XRF Program

Crucibles and casting dishes for the preparation of samples for X-ray fluorescence (XRF) analysis

XRF is used for routine quality assurance of production in many branches of industry. For example, in the iron and steel, the manufacture of cement, the animal feed and fertiliser, the refractories industry and in all fields of metal processing. Thanks to its high degree of precision, the analysis of samples which have been homogenized by a fusion process is becoming increasingly important.

The excellent stability of platinum – even in the 1100 – 1200°C temperature range – is further improved by the addition of 5% gold. This alloy has higher strength and, in particular when melting silicates, a low wettability so that the melt can be easily removed from the crucibles and casting dishes.

Crucible in a laboratory

The inner surface of the casting dishes must be smooth, bright and very flat in order to obtain a microscopically smooth surface on the fused bead. Beam scattering caused by surface effects could lead to false interpretation of the analysis results. Therefore, all our casting dishes undergo a post-treatment and a particularly critical final inspection.

The fusion method is a technique where sample material is prepared for further analysis by XRF (X-Ray Fluorescence Analysis), ICP-MS (Inductively Coupled Plasma - Mass Spectrometry), and AA (Atomic Absorption). Sample material is combined together with a solution inside a PtAu5% crucible and melted into a homogenous mixture. This process is performed manually or in an automatic fusion machine. This method does not involve the heating of a sample to its melting point, but rather the heating of the flux to just beyond its melting point (~1050 ºC). At this stage, the oxidized sample material dissolves into the lithium borate flux creating a homogenous mixture. This mixture is then poured into either a PtAu5% casting dish or a beaker containing solution, usually diluted acid.

The mixture that is poured into the PtAu5% casting dish, cools and solidifies into a glass bead, and is then analyzed by XRF. The mixture that is poured into the beaker containing the solution is further analyzed by ICP-MS or AA.

Download the XRF Platinum program of the following manufacturers:

Dispersion Hardened (DPH) Alloy

Through a special process, Heraeus has created a Dispersion Hardened (DPH) alloy. The inclusion of finely dispersed zirconia offers an economical way to increase the mechanical strength of the product resulting in longer service times.

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