Slurry sampling

Hinde and Lloyd [27] are more interested in extracting samples for continuous on-line analysis. They state that the process streams from industrial wet classifiers can vary in volume flow rate, solids concentration and particle size distribution. Any sampling technique should be able of coping with these variations without affecting the representativeness of the extracted sample. 

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Example 5 Solids Sampling by Linear Traversing Trajectory Cutter. Example 6 Slurry Sampling by Rotary Traverse of Gravity Flows. 

Example 6 Slurry Sampling by Rotary Traverse of Gravity Flow Increment volume, quantity of slurry extracted hy one cutter rotation, is S from hulk slurry flow B expressed in voliime-per-imit time. R is cutter rotation per minute. D is cutter angle opening, with D/360 extraction ratio for continuous cutter rotation. 

A pilot-scale continuous MSMPR crystallizer of 10 litre capacity is used to crystallize potash alum from aqueous solution, supersaturation. This is being achieved using a 15-min residence time, a 100-ml slurry sample was taken and the crystals contained in this sample subjected to a size analysis. The results of this analysis are given below... 

At temperatures greater than -10°C, the Cs NMR spectrum of a Cs-exchanged hectorite in contact with l.OM CsCl solution (a slurry sample) consists of two peaks, one between 3.5 and... 

Kurfurst U (1998) Solid Sample Analysis - Direct and Slurry Sampling using GF-AAS and ETV-ICP. Springer, Berlin, Heidelberg, New York. 

Carrion N, De Behzo ZA, Moreno B, Fernandez EJ, Flores D (1988) Determination of copper, chromium, iron and lead in pine needles by electrothermal atomisation spectrometry with slurry sample introduction. J Anal At Spectrom 3 479-483. 

Klemm W, Baumeach G (1995) Trace element determination in contaminated sediments and soils by ultrasonic slurry sampling and Zeeman graphite furnace atomic absorption spectrometry. Fresenius J Anal Chem 353 12-15. 

Solid and slurry sampling using the graphite furnace have been reviewed [220,221]. A monograph dealing with solid sample analysis is available [222]. 

In order to develop a continuous flux maintenance procedure, the present study examined the transmembrane flux values from the cross-flow filtration module with a filtration media area of 0.0198 m2 (0.213 ft2), a slurry density of approximately 0.69 g/cm3 at 200°C, 17 kg of simulated FT wax with a catalyst loading of 0.26 wt%, and a TMP between 0.68 and 1.72 bar (10-25 psig). The filtration process was run in a recycle mode, whereas clean permeate was added back to the slurry mixture, thus allowing the catalyst concentration to remain approximately constant over the course of the run (given minor adjustments for about 5 ml permeate and slurry samples collected throughout the test). 

FIGURE 15.14 Concentration of iron in permeate and slurry samples collected at different times. 

Capillary gas chromatography allows the analysis of complex mixtures of compounds to be carried out. However, the analysis time per sample is inherently long in order to obtain high resolution of the components, and this limits the throughput of samples. Slurry samples are biotic and therefore subject to continuing changes which are reflected... 

This product was among the top three effective performers in all systems. This product s main advantage over the others tested is that it effectively controlled the Methylobacterium sp. in all slurry samples. This is also a combination biocide that provides beneficial synergy and enables the use of lower dosages. The result is a safe biocide that decreases exposure to the handler and the end-user. The product is FDA-approved under the specified clearances. It is very effective over a pH range of 8.3-9.S and unlike the 1,5-pentanedial, it produced no offensive odour. 

Separation of carbon tetrachloride from biological samples may achieved by headspace analysis, purge-and-trap collection from aqueous solution or slurry samples, solvent extraction, or direct collection on resins. Headspace analysis offers speed, simplicity, and good reproducibility, but partitioning of the analyte between the headspace and the sample matrix is dependent upon the nature of the matrix and must be determined separately for each different kind of matrix (Walters 1986). 

The instrument consists of a steel sphere (2.063 cm. in diameter) attached by a length of thin steel wire to a load cell. The slurry sample rests on a horizontal cross arm which can be raised or lowered at controlled speeds. The load cell and cross arm which are part of an Instron Model TT-C testing instrument may be used. The sphere is placed in the lower third of the slurry sample, and the cross arm is lowered at a constant speed (8.5 X 10"4 cm./sec.). The resulting force on the load... 

Multi-element analysis by ETV-ICP-MS using ultrasonic slurry sampling of silicon based minerals such as talc or quartz is described by Rodriguez et al.33 The calibration was performed in the standard addition mode, where slurries were spiked with different weights (volumes) of a multi-element standard solution of the analytes of interest.33... 

The direct determination of eight trace impurities (Na, Mg, Ca, V, Mn, Fe, Ni and Ga) in A1203 ceramic based powders by ICP-MS using electrothermal evaporation (ETV) with slurry sampling has been studied by Wende and Broekaert.66 The authors investigated the capability of several palladium group modifiers. Optimum results were obtained with the PdCl2 modifier... 

Apart from multi-element analysis employed for large scale studies, single element analysis (e.g., especially of toxic elements such as Cd, Hg, Tl or Pb) is performed in environmental science for special applications. For example, Hg and Tl have been determined in environmental samples by slurry sampling using electrothermal vaporization (ETV) ICP-MS. If potassium permanganate is employed as a modifier in ETV at optimized pyrolysis temperatures of 300 °C for Hg and 500 °C for Tl, detection limits of 0.18p,gg 1 (Hg) and 0.07p,gg 1 (Tl) are obtained.58... 

The use of discrete sample volumes to provide improved tolerance of the detector to dissolved solids, organic solvents and sample viscosity. FI provides on-line dilution and a suitable means of handling slurried samples. 

M. J. Cal-Prieto, M. Felipe-Sotelo, A. Carlosena, J. M. Andrade, P. Lopez-Mahia, S. Muniategui and D. Prada, Slurry sampling for direct analysis of solid materials by electrothermal atomic absorption spectrometry (ETAAS). A literature review from 1990 to 2000, Talanta, 56, 2002, 1-51. 

Several systematic errors were investigated, mainly related to the sample pretreatment steps (microwave acid digestion, ultrasound acid leaching and slurry sampling), calibration mode and number of repeats. Experimental designs and principal components were used... 

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