Recycling of gneiss rock waste in the manufacture of vitrified floor tiles

Souza, Alexandre Jorge Duarte de; Pinheiro, Bruno Carlos Alves; Holanda, José Nilson França de

doi:10.1016/j.jenvman.2009.09.032

Cited by 43 publications

(22 citation statements)

References 10 publications

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“…É importante destacar que o óxido de cálcio (CaO) e óxido de ferro (Fe 2 O 3 ) nos resíduos levigação, polimento e granalha são oriundos da cal utilizada como lubrificante e granalha como abrasivo no processo de beneficiamento. A presença de óxidos fundentes nos resíduos é importante, pois tornam esses resíduos atrativos para uso como matéria-prima alternativa na formulação de massas cerâmicas para fabricação de materiais como pisos vitrificados e porcelanas diversas [12,[17][18][19]. Neste caso, o resíduo de rocha ornamental poderia substituir o material fundente natural normalmente utilizado, no caso feldspatos sódico e potássico.…”

Section: Resultsunclassified

“…De fato, existe extensa literatura [9][10][11][12][13] relacionada à caracterização e uso de resíduos sólidos provenientes da indústria de rochas ornamentais em materiais para a área. No entanto, estes trabalhos, via de regra, utilizam o resíduo de rocha ornamental de um único tanque de decantação, ou seja, sem a separação dos resíduos das diferentes etapas do processo de beneficiamento.…”

Section: Introductionunclassified

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Caracterização de resíduos de rochas ornamentais provenientes de diferentes processos de corte e beneficiamento

Santos¹,

Destefani²,

Holanda³

2013

Matéria (Rio J.)

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RESUMOO Brasil está entre os seis maiores responsáveis pela produção mundial de rochas ornamentais, sendo o centro produtor mais rico em granito. O setor de rochas ornamentais gera durante os processos de corte e beneficiamento enormes quantidades de resíduos sólidos poluentes, de tal modo que as quantidades de tais resíduos são esperadas para aumentar cada vez mais. O estado do Espírito Santo é o maior produtor e exportador nacional de rochas ornamentais e, nos processos de corte e beneficiamento são geradas grandes quantidades de resíduos sólidos que precisam ser reaproveitados, do contrário podem causar danos de difícil remediação ao meio ambiente. Dependendo do tipo de rocha e do tipo de processo de corte e beneficiamento, resíduos com distintas características podem ser gerados. Neste contexto, o presente trabalho objetiva caracterizar quatro resíduos de rochas ornamentais gerados em distintos processos de corte e beneficiamento denominados de resíduos granalha, dimantado, levigação e polimento. As amostras dos resíduos de rochas ornamentais foram caracterizadas em termos de composição química, morfologia, distribuição de tamanho das partículas, massa específica real e análise termogravimétrica (ATG/DTG). Os resultados experimentais indicaram que os resí-duos estudados apresentam diferentes características químicas e físicas. Os resíduos levigado, polimento e granalha são ricos em óxidos fundentes (K 2 O, CaO e Fe 2 O 3 ), enquanto que o resíduo diamantado é rico em SiO 2 . Os resíduos também apresentam distintos comportamentos granulométrico e térmico. Palavras-chave:Resíduo de rocha ornamental, caracterização, reciclagem. ABSTRACTBrazil is among the top six worldwide responsible by the production of ornamental rocks, being the richest production center in granite. The sector of ornamental rocks generates during the cutting and beneficiation processes huge amounts of pollutants solid waste, in such way that the amounts of such solid wastes are expected to increase more and more. The Espírito Santo state is the largest national producer and exporter of ornamental rocks. In cutting and beneficiation processes of ornamental rocks huge amounts of solid wastes that need to be reused are generated, otherwise they cause damage of difficult remediation to the environment. Depending on the type of rock and the type of cutting and beneficiation process, wastes with different characteristics can be generated. In this context, this work aims to characterize four ornamental rocks wastes generated in different cutting and beneficiation processes denominated as shot waste, diamond waste, levigation waste, and polishing waste. The ornamental rock wastes samples were characterized in terms of chemical composition, morphology, particle size distribution, real specific mass, and thermal analysis (TGA/TGD). The experimental results indicated that the studied ornamental rock wastes presented different chemical and physical characteristics. The levigation, polishing, and shot wastes are rich in K 2 O, CaO and Fe 2 O 3 , while t...

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Section: Resultsunclassified

Section: Introductionunclassified

Caracterização de resíduos de rochas ornamentais provenientes de diferentes processos de corte e beneficiamento

Santos¹,

Destefani²,

Holanda³

2013

Matéria (Rio J.)

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“…The industrial activities involving ornamental rocks involve the extraction, cutting and polishing of rocks such as granite, marble, slate, gneiss and quartzite (Souza et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Iron recovery from the waste generated during the cutting of granite

Junca

Oliveira

Espinosa

et al. 2013

Int. J. Environ. Sci. Technol.

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Metallic iron is present in the waste left when granite blocks are cut. Thus, the purpose of this study was to characterize this waste using chemical and particle size analyses. To achieve this, X-ray diffraction and scanning electron microscopy coupled with electron back-scattered diffraction were used. To find the method with the best metallic iron recovery from the waste of ornamental rock, three distinct methods were examined: magnetic separation, table concentration and cyclone processing. The first method involved three steps: (1) use of a wet high-intensity magnetic separator, where only the equipment's remaining magnetic field was present; (2) the material from the first step was then submitted to separation again, this time using a magnet for rare earth particles; and (3) this material after two separation processes was finally submitted to ferromagnetic separation. The second method used a concentration table set at various inclinations, oscillation frequencies and wash flow rates. Meanwhile, for the third method, the cyclone tests, only the water pressure was varied. After each test, a chemical analysis was performed to determine the metallic iron present in each sample. The tests revealed that magnetic separation presents the best results. Using this technique, a ferrous concentrate with 93 % metallic iron content and a granite concentrate with only 0.6 % metallic iron were obtained. On the other hand, in the table concentrator tests, the ferrous concentrate only had a metallic concentration of 13.6 %. In separation by the cyclone processing, the product barely contained metallic iron (7.2 % maximum).

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“…Many possible applications were suggested to incurporate proportions of the wastes in the processing of tiles [7][8][9][10][11][12], red ceramics [13][14][15][16], building materials [17], mortars [18], concrete aggregates and mixtures [6,19] and clay products [20,21].…”

Section: Introductionmentioning

confidence: 99%