Guidelines for Natural Stone Products in Connection with European Standards.

The selection of ornamental stones for specific applications requires technical guidance since it should be based on the durability, service life, and aesthetic value of the stones. In most cases, these fundamentals provide quantitative data on the usability and performance of ornamental stones. The present study attempts to put forward a quantitative classification system for natural stone products concerning critical rock properties. For this purpose, fundamental physical and mechanical rock properties are listed based on European standards. Then, minimum limit values are proposed for different applications of natural stone products based on retrospective analyses of numerous ornamental stone applications. The suggested limit values based on several physical and mechanical rock properties can guide relevant engineers to initially consider possible rock types for use as natural stones in a wide range of applications. In this context, it is believed that the present study contributes to the natural stone industry by discussing the minimum limit values for the consideration of a wide range of rock types possibly usable in the dimension stone industry.

Relationship of Mineralogical Composition to Thermal Expansion, Spectral Reflectance, and Physico-Mechanical Aspects of Commercial Ornamental Granitic Rocks.

The aim of the present study is to link the thermal expansion, spectral reflectance, and physico-mechanical aspects of different types of commercial granitic rocks with their mineralogical and chemical composition. The granitic rock types were characterized using several analyses, including petrography, chemical, mineralogical, and thermo-gravimetrical analysis using XRF, XRD, and TG/DTG/DSC techniques. The rock types were subjected to several performance tests, such as tests of their thermal expansion, spectral reflectance, and physico-mechanical properties. The results revealed that quartz, albite, and potash feldspar with minor amounts of mica (biotite/muscovite/annite) are the main mineralogical constitutes, in addition to some alteration minerals, such as kaolinite, saussorite, and prehnite. The studied granitic rocks were classified as monzogranite/syenogranite of high K-calc-alkaline and peraluminous characters and are related to late- to post-collisional settings. The thermogravimetrical analysis revealed that the overall mass loss over the whole temperature range up to 978 °C did not exceed 3% of the initial weight for all studied rocks. The results of thermal expansion revealed that the maximum change in linear thermal expansion for all rock types did not exceed 0.015% of their initial lengths at an unusual air temperature of 50 °C. The spectral analysis revealed that iron and hydroxyl ions are the main spectral absorption features that appeared in the VIS-NIR and SWIR regions, in addition to the appearance of the common and distinctive absorption peaks of the main mineral composition. Furthermore, the spectral reflectance demonstrated that the granitic rock types of low iron oxide content achieved a high reflectivity percent in the VIS-NIR and SWIR spectral regions compared with those of high iron content. As a general trend, the granitic rock types of high iron content and/or lower quartz content exhibited a high performance regarding their physical and mechanical properties, such as water absorption, apparent porosity, bulk density, compressive strength, and abrasion resistance. The results of water absorption, density, strength, and abrasion resistance of the studied granitic rocks are in the range of 0.14-0.31%, 2582-2644 kg/m3, 77.85-222.75 MPa, and 26.27-55.91 Ha, respectively, conforming to the requirements of ornamental stones according to the ASTM standard.

Aspectos de vida, trabalho e saúde de trabalhadores do setor de rochas ornamentais / Aspects of life, work and health among laborers in the ornamental stone industry

O processo saúde-doença é determinado socialmente, sendo o trabalho um fator que influencia fortemente o perfil de morbimortalidade. O objetivo deste artigo é estudar a relação entre as condições de trabalho e saúde referidas por trabalhadores da indústria de rochas ornamentais, moradores de um distrito de Cachoeiro de Itapemirim (ES). Estudo epidemiológico, transversal, com coleta de dados realizada através de questionário aplicado a 187 trabalhadores em seus domicílios. A análise utilizou métodos estatísticos descritivos e analíticos. Grande percentual de trabalhadores referiu morbidade aguda (45,5%) e crônica (44,9%), percebida por eles como relacionada ao trabalho (56,5% e 51,2%, respectivamente). Apesar da maior percepção dos riscos de insalubridade ambiental por parte dos trabalhadores, os que referiram morbidade relacionaram principalmente os aspectos ergonômicos do trabalho ao principal grupo de transtornos apresentados, os osteomusculares. O elevado percentual de morbidade é resultado da inserção desses indivíduos em um processo de trabalho onde as condições e a organização do trabalho geram desgaste físico e mental, sendo determinada pela divisão social do trabalho no setor.

The process of health and disease is socially determined, whereby work is a factor that strongly influences the morbidity/mortality profile. The scope of this article is to study the relationship between work and health conditions reported by the workers of the ornamental stone industry and residents from the district of Cachoeiro de Itapemirim, State of Espírito Santo. It is an epidemiological cross-sectional study with data collection through a questionnaire applied to 187 workers at their homes using statistical, descriptive and analytical methods. A considerable percentage of workers stated self-reported acute morbidity (45.5%) and chronic morbidity (44.9%), as being related to work (56.5% and 51.2% respectively). Despite the broad perception by the workers of the risks of the environmentally insalubrious work conditions, those who cited morbidity related the ergonomic aspects of work to musculoskeletal disorders in the main group of disorders presented. The high percentage of morbidity is the result of these individuals being subject to a work-related process where the conditions and the work organization cause physical and mental strain, being determined by the way work is socially divided in that sector.

Caracterização ambiental de lamas de beneficiamento de rochas ornamentais / Environmental characterization of processing sludge of ornamental stones

As lamas de beneficiamento de rochas ornamentais (LBRO) são resíduos que apresentam composição química variada em função da composição das rochas, do processo de beneficiamento, dos processos de reaproveitamento de águas e lamas, das propriedades dos insumos, entre outros fatores. A caracterização e classificação das LBRO são de grande importância, principalmente para o Estado do Espírito Santo, por possuir um expressivo número de empresas do setor. Neste trabalho, são apresentados os resultados de caracterização e classificação de lamas de desdobramento e polimento de mármores e granitos, segundo a NBR 10004/2004. Todas as amostras de lamas de tear convencional e de politriz analisadas foram classificadas como Classe IIA. Percebeu-se que a identificação dos resíduos por fonte geradora permite a proposição de tecnologias limpas, como o uso de teares a fio diamantado que utilizam o mínimo de insumos e de pastilhas diamantadas metálicas isentas de elementos tóxicos, contribuindo para a melhoria das características químicas das LBRO.

The sludges produced in the cutting and polishing of ornamental stones are residues with diverse chemical composition that depend on the composition of the stones, the cutting and polishing process, the processes involved in the recycling of water and sludges, among others. The characterization and classification of these resulting sludges have great importance, especially for the State of Espírito Santo, Brazil, which is an important producer of ornamental stones. In this work, the results of characterization and classification of developmental and polishing sludges were presented, according to the Brazilian standard NBR 10004/2004. All the sludge samples from the cutting and polishing equipment were classified as Class IIA. We observed that the identification of the residues according to the generation source allows the proposition of clean technologies usage, such as cutting equipment with diamond coated wires, that use a minimum of raw materials, and metal diamond coated pads, free of toxic material, thus contributing to improve the chemical characteristics of these sludges.