This study explores both pyrometallurgical and hydrometallurgical methods for decarbonizing recovering valuable metals from bauxite residue, with hydrogen plasma reduction direct acid leaching as the primary approaches. The goal is to offer innovative techniques extracting a by-product of Bayer process, which cannot be disposed in an environmentally sustainable manner. Additionally, reducing volume residue through combined treatments key objective. In contrast traditional carbon-based...

Red mud is a by-product of alumina production, which largely stored in landfills that can endanger the environment. mud, or bauxite residue, mixture inorganic compounds iron, aluminum, sodium, titanium, calcium and silicon mostly, as well large number rare earth elements small quantities. Although certain methods using red already exist, none them have been widely implemented on scale. This paper proposes combination two for utilization first by carbothermic reduction then, leaching under...

Abstract In this work, the influence of process parameters (temperature: 25 - 65 °C, ethanol content in extraction solvent: 30 90 vol.%, and solid-to-solvent ratio: 1:15 1:45 w/v) on ultrasound-assisted (UAE) (poly)phenols from blueberry leaves ( Vaccinium myrtillus ) was investigated. Statistical analysis performed using MINITAB 21 software, with application three-level full factorial designs. The Responses study are total (poly)phenols, flavonoids anthocyanins obtained extracts. leaf...

The present paper aims to discover the optimal conditions for ultrasound-assisted extraction (UAE) of (poly)phenolic chemicals from blueberry (Vaccinium Myrtillus) leaves. UAE was performed under following process conditions: temperature: 25 - 65 ?C, ethanol concentration in solvent: 30 90 vol.%, and solid-to-solvent ratio: 1:15 1:45 w/v. Statistical analysis using Design-Expert software, Box-Behnken design. study's Responses were content total (poly)phenols, flavonoids, anthocyanins derived...

Mesoporous silica particles were prepared from highly basic sodium silicate solutions, having different modulus and SiO2 concentrations, by adding sulphuric acid at temperatures. Pore structure of (aggregates) is strongly influenced processing conditions easy controllable in broad range the specific surface area, pore size, volume size distribution. It shown that there a clear correlation between absorbed oil parameters used preparation aggregates. Thus, absorption higher samples solution...

Abstract The aim of this research was to determine the influence SiO 2 /Al O 3 molar ratio on specific commercial properties NaA zeolite subtypes as final market products (4A,4A-AG and 4A-MS) under real production process conditions. value ratio, so-called silicate module, set independently variable effect physical chemical each zeolites examined. paper investigates how affects powders, namely ion exchange capacity, oil adsorption capacity water capacity. Some previous theoretical...

This paper presents the results of a survey carried out in 89 operating objects with food (restaurants, fast restaurants, distribution centers, stores, etc.) Bosnia and Herzegovina. The questions that employees have been asked (owners, managers, workers) were related to good hygiene practices, manufacturing practices HACCP principles, general knowledge about production preparation food. covered 520 people. Displayed level requires actions taking series measures improve it. best quickest will...

This study presents a comparative analysis of titanium leaching from tionite (a byproduct the dioxide production process) and carbothermally reduced red mud (derived aluminum residues). Tionites sulfate process residue are known for their environmental impacts due to metal content acidic/basic nature. explored as method recover other metals under high-pressure high-temperature conditions using sulfuric acid. Experiments were conducted in an autoclave with different parameter changes, like...

<p>Zeolite 13X is one of the best adsorbents among zeolites and most commercially available zeolites.  This paper investigates influence several process parameters on properties zeolite, including crystallization temperature, duration Si/Al molar ratio in starting reaction mixture. The quality obtained powders was examined detail through a series analytical instrumental methods, presented paper. Water CO<sub>2</sub> adsorption capacities...

Submicron and nanosized powders have gained significant attention in recent decades due to their broad applicability various fields. This work focuses on ultrasonic spray pyrolysis, an efficient flexible method that employs aerosol process synthesize titanium-based nanoparticles by transforming titanium oxy-sulfate. Various parameters are monitored better optimize the obtain results. Taking into account, influence of temperature transformation oxy-sulfate was between 700 1000 °C. In addition...

Red mud, byproduct of the aluminum industry, poses a significant environmental problem due to its chemical composition and large quantities generated. This study explores potential for valorization through multi-step process that includes reduction, leaching with acid solution, purification, ultrasonic spray pyrolysis (USP). In first step, red mud undergoes carbothermal during which metal oxides are transformed into phase slag. second slag is subjected under various conditions, including...

This paper presents research on hydrodynamics and mass transfer in a packed absorption column. Experimental data dry column pressure drop, flooding point, efficiency of CO2 water is obtained lab-scale with Raschig rings. Auxiliary parts equipment together chemical analyses provide simple monitoring collecting the data. All were used to test different mathematical models for given problem, i.e. determination point overall gas unit height. For developed primarily columns described best, Billet...

The influence of process parameters in the three-stage purification aluminate solution from Bayer and aluminum hydroxide was considered this paper. One ways is treating order to reduce concentrations starting raw material (solution) then at a certain temperature time obtain an alumina precursor adequate quality. itself divided into three phases. first phase involves treatment sodium with lime primarily remove Ca2+ (SiO3)2− impurities. Phase II aims impurities Zn2+, Fe2+, Cu2+ by controlled...

In a semi-ideal gas, entropy changes cannot be determined through the medium specific heat capacity in manner as by change of internal energy and enthalpy, i.e. amount exchanged. Taking this into account, authors conducted two models which it is possible to determine gas for arbitrary temperature interval using spread sheet method, mean values appropriate functions. The idea replace integration, occurs here evitably, with previous are derived based on functional dependence actual...

In this paper, for characteristic polytropic change of state ideal gas is given graphical planimetric representation the most important energy values in workplace and thermal diagram, trough appropriate area. we used differential forms First Second law thermodynamics basic equation which define observed state, written a suitable form. The results are applied to isobaric isochoric state. It shown that any ( q12, w12, wt12, Δh12, Δu12) can be present both (p, v) as well (T-s) diagram....

Starting from the fact that problem of loss technical work exit gases in a boiler stack involves state thermodynamic imbalance, this paper gives derivation suitable analytic relation for determining maximum work, or exergy, which is equivalent to lost gases. This serves as basis solving process confirms premiss problem. In order observe its full range, involved was represented both p-v diagram, heat T-s well an h-s diagram. The exergy function analysis conducted according most influential...

It is known that the temperature of crystallization during synthesis zeolite one most important process parameters. However, research work on 13X and introduction this material into regular industrial production, it was noticed heating rate starting reaction suspension can have an equally influence. This influence be so pronounced a difference just few minutes in reaching make significant product quality, affect presence other phases crystal, or even determine direction crystallization....

<p>In this paper, the influence of process parameters on morphological properties fine precipitated hydrate was examined. The research conducted with aim synthesizing aluminum hydroxide from aluminate solution obtained by Bayer process. Fine hydrates in way are mostly used non-metallurgical industry. synthesized should comply certain quality requirements such as granulometry (average particle diameter), purity, specific surface area, whiteness, etc. This paper shows...