Refractory Materials for Biofuel Boilers

The energy equipment usable for solid biofuel incineration usually operates upon aggressive conditions. The internal structures (lining) of the equipment are made of refractory materials that are affected by combined loads: thermal, mechanical and chemical (i.e. high temperature–up to 1200°C, chemical impact of alkaline compounds and slag, repeating thermal shocks, abrasive effect caused by solid particles and so on). A majority of traditional refractories usable for lining in such equipment are not durable. Upon certain conditions of use (such as high local temperatures, influence of alkaline biofuel combustion products and so on), durability of the traditional materials is 1–2 years only. The opportunities of new refractory materials application should be set upon taking into account the conditions of operation for biofuel boilers of specific types. In this section - the data on the peculiarities of using refractory materials in biofuel boilers are reviewed, and the impact of aggressive operating conditions of such thermal equipment on the properties of refractory materials is discussed. In addition, the investigations results of refractory castables alkali resistance and its explosive spalling are discussed. The recommendations for use of refractory materials in biofuel boilers are also presented

Zatorowość płucna powikłana opłucnowym zespołem podobnym do zespołu Dresslera

Pulmonary embolism was reported as one of possible complications after implantable cardioverter-defibrillator (ICD) lead implanting procedures. Pleural effusion, with fluid bloody in appearance and with predominance of granulocytes, can be a common resolution of lasting pulmonary embolism. In this paper we present a case of ICD lead exchange procedure causing pulmonary embolism and pleural effusion, with bloody lymphocytic fluid as its consequence, with good response to corticosteroids treatment.Zatorowość płucna była opisywana jako możliwe powikłanie zabiegów wszczepiania elektrod kardiowertera-defibrylatora. Wysiękowy krwisty płyn jest dość częstym następstwem długo trwającej zatorowości, a charakter wysięku jest najczęściej granulocytarny. W pracy omawiamy przypadek powikłanego zatorowością zabiegu wymiany elektrody urządzenia ICD oraz limfocytarnego wysięku opłucnowego jako następstwo ostrej zatorowości leczonego glikokortykosteroidami

Sposób wytwarzania zwartego klinkieru ogniotrwałego opis patentowy nr 212580 /

Tyt. z ekranu tyt.Zgłoszono 12 czerwca 2006 r.Zgłoszenie ogłoszono 24 grudnia 2007 r. BUP 26/07.O udzieleniu patentu ogłoszono 31 października 2012 r. WUP 10/12.Nr zgłoszenia P 379909.Dostępny również w wersji drukowanej.Tryb dostępu: Internet

DESIGN OF EXPERIMENTS IN THE STUDY OF BAUXITE REFRACTORY CASTABLE PROPERTIES

This paper presents results of an investigation of the influence of preparation conditions of low-cement refractory castables on their service properties using experiment planning methods. Using the orthogonal Plackett-Burman design, the influence of the amount of water, vibration time, curing conditions and firing conditions on the service properties of the finished refractory castable (apparent density, open porosity, permanent linear changes, Young's modulus, bending strength and compressive strength at ambient temperature) is demonstrated. It is found that, among the investigated properties under the conditions of the conducted experiment, only the mixing time is a negligible factor that has no significant influence on the process of developing service properties of low-cement bauxite castables

Current State of Application of Machine Learning for Investigation of MgO-C Refractories: A Review

Nowadays, digitalization and automation in both industrial and research activities are driving forces of innovations. In recent years, machine learning (ML) techniques have been widely applied in these areas. A paramount direction in the application of ML models is the prediction of the material service time in heating devices. The results of ML algorithms are easy to interpret and can significantly shorten the time required for research and decision-making, substituting the trial-and-error approach and allowing for more sustainable processes. This work presents the state of the art in the application of machine learning for the investigation of MgO-C refractories, which are materials mainly consumed by the steel industry. Firstly, ML algorithms are presented, with an emphasis on the most commonly used ones in refractories engineering. Then, we reveal the application of ML in laboratory and industrial-scale investigations of MgO-C refractories. The first group reveals the implementation of ML techniques in the prediction of the most critical properties of MgO-C, including oxidation resistance, optimization of the C content, corrosion resistance, and thermomechanical properties. For the second group, ML was shown to be mostly utilized for the prediction of the service time of refractories. The work is summarized by indicating the opportunities and limitations of ML in the refractories engineering field. Above all, reliable models require an appropriate amount of high-quality data, which is the greatest current challenge and a call to the industry for data sharing, which will be reimbursed over the longer lifetimes of devices

Position of Fe ions in MgO crystalline structure

Magnesium oxide (MgO) is one of the most important raw materials in many branches of industry. Magnesium oxide is a popular refractory raw material because of its high refractoriness and high resistance to basic slags and environment. In many cases, use of MgO is limited by its properties, especially the presence of secondary phases like iron oxides. The amount and distribution of iron oxides can strongly influence the technological properties of MgO and depend on the manufacturing method, particularly the heat-treatment process. The aim of the study was to evaluate the influence of the heat-treatment process on amount and distribution of iron ions in a magnesium oxide lattice. The 57Fe Mössbauer effect measurements of fused and sintered magnesium oxide samples doped by the iron oxide were conducted. Investigation reveals in both cases the presence of Fe2+ as well as Fe3+ ions. Fe2+ ions occupy Mg2+ octahedral sites in the MgO lattice, whereas the Fe3+ ions are located in highly distorted octahedral coordination. The amount of Fe2+ varies from around 66% for fused samples to 30% for sintered samples

The role and position of iron in 0.8CaZrO3-0.2CaFe2O4

The aim of the study was to characterize the 0.8CaZrO3-0.2CaFe2O4 composite structure with particular emphasis on the role and position of iron in the function of sintering temperature. The paper presents the results of 57Fe Mössbauer effect at room temperature. It was found that the increase of sintering temperature causes an increase in the amount of incorporated iron ions in the CaZrO3-crystal structure. Based on Mössbauer spectroscopy analysis, it was found that three different environments of Fe3+ ions were observed in the obtained materials. Two of them corresponded to CaFe2O4 phase and one was associated with the substitution of Zr4+ by Fe3+ in the CaZrO3 structure