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PROCESSING OF SPENT ULTRA-DEEP HYDRODESULFURIZATION CATALYSTS. This work discusses the recycling of spent NiMo/Al2O3 catalysts from ultra-deep hydrodesulfurization (HDS) units. They contain a refractory coke and fouling elements from the processed feedstocks. Samples were preoxidized (600 ºC) for 12 h using a very slow heating rate to eliminate coke and volatiles. Experiments were performed in the presence of HF + H2O2 mixtures under stirring at 25-60oC for 1-4 h. The amount of insoluble matter was the lowest (< 1 wt.% of the initial mass) after leaching for 2 h at 60oC using an excess of 50 vol.% HF and 20 vol.% H2O2. Leached molybdenum and vanadium were extracted together with Alamine 304 (tri-dodecylamine) in n-heptane at pH below 2. Aluminum and iron were precipitated from the raffinate as Na3AℓF6 (+ Na3FeF6) by adjusting pH at ~4 using 6 mol L-1 NaOH. Nickel was either recovered by solvent extraction using D2EHPA (bis-(2-ethylhexyl)phosphoric acid) in n-heptane at pH 6 or precipitated at pH 8 using 6 mol L-1 NaOH. The first method proved better as less contaminants were present. After slow evaporation of the final aqueous solution, a mixture of Na2SiF6 and NaF was recovered. Fluoride losses were very low (~0.10 wt.%).

https://doi.org/10.21577/0100-4042.20170800

Evidence of lead ions on palygorskite surface after adsorptive process: kinetic and isotherms studies process
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Simões, Karla Mayara Arguelles

; Novo, Bruna de Lemos

; Marçano, Giullia Bertrand

; Silva, Fernanda Arruda Nogueira Gomes da

; Teixeira, Viviane Gomes

; Afonso, Julio Carlos

; Bertolino, Luiz Carlos

; Yokoyama, Lidia

Matéria (Rio de Janeiro)

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2022, Volume 27 Nº 2 elocation e13224

Resumo: En | Texto: En | PDF: En

ABSTRACT Our previous work reported that palygorskite has potential for application as metal cations adsorbent due to its chemical and mineralogical properties. In this work, kinetic study and adsorption isotherms were performed in order to evaluate Pb (II) ions adsorption rate, maximum capacity and type of adsorption by using palygorskite as adsorbent. Adsorption tests were performed in batch, using pH of 5, 2 g of palygorskite, 40 mL of synthetic effluent solution and stirring for 1 hour. Kinetic experiments were performed using 34 mg L-1 of a lead synthetic effluent at same mass and pH conditions. Furthermore, after adsorption studies, the sample was characterized by X-ray fluorecence (XRF), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDS) analysis, in order to verify and understand the interaction of lead ions in palygorskite. The results demonstrated that palygorskite presented an equilibrium time of 10 min with 99.14% of removal, following pseudo-second order kinetic. The maximum adsorption capacity was 21.65 mg g-1 and Gibbs’ adsorption-free energy was -21.39 KJ mol-1, with Langmuir model being the most suitable for adjustment of the data. Thus, its presence was confirmed by characterization techniques, indicating that the metal is distributed homogeneously on palygorskite surface, proving its efficiency as lead ions adsorbent. properties II (II rate batch 5 4 hour 3 L1 L L- conditions Furthermore studies Xray X ray XRF, XRF , (XRF) FTIR (FTIR SEM (SEM Energydispersive Energy dispersive EDS (EDS analysis 9914 99 14 99.14 removal pseudosecond pseudo second 2165 21 65 21.6 g1 g- Gibbs adsorptionfree free 21.39 2139 39 -21.3 mol1, mol1 mol 1, mol-1 data Thus techniques surface (XRF 991 9 99.1 216 6 21. 21.3 213 -21. mol- 99. -21 -2 -

https://doi.org/10.1590/s1517-707620220002.1324

PROCESSING OF A METAL CONCENTRATE FROM GROUND WASTE PRINTED CIRCUIT BOARDS IN ACIDIC MEDIA USING HYDROGEN PEROXIDE AS OXIDANT
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Silva, Calvin Sampaio Moreira da

; Zeba, Guido Tande Crespo

; Rocha, Christiano Mota Rodrigues da

; Gismonti, Pedro Rosário

; Afonso, Júlio Carlos

; Silva, Rubens Souza da

; Vianna, Cláudio Augusto

; Mantovano, José Luiz

Química Nova

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Jul 2020, Volume 43 Nº 7 Páginas 914 - 922

Resumo: En | Texto: En | PDF: En

The recovery of precious and base metals of a metal concentrate from ground waste printed circuit boards (PCBs) is described in detail. Samples were treated with NaOHaq. to remove the soldering mask. Experiments were performed in acidic medium (HF, H2SO4, CH3COOH or H3PO4) using H2O2 as oxidant. Base metals were leached in high yields (>99 wt.%) at ~40 ºC after ~1 h (HF), ~2 h (H2SO4), ~4 h (H3PO4) and ~5 h (CH3COOH). Lead precipitated in the presence of H2SO4 and HF. Precious metals were not oxidized. Ceramic/fiberglass components were dissolved in the presence of HF. Silver, palladium and gold were recovered from the insoluble solid, in this order, by a sequential oxidative treatment in aqueous medium. Recovery of leached elements was possible by a combination of solvent extraction and precipitation. The choice of the extractant and the precipitant were essential to recover them with high yields. The leachates from H3PO4 + H2O2 experiments could not be processed above pH 2.5. Leaching of waste PCBs in the presence of a weak organic acid is possible but a multistage separation scheme for elements recovery is unavoidable as PCBs is a complex material in terms of composition.

https://doi.org/10.21577/0100-4042.20170575 410 downloads

MANGANÊS NO BRASIL: DESCOBERTA, EXTRAÇÃO, CONSUMO E COMERCIALIZAÇÃO NUMA PERSPECTIVA HISTÓRICA
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Afonso, Júlio Carlos

Química Nova

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Out 2019, Volume 42 Nº 10 Páginas 1172 - 1183

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

This work describes the occurrence and the economic importance of manganese in Brazil, covering a period of almost 130 years. After the gold cycle, manganese ores became the most important mineral commodity of Brazil’s export agenda until 1945. Brazil has one of the largest world reserves and has been among the world’s largest producers of manganese ore for over a century. The influence of international scenario on the manganese market affected its trade balance throughout the twentieth century. The Brazilian manganese ore production was strongly stimulated by external events (such as the I and II World Wars) and the development of the US and the European steel industries in the early XXth century. However, internal consumption increased as the Brazilian steel industry developed. The chief use of manganese in Brazil and in the world is in the steel production. Nonmetallurgical uses include battery cathodes, fertilizers, animal feed, water treatment, analytical chemistry (permanganometry), pigments, cosmetics and glasses. The perspectives for manganese in Brazil in the future are encouraging, but it is necessary to search for new deposits and develop processing of tailings and low grade ores.

https://doi.org/10.21577/0100-4042.20170435 14489 downloads

Incidence rates and temporal trends of cervical cancer relating to opportunistic screening in two developed metropolitan regions of Brazil: a population-based cohort study
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Teixeira, Júlio César

; Maestri, Carlos Afonso

; Machado, Helymar da Costa

; Zeferino, Luiz Carlos

; Carvalho, Newton Sérgio de

Sao Paulo Medical Journal

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Jul 2019, Volume 137 Nº 4 Páginas 322 - 328

Resumo: En | Texto: En | PDF: En

ABSTRACT BACKGROUND: Brazilian opportunistic screening programs for cervical cancer have limited impact. In the regions of two cities (Campinas and Curitiba) with high human development indices, consistent information from 96-97% of all cervical cancer cases managed within the public healthcare system is available. OBJECTIVE: To estimate the incidence rate (IR) and temporal trends in these regions, covering 2001-2012. DESIGN AND SETTING: A population-based cohort study was conducted under the assumption that all cervical cancer cases were managed in cancer referral center hospitals. METHODS: 3,364 records (1,646 from Campinas; 1,718 from Curitiba) were analyzed to provide estimates of IR, age-standardized IR (ASR) and cervical cancer trends (shown per 100,000 women/year). Longitudinal patterns were analyzed using linear regression and shown as annual percentage change (APC); P < 0.05 for significance. RESULTS: Annual IR and ASR estimates for cervical cancer ranged from 3.8 to 8.0 over 2001-2012, decreasing over more recent years, and were similar for the two regions. The age-specific IR was about 50% lower among women aged 45 years or older (IR-2001/IR-2012: Campinas = 14.8/8.0; Curitiba = 18.7/8.3; P < 0.001). There was an increasing APC trend in Campinas among women aged 15-24 years, and a decreasing IR trend for squamous-cell histology in both regions (P < 0.05). CONCLUSION: Cervical cancer incidence estimates showed slowly decreasing trends in both regions, most evidently for women aged 45 years or older and for squamous-cell histology. These findings reflect the opportunistic nature of the population screening program, despite the comparatively high economic development level in the two regions.

https://doi.org/10.1590/1516-3180.2018.0306220719 863 downloads

CHARACTERIZATION OF SILICON-ALUMINUM-ZIRCONIUM OXIDE OBTAINED BY THE SOL-GEL PROCESS
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Silva, Cristiano Nunes da

; Siqueira Júnior, José Márcio

; Veiga, Amanda Garcez

; Muchave, Germildo Juvenal

; Aranda, Donato Alexandre Gomes

; Afonso, Júlio Carlos

; Ribeiro, Emerson Schwingel

Química Nova

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Mai 2019, Volume 42 Nº 5 Páginas 513 - 521

Resumo: En | Texto: En | PDF: En

A new silicon-aluminum-zirconium ternary oxide (SiO2/Al2O3/ZrO2) was prepared by the sol-gel method followed by one-step washing with absolute ethanol or two-step washing with absolute ethanol followed by ultra-pure water. Both ternary oxides presented high surface area (over 340 m2 g-1). The binding energy values for Zr3d and Al2p levels showed the insertion of Zr and Al atoms in silica matrix, confirming the dispersion surface of these elements as shown by scanning electron microscope (SEM) and energy dispersive X-ray fluorescence spectroscopy (EDXRF) data. A weight loss around 40 wt.% was found for both samples submitted to thermogravimetric analysis (TGA). Crystallographic data showed the presence of monoclinic and tetragonal ZrO2 phases in different proportions according to the calcination temperature. Regarding the acid-base properties, temperature-programmed desorption of CO2 (CO2-TPD) profiles suggested that washing with water reduced the overall basicity of the samples and removed the strongest basic sites. However, according to temperature-programmed desorption of NH3 (NH3-TPD) profiles, washing significantly increased the amount of weak acid sites, in agreement with pyridine adsorption data. Brønsted acid sites (BAS) are ever dominant but washing with ethanol followed by water reduced the number of Lewis acid sites (LAS).

https://doi.org/10.21577/0100-4042.20170364 1056 downloads

CHARACTERIZATION OF SEVERAL GENERATIONS OF NiMo HYDROPROCESSING CATALYSTS EMPLOYED IN THE SAME HYDROTREATER
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Pessanha, Tatiana Marques

; Quintanilha, Carolina Leão

; Silva, Cristiano Nunes da

; Afonso, Julio Carlos

Química Nova

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Abr 2019, Volume 42 Nº 4 Páginas 397 - 404

Resumo: En | Texto: En | PDF: En

This work details the chemical characterization of four NiMo/Al2O3 hydroprocessing generation catalysts (1979-1986, 1993-1998, 2003-2008 and 2008-2011) employed to perform hydrodesulfurization (HDS) of diesel fractions in the same hydrotreater of a Brazilian refinery. The basic differences are the quality of the feedstocks and the HDS experimental conditions. Samples were characterized by X-ray fluorescence, X-ray diffraction, 13C CP-MAS NMR, elemental analysis, loss of volatiles, specific surface area and average pore volume. The amount and variety of foreign elements deposited on the catalyst increased in the most recent generations due to the higher amounts of impurities in the processed feedstocks. Coke became more aromatic and loss of textural properties was more prominent in these samples as expected from the more drastic HDS conditions and the quality of the crude diesel. On the other hand, loss of volatiles was lower due to the low carbon content, partial oxidation of sulfur to sulfate species and oxidation of some elements deposited on the catalyst. Coke tended to ignite as it became more aromatic. For this reason, leaching of decoked samples from the most recent generations by sulfuric acid presented very low yields due to the formation of refractory oxides that are insoluble in the leachant.

https://doi.org/10.21577/0100-4042.20170323 712 downloads

RECOVERY OF LEAD AND NOBLE METALS AFTER PROCESSING PRINTED CIRCUIT BOARDS FROM CELL PHONES BY LEACHING WITH MIXTURES CONTAINING HYDROGEN FLUORIDE
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Silva, Walner Costa

; Corrêa, Roger de Souza

; Gismonti, Pedro Rosário

; Afonso, Júlio Carlos

; Silva, Rubens Souza da

; Vianna, Cláudio Augusto

; Mantovano, José Luiz

Química Nova

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Set 2018, Volume 41 Nº 9 Páginas 1025 - 1032

Resumo: En | Texto: En | PDF: En

This work examines the leaching of printed circuit boards (PCBs) from cell phones in aqueous solutions containing HF + H2O2 or HF + NaClO under mild experimental conditions. The PCBs were not ground but were previously treated with 6 mol L-1 NaOH at 50 ºC for 1 h to remove their soldering mask. The HF + H2O2 mixtures leached copper and base metals (except lead) at 35-40 ºC, leaving a solid residue containing lead and noble metals. Leaching was fastest (1 h) when HF and H2O2 concentrations were at least 5 mol L-1 and 3 mol L-1, respectively. The processing of the solid residue is also described in detail. It was leached with water at ~90 ºC followed by HNO3aq. at 25 ºC. Lead, palladium and silver were recovered in this order, leaving gold as final solid. After 1 h at 35-40 ºC, 5 mol L-1 HF + 0.3 mol L-1 NaClO mixtures leached the base metals, copper, gold and palladium. Gold was recovered by liquid-liquid extraction with methyl isobutyl ketone. Silver precipitated as chloride. This salt was isolated by leaching with NH3aq. Loss of fluoride ions (as HF) was below 0.5 wt.% after leaching and handling the solid residue.

https://doi.org/10.21577/0100-4042.20170267 1407 downloads

10.

SEPARATION OF ZINC FROM MANGANESE BY SOLVENT EXTRACTION FROM ACIDIC LEACHATES OF SPENT ZINC-MnO2 DRY CELLS USING NEUTRAL ORGANOPHOSPHORUS EXTRACTANTS
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Ibiapina, Vinício Francisco

; Afonso, Júlio Carlos

; Silva, Rubens Souza da

; Vianna, Cláudio Augusto

; Mantovano, José Luiz

Química Nova

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Jul 2018, Volume 41 Nº 7 Páginas 770 - 777

Resumo: En | Texto: En | PDF: En

This paper describes a route for recovering manganese and zinc from spent zinc-MnO2 dry cells via acid leaching using sulfuric or hydrochloric acids as leachants. Hydrogen peroxide was added as reductant. Experiments were run at 25-40 °C for 1-3 h. Under the best optimal conditions, over 97.5 wt.% of zinc and manganese were leached by both acids. Zn(II) was best extracted at high free acidity (≥ 1 mol L-1) with tributylphosphate (TBP) or trialkylphosphine oxides (Cyanex 923) diluted in n-heptane. Cyanex 923 was a better extractant than TBP, and the extraction was better performed in hydrochloric leachates. Mn(II) was more co-extracted from hydrochloric leachates and when Cyanex 923 was the extractant, but was easily scrubbed with dilute leachant (~1-2 mol L-1). Zn(II) striping was possible using 5 mol L-1 HCl or H2SO4. Manganese was precipitated as oxalate (MnC2O4.2H2O), free of leached contaminants. High-purity sodium salts of the anions of the leachants were recovered after slow evaporation of the final solution.

https://doi.org/10.21577/0100-4042.20170249 1322 downloads

11.

Cervical Cancer Registered in Two Developed Regions from Brazil: Upper Limit of Reachable Results from Opportunistic Screening
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Teixeira, Julio Cesar

; Maestri, Carlos Afonso

; Machado, Helymar da Costa

; Zeferino, Luiz Carlos

; Carvalho, Newton Sérgio de

Revista Brasileira de Ginecologia e Obstetrícia

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Jun 2018, Volume 40 Nº 6 Páginas 347 - 353

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Resumo Objetivo Avaliar as tendências temporais e padrão de diagnóstico de câncer de colo de útero (CCU) através de programa de rastreamento oportunístico em duas regiões brasileiras desenvolvidas, no período de 2001 a 2012. Métodos Estudo observacional com 3.364 registros de câncer (n = 1.646 da região de Campinas e n = 1.718 da região de Curitiba) obtidos de sistemas de registro hospitalar de câncer. Para a região de Campinas foram analisados 1.836 registros adicionais de CIN3/AIS. A análise estatística avaliou os dados agrupados e por região considerando o ano de diagnóstico, grupo etário, estágio de câncer e tipo histológico, e utilizou o teste de tendência Cochran-Armitage com valor p < 0,05. Resultados O total anual de CCU registrado no período de 2001 a 2012 apresentou uma ligeira queda (273 para 244), comidade média de 49,5 anos, 13 amais que a idade média (36,8 anos) para CIN3/AIS. O total de diagnósticos realizados fora da faixa etária oficial de rastreamento foi 20,6% (1,6% abaixo de 25 anos). Houve uma tendência de aumento de casos nas faixas etárias inferior a 25 anos (p = 0,007) e de 25 a 44 anos (p = 0,003) para a região de Campinas. Ambas as regiões apresentaram maior proporção diagnósticos de câncer em estágio III (43% em média), sem modificação de tendência. Houve tendência crescente para diagnóstico em estágio I na região de Campinas (p = 0,033) e da proporção de tipos histológicos glandulares em ambas regiões (p = 0,002), 21,1% para a região de Campinas e 12,5% para Curitiba. Conclusão O número, o padrão e as tendências dos casos registrados de câncer de colo de útero apresentaram modificações pequenas e lentas ao longo do tempo, reflexo da efetividade limitada do programa de rastreio oportunista, mesmo em locais desenvolvidos.

Abstract Objective The aim of this study was to assess the time trends and pattern of cervical cancer diagnosed in the period from 2001 to 2012 by means of an opportunistic screening program from two developed regions in Brazil. Methods An observational study analyzing 3,364 cancer records (n = 1,646 from Campinas and n = 1,718 from Curitiba region) available in hospital-based cancer registries was done. An additional 1,836 records of CIN3/AIS from the region of Campinas was analyzed. The statistical analysis assessed the pooled data and the data by region considering the year of diagnosis, age-group, cancer stage, and histologic type. The Cochran-Armitage trend test was applied and p-values < 0.05 were considered significant. Results The total annual cervical cancer registered from2001 to 2012 showed a slight drop (273-244), with an age average of 49.5 y, 13 years over the average for CIN3/AIS (36.8 y). A total of 20.6% of the diagnoses (1.6% under 25 y) were done out of the official screening age-range. The biennial rate of diagnoses by age group for the region of Campinas showed an increase trend for the age groups under 25 y (p = 0.007) and 25 to 44 y (p = 0.003). Stage III was the most recorded for both regions, with an annual average of 43%, without any trend modification. There was an increasing trend for stage I diagnoses in the region of Campinas (p = 0.033). The proportion of glandular histologic types registered had an increased trend over time (p = 0.002), higher for the region of Campinas (21.1% versus 12.5% for the region of Curitiba). Conclusion The number, pattern and trends of cervical cancer cases registered had mild and slow modifications and reflect the limited effectivity of the opportunistic screening program, even in developed places.

https://doi.org/10.1055/s-0038-1660841 981 downloads

12.

LIXIVIAÇÃO ÁCIDA DE BATERIAS ÍON-LÍTIO
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Silva, Rafael Gundim

; Afonso, Júlio Carlos

; Mahler, Claudio Fernando

Química Nova

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Mai 2018, Volume 41 Nº 5 Páginas 581 - 586

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

This paper describes a route for recovering cobalt and lithium from spent Li-ion batteries via acidic leaching. Sulfuric, hydrochloric, hydrofluoric and formic acids were used as leachants. Hydrogen peroxide was added as reductant, except for formic acid since it is itself a reductant. Experiments were run at 25-40 ºC for 1-3 h. Under the best optimal conditions, the leaching efficiency order was HCl ≈ HF > H2SO4 > HCOOH. Over 90 wt.% of cobalt and lithium were leached by the inorganic acids. The insoluble matter corresponds mainly to the carbon from the cathode. Co(II) was extracted with D2EHPA 16 vol.% diluted in n-hexane at pH ~5 (A/O ratio 1/1 vol/vol, one stage, 25 ºC). Co(II) striping was possible using a dilute leachant (1-2 mol L-1 HCl or H2SO4, 4-5 mol L-1 HF or HCOOH). Lithium was isolated from the raffinate by precipitation as carbonate or phosphate.

https://doi.org/10.21577/0100-4042.20170207 1875 downloads

13.

PROCESSING OF SPENT ZINC-MnO2 DRY CELLS IN VARIOUS ACIDIC MEDIA
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Ibiapina, Vinício Francisco

; Florentino, Ulysses dos Santos

; Afonso, Júlio Carlos

; Gante, Valdir

; Vianna, Cláudio Augusto

; Mantovano, José Luiz

Química Nova

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Fev 2018, Volume 41 Nº 2 Páginas 176 - 183

Resumo: En | Texto: En | PDF: En

This paper describes a route for recovering manganese and zinc from spent zinc-MnO2 dry cells via acid leaching. Sulfuric, hydrofluoric and formic acids were used as leachants. Hydrogen peroxide was added as reductant, except for formic acid since it is itself a reductant. Experiments were run at 25-40 ºC for 1-3 h. Under the best optimal conditions, over 95 wt.% of zinc and manganese were leached irrespective of the leachant. Leaching of contaminants was strongly dependent on the leachant due to the insolubility of salts or complexing reactions. Zn(II) was best extracted with D2EHPA diluted in n-heptane at pH > 1, particularly from the leachates of weak acids. Mn(II) was much more co-extracted from sulfuric leachates, but was easily scrubbed with dilute leachant (~2 mol L -1). Zn(II) striping was possible using 5 mol L -1 H2SO4. Manganese was isolated as MnO2 carrying the leached contaminants. High-purity sodium salts of the anions of the leachants were recovered after slow evaporation of the final solution.

https://doi.org/10.21577/0100-4042.20170162 1413 downloads

14.

SEPARAÇÃO SÓLIDO-LÍQUIDO: CENTRÍFUGAS E PAPÉIS DE FILTRO
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Bastos, Alexander Rangel

; Afonso, Júlio Carlos

Química Nova

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Jun 2015, Volume 38 Nº 5 Páginas 749 - 756

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

<p>This work describes the fundamentals and evolution of two current solid-liquid separation methods found in the chemical laboratory: the filter paper and the centrifuge. Both methods were developed in the 19th century and are recognized as valuable techniques for industrial and laboratory purposes. However, significant improvements were introduced only from the end of the 19th century. The classical manual centrifuge was replaced by electric models: safety, maximum speed and number of samples that can be centrifuged at a time were greatly increased. The manufacture of filter paper was initially done by hand, but later benefited from papermaking industrial technologies. Many pretreatments of the wooden fibers were developed, particularly after 1880, thus resulting in many filter paper types for qualitative and quantitative applications. These two separation techniques are also found in various procedures in our everyday life.</p>

https://doi.org/10.5935/0100-4042.20150043 19563 downloads

15.

Uma proposta inovadora de ensino de física experimental no início do Século XX
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Afonso, Júlio Carlos

; Chaves, Francisco Artur Braun

Revista Brasileira de Ensino de Física

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Mar 2015, Volume 37 Nº 1 elocation 1601

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Este trabalho analisa os três volumes da obra Problemas Práticos de Physica Elementar, de Heitor Lyra da Silva, editada entre 1916 e 1929, destinada a alunos dos então cursos regulares (primário e secundário) e profissional. Rompendo com os padrões de ensino da época, sua didática pretendia ser a mais simples e objetiva possível. O instrumental proposto foi concebido para que fosse acessível a todas as regiões do país. A metodologia de ensino é de aprendizado direto, por repetição e análise crítica dos resultados experimentais. A estrutura e a finalidade da obra se inseriam no contexto do chamado Movimento Renovador, consolidado na década de 1920, que visava uma educação individualizada que respeitasse as diferenças no desenvolvimento de cada estudante. No entanto, as ideias inovadoras da educação sob princípios liberais não conseguiram se impor às correntes conservadoras que dominavam o cenário educacional brasileiro, sendo a nova proposta didática relegada ao esquecimento.

This work analyses the book Practical Problems of Elemental Physics, written by Heitor Lyra da Silva and published between 1916 and 1929. It was written to students of the elementary and high schools, and technical courses. Unlike the current teaching methods, didactics intended to be as simple and objective as possible. The proposed instruments are of a basic conception and can be easily assembled by teachers and students anywhere in the country. The teaching method is direct learning, based on repetition of the experiments and a critical analysis of experimental data. The structure and the objective of the book show characteristics of the so called Renovation Movement, consolidated in the 1920s, whose objective was to establish an individual education, respecting the differences of the development of each student. However, the new educational ideas under liberal principles have failed to overcome the conservative currents that dominated the Brazilian educational scenario. This new didactic proposal was later abandoned.

https://doi.org/10.1590/S1806-11173711642 4181 downloads

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