Feliciane Andrade Brehm

Characterization study of electric arc furnace dust phases

Electric arc furnace dust (EAFD) is a solid waste generated in the collection of particulate material during steelmaking process in electric arc furnace. The aim of this work is to carry out a chemical and structural characterization of two EAFD samples with different Zn contents. Optical emission spectroscopy via inductively coupled plasma (ICP), X ray diffractometry (XRD) and Mossbauer spectroscopy analysis were carried out in such EAFD samples. From XRD measurements, the samples exhibits the following phases: ZnFe2O4, Fe3O4, MgFe2O4, FeCr2O4, Ca0.15Fe2.85O4, MgO, Mn3O4, SiO2 and ZnO. The phases detected by Mossbauer spectroscopy were: ZnFe2O4, Fe3O4, Ca0.15Fe2.85O4 and FeCr2O4. Magnesium ferrite (MgFe2O4), observed in the XRD patterns as overlapped peaks, was not identified in the Mossbauer spectroscopy analysis.

Review of the rice production cycle: By-products and the main applications focusing on rice husk combustion and ash recycling:

One of the consequences of industrial food production activities is the generation of high volumes of waste, whose disposal can be problematic, since it occupies large spaces, and when poorly managed can pose environmental and health risks for the population. The rice industry is an important activity and generates large quantities of waste. The main solid wastes generated in the rice production cycle include straw, husk, ash, bran and broken rice. As such, the aim of this article is to present a review of this cycle, the waste generated and the identification of opportunities to use them. Owing to impacts that can be minimised with the application of rice husk ash as a by-product, this work is focused on the recycling of the main wastes. In order to achieve that, we performed theoretical research about the rice production cycle and its wastes. The findings point to the existence of an environmentally suitable use for all wastes from the rice production cycle. As rice, bran and broken rice have their main use in the food industry, the other wastes are highly studied in order to find solutions instead of landfilling. Straw can be used for burning or animal feeding. The husk can be used for poultry farming, composting or burning. In the case of burning, it has been used as biomass to power reactors to generate thermal or electrical energy. This process generates rice husk ash, which shows potential to be used as a by-product in many different applications, but not yet consolidated.

Influence of Cellulose Pulp Waste in Plastering Mortar

The objective of the present study was to assess the properties of plastering mortar that uses cellulose pulp waste as absorbent material. Waste was characterized by thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD, and absorption of aqueous solutions with pH variations. The incorporation of 0.5%, 1% and 1.5% of waste in a plastering mortar prepared with Portland cement, lime and sand (1:1:6) was proved viable. Mortars were analyzed and compared with a control mortar. The properties of fresh mortars analyzed were: consistency index, squeeze-flow, incorporated air, water retention and density. The properties of hardened mortars analyzed were (after 28 days): tensile resistance on flexural stress, compression strength, density, absorption by capillarity and capillarity coefficient, total water absorption, void index, specific weight and linear retraction. The addition of waste resulted in improved mechanical properties, compared to the control mortar. An increase of 4% was observed in tensile resistance on flexural stress, and of 7% in compression strength for the mortar prepared with 1.5% cellulose pulp.

Análise da estabilização por solidificação de lodo de fosfatização em matrizes de cimento Portland e de cerâmica vermelha para a utilização na construção civil

O lodo de fosfatizacao gerado no tratamento de efluentes do processo de revestimento fosfatico de aco e um residuo solido Classe IIA – Nao Inerte, geralmente disposto em aterro industrial. Uma alternativa para o tratamento de residuos e a estabilizacao por solidificacao em matrizes cerâmicas e a base de cimento Portland. Isto permite a reciclagem do residuo como materia-prima para a construcao civil, diminui os custos de tratamento e disposicao final e reduz areas de aterros. O presente estudo tem como objetivo verificar a estabilizacao por solidificacao de lodo de fosfatizacao em matrizes de cerâmica vermelha, empregada na producao de blocos cerâmicos de alvenaria, e em concretos de cimento Portland. Foram realizadas caracterizacoes dos materiais envolvidos e ensaios de lixiviacao e solubilizacao das matrizes estudadas com e sem a incorporacao do lodo. Os resultados indicam que ha uma tendencia a estabilizacao por solidificacao dos parâmetros avaliados tanto na matriz cerâmica quanto na matriz de cimento Portland.

Environmental Evaluation of Stabilized and Solidified Products in Brazil: A Review

The diversity of industrial solid waste has grown exponentially in recent years, requiring waste management strategies focused on the reduction of associated environmental impacts. The solidification/stabilization (S/S) technique is increasingly used in the disposal or recycling of this waste. The Brazilian standard about the leaching of hazardous compounds in waste is being used to evaluate S/S products in their end disposal in landfills, with no description of any protocol to investigate performance during their life cycle, as observed when they are used as admixture to building materials. In this context, this study describes a qualitative review of leaching methods in use to assess S/S products in Brazil, in comparison with the main techniques adopted in other countries.

Influência da segregação granulométrica e do emprego de aditivos de moagem na adequação de cinzas de casca de arroz como coproduto

A cinza de casca de arroz (CCA) e um residuo proveniente da combustao da casca de arroz utilizada como biomassa na producao de energia. Esta cinza e gerada em grandes quantidades e possui baixa massa especifica, o que dificulta o seu gerenciamento, pois demanda muito espaco para o devido armazenamento e descarte. A CCA possui um elevado teor de silica em sua composicao, fator este que pode torna-la um material atrativo para varios segmentos industriais. Neste contexto, este trabalho tem como objetivo avaliar a influencia do beneficiamento fisico da cinza de casca de arroz, por meio de processos de segregacao granulometrica e moagem, com e sem o uso de aditivos, nas caracteristicas deste material e na sua adequacao como coproduto. A metodologia experimental utilizada para o desenvolvimento deste trabalho envolveu a segregacao e moagem da CCA (com e sem aditivos de moagem), caracterizacao quimica, fisica e estrutural das amostras de CCA bruta, segregadas e moidas. Os resultados obtidos indicam que a segregacao granulometrica se apresenta como fator determinante para a utilizacao da CCA como coproduto. Com relacao a moagem, pode-se verificar que o diâmetro medio das particulas diminui e a massa especifica das amostras aumenta, com o aumento do tempo de moagem. Entretanto, verifica-se que os aditivos usados neste trabalho, nas concentracoes testadas, nao influenciam significativamente na reducao do diâmetro das particulas.

Monitoring and Evaluation of Industrial Production of Fired-Clay Masonry Bricks with 2.5% of Phosphatization Sludge

The present study reports the industrial production of fired-clay masonry bricks containing 2.5% phosphatization sludge, the result of a research project carried out in three stages: laboratory, pilot production, and industrial production. After validation of the results of the first and second stages, the local environment authorities issued a permit to produce these bricks on industrial scale and to commercialize them. One of the requirements was the monitoring of the dimensional, mechanical and environmental performance of these bricks at 6-month intervals. This study presents the results of the monitoring of these characteristics in a 5-year period. After each sampling, bricks containing phosphate sludge were measured and submitted to compressive strength, as well to environmental analyses following the official Brazilian standards. The analyses of results of measurements and compressive strength show that the bricks manufactured with 2.5% phosphate sludge were approved for use in the construction industry. Additionally, the fired-clay bricks were classified as a non-inert material. This is not be considered an obstacle to commercializing these bricks, since conventional fired-clay bricks belong to the same class, and present higher levels of solubilized iron and aluminum, above the value defined in the national standard. The results obtained in the environmental, dimensional and mechanical analyses of fired-clay masonry bricks with phosphatization sludge demonstrate that they meet the requirements for production and commercialization.

Contribuição à avaliação ambiental de materiais e componentes construtivos: proposta de método para obtenção de extrato lixiviado

Os materiais de construcao civil estao sujeitos a lixiviacao de seus constituintes, que podem levar a contaminacao do ambiente. No Brasil, a avaliacao ambiental de materiais e componentes com residuos e realizada por lixiviacao, empregando-se os mesmos metodos e parâmetros destinados a residuos, em pequenas amostras solidas, que nao reproduzem a forma de exposicao a que o componente e submetido. O presente trabalho propoe e discute a viabilidade de utilizacao de dois metodos de ensaio para a obtencao do extrato lixiviado para avaliacao ambiental de materiais e componentes construtivos: um por imersao, que simula um cenario de exposicao de intenso e prolongado contato com o lixiviante, como um alagamento; e outro por irrigacao, que busca simular uma exposicao a chuva acida. Como corpo de prova do material a ser testado, e proposto o emprego de placas com dimensoes de 25x200x400 mm, e, como meio lixiviante, uma solucao de acido nitrico ajustada para pH 3,0 ± 0,05. Foram produzidos corpos de prova de cerâmica vermelha, com e sem a incorporacao de oxido de cromo. Os testes foram conduzidos em quatro ciclos de 7 dias; ao final de cada ciclo foram coletas amostras do extrato lixiviado, renovando-se a solucao ao iniciar-se o ciclo seguinte. O extrato lixiviado apresentou comportamento coerente e compativel com os resultados obtidos pelo metodo proposto na NBR 10005 (ABNT, 2005a). Apos quatro ciclos de 7 dias de exposicao, foi possivel observar tendencia a estabilizacao na concentracao de Cr no extrato lixiviado, o que corrobora a viabilidade do experimento em 4 semanas.

Collaborators perception of the risks and dangerous in the operations carried out in the foundry sector

Classificam-se as industrias de fundicao, grau de risco 4, segundo a Norma Regulamentadora - NR 4. O ambiente de trabalho na area de producao pode ser considerado insalubre e ha risco de ocorrencia de acidentes de trabalho. Por isso, este artigo apresenta parte de uma inve stigacao realizada no setor de fundicao de uma industria metal-mecânica. Foram levantadas informacoes sobre a percepcao dos riscos e perigos que os operadores ficam expostos nas operacoes realizadas no seu dia a dia e confrontou-se com os resultados obtido s de uma investigacao quantitativa nos registros da empresa (SESMT), em relacao aos acidentes ocorridos nos ultimos tres anos neste setor. Evidencio-se atraves da aplicacao da ferramenta GUT (gravidade, urgencia e tendencia), que os numeros levantados esta o coerentes com a percepcao dos operadores entrevistados com relacao aos riscos potenciais do setor. Foundry industries are classified on the risk level 4, according to Norm - NR 4. The working environment in the production area can be considered unsafe a nd there is risk of accidents. Therefore, this article presents part of an investigation carried out in the foundry sector of a metalmechanic industry. Raising awareness about the risks and dangers that operators are exposed in operations in their day to day and comparing with the results of a quantitative research in the records of the company (SESMT) in relation to accidents in the last three years. It was evidenced through the application of the GUT tool, which raised numbers are consistent with the per ception of interviewed operators in relation to the potential risk of the sector.

Utilization of rice husk in the removal of hexavalent chromium

A crescente preocupacao das industrias em tratar seus efluentes somada a busca por adsorventes de baixo custo justificam a proposta deste estudo que visa avaliar a po tencialidade de aplicacao de cinza de casca de arroz (CCA) na adsorcao de cromo hexavalente. A CCA foi gerada a partir do processo de queima de casca de arroz para aproveitamento energetico. As amostras de cinzas foram submetidas ao processo de moagem e ca racterizadas atraves de parâmetros fisicos, quimicos e microestruturais. Os ensaios de adsorcao foram realizados com solucao padrao de Cr (VI) com concentracao inicial de 25ppm. As variaveis analisadas foram: granulometria de adsorvente, pH e tempo de contato. A quantificacao de Cr (VI) residual foi realizada atraves do metodo colorimetrico da 1,5difenilcarbazida. Nos ensaios de adsorcao observouse que as taxas de remocao de Cr (VI) variaram de 25 a 84%, demonstrando a potencialidade de aplicacao de CCA na adsorcao de Cr(VI) quando ajustados os parâmetros do processo. The growing concerns for treating effluents oblige the industries for searching low cost adsorbents. As a result of that, the present work is justified, which has the aim of evaluate the potentiality of rice husk ash (RHA) in the adsorption of hexavalent chromium. The RHA was obtained from the burning process of rice husk to generate energy. Ash samples were grinded and characterized through physical, chemical and micro structural parameters. T he adsorption tests were carried out using standard solution of Cr (VI) with 25 ppm of initial concentration. The analyzed variables were: adsorbent granulometry; pH and contact time. The quantification of Cr (VI) was carried out via colorimetric method of 1.5-diphenilcarbazide. During the tests it was observed that the removal rate of Cr (VI) varied from 25 to 84%. These results demonstrated the potentiality of RHA application in the adsorption of Cr (VI) when the process parameters are well adjusted.