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Number of results: 7
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Abstract

The ceaseless progress of nanotechnology, observed in the last years, causes that nanomaterials are more and more often applied in several

fields of industry, technique and medicine. E.g. silver nanoparticles are used in biomedicine for disinfection and polymer nanoparticles

allow insulin transportation in pharmacology. New generation materials containing nanoparticles are also used in the chemical industry

(their participation in the commercial market equals app. 53 %). Nanomaterials are used in electronics, among others for semiconductors

production (e.g. for producing nanoink Ag, which conducts electric current).

Nanomaterials, due to their special properties, are also used in the foundry industry in metallurgy (e.g. metal alloys with nanocrystalline

precipitates), as well as in investment casting and in moulding and core sand technologies. Nanoparticles and containing them composites

are applied in several technologies including foundry practice, automotive industry, medicine, dentistry etc. it is expected that their role

and market share will be successively growing.

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Authors and Affiliations

A. Kmita
A. Roczniak
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Abstract

The nanocomposites based on water glass matrix were attempted in the study. Nanoparticles of ZnO, Al2O3 or MgO in organic solutions

were applied into water glass matrix in the amounts of: 1.5; 3; 4 or 5 mas. %. Wettability of the quartz sad by the nanocomposites based on

water glass matrix was determined by testing changes of the wetting angle θ in time τ for the system: quartz – binder in non-stationary

state, by means of the device for measuring wetting angles. Wettability measurements were carried out under isothermal conditions at an

ambient temperature (20 – 25 oC). The modification improves wettability of quartz matrix by water glass, which is effective in improving

strength properties of hardened moulding sands. Out of the considered modifiers in colloidal solution of propyl alcohol water glass

modified by MgO nanoparticles indicated the smallest values of the equilibrium wetting angle θr. This value was equal app. 11 degrees and

was smaller no less than 40 degrees than θr value determined for not modified water glass. Viscosity η of nanocomposites based on water

glass matrix was determined from the flow curve, it means from the empirically determined dependence of the shearing stress τ on shear

rate γ: τ = f (γ) (1), by means of the rotational rheometer. Measurements were carried out at a constant temperature of 20 oC. The

modification influences the binder viscosity. This influence is conditioned by: amount of the introduced modifier as well as dimensions and

kinds of nanoparticles and organic solvents. The viscosity increase of the modified binder does not negatively influence its functional

properties.

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Authors and Affiliations

A. Kmita
A. Roczniak
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Abstract

The growing increase in the use of cars and transportation in general is causing an increase the emission of pollutants into the atmosphere. The current European Union regulations impose the minimization of pollution through the use of automotive catalytic converters on all member countries, which stops toxic compounds from being emitted into the atmosphere thanks to their contents of platinum group metals (PGMs). However, the growing demand for cars and the simultaneous demand for catalytic converters is contributing to the depletion of the primary sources of PGMs. This is why there is now increasing interest in recycling PGMs from catalytic converters through constantly developing technologies. There are newer and more sustainable solutions for the recovery of PGMs from catalytic converters, making the process part of a circular economy (CE) model. The purpose of this article is to present two innovative methods of PGM recovery in the framework of ongoing research and development projects.
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Authors and Affiliations

Natalia Generowicz
1
ORCID: ORCID
Agnieszka Nowaczek
1
ORCID: ORCID
Leszek Jurkowski
2
Iakovos Yakoumis
3

  1. Mineral and Energy Economy Research Institute Polish Academy of Sciences, Kraków, Poland
  2. Unimetal Recycling sp. z o.o., Trzebinia, Poland
  3. MONOLITHOS Catalysts and Recycling Ltd, Athens, Greece
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Abstract

The work is a part of research into the reduction of energy consumption in the production of EPSthrough the modernization

of technological equipment used. This paper presents the results of research and analysis of heat transfer process between the water vapor

that was provided to machine, the mold, the product and the environment. The paper shows the calculation of the heat balance of the

production cycle for two types of mold: standard and modernized. The performance tests used an infrared imaging camera.

The results were used to develop a computer image analysis and statistical analysis. This paper presents the main stages of the production

process and the construction of technological equipment used, changing the mold surface temperature field during the production cycle

and the structure of the heat balance for the mold and its instrumentation. It has been shown that the modernization of construction

of technological equipment has reduced the temperature field and as a consequence of decreased of demand for process steam production

cycle.

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Authors and Affiliations

R. Władysiak
T. Pacyniak
W. Bogus
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Abstract

The aim of this study is to demonstrate the possibility of using moulding sands based on inorganic binders hardened in a microwave chamber in the technology of ablation casting of aluminium alloys. The essence of the ablation casting technology consists in this that a mould with a water-soluble binder is continuously washed with water immediately after being poured with liquid alloy until its complete erosion takes place. The application of an environmentally friendly inorganic binder improves the ecology of the whole process, while microwave hardening of moulding sands allows moulds to be made from the sand mixture containing only a small amount of binder.

The studies described in this article included microwave-hardened sand mixtures containing the addition of selected inorganic binders available on the market. The strength of the sands with selected binders added in an amount of 1.0; 1.5 and 2.0 parts by mass was tested. As a next step, the sand mixtures with the strength optimal for ablation casting technology, i.e. about 1.5 MPa, were selected and tested for the gas forming tendency. In the four selected sand mixtures, changes occurring in the samples during heating were traced. Tests also included mould response to the destructive effect of ablation medium, which consisted in the measurement of time necessary for moulds to disintegrate while washed with water. Tests have shown the possibility of using environmentally friendly, microwave-hardened moulding sands in ablation casting of aluminium alloys.

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Authors and Affiliations

S. Puzio
ORCID: ORCID
J. Kamińska
ORCID: ORCID
M. Angrecki
ORCID: ORCID
K. Major-Gabryś
ORCID: ORCID
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Abstract

The paper presents the results of studies on the development of manufacturing technologies to cast hearth plates operating in chamber

furnaces for heat treatment. Castings made from the heat-resistant G-X40CrNiSi27-4 steel were poured in hand-made green sand molds.

The following operations were performed: computer simulation to predict the distribution of internal defects in castings produced by the

above mentioned technology with risers bare and coated with exothermic and insulating sleeves, analysis of each variant of the technology,

and manufacture of experimental castings. As a result of the conducted studies and analysis it was found that the use of risers with

exothermic sleeves does not affect to a significant degree the quality of the produced castings of hearth plates, but it significantly improves

the metal yield.

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Authors and Affiliations

A. Drotlew
B. Piekarski
M. Garbiak
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Abstract

The aging granulate is to activate the blowing agent during the manufacturing process to granulate models can re-expand and shape the

model of well-sintered granules, smooth surface and a suitable mechanical strength.

The article presents the results of studies which aim was to determine the optimum time for aging pre-foamed granules for pre-selected

raw materials.

The testing samples were shaped in an autoclave, with constant parameters sintering time and temperature. Samples were made at 30

minute intervals. Models have been subjected to flexural strength and hardness.

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Authors and Affiliations

K. Buczkowska
T. Pacyniak

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