Study of Pigments from the Colonial Convent of Actopan, Hidalgo, Mexico

In this work, scanning electron microscopy (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR) techniques were used to study blue, red, and ochre pigments from wall paintings of the 16th century colonial convent of San Nicolás de Tolentino in Actopan, Hidalgo, Mexico. In the blue pigments, nanometric fibers with a chemical composition of mostly O, Si, Al, and Mg were identified. XRD and FTIR analysis indicated the presence of palygorskite clay, which suggests that these analyzed blue pigments are similar to Mayan blue. In the red pigment, structures with different morphologies (spines and flake shapes, for instance), with a composition of C, O, Al, Si, S, Ca, Na, Mg, and K and a higher concentration of Fe and Pb, were observed. Complementary analysis showed that the red color originates from hematite and lead. Finally, the ochre pigment showed a significant presence of O and Fe, which was associated with the goethite mineral, while calcite was a crystalline phase identified in all analyzed pigments; these show that these pigments are characteristic of the known Mexican Colonial color palette.

Highly regenerative and efficient adsorption of phosphate by restructuring natural palygorskite clay via alkaline activation and co-calcination

Herein, we present a new strategy to create a highly regenerative and efficient phosphate adsorbent based on activating natural palygorskite structure. Both the regeneration via alkaline activation and synthesis via...

Iron-containing palygorskite clay as Fenton reagent for the catalytic degradation of phenol in water

Mechanism diagram of palygorskite clay degradation of phenol-containing wastewater.

The Performance of Iraqi Palygorskite in Salt Drilling Fluid

In drilling fluid program, selecting the drilling fluid that will reduce the lost time is the first objective, and will be economical regardless of its cost. The amount and type of solids in drilling fluid is the primary control of the rheological and filtration properties. Palygorskite clay (attapulgite) is an active solid that has ability to reactive with its environment and form a gel structure within a fluid and due to its stability in the presence of brines and electrolytes this type of clay is preferred for use. The aim of this study is to calculate the yield of clay for both types of local PAL in both fresh and salt water based mud. Determine the effect of aging time. Besides that, the effect of chloride sodium (NaCl) on rheological properties of drilling fluid by preparing salt water based drilling fluid with Bahr Al-Najaf PAL in three different procedures. The palygorskite claystone of Late Cretaceous age is present in the Western Desert within the Digma Formation. In this study, from two areas in Western Desert palygorskite were obtained, Bahr Al-Najaf and Trefawi. The results showed that, the clay yield of Bahr Al-Najaf PAL (49.54 bbl/ton), Trefawi PAL (57 bbl/ton), and commercial PAL (166.8 bbl/ton) in fresh water environment was higher than in salt water environment. As observed in this study, the clay yield of Bahr Al-Najaf PAL, Trefawi PAL, and commercial PAL in salt water environment were 37.9, 50.7, and 135.6 bbl/ ton respectively. Poor yield of clay was obtained with Trefawi PAL (Grinding) so it was not used to prepare samples in this study. This experimental investigation, 16 hours aging time after preparation drilling fluids was applied.

Use of palygorskite as a viscosity enhancer in salted water-based muds: effect of concentration of palygorskite and salt

Drilling fluids are essential for the operation and productivity of petroleum wells. This study compares the efficiency of a salted water-based mud for which the viscosity has been enhanced with polymeric compounds with that of a new salted water-based mud containing palygorskite clay, which mainly functions as a viscosity enhancer. The experiment measured the density, apparent viscosity, plastic viscosity, yield point, American Petroleum Institute filtrate and pH of the samples. The results indicate that the rheological properties of the fluids containing greater amounts of palygorskite were not affected significantly by the addition of salt. However, when the concentration of palygorskite was low, the rheological behaviour of the samples was appropriate to the drilling operation only with lesser amounts of salt. In addition to its good rheological properties, the filtrate volume obtained for samples containing greater concentrations of palygorskite was lower, which suggests that the filtration properties at the bottoms of the wells were controlled appropriately.