Wyniki wyszukiwania - BazTech

1

The valorization of flotation tailings in terms of the concept of the circular economy: characterization, environmental risk assessment, and waste utilization routes

Mikoda Bartosz, Potysz Anna, Siepak Marcin, Kmiecik Ewa

Geology, Geophysics and Environment

|

2024

|

Vol. 50, no. 4

401--420

EN

Flotation tailings originating from copper ore processing were evaluated in terms of chemical and mineralogical features, leaching, and resource potential. The results demonstrated that flotation tailings show varying degrees of the leachability of elements when exposed to different pH conditions (2–13); the Zn, Cu and Co leachabilities decrease as pH increases, whereas Mo, Ag and Sb revealed U-shaped leaching trend as a function of pH. Flotation tailings were found to be fairly reactive when exposed to water leaching and rainfall conditions. The environmental risk analysis demonstrated Zn to be the most susceptible element to liberation from the flotation tailings studied. Recovery tests demonstrated sulfuric acid to be slightly more efficient extracting agent as compared to citric acid. Hybrid approach to metal recovery was rather unsuitable for studied tailings due to lower extraction yield (not exceeding 20%) as compared to chemical treatment (not exceeding 40%).

2

Bioleaching using Acidithiobacillus Thiooxidans – an option for element recovery from highly alkaline waste incineration ash?

Kasina Monika, Jarosz Kinga, Salamon Klaudiusz, Wierzbicki Adam, Mikoda Bartosz, Michalik Marek

Gospodarka Surowcami Mineralnymi

|

2022

|

T. 38, z. 3

105--120

EN

Bioleaching research considers both the bio- and anthroposphere in the search for novel ways to recover resources and elements, which is important to the concept of sustainable development. Since the efficient, cost-effective and simple recovery of resources is of increasing importance in the circular economy model, the bioleaching of metals is a method currently gaining interest. The process is also of importance considering the need for the neutralization of waste materials/resources that allow for their safe storage and use. In this study, Acidithiobacillus thiooxidans bacteria, which is commonly found and widely utilized in the bioleaching process due to its high tolerance to heavy metals, was used in a twenty-eight-day experiment. The manner in which bacteria inhabit incineration residues was observed using fluorescence optical microscopy and scanning electron microscopy. The concentration of elements in incineration residues and in the post-reaction solutions was measured using inductively coupled plasma mass spectrometry and the efficiency of element recovery was calculated based on the results. Municipal waste incineration bottom ash and sewage sludge incineration fly ash were considered in the experiment. The extraction rates were far from satisfactory, with the average 20 and 50% for bottom ash and sewage sludge ash, respectively. The obtained results were consistent with microscopic observations where the relative number of bacteria increased only slightly over time in the sewage-sludge fly ash and was barely observed in the bottom ash of municipal-waste incineration.

PL

Badania procesów bioługowania to analiza przenikania się bio- i antroposfery, w poszukiwaniu nowych sposobów na odzyskiwanie zasobów i pierwiastków. Granica tych sfer ma duży potencjał dla wdrażania modelu zrównoważonego rozwoju. Ze względu na fakt, że efektywne, tanie oraz proste metody odzyskiwania surowców mają rosnące znaczenie w gospodarce o obiegu zamkniętym, bioługowanie metali jest metodą, która obecnie cieszy się coraz większym zainteresowaniem. Jest to również proces istotny w kontekście neutralizacji surowców odpadowych umożliwiającej ich bezpieczne magazynowania i zastosowanie. W przeprowadzonym badaniu powszechnie występujące bakterie Acidithiobacillus thiooxidans, które są często używane w procesach bioługowania ze względu na fakt ich wysokiej tolerancji na metale ciężkie, zostały wykorzystane w 28-dniowym eksperymencie. Sposób i zmienność w czasie, w jaki bakterie zasiedlają osad po spalaniu, został zaobserwowany przy pomocy fluorescencyjnej mikroskopii optycznej i skaningowej mikroskopii elektronowej. Stężenie pierwiastków w osadach po spalaniu i w poreakcyjnych roztworach zostało zmierzone przy użyciu indukcyjnie sparowanej plazmowej spektrometrii mas, a efektywność odzyskiwania pierwiastków została obliczona na podstawie uzyskanych wyników. Popioły po spalaniu odpadów komunalnych oraz popioły lotne ze spalania osadów ściekowych zostały ujęte w eksperymencie. Stosunki ekstrakcji pierwiastków były dalekie od zadowalających ze średnią 20 oraz 50% dla popiołów po spalaniu odpadów komunalnych oraz popiołu z osadów ściekowych. Pozyskane wyniki są w zgodzie z obserwacjami dokonanymi przy pomocy mikroskopii, gdzie relatywna liczba bakterii wzrosła niewiele we wspomnianym czasie w przypadku popiołów ściekowych i była w zasadzie niedostrzegalna w przypadku popiołów dennych.

3

Vanadium removal from spent sulfuric acid plant catalyst using citric acid and Acidithiobacillus thiooxidans

Mikoda Bartosz, Potysz Anna, Kucha Harry, Kmiecik Ewa

Archives of Civil and Mechanical Engineering

|

2020

|

Vol. 20, no. 4

514--527

EN

Spent catalysts being considered hazardous wastes exhibit a high metal content in mobile forms. In addition, growing demand for circular economy policy applications requires proper utilization of these wastes. This study aimed at the assessment of vanadium leaching from spent desulfurization catalyst derived from sulfuric acid plant dump located nearby a copper smelter. Chemical and phase composition of the catalyst has been characterized. The extraction has been performed using chemical (0.1-M and 1-M citric acid) and biological (biotic solution with Acidithiobacillus thiooxidans) methods, using different experimental parameters (pulp density, particle size, leaching time) to observe V leaching behavior and kinetics. The results revealed that both citric acid and bacteria carried out the extraction process well. The optimal parameters for acid leaching were < 0.2-mm particle size and 2% pulp density, which allowed to leach out 95% of V from spent catalyst within 48 h. The bacterially mediated extraction resulted in 93% V leached out within 21 days with 2% pulp density. The experiments showed that V present in the catalyst is susceptible to bioleaching and organic acid leaching with the latter being a quicker process.