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Representative results require adequate sample preparation
The following situation is typical for many production plants: After a routine quality check, the production process is stopped or an already produced batch is suspended, because the analysis results were not within the relevant critical values. But does the tested product really deviate from the specifications? The quality control managers are convinced of this because modern analysis instruments provide results with very low tolerances. The sample in question was tested several times and the result was confirmed. The question is why the product does not match the specifications although the production parameters have not been changed in any way.
The possibility that the tested product is indeed deficient cannot be excluded. However, it is often not the product itself which causes irregular analysis results but a lack of understanding of the steps which come before the analysis.
Sieving of agglomerating powders with the air jet sieving machine AS 200 jet
Air jet sieving is usually the method of choice for dry sieving of materials with particle sizes below 40 microns. However, it is also a faster alternative to vibratory sieving of materials of up to 250 microns.
Separation of large sample volumes with the AS 450 control
Particle analysis of large quantities of bulk goods is usually done by vibratory sieving. In most vibratory sieve shakers in the market the sieve stack is mounted
on springs which oscillate vertically. However, to evenly distribute the material
over the entire sieve surface, the so called 3D vibratory sieving as it is used in the AS 450 control is the most suitable method. This is characterized by a circular
motion superimposing the vertical throwing motion so that the sample material
is moved over the whole sieve.
Air Jet Sieving of Bulk Materials
Particle size analysis and particle size distribution are important criteria for the quality control of bulk materials. In a running production process, the results of a quality check must be available quickly to allow for immediate adjustment of the production parameters. Depending on the expected particle size and sample volume, different sieving methods and sieving machines are suitable for analysis. The method used for particle size analysis is primarily determined by the fineness of the material to be sieved. For dry sieving of samples with particle sizes below 40 microns, air jet sieving is the method of choice.
Renewable raw materials are gaining ground
The representative sample preparation of plants requires experience
Fast and Reproducible Sample Preparation with a Vibratory Disc Mill
The Vibratory Disc Mill RS 200 from Retsch is used for the quick, loss-free grinding of hard, brittle and fibrous materials to analytical fineness.
Cement - representative sample preparation is important
To produce high-quality cement, the mineralogical and chemical composition of raw materials as well as intermediate and finished products has to be determined. At each stage of the production, samples have to be taken, processed and analysed to ensure quality control without gaps. Retsch offers a range of instruments that are used for sample preparation during the complete production process, from the quarrying of the raw materials to the final product. The typical sample preparation process involves preliminary size reduction, sample division and fine size reduction before the sample can be submitted to further analyses....
Size reduction within the context of sample preparation
In general “size reduction” is taken to mean the disintegration of solid substances by mechanical forces without altering their state.
Sample Preparation of Solid Materials for the XRF-analysis
X-Ray fluorescence is one of the most versatile methods to determine elements in a sample. The material is exposed to x-rays that cause each element to emit its own unique fluorescent x-ray. The subsequent analysis of the results is based on comparisons to standard samples with given chemical composition.
Die neue Power Generation
Planeten-Kugelmühlen haben seit jeher einen festen Platz in der täglichen Laborpraxis zur Feinzerkleinerung unterschiedlichster Materialien. Neben dem Mischen und Zerkleinern hat sich in den letzten Jahren auch im mechanischen Legieren z.B. thermoelektrischer oder hochkoerzitiver Materialien ein weiteres Anwendungsgebiet ergeben.
Molienda ultrarrápida y ultrafina
El nuevo molino ultracentrífugo ZM 200 de RETSCH es un molino de rotor no sólo extremadamente rápido y cuidadoso con el material molido, sino también de uso universal gracias a su amplia gama de accesorios.
Preparación de muestras altamente heterogéneas para el control de calidad
El agotamiento de los recursos y el aumento del precio de los combustibles primarios tales como el petróleo, el gas o el carbón han obligado a la industria del cemento a buscar fuentes alternativas de energía. Otro factor contribuyente es, sin duda, el comercio de emisiones que hace todavía más rentable el cambio a fuentes de energía con un balance neutro de CO2, en su mayoría combustibles no fósiles. En los últimos años, se ha registrado un incremento en el uso de fuentes de energía alternativas, especialmente por aquellas industrias con una alta demanda energética. En consecuencia, viene ganando cada vez más importancia el empleo de combustibles secundarios o alternativos, que en su mayoría son extraídos de residuos urbanos e industriales – es decir, residuos urbanos que no han podido ser recuperados ni reciclados.
