National Repository of Grey Literature 8 records found  Search took 0.00 seconds. 
Preparation of the alpha plaster by a non-pressure method in H2SO4 solution
Zájeda, Lukáš ; Gazdič, Dominik (referee) ; Dvořák, Karel (advisor)
This bachelor thesis deals with the production of alpha gypsum by a non-pressure method in H2SO4 solution. The theoretical part focuses on the current knowledge in the field of preparation of alpha plaster by a pressureless method. The practical part focuses on the possibility of preparing alpha gypsum in sulfuric acid solution of different concentrations.
Recycling of steel-works flue dusts from electric arc and inductive furnaces
Huczala, Vít ; Koplík, Jan (referee) ; Šoukal, František (advisor)
This bachelor thesis deals with an application of electric arc furnace dust from steel production as secondary raw material for production of zinc and industrially process able zinc products. In this thesis the dust was processed by methods based on various physical and chemical properties. The most experiments were performed during the treatment with leaching in sulphuric acid. For this leaching the optimal concentration of sulphuric acid and the optimal ratio acid:dust was determined. The final products were prepared by precipitation or by evaporation of filtrate obtained after leaching. There were also used hydrolysis of dust and oxidative precipitation of filtrate during the processing. These steps led to increase of the quality of the final products. The price balance was also performed for the prepared products.
Study of the process of dehydration of gypsum in acid solutions
Zájeda, Lukáš ; Moldrzyk, Jan (referee) ; Dvořák, Karel (advisor)
The diploma thesis deals with the production of alpha gypsum by the non-pressure method in a solution of concentrated H2SO4. The theoretical part summarizes the present knowledge of the non-pressure method of alpha gypsum. In the practical part there is performed reproducibility of achieved results and optimization of apparatus with verification of functionality.
Using a modified biocharge to capture ammonia from the exhaust air
Kozlíková, Nikola ; Innemanová, Petra (advisor) ; Cajthaml, Tomáš (referee)
In my work I have dealt with the comparison of different types of biochar based solid materials, which could serve as a filling for ammonia capture filters. Three samples of biochar prepared from anaerobically stabilized sewage sludge were used to test the most suitable material at temperatures of 200 ř C, 400 ř C and 600 ř C, 3 samples of biochar prepared from oak wood at temperatures of 260 ř C, 400 ř C and 600 ř C, 2 samples of biochar prepared from a mixture of sewage sludge and wood chips pre-dried in a pilot scale biological drying plant, dried anaerobically stabilized sewage sludge and charcoal. The materials were impregnated with 50% sulfuric acid solution. They were then exposed to ammonia vapors for the time needed to complete the reaction on the surface of the impregnated material. Due to the chemical reaction, ammonium sulfate is produced, which can be used as a fertilizer in agriculture. It is known that the addition of biochar has a positive effect on the soil. In the case of a combination of biochar and ammonium sulphate, this may be an interesting soil additive. It could be an alternative to so-called scrubbers, where ammonia is trapped by bubbling dilute sulfuric acid. Transportation and application of the ammonium sulphate solution thus formed is not economically advantageous. To...
Preparation of the alpha plaster by a non-pressure method in H2SO4 solution
Zájeda, Lukáš ; Gazdič, Dominik (referee) ; Dvořák, Karel (advisor)
This bachelor thesis deals with the production of alpha gypsum by a non-pressure method in H2SO4 solution. The theoretical part focuses on the current knowledge in the field of preparation of alpha plaster by a pressureless method. The practical part focuses on the possibility of preparing alpha gypsum in sulfuric acid solution of different concentrations.
Development and Use of Electrochemical Detector for Analysis of Czech Coal Combustion Products
Sokol, Martin ; Nesměrák, Karel (advisor) ; Vyskočil, Vlastimil (referee)
This work examines an electrochemical determination of mixed nitric and sulphuric acid solution that is formed during calorimetric determination of gross calorific value of coal carried out under the ISO 1928:1995 standard. Knowing the amount of these acids is necessary for calculating net calorific value. The named standard only allows use of volumetric methods which are time-consuming. Conductivity and ion-selective measurements were used here which significantly shortened analysis time. Overall conductivity measurement was taken with a 4-electrode meter while nitric acid was measured with a nitrate ISE by known addition method. Sulphuric acid was then calculated according to actual temperature. This research has defined the calibration relations and temperature effect. Several simulated and real-world samples were analysed and the method was evaluated for a possible use in a future automated analyser.
Recycling of steel-works flue dusts from electric arc and inductive furnaces
Huczala, Vít ; Koplík, Jan (referee) ; Šoukal, František (advisor)
This bachelor thesis deals with an application of electric arc furnace dust from steel production as secondary raw material for production of zinc and industrially process able zinc products. In this thesis the dust was processed by methods based on various physical and chemical properties. The most experiments were performed during the treatment with leaching in sulphuric acid. For this leaching the optimal concentration of sulphuric acid and the optimal ratio acid:dust was determined. The final products were prepared by precipitation or by evaporation of filtrate obtained after leaching. There were also used hydrolysis of dust and oxidative precipitation of filtrate during the processing. These steps led to increase of the quality of the final products. The price balance was also performed for the prepared products.
International Trade in Sulphur and Sulphuric Acid
Čengerová, Helena ; Černá, Iveta (advisor) ; Taušer, Josef (referee)
The thesis is aimed at the international trade in sulphur and sulphuric acid. The main contribution of this thesis is to show how important in almost all industrial fields these chemicals are and to analyze the current situation on the market. The produced, consumed and traded amount of these commodities is significant and influances the international trade as a whole. The first and second parts contain general information about these chemicals, occurance of sulphur, production of sulphuric acid and their usage. The fourth part is focused on the long history and finally the fifth part describes the international trade in these chemicals. There are shown the main producers, consumers and trade flows. In the last chapter is explained the unusual price increase from 2006 till 2008 and try to find the reasons why this situation occured.

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