Chromium containing slags from stainless steelmaking may be leached by acidic environments, therefore they should be treated before being stockpiled or land filled. In this work, synthetic slags were prepared and the effect of CaO/SiO2, Cr2O3, MgO and Al2O3 contents on the stability of the mineralogical species formed was analysed. The morphology and composition of the slags were determined by XRD and SEM‐EDS, whilst their chemical stability was evaluated by leaching with an aqueous acetic acid solution. It was found that CaCr2O4 and CaCrO4 are present in slags prepared with neither MgO nor Al2O3. The Al2O3‐based slags mainly produced Ca2Al2SiO7 and the Cr(VI)‐containing oxide complex Ca4Al6CrO16, whilst MgO‐based slags produced Mg Cr2O4 as main mineralogical species. Additionally, Eh‐pH diagrams for the Ca‐Cr‐H2O and Mg‐Cr‐H2O systems at 25°C were constructed. The results showed that the lowest chromium concentration levels in the leaching liquors corresponded to MgO‐based slags owing to the stable binding of chromium in spinel with MgO. It was also observed in the Al2O3‐based slags that when increasing the slag basicity from 1 to 2, the leachability of the slags was notably increased.

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The objective of this study is to analyze the effect of MgO content and the slag basicity on the stability of the mineralogical species of the SiO 2 -CaO-MgO-Cr 2 O 3 system. Slag samples were prepared in equilibrium at 1600 °C under reducing conditions (pO 2 = 10 -9 atm). The MgO content ranged from 0 to 12 mass%, Cr 2 O 3 was 10 % and the slag basicity was held at 1 and 1. ResumenEl objetivo de este estudio es analizar el efecto del contenido de MgO y la basicidad de la escoria sobre la estabilidad de las especies mineralógicas del sistema de escoria SiO 2 -CaOMgO-Cr 2 O 3 . Se realizaron ensayos al equilibrio a 1600 °C bajo condiciones reductoras (pO 2 =10 -9 atm). El contenido de MgO fue de 0 a 12 % masa, el Cr 2 O 3 de 10% y la basicidad de 1 y 1,5. También se realizó un análisis termodinámico para determinar las fases mineralógicas más estables en la escoria. Los resultados experimentales y calculados muestran que el Cr 2 O 3 se encuentra principalmente ligado en una fase espinela MgCr 2 O 4 , incluso a bajos contenidos de MgO. Los resultados obtenidos por microscopia electrónica de barrido (MEB-EDS), muestran la evidencia de tres estructuras cristalinas: (A) Octaedros, los cuales corresponden a la espinela MgCr 2 O 4 , (B) Cristales alargados que corresponden a la formación de silicatos cálcicos y (C) Matriz de silicatos cálcicos con impurezas de Mg y Cr que no cristalizaron por completo.

Given the frequency of K-RAS mutations in Mexicans, making a genetic study before deciding to treat mCRC patients with monoclonal antibodies is indispensable.

In the synthesis and industrial production of Erlotinib, the formation of organic impurities has been detected, so the identification and control of these is a critical point within the process. Standards for the consumption of pharmaceutical products are well established for active substances. In this sense, the synthesis and unequivocal identification of two impurities of Erlotinib as structural isomers was developed in the present study. The structural characterization of both isomers was confirmed by 1H and 13C-NMR as well as by their X-ray diffraction study.