Washability Test

For certain gasification processes it may be necessary to limit the ash fraction in the coal to a certain value. Because the mineral matter has in general a higher density than the organic fraction of the coal, a density or float-sink separation can be carried out to remove material of increased mineral matter. This process is suitable for higher-rank coals and is accomplished using a liquid with an adjusted density. Therefore, it is also called washing of coal. 

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In order to characterize the cleanability of a coal, washability tests are typically performed for a range of particle sizes and... 

The net result of the washability test methods is to subdivide coal into fractions having progressively decreasing mineral matter ash content and progressively... 

Use 1 to 2 oz/gal for cleaning floors and walls. Use full strength to remove oil, grease, tar, gum, asphalt, fresh paint, adhesives, scuff marks and lipstick stains. Brush where necessary. Rinse with water. For prolonged use, wear rubber gloves. Gardner Straight Line Washability Test ... 

Malik presented data [27] on the detergency of C12 and C13.6 SMEs via a modified Gardner Straight Line Washability Test [39]. The test solutions consisted of 0.6% of the test surfactant and 0.12% tetrapotassium pyrophosphate in 140 ppm as CaCOj water at 25°C. The C12 SME gave equivalent performance compared to decyl and branched dodecyl diphenyl oxide disulfonates. The Cl3.6 SME slightly outperformed the Cl2 SME but was not quite as good as the C8-10, 5-mole ethoxylated phosphate ester that was also included. Both SMEs contained the analog sulfonated fatty-acid sodium salts as secondary snrfactants. 

This paper describes the result obtained in a study of AFCEN (French Society for Design and Construction Rules for Nuclear Island Components) in order to characterize dye penetrant product family, based on experimental test methods of french standards NFA 09.520 and NFA 09.521. In particular, sensitivity tests have been carried out on artificial defects, and correlated with tests on real defects. Some tests on penetrant washability have also been performed. The results obtained with these three series of tests show that the choiee of a dye penetrant product family is not without influency on results obtained, and that is not so simple to make the good choice which could, in certain cases, be the less bad compromise. 

The removing penetrant test is performed on sanded and cracked reference block defined in standard NFA 09.520 ( see figure 1, annex 1) and permits the evaluation of the washability of penetrants. 

Determination of the washability characteristics of coal by the float and sink (float-sink) method can be applied to coal of any particle size provided suitably large vessels to hold the larger lumps are available. Air-dried coal, not dry coal, should be used since the separation depends partly on the difference in specific gravity of the clean coal and dirt particles, and the specific gravity, in turn, is dependent on the moisture content of the coal. If the coal is dried before the test is carried out, the conditions will then differ from those in commercial washers, and the results will be at variance with those obtained in practice. 

ASTM D-4371. Standard Test Method for Determining the Washability Characteristics of Coal. 

Test Method for Determining the Washability Characteristics of Coal," Method D 4371, Annual Book of ASTM Standards. Vol. 5.05, Amer. Soc. for Testing and Materials, Philadelphia, PA, 1988. 

These define and give methods of test for dimensions of rolls, washability, and colour fastness when exposed to light. Means of application, the matching of patterns, and the removal of wallcoverings also are discussed. 

Dye solutions should be chosen with some care they should be easily washable from the ampoule surfaces after the test and should not be toxic in the event of unsatisfactory washing they should also have a high color intensity or fluorescence, and these properties should not be lost by interaction with the ampoule contents. 

The development status of process control instrumentation lags that of the quality control instruments significantly Nuclear density gauges function in the coal preparation plant environment The slurry concentration meter has application in the intermediate and fine sized coal cleaning circuits and needs to be tested in a preparation plant Other devices, such as ash monitors to control the operation of heavy media baths or jigs are not available and instruments developed for other process industries are not suitable for use in coal preparation plants Modeling studies of the various unit operations are required in order to ascertain the fundamental parameters required to automate the control of these systems Primary process control instrument needs include ash, sulfur, and moisture monitors secondary needs include an on-line washability and ash fusion measurement ... 

Washability curves Graphical presentation of the float-sink test results. Two types of plots are in use Henry-Reinhaid washability curves and M-curves. 

Imagine instead an environment where the surfaces could not only alert you to die presence of infection but could even communicate the level of contamination and whether or not the mvironment had become dangerous. There is a need for a visual warning indicator, preferably within the immediate vicinity of contamination and that responds whilst in situ and is not reliant on off site lab tests. A textile-based substrate would have advantages of being washable, renewable and cost effective. 

Washability Ease with which the dirt can be removed from a paint surface by washing also refers to the abihty of the coating to withstand washing without removal or substantial damage. Koleske JV (ed) (1995) Paint and coating testing manual. American Society for Testing and Materials. 

ASTM International, D4488-95R01E01 Guide for Testing Cleaning Performance of Products Intended for Use on Resilient Flooring and Washable Walls, ASTM International, West Conshohocken, PA, 2006-2007. 

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