Research on Selected Types of Lustrous Carbon Carriers After the High - Temperature Pyrolysis

For research purposes and to demonstrate the differences between materials obtained from the carbonaceous additives to classic green moulding sands, five lustrous carbon carriers available on the market were selected. The following carbonaceous additives were tested: two coal dusts (CD1 and CD2), two hydrocarbon resins (HR1 and HR2) and amorphous graphite (AG1). The studies of products and material effects resulting from the high-temperature pyrolysis of lustrous carbon carriers were focused on determining the tendency to gas evolution, including harmful compounds from the BTEX group (benzene, toluene, ethylbenzene and xylene). Moreover, the content of lustrous carbon (LC), the content of volatile matter and loss on ignition (LOI) of the carbonaceous additives were tested. The solid products formed during high-temperature pyrolysis were used for the quantitative and qualitative evaluation of elemental composition after the exposure to temperatures of 875oC in a protective atmosphere and 950oC in an oxidizing atmosphere. The conducted studies have indicated the necessity to examine the additives to classic green moulding sands, which is of particular importance for the processing, rebonding and storage of waste sand. The studies have also revealed some differences in the quantitative and qualitative composition of elements introduced to classic moulding sands together with the carbonaceous additives that are lustrous carbon carriers. It was also considered necessary to conduct a research on lustrous carbon carriers for their proper and environmentally friendly use in the widely propagated technology of classic green sand system

The Effect of Reclaim Primary Quality on Moulding Sand Parameters and Quality of Ductile Iron Casting Surface Layer

The aim of the research was to determine the effect of the primary quality of reclaim from dry mechanical reclamation on the strength properties and service life of moulding sands based on this reclaim. Another aim was to establish the effect of the quality of reclaim, sulphur content - in particular, on the surface quality and thickness of the deformed surface layer in ductile iron castings. The research has revealed differences in the strength parameters and service life (mouldability) of sands based on the tested reclaims, depending on the type of the furfuryl resin used, including resins whose synthesis was done as part of the Żywfur project. Examinations of the structure of the surface layer of test castings poured in moulds made of loose self-hardening sands containing the addition of reclaim have confirmed the occurrence of degenerated spheroidal graphite in this part of the casting. It should be noted here that when massive castings with a long solidification time are made, the graphite degeneration effect can be more visible and the layer with the changed structure can increase in thickness. The research has clearly shown that it is necessary to control the parameters of the reclaim, including sulphur content which is transferred from the hardener and accumulates on the grains. This phenomenon has a negative impact not only on the sand strength and technological properties but also on the surface layer of castings

The Effect of the Addition of Bentonite Clay to Traditional Sand Mixtures on the Surface Quality of Iron Castings

Successful casting demands that during pouring of the foundry mould with molten metal the mould cavity suffers no deformation. This, in turn, demands the use of binding materials that can give the base sand adequate strength. The main bonding materials are clay binders. The foundry industry uses minerals rich in clay, such as kaolinite, halloysite, hydromica, montmorillonite, polygorskite, vermiculite and allophane. Due to their binding capacity, montmorillonites are the most interesting minerals of all the plastic clay rocks. The basic clay rock containing montmorillonite, used as a common binding material for traditional foundry sand mixtures, is bentonite. The domestic demand for raw bentonite materials is almost entirely satisfied by imports from Slovakia, Turkey, Italy, Germany and the Czech Republic, in order of import size. In Poland, the bentonite deposits occur in very small quantities. The exploitation of bentonites is carried out only in the Krzeniów deposit, where they constitute a mineral accompanying basalt. Much more common are bentonite clays containing in addition to smectites also a large amount of other clay minerals. The article presents the results of studies of the physico-chemical and mechanical properties of moulding sand mixtures containing pure bentonite, pure clay or hybrid bentonites which are a bentonite-clay mixture. Melting was also carried out to determine the effect of the type of binder on the surface quality of iron castings

Preliminary Tests of Innovative Eco-Friendly Furfuryl Resins and Foundry Sand Mixtures Based on These Resins

The foundry industry in Poland and EU member states is growing steadily. The alloys based on ferrous metals (cast steel and cast iron) largely contribute to this upward trend. Currently, foundries are facing the problem of increasing requirements, which enforce the production of castings characterized by high dimensional accuracy and surface smoothness with parallel elimination of casting defects. Castings are mostly made in moulding sand mixtures, which are also subject to more and more stringent requirements to meet the above-mentioned casting acceptance conditions. Additionally, moulding sands should ensure adequate mould stiffness to avoid the risk of dimensional deformations during the pouring of liquid metal to this mould and casting solidification. For these reasons, the production of this type of castings has been dominated by loose self-hardening sands with furfuryl resin, commonly called furan sands. In the group of self-hardening sands with synthetic resins, loose self-hardening sands with furfuryl resin enjoy the greatest popularity. What accounts for this fact is the high level of the reclamability of these sands, the possibility of obtaining castings with high dimensional accuracy, the ability to make intricate moulds and cores, the binding process taking place at ambient temperature, and low content of binder. Unfortunately, this technology also has some disadvantages, which include short lifetime of the sand mixture, harmful gases emitted from the sand, and currently also high cost of the sand mixture. The anticipated tightening of the environmental protection regulations in the EU countries, including limiting the content of free furfuryl alcohol in resins (<25% by mass) and reducing the emission of furfuryl alcohol, formaldehyde and BTEX compounds at workplaces, necessitated the development of a new generation of furfuryl resins friendly to the environment. The article compares the results of testing the strength properties of foundry moulding sands using two types of resins, i.e. the resin of a new generation synthesized by Grupa Azoty JRCh and a commercial resin used in the foundry industry. Additionally, derivatographic studies of the above mentioned sand mixtures were conducted, and the loss on ignition and the amount of gases emitted by the sand mixture were determined. Melting was also carried out to study the impact of the resin used on the surface quality of iron castings

Jakość biologiczna zielonych roślin pszenżyta biofortyfikowanych jodem

Plant biofortified with iodine may be an alternative source of this element in human diet. The purpose of the research was to determine the effect of fertilization on quality of green plant biological iodine. Iodine in the form of KIO3 or KI was applied to the soil or sprayed on the plants. Iodine application (2.50 or 5 kg ∙ ha–1) was split, with the first half applied together with spring nitrogen fertilization and the other half applied one month before sampling for laboratory tests. In all the tested combinations of fertilization iodine increases iodine content in green plants compared to control. The application rates and means of fertilization with iodine salts did not adversely affect the biological quality of the plants.Rośliny biofortyfikowane jodem mogą być alternatywnym źródłem tego pierwiastka w diecie człowieka. Celem badań było określenie wpływu nawożenia jodem na jakość biologiczną zielonych roślin pszenżyta. Jod w postaci KIO3 lub KI (2,50 lub 5 kg ∙ ha–1) był stosowany w glebie lub rozpylany na rośliny. Dawka jodu została podzielona, pierwszą połowę stosowano wraz z wiosennym nawożeniem azotem, a drugą połowę stosowano na jeden miesiąc przed pobraniem próbek do badań laboratoryjnych. We wszystkich badanych kombinacjach nawożenia jodem obserwowano wzrost zawartości jodu w zielonych roślinach pszenżyta w porównaniu do kontroli. Zastosowane dawki i sposoby nawożenia solami jodu nie wpłynęły negatywnie na jakość biologiczną zielonych roślin pszenżyta