Research on the production of fertilizers and aluminum compounds based on potash and alunite ores
Students Name: Mural Ihor Viktorovych
Qualification Level: master (ESP)
Speciality: Chemical Technology and Engineering
Institute: Institute of Chemistry and Chemical Technologies
Mode of Study: full
Academic Year: 2022-2023 н.р.
Language of Defence: англійська
Abstract: The process of processing alunite ores of deposits of Ukraine is considered as an alternative method of obtaining fertilizers and aluminum compounds, which will have practical use in agriculture and various industries. Alunite ores are an important source of potassium and aluminum sulfates and aluminum hydroxides. In the master’s qualification work, it is proposed to process them by alkaline decomposition with the production of aluminum hydroxide, which can be processed into alumina or other materials. During processing, solutions of potassium and sodium sulfates are formed, which can be directly used in the technological process of obtaining kalimagnesia to bind excess magnesium chloride, which is formed as a result of crystallization of the sulfate mineral shenite from chloride-sulfate solutions. The use of a solution after the alkaline dissolution of alunite also simplifies the technology of processing alunite ores, since there is no need to extract potassium fertilizer from it and dispose of sodium sulfate according to known technologies. The purpose of the work is to study the production of fertilizers and aluminum compounds based on potash and alunite ores. It is shown that raw alunite ore contains about 40% by mass. alunite and 60% by mass. quartz, and in the calcined alunite rock, the main mineral is quartz, in addition, there are impurities of orthoclase and potassium pyrosulfate. This is due to the fact that at a temperature of 650 ?С, alunite turns into an amorphous mass of aluminum potassium alum with the above-mentioned impurities. Comparative studies of the influence of the type of solvent on the extraction of potassium and aluminum from calcined and raw crushed alunite rock were carried out. It was established that the dissolution of alunite ore occurs in NaOH solutions, and significant changes are noticeable depending on the concentration of the reagent. 11 The alunite solution obtained after alkaline decomposition, containing potassium and sodium sulfates, was fed to the conversion processing of polymineralic potassium ore, which made it possible to increase the output of calymagnesia and its K2O content. The influence of centrifugation conditions on the efficiency of separation of clay impurities from alunite ore was investigated. It was established that for the same centrifugation time, but with different rotation frequencies of the centrifuge rotor, a decrease in the moisture content in the clay slurry to 27.70% is achieved. The influence of PAA flocculant on the sedimentation rate of clay sediment was studied. It is shown that the sedimentation rate increases and this leads to a decrease in the sedimentation rate of clay particles, which can be explained by the formation of smaller flocs, since the distance between the particles increases sharply. The material balances of ore conversion, dissolution of converted ore, stages of crystallization. A technological scheme for obtaining fertilizers and aluminum compounds based on potash and alunite ores is proposed. In the economic part, the main cost calculations for the production of fertilizers and aluminum compounds based on potash and alunite ores are given. Keywords - potash raw materials, alunite ores, potash fertilizers, aluminum compounds.