S. S. Amritphale

Adsorption of cyanide from aqueous solutions at pyrophyllite surface

The adsorption of cyanide from aqueous solutions at pyrophyllite mineral surface has been studied by investigating the effect of initial concentration of adsorbate, amount of adsorbent, pH and temperature of test solutions. The adsorption efficiency is observed to be 99% in dilute solutions but decreases down to 40% with increase in cyanide concentration to 10 ppm. The adsorption is observed to be maximum from neutral solutions and is observed to increase with increase in temperature. The adsorption data have been fitted in Langmuir and Freundlich isotherms and the adsorption has been found to be endothermic in nature in the temperature range 30–60°C.

Phase transformation, improved ferroelectric and magnetic properties of (1 − x) BiFeO3–xPb(Zr0.52Ti0.48)O3 solid solutions

The authors prepared (1 − x)BiFeO3 – (x)Pb(Zr0.52Ti0.48)O3 for x ≤ 0.30 by sol-gel method and investigated the materials structures, magnetic and electrical properties. Detailed Rietveld analysis of X-ray diffraction data revealed that the system retains distorted rhombohedral R3c structure for x ≤ 0.10 but transforms to monoclinic (Cc) structure for x > 0.10. Disappearance of some Raman modes corresponding to A1 modes and the decrease in the intensities of the remaining A1 modes with increasing x in the Raman spectra, which is a clear indication of structural modification and symmetry changes brought about by PZT doping. Enhanced magnetization with PZT doping content may be attributed to the gradual change and destruction in the spin cycloid structure of BiFeO3. The leakage current density at 3.5 kV/cm was reduced by approximately three orders of magnitude by doping PZT (x = 0.30), compared with BFO ceramics.

Separation of Lead Ions on Francolite Surfaces

The separation of aqueous Pb2+ onto a low-grade (<15% P2O5) carbonate-substituted rock phosphate (Francolite) mineral from Madhya Pradesh (India) was investigated. The effects of different parameters such as initial concentration of Pb2+, particle size of Francolite, and amount of substrate on lead-ion separation were studied under natural conditions by equilibrating different amounts of Francolite with aqueous lead solutions of different concentrations. Francolite was found capable of lead-ion separation at par with hydroxyapatite or high-grade (<25% P2O5) rock phosphate. Francolite was found very effective in removing Pb2+ with a minimum lead removal of 82–99.9% and a maximum LRC (lead removal capacity) of 0.082 g of lead/g of Francolite.

Sintering behaviour of pyrophyllite mineral : effect of some alkali and alkaline-earth metal carbonates

Pyrophyllite mineral was heat treated with alkali and alkaline-earth metal carbonates in equimolar ratios at 1000 °C for 2 h and the various phases formed in the sintered products were investigated using X-ray powder diffraction and infrared spectroscopy. The morphology of the products was studied using scanning electron microscopy. In each case formation of aluminosilicate phase of respective cation was observed, but the presence of mullite in sintered products was not detected.

Synchronising effect of microwave and cytosine for the synthesis of hybrid homogenised nanosized cerium oxide and cerium oxycarbonate hydrate material

A novel microwave irradiation process has been developed for the synthesis of hybrid homogenised nanosized cerium oxide and cerium oxycarbonate hydrate material. Aqueous cerium(IV) sulfate and cytosine were reacted in the presence of microwave irradiation for 10–15 min at a temperature of 40–45 °C. Cytosine acts as a novel multifunctional agent, as a source of alkaline amine, a source of carbon-containing moieties and also as a highly effective capping agent. This enables the synthesis of light yellow hybrid homogenised nanosized advanced material. The synthesised material was characterised by various complementary techniques, namely X-ray diffraction, Fourier transform infrared spectroscopy, UV-Vis spectroscopy, field emission scanning electron microscopy and energy dispersive X-ray analysis. The characterisation showed that the size of the nano particles were in the range 27–48.3 nm.