TABLE 1 - uploaded by Stephen Hillier
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The construction and operation of a spray drier is described where the spray is produced using an air brush, essentially a miniature spray gun. The spray-dried products consist of spheres 50-60 mu m in diameter and typical product recoveries are 80%, a marked improvement over simple two-nozzle systems. The spray-dried samples are easy to load into...
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A short discussion on the structure of H2TiO3 presented in the article entitled Lithium recovery from salt lake brine by H2TiO3 (Ramesh Chitrakar, Yoji Makita, Kenta Ooi and Akinari Sonoda, Dalton Tansactions, 2014, 43, 8933) is given. In our opinion, it is not correct to identify the phase of H2TiO3 as the monoclinic one. XRD pattern of H2TiO3 dif...
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... Polyvinyl alcohol helped to bind the dried product, while 1-octanol prevented foaming during so-243 lution dispersion and formation of air bubbles in the dried granules, and facilitated the transfer of 244 samples between containers (Hillier 1999a). Afterwards, the slurries were homogenized for 60 s in 245 a McCrone mill. ...
... 552 Therefore, we found no significant difference between the conventional and spray-drying sample 553 preparation methods for the quantification of crystalline minerals and iXAMs in mineral mixtures 554 using Rietveld analysis. Spray drying slightly improved the precision of iXAM quantification and 555 is therefore preferable to the conventional sample preparation method when accounting for the 556 effects of preferred orientation of crystalline minerals (Bish and Reynolds 1989;Hillier 1999aHillier , 557 2000. However, spray drying produced a higher precision variability as controlled by sample 558 complexity when compared to the conventional sample preparation method (Fig. 8) aration methods, which is identical to estimates of maximum uncertainties for crystalline minerals 574 following QPA of PXRD data published by Hillier (2000) for the RIR method and by Gualtieri 575 (2000) for the Rietveld-RIR method. ...
Inorganic X-ray amorphous materials (iXAMs) such as vitreous phases, minerals having an insufficient number of repeating structural units to diffract X-rays, and inorganic solids with exclusively structural short-range order are ubiquitous in soils and relevant for numerous environmental processes, but are notoriously difficult to identify and quantify. To test for the quantification and chemical composition of iXAMs in soil, we prepared four mineral mixtures containing quartz, calcite, feldspars, and clay minerals in different proportions typical of soils and amended them with 10–70 wt% iXAMs in the form of a 1:1 weight mixture of ferrihydrite and opal-A. We quantified these iXAMs in mineral mixtures by analyzing powder X-ray diffraction (PXRD) data using the Rietveld method and compared the results for different sample preparation techniques (conventional and spray drying) based on the internal standard method in Rietveld analysis. The mineral mixtures were also analyzed for their chemical composition by X-ray fluorescence (XRF) spectrometry, and mass balance calculations combining Rietveld and XRF data were carried out to estimate the chemical composition of iXAMs in mineral mixtures. Both sample preparation methods showed no significant difference in determined iXAM contents and yielded accurate results for iXAM contents within ±3 wt% at the 95 % confidence level (2σ). The relative accuracy deteriorated with decreasing iXAM content, but remained below 10 % for iXAM contents > 10 wt% (mean = 3 %). The precision of iXAM content quantification in mineral mixtures prepared by spray drying was slightly better though statistically equivalent to the conventionally prepared mixtures (2σ = 1.49 and 1.61 wt%). The average precision of both sample preparation methods was ±2 wt% at the 95 % confidence level. Levels of detection and quantification of iXAMs in spray-dried mineral mixtures containing 1–10 wt% iXAMs were estimated at 0.8 and 4.0 wt%, respectively. The chemical composition of iXAMs in terms of major oxides was accurately assessed by mass balance calculations with average relative errors for nominal SiO2 and Fe2O3 contents of 9.4 and 4.3 %, respectively (range = 0.02–54.7 %). Even though adsorbed H2O and structural H2O/OH- as quantified by the loss 50 on ignition comprised an important portion of the iXAMs (15.3 wt%), their LOI in mineral mixtures as derived from mass balance calculations could only be quantified with an average relative error of 67.2 % (range = 1.30–371 %). We conclude that iXAMs in soil and related geomaterials present at levels > 4 wt% can be quantified by Rietveld analysis of PXRD data with an accuracy of ±3 wt% at best. Combined results of Rietveld and XRF analyses can yield accurate results for the chemical composition of iXAMs within a relative error of 10 % for major oxides, provided iXAM contents exceed 10 wt% and the content and chemical composition of all crystalline mineral phases is accurately assessed. The results presented in this study lay the foundation to explore iXAM contents and chemical compositions in soils and to examine their impact on soil physicochemical properties and biogeochemical element cycles.
... Therefore, we chose it to prepare CRSD formulations to enable a miniaturized screening by our platform tool with the aim to not only comprehensively characterize the product in vitro, but also use it in preclinical in vivo experiments. A few methods for miniaturizing the process of spray drying on air brush like devices have already been reported (Hillier, 1999;Ousset et al., 2018). Nevertheless, these methods are limited to screen solubility enhancement of drugs. ...
... This setup generated a highly reproducible spraying cone and simultaneously allowed live adjustment of the solution-feed by the operator (e.g., in case of clogging). For the drying process, a drying chamber was constructed in-house, which was similar to the one described by Hillier et al. (Hillier, 1999). However, it was smaller in size, and heating was controlled across the full length of the drying chamber. ...
... The metal abundance data were used to calculate the chemical index of alteration (CIA) for to produce random powder specimens (Hillier, 1999). X-ray diffraction (XRD) patterns were 290 recorded from 4-70 °2θ using Cu K-ɑ radiation and counting for 96 sec per 0.019° step with a 291 Linxeye XE detector on Bruker D8 Advance. ...
... Therefore, successful quanti ication of minerals in a sample depends greatly on the method of sample preparation, back loading against sandpaper or frosted glass has been shown to be e ective for producing good quality data (Turvey et al., 2018b;Wilson et al., 2006). Spray drying is an alternative method to loading against a roughened surface method to achieve completely random orientation of crystallites, however it requires speci ic sample preparation equipment that may not be present in all laboratories (Hillier, 1999). ...
Geochemical carbon dioxide removal (CDR) technologies capture and store carbon dioxide (CO2) from the atmosphere using alkaline materials that are rich in calcium (Ca) and magnesium (Mg). Alkaline materials include natural rocks such as basalt, industrial by-products such as steel slag, or artificially generated and industrially produced materials such as lime. Geochemical CDR technologies speed up the reactions of such materials with air or other CO2-bearing gases, and convert the CO2 into solid carbonate minerals or dissolved inorganic carbon in the ocean. Gigatonne (Gt) scale removal is potentially possible with geochemical CDR owing to the abundant quantities of alkaline materials, in addition to durable carbon storage over thousands of years.
Interest in geochemical CDR has expanded considerably over the past 5 years, as researchers and practitioners explore its feasibility. However, further research, development, and deployment of geochemical CDR may be limited by a lack of robust and standardised approaches to measurement. In this work, aspects of measurement in geochemical CDR are considered with the objectives of i) accounting for carbon accumulation in a material or solution, ii) assessing the capacity of the material to react with CO2, iii) understanding how material properties may impact the speed of reaction with CO2, iv) collecting sufficient information on a material to aid in the design of a reaction process, and v) collecting sufficient information such that risks associated with a mineral can be assessed. In order to help meet these objectives, materials properties must be collected via analytical techniques.
Here we present guidance for the application of these analytical techniques in the form of standard operating procedures (SOPs), tailored to meet the needs of geochemical CDR projects. The collection of accurate data obtained through standardised methods could facilitate project feasibility, design and operation, carbon accounting, and foster regulatory confidence in the industry. Given the often-heterogeneous nature of alkaline materials and the range of technologies that might facilitate their reaction with CO2, this document is for guidance only and the protocols should be adapted to suit the needs of the user. As the field innovates, we anticipate updating this report with additional operating procedures, and welcome such contributions to future editions.
... Ethanol was added to 3.0 g of each milled sample and milled again for 10 min with a McCrone Micronizing Mill (Retsch GmbH, Germany). The wet samples were then spray-dried with an airbrush pistol using equipment designed according to Hillier (1999). Samples were front loaded and measured from 5 -75 • 2θ, with step size of 0.01 • A D8 Advance diffractometer (Bruker, Germany) with Cu-Kα radiation was used for the measurements. ...
... The mineralogical composition of the soil and sediment profile was determined using X-ray Powder Diffraction (XRPD) at the James Hutton Institute, Aberdeen, Scotland. Bulk samples were ground in ethanol for 12 min in a McCrone mill and spray dried to produce random powder specimens (Hillier, 1999). X-ray powder diffraction (XRPD) patterns were recorded from 2 to 75 • 2θ using cobalt Kα radiation, counting for 2 s per 0.02 • step on a Siemens D5000 X-ray diffractometer (XRD). ...
To help understand the bioaccumulation of Cd and Tl in beaver tissue, we examined the enrichment of these metals in vegetation available to the animals. Bark was collected from 40 species of trees and shrubs, along with a complete soil weathering profile, within a small watershed devoid of trace metal contamination. Weathering resulted in a 5x enrichment of Cd in the soils relative to the underlying sediments, and a 6x Tl depletion: while Cd was lost from calcite and accumulates in the organic matter and oxyhydroxide fractions, Tl occurred only in the residual fraction. Soil processes alone, however, cannot explain the anomalous concentrations and enrichments of Cd in willow and poplar which contain up to 8.5 mg/kg Cd. The concentrations of Cd and Tl in the dissolved fraction (<0.45 μm) of the Wye River are similar (1.2 ± 0.4 and 1.6 ± 0.1 ng/L, respectively), and are taken to estimate their bioavailability in soil solutions. Normalizing the Cd/metal ratios in bark to the corresponding ratios in water yields the Stream Enrichment Factor: this novel approach shows that all plant species are enriched in Cd relative to Ni; 33 relative to Cu, 13 relative to Zn, and 7 relative to Mn. Thus, many plants preferentially accumulate Cd, especially willow and poplar, over these essential micronutrients. Clearly, the enrichment of Cd over Tl in bark is not a reflection of differences in bioavailability, but rather on the preferential uptake of Cd by the plants. The profound natural bioaccumulation of Cd in the bark of willow and poplar, the two favourite foods of the beaver, has ramifications for the use of these aquatic mammals as biomonitors of environmental contamination, as well as for the direct and indirect consumption of bark for traditional food and medicine.
... This may be prevented by poor particle statistics, preferred orientation and microabsorption, well known factors discussed in the literature (Klug & Alexander, 1954;Bish & Reynolds, 1989; Moore & Reynolds, 1997;Zhang et al., 2003;Dermatas et al., 2007;Kleeberg et al., 2008;Madsen et al., 2019). A number of preparation techniques have been developed to resolve those issues in multiphase samples (Klug & Alexander, 1954;Bish & Reynolds, 1989;Moore & Reynolds, 1997;Hillier, 1999;Monecke et al., 2001;Dermatas et al., 2007;Kleeberg et al., 2008). ...
The quantitative phase analysis using X-ray diffraction of pyrite ore concentrate samples extracted from the Thackaringa mine is problematic due to poor particle statistics, microabsorption and preferred orientation. The influence of sample preparation on these issues has been evaluated, with ball milling of the powder found most suitable for accurate and precise quantitative phase analysis. The milling duration and other aspects of sample preparation have been explored, resulting in accurate phase reflection intensities when particle sizes are below 5 µm. Quantitative phase analysis on those samples yielded precise phase fractions with standard deviations below 0.3 wt%. Some discrepancy between the elemental composition obtained using X-ray powder diffraction data and that determined using wavelength-dispersive X-ray fluorescence was found, and is thought to arise from unaccounted for crystalline phase substitution and the possible presence of an amorphous phase. This study provides a methodology for the precise and accurate quantitative phase analysis of X-ray powder diffraction data of pyrite ore concentrate from the Thackaringa mine and a discussion of the limitations of the method. The optimization process reveals the importance of confirming reproducibility on new samples, with as much prior knowledge as possible.
... For each of the clay minerals used, quantitative bulk and clay fraction powder X-ray diffraction analysis (XRD) was undertaken at the James Hutton Institute, Aberdeen to verify mineralogical composition. For bulk (whole sample) quantitative analysis samples were wet ground for 12 min (in ethanol or water) in a McCrone mill (Retsch, Haan, Germany) and spray dried to produce random powder specimens, as shown in Figures S3 and S4 for the NAu-2 and IMt-2 samples, respectively [27]. X-ray powder diffraction (XRPD) patterns were recorded (Panalytical X-pert Pro, Almelo, The Netherlands) from 4-70 • 2θ using Ni filtered Cu radiation and counting for 96 s per 0.019 • step. ...
... X-ray powder diffraction (XRPD) patterns were recorded (Panalytical X-pert Pro, Almelo, The Netherlands) from 4-70 • 2θ using Ni filtered Cu radiation and counting for 96 s per 0.019 • step. Quantitative analysis was made by a normalised full pattern reference intensity ratio (RIR) method as described in references [27,28]. Unless stated otherwise, expanded uncertainty using a coverage factor of 2, i.e., 95% confidence, is given by ±X 0.35, where X = concentration in wt%., e.g., 30 wt% ± 3.3 [29]. ...
... The specific surface area (SSAw) calculated from the water adsorption isotherm at 298 K by the Brunauer, Emmett Teller (BET) method through multipoint calculation, using the best linear fit in the 0. 0.3 P/P0 range. The calculated BET SSAw for the adsorption branch (Table 1) were ba on a classic adsorbate cross-sectional area (σ), for which a water molecule area of 14.8 was used [27,28]. The SSAw increased for the NAu-2 samples, correlating with exten reduction, more than doubling from 115 m 2 /g to 270 m 2 /g, whereas the SSAw for IM decreased slightly when reduced, from 68 m 2 /g to 53 m 2 /g. ...
Ferruginous clay minerals in saturated soils and within hydrocarbon deposits often exist in a reduced state. Upon introduction of dissolved oxygen, or other oxidants, the clay minerals oxidise and changes in mineral surface charge and sorption capacity occur, resulting in changes in hydration as well as flux of intercalated species. Here we examine the sorption of water to the Fe-containing clay minerals nontronite NAu-2 (23 wt% Fe) and illite IMt-2 (7 wt% Fe) as a function of Fe oxidation state and exchangeable cations by means of water vapour volumetry and N2 surface area analysis. The clay minerals were chemically reduced using sodium dithionite. Sorption isotherms of water vapour and nitrogen, controlled relative humidity diffractograms, and chemical analyses were recorded. The results show that, after reduction using sodium dithionite, increased amounts of water vapour and nitrogen were adsorbed to the high Fe content nontronite, despite decreased interlayer separation. Little change was observed for the non-swelling and low Fe content illite. Sodium from the reducing agent was found to exchange with calcium present in the starting clay minerals, and sodium balanced the additional mineral charge generated during reduction. The findings presented in this study deliver improved understanding of sorption at the surface of the reduced clay minerals, which aid constrain the role of clay mineral interfaces in subsurface environments.
... Exactly 4.50 g of the samples tested were mixed with 0.5 g of ZnO (internal standard) and 15 mL of ethanol followed by milling for 5 minutes in a micronizer to eliminate preferential orientation of the particles. The suspension was then spray-dried (Hillier (1999)) in a heated chamber to generate spherical aggregates. The spray-dried samples were then side loaded prior to XRD analysis. ...
Modification of mine waste tailings to improve their strength and stability reduces operational and reclamation risks for mine operators. Lime has been used in soil treatment applications with proven performance for decades to dewater and stabilize expansive soils. Re-cent research has shown that this technology can also be applied to beneficially modify fine clay fractions in mine waste tailings to improve their geotechnical characteristics and accelerate rec-lamation timeframes.
The objective of this study was two-fold. First, to investigate the impact of lime treatment on improving the unconfined compressive strength (UCS) of a non-plastic tailings deposit in Mexico. Second, to understand the non-traditional mechanisms governing strength gain through mineralogical evaluation. Despite low clay levels, the lime treated tailings exhibited nearly 25 times higher UCS within 28 days after treatment compared to the untreated deposits. The changes in chemical composition of non-clay minerals in this deposit after lime addition influenced strength development.
... The resulting slurry was placed into a 20 mL glass jar and attached to a small, compressed air-driven spray paint device. The slurry was gently agitated while spraying the contents into a cylindrical chamber heated to 150 • C, with a thermocouple-controlled belt heater to produce a spherical agglomerated sample for XRD analysis [39]. The spherical agglomerates were collected and stored in containers. ...
Quantification of halloysite and kaolinite in clay deposits from X-ray diffraction (XRD) commonly requires extensive sample preparation to differentiate the two phyllosilicates. When assessing hundreds of samples for mineral resource estimations, XRD analyses may become unfeasible due to time and expense. Fourier transform infrared (FTIR) analysis is a fast and cost-effective method to discriminate between kaolinite and halloysite; however, few efforts have been made to use this technique for quantified analysis of these minerals. In this study, we trained machine- and deep-learning models on XRD data to predict the abundance of kaolinite and halloysite from FTIR, chemical composition, and brightness data. The case study is from the Cloud Nine kaolinite–halloysite deposit, Noombenberry Project, Western Australia. The residual clay deposit is hosted in the saprolitic and transition zone of the weathering profile above the basement granite on the southwestern portion of the Archean Yilgarn Craton. Compared with XRD quantification, the predicted models have an R2 of 0.97 for kaolinite and 0.96 for halloysite, demonstrating an excellent fit. Based on these results, we demonstrate that our methodology provides a cost-effective alternative to XRD to quantify kaolinite and halloysite abundances.
