摘要:
A method for treating a solid substrate comprising a support comprising, preferably consisting of, at least one oxide chosen from the oxides of a first metal chosen from the rare earths, the mixed oxides of a first metal chosen from the rare earths and at least one second metal different from the first metal, and the mixtures of an oxide of a first metal chosen from the rare earths and at least one oxide of at least one second metal different from the first metal, said support comprising at least one surface on which there are deposited particles consisting of at least one noble metal, in order to separate the first metal, the optional second metal, and the noble metal which constitutes the particles, said method comprising a step of selectively dissolving the support, during which the substrate is brought into contact with a dissolving solution comprising at least one mineral acid and at least one reducing agent for reducing the rare earth or rare earths of the support chosen from natural antioxidant molecules such as ascorbic acid, catechol, gallic acid and the mixtures of same, thereby obtaining a solution containing the first metal and the possible second metal in the dissolved state, in which there are suspended the particles consisting of the noble metal.
摘要:
System for analysing, by laser induced plasma spectroscopy, the composition of the surface layer of a material and for taking samples with a view to performing complementary analyses or examining this superficial layer, and method related thereto. The system comprises a single pulse laser (6), for generating a pulse laser beam, able to interact with the superficial layer of the material and produce a plasma on the surface of the material (4); a device (10, 12) for focusing the laser beam onto the surface of the material; a device (18, 20) for collecting the light emitted by the plasma; and a device (22) for analysing the spectrum of the collected light and for determining the elementary composition (nature and relative concentration of the elements) of the superficial layer from this spectral analysis. According to the invention, it furthermore comprises a device (30, 32, 34) for sucking up and collecting particles representative of the superficial layer, extracted from the latter, under the effect of the laser beam, with a view to performing qualitative or quantitative complementary analyses or examininations on the basis of said particles.
摘要:
The invention relates to an induction melting furnace comprising shell (7) and a lower sole (11) forming the main part of the structure. In addition, the furnace comprises a removable inner crucible (1) formed by an inner layer (4) that is resistant to heat and to the aggressive nature of the molten bath (20), an outer layer (6) defining the crucible, and an intermediate insulating layer (5). The crucible (1) is a single-use crucible and can be stored, together with its charge, in a suitable container. Heat losses are low, even if the shell (7) is cooled. In addition, stresses due to differential thermal expansions are also very low.