Jana Ficeriová - Academia.edu (original) (raw)

Papers by Jana Ficeriová

This paper deals with mechanical activation of gold- and silver bearing sulphide minerals. Mechan... more This paper deals with mechanical activation of gold- and silver bearing sulphide minerals. Mechanical activation belongs to methods of physical pretreatment and was applied in Russia, South Africa and Australia for ultrafine grinding of gold and silver bearing arsenopyrite and pyrite concentrates. The new method of mechanochemical leaching has been developed at the Institute of Geotechnics of the Slovak Academy of Sciences in Košice. The method proved to be succesful as pretreatment step for silver leaching from the tetrahedrite concentrate.

Bulletin of Materials Science, 2021

In this work, it is demonstrated that visible-light photocatalytic activity for degrading methyl ... more In this work, it is demonstrated that visible-light photocatalytic activity for degrading methyl orange (MO) could be improved by co-milling of TiO2 (Degussa P25) with thiourea. The photocatalysts have been prepared by combined mechanochemical/thermal synthesis. Structures and morphology of the as-prepared TiO2 nanoparticles were characterized by X-ray powder diffraction, N2 adsorption–desorption isotherms, UV‒Vis diffuse reflectance spectroscopy and scanning electron microscopy. It is shown that co-milling of TiO2 with thiourea favours formation of brookite phase and it results in the occurrence of more porous structures. The optical properties are modified and the band gap energy values of the samples become smaller, when thiourea is introduced. Ball-milled samples show better photocatalytic activities during oxidative discolouration of MO than that of the initial TiO2. The discolouration degree is above 99% for ball-milled TiO2/thiuourea nanoparticles, while it is 2% for pure and 15% for ball-milled TiO2.

Obsah 1. Úvod 2. Porézna uhlíková plsť 3. Elektrolyzér pre spracovanie odpadov s obsahom zlata 4.... more Obsah 1. Úvod 2. Porézna uhlíková plsť 3. Elektrolyzér pre spracovanie odpadov s obsahom zlata 4. Prevádzka elektrolyzéra 5. Schéma aparatúry pre elektrolýzu zlata s navrhnutým elektrolyzérom 6. Technologická schéma elektrolytického spracovania Au-odpadu 7. Elektrolytické spracovanie tiomočovinového roztoku s obsahom Au-odpadu 8. Záver 1. Úvod Problematika spätného získavania zlata z druhotných surovín je podmienená nedostatkom primárnych surovín ako aj nutnosťou ochrany životného prostredia 1. Jedná sa o celosvetový problém. Tiomočovinový proces získavania zlata z druhotných surovín pozostávajúci z vylúhovania zlata do tiomočovinového roztoku je perspektívnou alter-natívou doposiaľ stále najviac používanej toxickej kyani-začnej metódy 2. Vzhľadom k cieľu vylúčenia zlata z tio-močovinových roztokov s možnosťou regenerácie použité-ho roztoku sa ukázal ako perspektívny postup elektrolytic-kého získavania zlata. Z doposiaľ známych údajov o uve-denom postupe vyplýva, že v súčasnosti je ...

Mechanical activation in processes of gold and silver extraction from sulphide minerals This pape... more Mechanical activation in processes of gold and silver extraction from sulphide minerals This paper deals with mechanical activation of gold-and silver bearing sulphide minerals. Mechanical activation belongs to methods of physical pretreatment and was applied in Russia, South Africa and Australia for ultrafine grinding of gold and silver bearing arsenopyrite and pyrite concentrates. The new method of mechanochemical leaching has been developed at the Institute of Geotechnics of the Slovak Academy of Sciences in Košice. The method proved to be succesful as pretreatment step for silver leaching from the tetrahedrite concentrate. Úvod Jestvujúce technológie nie sú schopné spracovávať komplexné sulfidické rudy s obsahom antimónu, za účelom extrakcie zlata a striebra ekonomickým spôsobom, pri ich dostatočnej výťažnosti. Jedným z problémov je forma, v ktorej sa uvedené drahé kovy nachádzajú v minerálnej matrici. Zlato sa napr. často vyskytuje fyzikálne uzavreté vo forme jemne rozptýlených...

Contens Marcela Achimovičová, Aleksander Rečnik, Martin Fabián and Peter Baláž: Characterization ... more Contens Marcela Achimovičová, Aleksander Rečnik, Martin Fabián and Peter Baláž: Characterization of tin selenides synthesized by high-energy milling 123 Jana Ficeriová, Peter Baláž and Eberhard Gock: Leaching of gold, silver and accompanying metals from circuit boards (PCBs) waste 128 Iveta Štyriaková, Igor Štyriak and Katarína Jablonovská: The role of biostimulation in iron bioleaching and purification of quartz sands 132

activation and electrolysis of gold from goldsmith's waste

Acta Montanistica Slovaca, 2010

The intensification of leaching of gold from a waste using mechanical activation (milling in wate... more The intensification of leaching of gold from a waste using mechanical activation (milling in water) and mechanochemical activation (milling in thiourea solution) were studied as the pretreatment steps. The leaching of “as-received“ sample in an acid thiourea solution resulted in 78 % Au dissolution, after mechanical activation 98 % and mechanochemical activation up to 99 % of the gold was leached during 120 min. The mechanochemical activation resulted in an increase of the specific surface area of the waste from 0.6 mg to a maximum value of 20.5 mg. The activation was performed in an attritor using variable milling times. The physico-chemical changes in the waste as a consequence of mechanochemical activation had a pronounced influence on the subsequent gold extraction.

IOP Conference Series: Earth and Environmental Science, 2020

The deficiency of primary raw materials and the difficult processing of sulphide concentrates wit... more The deficiency of primary raw materials and the difficult processing of sulphide concentrates with low gold content, as well as the long-time use of the dangerous cyanide method, instigated to the search a more effective and environmentally conscious method of acquirement this noble metal. For this reason, this work was focused on gold obtaining from a refractory sulphide complex concentrate (Pezinok, Slovakia) with the application of the non-cyanide mechanochemico-biological process. Gold in this complex concentrate occurs physically enclosed in the intercrystalline space of sulphide minerals, and is also isomorphic and fills structure defects in sulphides. The exclusion of gold from such complex mineral matrices of the concentrate can be achieved by using a mechanochemico-biological process. This innovative process makes possible obtaining of gold using an application of a thiourea solution, which is a convenient alternative opposite to the toxic cyanidation method. The utilized o...

The intensification of the gold thiourea leaching from a filtration waste (Kosice, Slovakia) usin... more The intensification of the gold thiourea leaching from a filtration waste (Kosice, Slovakia) using mechanical activation as the pretreatment step has been studied. The leaching of “as-received“ sample in an acid thiourea solution resulted in 65 % Au dissolution. However, after mechanical activation in a planetary mill 99 % of the gold was leached. The optimum redox potential for electrolysis is in the range 500-523 mV for the gold extraction 99.79 % from the mechanically activated sample. The mechanical activation resulted in an increase of the specific surface area of the waste from 0.7 m 2 g -1 to a maximum value of 13.5 m 2 g -1 . The physicochemical changes in the filtration waste as a consequence of mechanical activation had a pronounced influence on the subsequent gold extraction.

Chemicke Listy, 2011

The electrolyser for obtaining metallic Au from Au waste used a porous carbon-felt cathode. Its h... more The electrolyser for obtaining metallic Au from Au waste used a porous carbon-felt cathode. Its high surface area, high mass transfer and uniform potential distribution in the cathode allow for efficient processing of solutions with very low Au concentrations (2 g l-1).

Global Journal of Science Frontier Research, 2021

The difficult and predominantly toxic processing of sulphide concentrates with a low gold content... more The difficult and predominantly toxic processing of sulphide concentrates with a low gold content has prompted the finding of a more efficient and environmentally friendly method of obtaining this noble metal. This work was therefore focused on the recovery of gold from the concentrate of refractory sulphide complex (Banská Hodruša, Slovakia) using a non-cyanide mechanochemico-biological process. Gold in this complex concentrate is physically located in the intercrystalline space of sulfide minerals and fills in structural defects in sulfides. The precipitation of gold from the complex mineral matrices of the concentrate can be achieved using a mechanochemico-biological process. This innovative process makes it possible to recover gold by applying a thiourea solution, which is a preferred alternative to toxic a cyanidation. The use of a biological process with the application of algae has shown that algae with siliceous structures make it possible to obtain gold from a complex conce...

Acta Montanistica Slovaca, 2012

The intensification of the thiourea leaching of gold from goldsmith's waste (Košice, Slovakia... more The intensification of the thiourea leaching of gold from goldsmith's waste (Košice, Slovakia) using mechanical activation as the pretreatment step. The leaching of “as-received“ sample in an acid thiourea solution resulted in 77 % Au dissolution, after mechanical activation 98 % of the gold was leached during 120 min. The activation was performed in an attritor using variable milling times. The physico-chemical changes in the waste as a consequence of mechanical activation had a pronounced influence on the subsequent gold extraction. Maximum recovery of gold was reached behind 60 minutes at optimum conditions of electrolysis.

Spôsob spracovania zlatníckych a elektronických Au-Ag odpadov Veľké množstvá odpadov z elektrický... more Spôsob spracovania zlatníckych a elektronických Au-Ag odpadov Veľké množstvá odpadov z elektrických a elektronických zariadení sa hromadia v celej Európe. Každý spotrebiteľ vyprodukuje priemerne 16 kg tohto odpadu za rok, čo v Európe predstavuje celkovo šesť miliónov ton za rok. Ide o obrovské plytvanie zdrojmi. Znamená to taktiež veľké ekologické nebezpečenstvo, keďže elektrické spotrebiče a elektronické zariadenia obsahujú vysoko toxické ťažké kovy a organické znečisťujúce látky. Podľa nových predpisov EÚ budú musieť výrobcovia odteraz platiť za zber a likvidáciu týchto výrobkov. Odpady ušľachtilých kovov Au-Ag predstavujú širokú škálu typov a foriem odpadov s rôznymi balastnými prvkami aj zložkami. Problematika spracovania odpadov s obsahom Au a Ag je vysoko aktuálnou v celosvetovom meradle z hľadiska hodnoty a špecifických vlastností týchto kovov ako aj ich nenahraditeľnosti v oblasti bankovníctva, zdravotníctva, priemyslu a v neposlednom rade aj v samotnej výrobe a predaji zlatníckych výrobkov. Predkladaný návrh možnosti spracovania Au-Ag zlatníckych a elektronických odpadov si kladie za cieľ získať zlato a striebro v kovovej forme. Aplikácia navrhovaného procesu spracovania uvedených Au-Ag odpadov predstavuje pre spoločnosť praktický, ekonomický a zároveň ekologický význam pri ich spracovávaní. Získavanie zlata, resp. striebra z Au-Ag odpadov je mimoriadne dôležité v podmienkach inflačného vývoja, kedy tieto ušľachtilé kovy sú stabilným zdrojom pokrývania potrieb spoločnosti.

Acta Montanistica Slovaca

Au-Ag noble metal wastes represent a wide range of waste types and forms, with various accompanyi... more Au-Ag noble metal wastes represent a wide range of waste types and forms, with various accompanying metallic elements. The presented leaching strategy for Au-Ag contained in circuit boards (PCBs) aims at gaining gold and silver in the metallic form. Application of the proposed ammonium thiosulphate leaching process for the treatment of the above mentioned Au-Ag containing wastes represents a practical, economic and at the same time an ecological solution. The ammonium thiosulphate based leaching of gold and silver from PCBs waste, using crushing as a pretreatment, was investigated. It was possible to achieve 98 % gold and 93 % silver recovery within 48 hours of ammonium thiosulphate leaching. This type of leaching is a better leaching procedure for recovery of gold and silver from PCB waste than the classical toxic cyanide leaching. 84

ChemInform, 2006

ABSTRACT For Abstract see ChemInform Abstract in Full Text.

The Open Chemical Engineering Journal, 2008

Au-Ag noble metal wastes represent a wide range of waste types and forms with various ballast ele... more Au-Ag noble metal wastes represent a wide range of waste types and forms with various ballast elements and components. The thiourea process of gold and silver extraction from ores, concentrates or secondary raw materials consists of gold and silver leaching into the thiourea solution and the consequent precipitation of these metals from the solution. Due to the non-toxic character of thiourea it is the perspective alternative to the up to now most frequently used cyanide method. The thiourea leaching of gold and silver from electronic waste, goldsmith’s waste and ceramic waste using crushing as the pretreatment step was investigated. For electronic waste, it was possible to achieve 97 % gold and 94 % silver recovery within 120 minutes of thiourea leaching. Up to 98 % of gold and 96 % of silver were recovered from goldsmith’s waste after 60 minutes of leaching. In the case of ceramic waste, we achieved up to 98 % gold and 97 % silver extraction efficiency after only 45 minutes of lea...

Mineral Processing and Extractive Metallurgy, 2012

The hydrometallurgical processing of complex concentrates represents an ecologically attractive a... more The hydrometallurgical processing of complex concentrates represents an ecologically attractive alternative with respect to classical pyrometallurgical technologies. In this study, the aim is to investigate bismuth recovery from fine lead sulphide concentrate by using hydrochloric acid, sulphuric acid with sodium chloride and sodium thiosulphate. Experimental studies were carried out on the sulphide sample from Atacocha (Peru) deposit, which contains 1?3% bismuth. Only 38% of bismuth was recovered from the 'as received' concentrate in 60 min. Mechanical activation proved to be an appropriate pretreatment for this concentrate before extraction of bismuth into solutions. The physicochemical changes in the complex sulphide concentrate due to mechanical activation have an influence on the increase in the recovery of bismuth for subsequently thiosulphate leaching. It was possible to achieve y99% bismuth recovery within 3 min for a sample mechanically activated. Thiosulphate leaching is an advantageous leaching reagent for selective and notable kinetic.

leaching reagents. The leaching of the concentrate with ferric chloride solution afforded 23 % re... more leaching reagents. The leaching of the concentrate with ferric chloride solution afforded 23 % recovery of Cu, 99 % of Pb and 28 % of Zn. 9 % recovery of Cu, 17 % of Pb and 3 % of Zn were achieved by the leaching with thiourea. Thus results showed that the extraction of Cu, Zn and also Pb in the case of thiourea leaching was low. The use of milling in the attritor as an innovation method of pretreatment leads to the structural degradation and increasing the surface area of the investigated concentrate from the original value of 0.18 m 2 g -1 to the maximum value of 4.67 m 2 g -1 . This fact manifested itself in the subsequent process of extraction of Cu, Pb and Zn into the chloride and thiourea solutions. Our results indicate more effective leaching of pretreated concentrate in the chloride medium with recoveries of 84 % Zn and 100 % Pb. In thiourea, the recoveries for Zn and Pb were low, however 99 % Cu can be recovered. In regard to the economy, the extraction of Cu, Pb and Zn was...

Mineral Processing and Extractive Metallurgy, 2013

Thiosulphate leaching agent for silver is an alternative to cyanide leaching for certain types of... more Thiosulphate leaching agent for silver is an alternative to cyanide leaching for certain types of refractory ores or secondary sources of the metal. Cementation of silver onto mechanically activated zinc powder after leaching is the most used method of the recovery of silver. The thiosulphate leaching of X-ray photos and cementation of silver by zinc from the solution are described in this paper. Application of cementation methods of processing silver from waste solutions represents economic as well as ecological importance for the whole society.

Transactions of Nonferrous Metals Society of China, 2011

The use of mechanical activation to enhance gold recovery from a CuPbZn complex sulfide concentra... more The use of mechanical activation to enhance gold recovery from a CuPbZn complex sulfide concentrate was investigated. The effects of milling time, ball size, sample to ball ratio and milling speed on thiosulfate leaching were studied. Under optimum conditions of milling time 1 h, ball size 20 mm, sample to ball ratio 1/15 and mill speed 600 r/min, nearly 78% of sample is amorphized, particle size decreases from d 100 =30 µm to d 100 =8 µm, specific surface area increases from 1.3 m 2 /g to 4.6 m 2 /g and gold recovery enhances from 17.4 % in non-activated sample to 73.26 %.