifier, classifying cut of monomineral samples in the range of 3 -70 μm,
• vibrating classifier TE-III,
• Different mesh size of sieves: mesh size from 40 µm to 50 mm (40 µm, 45 µm, 50 µm, 56 µm, 63 µm, 71 µm, 80 µm, 90 µm, 100 µm, 125 µm, 150 µm, 160 µm, 180 µm, 200 µm, 250 µm, 280 µm, 315 µm, 355 µm, 400 µm, 500 µm, 630 µm, 710 µm, 750 µm, 800 µm, 900 µm, 1 mm, 1.25 mm, 1.6 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 7 mm, 8 mm, 10 mm, 12 mm, 16 mm, 18 mm, 20 mm, 25 mm, 30 mm, 40 mm, 50 mm),
• mesh size of sieves for microclassifying in ultrasonic bath from 5 to 45 µm (5 µm, 10 µm, 15 µm, 20 µm, 25 µm, 30 µm, 35 µm, 40 µm, 45 µm).

 
Ovens

• laboratory tube oven operating at different atmospheres (maximum temperature – 1200°C),
• muffle oven CE-4 (maximum temperature – 1150 °C),
• hardening furnace HG 4/3 (maximum temperature – 1350 °C),
• microwave ovens Panasonic NN 5251B ( 900 W, 2450 MHz), Panasonic NE-3240 (1800W, 2450 MHz), Whirlpool AVM 434 – modified (850 W, 2450 MHz),
• microwave generator MWG3K-08 (5kW).

Other Laboratory Equipment

• centrifuge – Rotina 380 (Hettich),
• teslameter Tesla 706509, measuring ranges 0 – 0.2 T, 0 – 0.5 T and 0 – 2 T,
• pH meter WTW pH 340i, electrode SenTix 41-3 with installed temperature sensor,
• combined redox electrode WTW SenTix ORP,
• contactless thermometer Raytek RAYMX4PG (-30 °C – +900 °C),
• contactless thermometer Raytek Marathon MM 2MH (450 °C – +2250 °C),
• ultrasonic bath Tesla UC 002 BM1, operating frequency 20 kHz ± 1.5 kHz,
• magnetic stirrers MM1, HI 300N,
• moisture meter GREISINGER GHH91 (powdered materials, wood) with correcting thermometer and humidity meter GFTH95 (ambient air),
• analytical scales, sensitivity – 0.001 g
• Mohr´s balance for determination of heavy liquids density
• densimeters – 0.6 ÷ 2.02 g.cm^-3
• water bath LAZNIA LW-4
• laboratory dryer MMM Venticell (250 °C)
• electrolytic apparatus (electro-chemical degradation of organic pollutants)
• power ultrasound homogenizer.

 
RESEARCH STAFF