Metallurgical-grade fluorspar — Determination of silica content — Reduced-molybdosilicate spectromet...
The principle of the method specified is to decompose a test portion by alkaline fusion with sodium carbonate and subsequent acidification with hydrochloric acid in the presence of boric acid to complex fluoride, selective reduction to the blue molybdosilicic acid complex, spectrometric measurement of the absorbance of the coloured complex at a wavelength corresponding to the absorption maximum…
Acid-grade and ceramic-grade fluorspar — Determination of iron content — 1,10-Phenanthroline spectro...
The method specified is based on alkaline fusion of a test portion with a mixture of sodium carbonate and boric acid, dissolution of the melt in excess hydrochloric acid, reduction of the iron(III) with hydroxylammonium chloride, formation of the iron(II)-1,10-phenanthroline complex in a buffered medium (pH between 3 and 5), spectrometric measurement of the absorbance of the coloured complex at a…
Acid-grade and ceramic-grade fluorspar — Determination of silica content — Reduced-molybdosilicate s...
The method specified is based on decomposition of a test portion by fusion with sodium carbonate and subsequent acidification with hydrochloric acid in the presence of boric acid to complex fluoride, formation of the molybdosilicic acid complex and selective reduction to the blue molybdosilicic acid complex with addition of tartaric acid to prevent interference from phosphate, spectrometric…
Acid-grade and ceramic-grade fluorspar — Determination of total phosphorus content — Reduced-molybdo...
The method specified is based on dissolution of a test portion by fusion with a mixture of sodium carbonate, boric acid and sodium nitrate and subsequent acidification with nitric acid, formation of the molybdophosphate complex and extraction with a mixture of ethyl acetate and butyl acetate, followed by selective reduction of the complex to molybdenum blue by means of tin(II) chloride added to…
Ductile iron pipelines — Rubber sealing rings for pipelines carrying potable water
Lays down the material specifications of solid vulcanized rubber sealing rings and specifies requirements for their effect on the organoleptic properties (colour, taste and odour) and the total organic carbon content of water. In the case of composite seals (which comprise, e.g. both rigid and flexible rubbers), applies only to the requirement for their effect on the total organic carbon content…
Metallurgical-grade fluorspar — Determination of total phosphorus content — Reduced-molybdophosphate...
The principle of the method specified is to decompose a test portion by alkaline fusion and subsequent dissolution of the melt in excess of nitric acid, precipitation of iron(III) phosphate with ammonia solution, dissolution of the precipitate in nitric acid, formation of the molybdophosphate complex and extraction, followed by selective reduction of the complex to molybdenum blue, spectrometric…
Acid-grade and ceramic-grade fluorspar — Determination of flotation agents
The principle of the method is treatment of a test portion with a mixture of dilute hydrochloric acid and an organic solvent, removal of the insoluble fluorspar by filtration under vacuum, separation of the organic phase containing the flotation agent, evaporation of the solvent and weighing of the residue. Applies to materials which have been subjected to flotation process and which have…
Helical-scan digital composite video cassette recording system using 19 mm magnetic tape, format D2 ...
Specifies the content, format and recording method of the data blocks forming the helical records of the tape containing video, audio and associated data using the 19 mm type D-2 cassette. In addition, this document specifies the content, format and recording method of the longitudinal record containing tracking information for the scanning head associated with the helical records.
