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One of the main uses of catalysts in the oil industry is in the fluidized catalytic cracking process, which generates large quantities of waste material after use and regeneration cycles and that can be treated by the electrokinetic remediation technique, in which the contaminant metals are transported by migration. In this study, deactivated FCC catalyst was characterized before and after the electrokinetic remediation process to evaluate the amount of metal removed, and assess structural modifications, in order to indicate a possible use as an adsorbent material. The analyses included pH measurement and the concentration profile of vanadium ions along the reactor, X-ray microtomography, X-ray fluorescence, BET analysis and DTA analysis. The results indicated that 40% of the surface area of the material was recovered in relation to the disabled material, showing an increase in the available area for the adsorption. The remediation process removed nearly 31% of the vanadium and 72% of the P2O5 adhering to the surface of the catalyst, without causing structural or thermal stability changes.

This work focused on the applicability and viability analysis of oil-contaminated diatomite waste and other two industrial residues (galvanic sludge and glass waste materials) in red ceramic fabrication. Red ceramic samples were produced varying the amount of waste materials. Diatomite content, galvanic sludge, and glass wastes in new materials ranged from 25% to 35%, 20% to 25%, and 5% to 20%, respectively. Natural clay was present by 30%. Mixtures of initial components were hydrated, compacted, dried and baked with different temperatures (950 °C, 1000 °C, 1050 °C, and 1100 °C) during 6 h. The materials were analyzed by Scanning Electronic Microscopy (SEM), Electron Dispersive Spectroscopy (EDS), X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD) techniques. Red ceramic samples were subjected to flexion resistance tests. High resistance, low dilatation values, water absorption, solubility and leaching of heavy metals could be observed in the obtained ceramic samples. Those outcomes can be explained by melting of some crystal structures of raw components (completely of Illite and partly of Quartz) and partial transition to amorphous glassy formations, well visible by SEM micrographs. The developed materials can be highly economically attractive because of the utilization of industrial wastes to produce construction materials. The wide-scale use of the method can be environmentally effective.

The current trend for processing more aggressive crude oils has resulted in a considerable increase of corrosion and hydrogen damage at Fluid Catalytic Cracking Units in Brazil. Therefore, it was proposed a new method for on-line and real time corrosion monitoring: evaluation of the integrity of the iron sulfide film by the voltammetric technique. This methodology would allow one to detect and inhibit the destruction of the sulfide layer by cyanide ions before a significant amount of hydrogen is generated and permeates the steel. Therefore, the lifetime of industrial equipment would be considerably improved. The feasibility of the proposed methodology was validated through bench scale tests.

The aim of this study was to apply Central Composite experimental design in the removal of lead and nickel ions from sand by electrokinetic remediation. Sand was used for an initial study since it is inert, thus making it possible to analyze the parameters influencing the process. Central Composite Design was used to create an experimental program to provide data to model the effects of various factors on removal efficiency. The variables chosen were ion concentration (C), applied potential (E) and time (t). The mathematical relationship between removal efficiency and three significant independent variables can be approximated by a second-order quadratic model. Response Surface Methodology (RSM) was used to describe the individual and interactive effects of three variables at five levels, combined according to a Central Composite Design. This study has shown that Central Composite Design can be applied to the removal of lead and nickel ions from sand, and it is an economical way of obtaining the maximum amount of information with the fewest experiments.

Recycling of automotive batteries for the recovery of secondary lead is extremely important in Brazil, for the country does not possess large reserves of this metal. Lead is one of the most widely used metals in the world, but it is highly toxic, posing risks for humans and for the environment if not utilized or treated adequately. Industrial waste containing lead in Brazil are classified by the Brazilian Residue Code (NBR—10004:2004) as hazardous. The lead recycling process employed by the recycling industry in Brazil is the pyrometallurgical process in a rotary furnace. This process consists of four stages: (1) grinding of the battery to separate plastic, electrolyte and lead plates; (2) lead reduction in a rotary furnace; (3) separation of metallic lead from slag; and (4) refining of recycled lead. The purpose of this work is to propose process improvements aimed primarily at increasing production output by reducing the loss of lead in slag and particulates, thereby providing a healthier work environment in line with Brazilian environmental and labor laws.

The aim of this work is to study an electrochemical reactor using metallic particles as cathode for lead, copper and nickel ions recovery from acidified aqueous solutions for different process parameters as metallic ion concentration, current density and bed expansion. The reactor performance was evaluated considering the system efficiency and energy consumption. Taguchi method was selected as the statistical technique since it allows the main effects to be estimated with a minimum number of experimental runs. Moreover, it makes use of fractional factorial and orthogonal arrays to identify the factors, which present the greatest influence on the system, and the optimum factor setting for each experiment run. The highest current efficiency obtained were 75.8%, 89.9% and 30.3% for lead, copper and nickel, respectively.

The objective of this work was to study the recovery of lead ion using a fluidized bed electrode to simulate an industrial effluent. The reactor’s performance was evaluated based on dimensionless variables: voidage of the bed (e), current density (i)/limiting currents density (Ilim), transport number of lead (tPb) and transport number of support electrolyte (tNa), and their influence on current efficiency (EC) and power consumption (CE). Due to the almost total absence of mathematical models that fit the system and also due to the complexity of such models, the choice fell upon a statistical technique, the central composite design (CCD), to obtain the desired responses as empirical functions. Response surfaces were then plotted to identify the behavior of current efficiency and power consumption when the values of variables dimensionless were changed. © 2004 Elsevier B.V. All rights reserved.

One of the biggest problems with ore processing in extractive metallurgical industries is the high toxicity of the heavy metals waste content (e.g., copper, lead, nickel and chrome). This work investigates the copper (II) íons removal from aqueous solutions in concentrations up to 1000 ppm. Therefore, a fluidized bed electrolytic reactor was used with flow-by configuration considered as a hopeful method due to the large specific surface area and the high mass transfer rate. The performance of the electrochemical reactor was investigated by using different porosities. Dimensionless Sherwood and Reynolds numbers were correlated to characterize the mass transport properties of the reactor, and they were fitted to the equation Sh = a.Reb.Sc1/3.