Chemical composition of soil and vegetation of large petrochemical complex of Tobolsk

For the study, sites were selected that were located in the immediate vicinity of the construction site of a large petrochemical complex. The chemical composition of the total phytomass of monitoring sites was determined. The accumulation range, the most accumulated heavy metals and trace elements, varied within the limits: Zn (0,88-5,45); Cd (0.10-0.13); Co (0.20-0.18); Pb (0.42-0.52); Cr (0.14-1.48); Ni (1.72-5.19) mg / kg. The biogenic and salt compositions of the soil were studied. It was revealed that the soils of the plots are nonsaline, slightly acidic, biogenic elements are concentrated in the upper horizons

Clínqueres Pórtland Belíticos. Síntesis y Análisis Mineralógico

[EN] The quaternary system CaO-SiO2-Al2O3-Fe2O3 has been taken into account to design five compositions of belite Portland clinkers with belite (Ca2SiO4) contents ranging from 60 to 65 wt%, located in its primary phase field of crystallization. The synthesis of these belite clinkers has been studied by high temperature microscopy, dilatometry, differential thermal analysis and thermogravimetric analysis. As a result, the optimum clinkerization temperature has been established at 1360 ± 5ºC. The quantitative phase analyses of the clinkers were carried out by X-ray powder diffraction with the Rietveld methodology. The mineralogical composition depends on the initial dosages, on the highest temperature achieved and on the time of residence at this temperature. The reaction was completed at 1365ºC during 15 min (free CaO <0.5 wt%), in those conditions the β-belite form is stabilized and the harmful transformation β→γ is avoided.[ES] Teniendo en cuenta el sistema cuaternario CaO-SiO2-Al2O3-Fe2O3, se han diseñado cinco composiciones de clínqueres Pórtland belíticos, con contenidos del 60 y del 65% en peso de belita (Ca2SiO4), situadas en su campo primario de cristalización. La síntesis de estos clínqueres belíticos se ha estudiado “in situ” por microscopía de alta temperatura, dilatometría y análisis térmico diferencial y termogravimétrico. La temperatura óptima de clinquerización, determinada con estas técnicas, ha sido de 1360 ± 5ºC. Los análisis cuantitativos de los clínqueres se llevaron a cabo por difracción de rayos-X con la metodología Rietveld. Los porcentajes de las diferentes fases dependen de las dosificaciones iniciales, de la temperatura alcanzada y del tiempo de residencia a dicha temperatura. Se ha conseguido una reacción total (%CaO libre < 0.5% en peso) tratando a 1365ºC durante 15 min, en cuyas condiciones se estabiliza la forma β de la belita y se evita la transformación perjudicial β→γ.Peer reviewe