Sodium fluoride for industrial use — Preparation and storage of test samples
Relates to crude samples intended for the determination of moisture content and dried samples for chemical tests. Processing by grinding and sieving until the sample passes completely through a sieve of mesh aperture 0.125 mm. Thoroughly mixing and drying and storing in a tightly closed container.
Fibre building boards — Determination of sand content
The purpose of the method specified is to obtain an indication of machinability by cutting tools. The principle is based on the complete combustion of test pieces and weighing the sand remaining in the desiccator at the end of the procedure. The tubular hearth used to ignite the test pieces is shown in the figure.
Boric acid, boric oxide and disodium tetraborates for industrial use — Determination of chromium con...
Alkaline fusion of a test portion by sodium carbonate and subsequent neutralization by sulphuric acid. Measurement of the absorption of the complex formed by chromium and diphenylcarbazide at a wavelength of abour 540 nm after adding sodium azide for elimination of the colour caused by manganese.
diSodium tetraborates and crude sodium borates for industrial use — Determination of water content ...
Heating a test portion in a combustion tube at 250 0C, later at 500 0C. Passing through the liberated water carried by a flow of nitrogen into a tared absorption vessel filled with magnesium perchlorate. Weighing the absorption vessel and determination of the mass of water by difference.
Boric acid, boric oxide and disodium tetraborates for industrial use — Determination of chloride con...
The principle consists in titration of the cloride ions with standard volumetric mercury(II) nitrate solution in presence of diphenylcarbazone as indicator until the colour of the solution matches the mauve of the standard end-point matching solution.
Boric acid, boric oxide, disodium tetraborates, sodium perborates and crude borates for industrial u...
Preliminary reduction of the iron(III) by hydroxylammonium chloride, if required, suppression of the interference of tin by oxalic acid. Formation of the coloured iron(III)-2,2'-dipyridyl complex in a buffered medium. Photometric measurement of the coloured complex at a wavelength of about 522 nm.
Crude sodium borates for industrial use — Determination of iron soluble in alkaline medium — 2,2...
Applicable to products in which the content of soluble iron exceeds 2 mg/kg. The preparation of the test solution is carried out according to ISO 2217. Reduction of the iron(III), contained in the aliquot part of the solution, with hydroxylammonium chloride. Formation of the coloured complex between iron(II) and 2,2'-dipyridyl in buffered solution. Photometric measurement of the coloured…
Crude sodium borates for industrial use — Determination of aluminium soluble in alkaline medium — ED...
Applicable to products in which the content of soluble aluminium, expressed as Al2 O3 , exceeds 100 mg/kg. The preparation of the test solution is carried out according to ISO 2217. The reaction proceeds with the formation of the complex between EDTA and aluminium in an aliquot part of solution. Decomposition of the complex using sodium fluoride. Titration of the amount of liberated EDTA against…
Aqueous hydrofluoric acid for industrial use — Sampling and methods of test
Contains also titrimetric methods for determination of the total acidity, the hexafluorosilicic acid content and the non-volatile acids content and a method for calculating the hydrogen fluoric content. Specifies the scope and the field of application of these methods and declares the principle of the procedures. This second edition results from the incorporation of Addendum in the first one.…
