The determination of aluminum in refractories is a complex task. When chemical methods are used for this purpose, the aluminum is very often separated from the other components. This prolongs the analysis and makesit very labor-consuming.The atomic-absorption method is promising as it can be done accurately and at high speed. Many publications [1][2][3][4][5][6][7][8] deal with the atomic-absorption method of determining aluminum. However, the published data are contradictory and they are difficult to use because of the great variety of compositions of the refractories, the use of various types of atomic-absorption spectrophotometers, sources of light, etc.The present paper reports some results of a refinement of the optimum measurement conditions for the atomic-absorption analysis of A1 and a study of the effect of the components involved in the composition of the solutions to be analyzed.We have developed and documented the method of measuring the mass fraction of A1203 in refractory materials.The work was carried out in an AAS-IN atomic-absorption spectrometer (made by CarlZeiss, Jena, GDR) using an acetylene-~itrous oxide flame as the atomizer.The atomic absorption of A1 was measured at a wavelength of 309.3 nm and a slot width of 0.025 mm. The source of radiation was a lamp with a hollow cathode of the LSP-I type. A coupler was used to couple the Soviet-made lamp to the fitting of the device. The current in the lamp was the maximum possible for the spectrophotometer (15 mA). The measurements were made in a regime where there was a once-only passage of the beam through the flame since the use of a threefold passage of the beam introduces additional noise in the atomic-absorption measurements in the case of A1 atomized in a limited region of flame.Sodium in a concentration of 2 g/dm 3 was added as the ionization buffer.The main solution of A1 with a concentration of 1 g/dm 3 was prepared by dissolving metallic A1 (Technical Specification 6-09-3742--74) in HCI. The working solutions were obtained by the appropriate dilution of the main solution.The effect of the composition of the gas mixture on the absorption of A1 was studied with a steady consumption of N20 of 230 liters/h and of acetylene of from 150 to 180 liters/h. It was found that a change in the consumption of acetylene has an intense effect on the analytical signal from A1 and therefore the consumption of acetylene must be maintained strictly constant. With an increase in the consumption of acetylene, the absorption of A1 increases. As the optimal acetylene consumption we took 170 liters/h (height of red zone of flame, i0 mm) since with a further increase in the consumption of acetylene, carbon deposits rapidly form on the burner.In selecting the optimal height of the flame zone we established that when the. burner is raised to its maximum possible position, the atomic absorption of A1 increases.By changing the dimensions of the eccentric roller we were able to raise the burner another i0 mm, and this made it possible to increase significantly the sen...