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Orosco P.,Institute Investigaciones en Tecnologia Quimica INTEQUI | Orosco P.,National University of San Luis | Ruiz M.D.C.,Institute Investigaciones en Tecnologia Quimica INTEQUI
Thermochimica Acta | Year: 2015

The potassium chloride is one of the most important fertilizers used in agriculture. The current demand of this salt makes interesting the study of potassium chloride production from unconventional potassium resources. In this work the potassium chloride production by chlorination of microcline was investigated. The starting reagents were microcline, hydromagnesite and chlorine. Non-isothermal and isothermal chlorination assays were carried out in a thermogravimetric device adapted to work in corrosive atmospheres. The temperature effect on potassium extraction and the phase transformations produced during chlorination of microcline were studied. The reagents and reaction products were analyzed by X-ray fluorescence (XRF) and X-ray diffraction (XRD). The experimental results indicated that by chlorination of microcline an important extraction of potassium in the temperature range from 800 to 900 °C was produced. Moreover, at 800 °C the forsterite, enstatite and magnesium aluminate spinel phases were generated. © 2015 Elsevier B.V. All rights reserved. Source


Saitua H.,Institute Investigaciones en Tecnologia Quimica INTEQUI | Gil R.,Institute Quimica San Luis INQUISAL | Padilla A.P.,Institute Investigaciones en Tecnologia Quimica INTEQUI
Desalination | Year: 2011

In this research, the efficiency and the arsenic removal mechanism with a Nanofiltration (NF) pilot plant from naturally contaminated groundwater have been evaluated. The process integral evaluation at 7bar shows an arsenate (HAsO4 2-) rejection over 95% and a total sulfate (SO4 2-) rejection. Divalent ions calcium and magnesium (Ca2+ and Mg2+) rejection produced an 81% reduction of the total hardness. The total dissolved solids TDS concentration decreased to 53%. Monovalent ions moderated rejections contributed to the membrane hydraulics stability. The arsenate (HAsO4 2-) rejection from an electrolytes solution (SO4 2-, HCO3 -, F-, Cl-, NO3 -, Ca2+, Mg2+, K+ and Na+) was prevalently ruled by Donnan exclusion combined with the preferential passage of more permeable ions. Results show the importance of ionic composition on ion transmission and rejection in the studied membrane. Ion rejection in multicomponent solutions showed to be significantly different to that in individual salt solutions. Whereas monovalent anion rejections remarkably decreased, divalent cation rejections were three times superior. In arsenate rejection (HAsO4 2-) from artificially contaminated natural groundwater, the membrane showed the same selectivity. © 2011 Elsevier B.V. Source


Orosco P.,Institute Investigaciones en Tecnologia Quimica INTEQUI | Orosco P.,National University of San Luis | Barbosa L.,Institute Investigaciones en Tecnologia Quimica INTEQUI | Barbosa L.,National University of Cuyo | And 2 more authors.
Materials Research Bulletin | Year: 2014

A pyrometallurgical route for the synthesis of magnesium aluminate spinel by thermal treatment of a mechanical mixture containing 29 wt% MgO (periclase) and 71 wt% Al2O3 (alumina) in chlorine atmosphere was developed and the results were compared with those obtained by calcining the same mixture of oxides in air atmosphere. Isothermal and non-isothermal assays were performed in an experimental piece of equipment adapted to work in corrosive atmospheres. Both reagents and products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF). Thermal treatment in Cl2 atmosphere of the MgO-Al2O 3 mixture produces magnesium aluminate spinel at 700 °C, while in air, magnesium spinel is generated at 930 °C. The synthesis reaction of magnesium aluminate spinel was complete at 800 °C. © 2014 Published by Elsevier Ltd. Source


Padilla A.P.,Institute Investigaciones en Tecnologia Quimica INTEQUI | Saitua H.,Institute Investigaciones en Tecnologia Quimica INTEQUI
Desalination | Year: 2010

The coexistence of arsenic and fluorine in high concentrations in groundwater from Argentina restricts its use as a drinking water supply source. The behavior of a spiral membrane of nanofiltration (NF) at pilot-scale was investigated over the simultaneous removal of arsenate, fluoride and bicarbonate from a synthetic solution containing 180 μg As(V)/l, 5 mg F/l and 84 mg HCO3/l. At pH 8 and 7 bar, the rejections of arsenate, fluoride and bicarbonate were 93%, 89% and 85%, respectively. Elevated rejections of monovalent ions in the presence of a divalent ion were attributed to a high electric repulsion between the ions and the membrane and to a negligible influence of the divalent ion due to its low concentration. At 2 bar, the rejections of arsenate, fluoride and bicarbonate were 91.6%, 73.3% and 73.8%, respectively. The decrease in rejections can be attributed to the so-called 'dilution effect'. Based on the obtained rejection results, the regulations concerning the arsenate and fluoride levels can be met. The operational low pressure required for the process (2 bar ó 0.19 MPa) might be achieved by using a bicycle pump in areas where power supply is limited. In all experiments, permeate pH was lower than feed pH. © 2010 Elsevier B.V. All rights reserved. Source

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