ASTM D718-86 pdf free.Standard Test Methods for Analysis of Aluminum Silicate Pigment.
Reagent grade chemicals shall be used in all tests.Unless otherwise indicated, it is intended that all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society,5 where suchspecifications are available. Other grades may be used, pro-vided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.Unless otherwise indicated, references to water shall beunderstood to mean Type ll of Specification D 1193.
If an appreciable residue remains after the treatmentwith HF in accordance with 7.4 of Test Methods D 717, fusethe residue with a small amount  until it is dissolved.Leach the pyrosulfate melt out of the crucible with water andcombine the solution with the filtrate reserved in accordancewith 7.3 or Test Methods D 717.Bring the volume of the combined solution to 250 mL,and, if necessary, add in order to ensure a total of 10 to 15mL of HCl, add a few drops of methy1 red indicator solution,and heat to boiling. Add concentrated (sp gr 0.90)dropwise until 1 drop changes the color of the solution to adistinct yellow.Reheat the solution containing the precipitatedhydroxides to boiling, boil for 1 or 2 min, and filter. Carefully weigh out the proportion of the standardextender pigment and standard zinc oxide mutually agreedupon, and rub up to a fairly stiff paste with a glass muller on aglass plate or stone slab with raw linseed oil conforming toSpecification D 234.Note the volume of the oil required.Prepare a similar paste with the sample using the same weightof pigment, volume of oil, and number of strokes of the glassmuller as used in the preparation of the paste of the standardpigments. Spread the pastes adjacently on a microscope slide,draw a scraper lightly across them to present them on an evenplane, and judge the color immediately.ASTM D718 pdf download.