Nontronite is a significant component of commercially important nickel laterite ores. Its behavior during high-pressure acid leaching of such ores may have an impact upon the efficiency of the process. The present study was conducted in order to further investigate the response of this material during high-pressure acid leaching. In situ synchrotron powder X-ray diffraction data were collected from a number of nontronite samples during hydration and leaching reactions at ambient and elevated temperatures. The present study followed previous high-pressure acid-leaching studies of nontronite where unexpected contraction and expansion behavior of the clay was observed by means of in situ X-ray diffraction. In the earlier studies the data sets only extended to ~20 Å so that when the nontronite expanded to greater than 19.5 Å (hydrated) the main 001 peak was only partially visible in the observed d-spacing range. The aim of the current work was to collect similar in situ diffraction data over a greater d-spacing range to observe more fully the movement of the main 001 reflection in order to better understand the changes taking place. This work was undertaken at the powder diffraction beamline of the Australian Synchrotron which was configured such that an upper d-spacing limit of ~34.5 Å could be achieved. Suggestions arising out of the previous work were confirmed along with additional information from testing of samples from the Source Clays Repository of The ClayMinerals Society. These results also show contradictory behavior of clays with the layer charge distributed over tetrahedral and octahedral sheets.

A ternary compound Al3CoNd2 was synthesized and its crystal structure parameters were determined by the Rietveld refinement method based on powder X-ray diffraction data. Results show that the compound crystallizes in the MgCu2-type structure (cubic Laves C15 phase, space group $Fd\bar{3}m$), with the lattice parameter of a = 7.8424(2) Ǻ, unit-cell volume of V = 482.33 Å3, and calculated density of Dcalc = 5.90 g.cm−3. The residual factors converge to Rp = 0.1024 and Rwp = 0.1287. The reference intensity ratio value obtained experimentally is 3.03. Magnetic susceptibility measurements indicate an agreement with the Curie–Weiss law in the temperature range of 385–450 K, and paramagnetic Curie temperature of θp = 379.9 K. Both rare-earth elements and cobalt ions contribute to the paramagnetic moment. The saturation magnetic moment and magnetic hysteresis loop were measured for the Al3CoNd2 compound at various temperatures. Results show that the saturation magnetic moment value decreases with an increase in temperature and the compound becomes a ferromagnet below the Curie temperature Tc.

Minerals with the general formula Cu4(OH)6A2/nn ± pH2O (A = Cl–, NO3–, SO42–) were synthesized and their behaviour following treatment with chloride, nitrate and sulfate solutions was studied by powder XRD and SEM. Two types of transformation were found: (1) an ion-exchange reaction manifested by preservation of both the precursor's morphology and structural type; (2) a dissolution-crystallization mechanism characterized by changes in the structural type and the morphology.

The results were considered by simultaneous application of the binary presentation of the structures, a bond valence approach and the ion-exchange ability. It was found that the structures of minerals with ion-exchange properties are built from similar layered structural unit of edge-shared and corner-shared Jahn-Teller square frameworks and different interstitial complexes of exchangeable ions, water molecules and cation-water groups. On the basis of their structural features the position of the investigated minerals in mineralogical classifications is also discussed.

The decrease in quality of Australian iron ore, coupled with the demand for more efficient energy use, means that closer monitoring and optimisation of process conditions for iron ore sinter production is required. Here, the suitability of using partial least-squares regression analysis of powder X-ray diffraction data, collected for iron ore sinter samples, for the prediction of iron ore sinter strength has been further assessed. In addition, a preliminary assessment of the effect of 2θ range on the quality of prediction has been made. For the purposes of process control, the level of correlation between predicted strength and actual sinter strength would inform an operator whether or not the process was operating within the acceptable limits, or whether there was a potential problem requiring further investigation or rapid intervention. Reducing the 2θ range was found to reduce the level of correlation between predicted and actual strength, to a point where the particular analysis may no longer be suitable for process control.

A series of mixed fluoride compositions with PbF2 and ScF3 were prepared by heating the intimate mixtures of component fluorides at 600 °C for 10 h followed by slowly cooling to room temperature. The products obtained were analyzed by powder XRD to reveal the phases present in them and hence the low-temperature phase equilibria in the PbF2-ScF3 system. The phase equilibria show the fluorite-type solid solution up to the composition of about 15 mol% of ScF3 in the PbF2 lattice. The unit cell volume decreases with increasing ScF3 contents in the fluorite-type solid solutions. Beyond the solubility limit, the biphasic mixture of the cubic fluorite-type solid solution and leftover ScF3 is found to exist.