Browsing by Author "Stefanov E."

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    Speciation Analysis of Arsenic in Copper Electrolyte Baths Using Liquid-liquid Extraction and ICP-OES Method Detection
    (2022-01-01) Stefanov E.; Georgieva S.
    The present study describes a method for the determination of As (III) and As (V) in copper electrolytes. The method is based on the separation of As (III ) from a copper electrolyte by triple liquid-liquid extraction using a non-polar organic solvent in a medium of 10-12 mol L-1HCl. The extract contains As (III) and the raffinate-As (V), respectively. As(III) specie can be re-extracted from the organic solvent through the water. Analyzes of the concentration of As in the re-extract and raffinate were performed by ICP-OES spectroscopic method. The average recovery of arsenic by the proposed method is about 99%. Repeatability was estimated with RSD (n = 6). Selectivity and accuracy were proven by the standard addition method. The relative error for restoring the standard addition of As (III) is about 0.3%. The speciation method analysis could be applied for determination of the arsenic species in the analytical quality control of refined copper in copper tanks in the production of copper cathodes.
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    TREATMENT OF COPPER FLUE DUST FROM FLASH FURNACE WASTE HEAT BOILER FOR IMPURITIES CONTROL
    (2024-01-01) Kadiyski M.; Angelov N.; Iliev P.; Stefanov E.; Semerdzhiev T.; Sopotenska I.
    During the pyrometallurgical processing of copper sulphide raw materials, part of the charge leaves the furnace space together with the exhaust gases in the form of dust entrainment. Volatile components also pass into the dust-gas flow, due to which it is enriched with impurities, some of which are harmful to the technological process. The formed dust-gas flow passes through dust collection equipment, where the main part of it is captured. Most often, the captured dust is recirculated, which leads to a decrease in the productivity of the furnace unit and a gradual increase in the content of impurities in the condensed products of the smelting. To overcome these disadvantages, it is necessary to take part or all the recirculating dust out of the melting cycle and process it independently to extract the valuable metals and dispose of the harmful substances. In metallurgical practice, industrial application for the processing of recirculating dust entrainment has mainly been accomplished by hydrometallurgical methods based on treating the flue dust in aqueous solutions of acid or alkaline reagents. In the present research work, laboratory results on hydrometallurgical leaching of flue dust from a flash furnace waste heat boiler (FF-WHB) are presented. The effect of the main technological parameters affecting the degrees of recovery of the main metals in solution was studied. Based on the experimental results, the optimal conditions for hydrometallurgical treatment of the FF-WHB flue dust were determined. By treating the dust under optimal conditions, the main tasks of the research are achieved - removal of impurities harmful to the technological process and reduction of the amount of flue dust processed in the flash furnace.