Pneumoconiosis is the result of the long-continued inhalation of dusts and it depends on the interaction between the man and the cloud to which he is exposed. The health effects of dusts, especially silica dust exposure have been since Egyptians had constructed the pyramids in ancient times. Subsequently, many works, including miners, milers, quarry workers, sandblasters, tunnel drivers, are occupationally exposed to mineral dusts. These workers may develop pneumoconiosis and in some instances, malignant neoplasms, particularly lung cancer, as a result of such exposures.Both quantity and quality of mineral dusts in the lungs show significant correlation with the degree of damage from pneumoconiosis. So mineralogical techniques require in pathological studies and in estimation of the airborne dusts in working places.Mineralogy has played an important role in both branches of the protective procedure. This lecture presents the knowledge on lung dust, cytotoxicity and fibrogenetic activity of minerals and control procedures for pneumoconiosis from pont of mineralogist.
The reaction path of water-gneiss in 200m borehole at the Soorichi site of Yugu Myeon, Chungnam was simulated by the EQ3NR/EQ6 program. Mineral composition of borehole core and fracture-filling minerals, and chemical composition of groundwater was published by authors. In this study, chemical evolution of groundwater and formation of secondary minerals in water-gneiss system was modelled on the basis of published results. The surface water was used as a starting solution for reaction. Input parameters for modelling such as mineral assemblage and their volume percent, chemical composition of mineral phases, water/rock ratio reactive surface area, dissolution rates of mineral phases were determined by experimental measurement and model fit. EQ6 modelling of the reaction path in water-gneiss system has been carried out by a flow-centered flow through open system which can be considered as a suitable option for fracture flow of groundwater. The modelling results show that reaction time of 133 years is required to reach equilibrium state in water-gneiss system, and evolution of present groundwater will continue to pH 9.45 and higher na ion concentration. The secondary minerals formed from equeous phase are kaolinite, smectite, saponite, muscovite, mesolite, celadonite, microcline and calcite with uincreasing time. Modeling results are comparatively well fitted to pH and chemical composition of borehole groudwater, secondary minerals identified and tritium age of groundwater. The EQ6 modelling results are dependent on reliability of input parameters: water-rock ratio, effective reaction surface area and dissolution rates of mineral phases, which are difficult parameters to be measured.
Acid sulfate soils occur in the Gimhae plain where they have been formed from brackish alluvial sediments along the sea coast and river estuary. Acid sulfate soils suffer extremely acidity as a result of oxidation of pyrite. Total sulfur content of the soils was the highest in B horizon of Gimhae series and the lowest in A horizon of Deunggu series. The dominant fractions of sulfur in the soils were jarosite-S for Gimhae series, pyrite-S for Bongrim and Haecheog series, and organic-S for Deunggu series. The essential chemical processes of acid sulfate soils are, firstly, the formation of pyrite in waterlogged environment, and subsequently, the oxidation of this pyrite following natural or artificial drainage. Jarosite [K Fe3(SO4)2(OH)6] is a common sulfur mineral of the oxidation condition. Jarosite shows cubic particles with tetrahedral faces.
the crystal structure of pale green gem-quality olivine from Bisbee mine,Arizona, (Mg1.83Fe0.18)Si0.99O4, a=4.7608(4)a, c=5.9903(6)a, c=5.9903(4)a, V=291.49(1)a, Pbnm, Z=4 has been refined by both single-crystal and Rietveld methods to R(%) indices of 2.20 and 9.07, respectively. Comparison of site occupancies, cell dimensions, atomic coordinations, and interatomic distances/angles obtained from both methods shows that the Rietveld method produces more accurate site scattering values, cell dimension, and atomic positions than the single-crystal method. This indicates that the Rietveld method is a useful technique for the structural characterization and crystal-chemical study of powdered samples of natural minerals and synthetic materials.
The talc of the Daeheung, Pyeongan, and Cheongdang (Shinyang) talc deposits in the Yesan-Gongju-Cheongyang area is a hydrothermal alteration product of serpentinite originated from ultramafic rocks. The mineral assemblages in alteration zones are: serpentine, serpentine-talc, talc, talc-chlorite, talc-phlogopite-chlorite, and talc-tremolite-chlorite. Chemical distributions in both the Al2O3-FeO-MgO system and the immobile elements suggest that the serpentine-talc and talc rocks are the reaction product of ultramafic rocks and silicic hydrothermal solution without addition of other granitic components, whereas chlorite-, phlogopite-, and tremolite-bearing rocks are the metasomatic alteration product of serpentinite by hydrothermal solution affected by granitic gneiss. Discontinuities in the immobile element ratios of mineral assemblages are due to changes in their mineralogy. The relative contents of Al2O3, TiO2, Zr in the talc-phlogopite-chlorite and talc-tremolite-chlorite rocks increase irregularly with increasing phlogopite, tremolite, and/or chlorite contents in contrast to other ore types. But the relative contents of Cr, Ni, and Co are uniform in all the mineral assemblages. Chemistry of each mineral assemblage formed by steatitization of serpentinite suggests that Cr, Co, Ni, MgO, and Fe2O3 are relatively immobile during the alteration, whereas SiO2, Al2O3, CaO, and K2O are highly increased. The contents of chlorite, phlogopite, and tremolite in each mineral assemblage might be controlled by addition of Al2O3, K2O, and CaO, respectively. The high contents of other elements than immobile elements in the altered rocks as compared with unaltered rocks indicate that a large amount of elements were introduced from hydrothermal solution up to about 8∼41% in total mass showing maximum value in the talc-phlogopite-chlorite rock.