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Analysis of silicon dioxide particles according to the European standard EN 12904.

December 28, 2025
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The analysis of the particle size distribution of silicon dioxide is one of the most important quality control methods in water treatment,     filtration     , and refractory material manufacturing. The standard EN 12904 describes a method for determining the particle size distribution of silicon dioxide used in water treatment plants. This article provides a comprehensive overview of the test methodology, the required equipment, and the significance of the results.

The importance of silicon dioxide particle size analysis.

1. Filtration efficiency

  • This directly affects the efficiency of particle removal.

  • This is due to a voltage drop in the system.

  • Effects on the backwashing process

2. Service life of the filter layer

  • Prevention of particle compression

  • Reduction of equipment wear and tear

  • Prevents the injectors from becoming clogged.

3. Wastewater quality

  • Its influence on the turbidity of purified water.

  • Function: Removal of colloidal particles.

  • Regarding backwashing requirements

Equipment required for the test

  1. Standard sieve      (conforms to the standards of the ISO 3310 series)

    • Common font sizes: 0.5, 0.7, 1.0, 1.4, 2.0, 2.8, 4.0 mm

  2. mixer  

    • It allows horizontal and vertical movements.

    • The duration and intensity of the vibration can be regulated.

  3. precise scales

    • The accuracy is at least 0.1 grams.

    • Sufficient bandwidth

  4. Laboratory furnace

    • Temperature 105 ± 5 degrees Celsius

    • It is used for drying samples.

Tested according to European standard EN 12904.

Step 1: Sample preparation

  • Take a random sample from the entire batch of goods (at least 5 items).

  • Homogeneity of the original sample

  • Reduce the sample quantity to the amount required for analysis (approx. 500 grams).

  • Place the sample in the oven to dry for two hours.

Second step: Perform a vibration test.

  • Arrange the sieves in descending order of particle size (largest sieve on top).

  • Place the sample on the top sieve.

  • Assembly of the rocking bed (duration: 15 minutes).

  • Weigh the remaining material on each sieve.

Step 3: Calculation and analysis of the results

  1. Calculate the percentage of material retained on each sieve     :

    text
    Percentage residual content = (weight of material on the sieve / total weight of the sample) x 100

  2. Specify the effective size (d10)     :

    • Only 10% of particles of a certain size pass through the filter.

  3. Calculation of the unification coefficient (UC)     :

    text
    UC = d60 / d10

    • The optimal value for a sand filter is between 1.3 and 1.7.

  4. Determine the curvature modulus (CC)     :

    text
    CC = (d30)² / (d10 × d60)

    • Application range: 0.8-1.2

Important criteria for particle size analysis

1. Effective size

  • Definition: The diameter of a particle through which 10% of the resin passes.

  • Standard filtration range: 0.35–1.2 mm

2. The unification factor

  •    Particle size distribution index   

  • A higher value indicates a wider range of particle sizes.

3. Particle size range

  • Minimum and maximum permissible particle size

  • The thickness of sand filters is typically between 0.5 and 2.0 mm.

Application of the results of the particle size distribution analysis.

1. Design of the filtration system

  • Set the height of the filter level.

  • Determine the optimal filtration rate

  • Backwash system design

2. Quality control of the silicon dioxide used.

  • Compliance with procurement standards

  • Detection of pollutants and contaminants

  • Check if there are differences between  different  product batches.

3. Troubleshooting the cleaning system.

  • Diagnosis of problems related to low blood pressure

  • Investigate the reasons for    the decline    in filtration efficiency.

  • Determination of filter layer corrosion

Key points of the exam

  1. Correct sampling     :

    • Application of common   sampling methods

    • Prevent particle separation during sampling.

  2. Test requirements     :

  3. Device calibration     :

Compared to other criteria

standard scope How does it work? Report parameters
EN 12904 Water filtration Dry mix d10, UC, CC
ASTM C136 Building materials Dry/Wet Smoothie The distribution is complete.
ISO 565 food industry The air trembled. Approval rate

Common problems and solutions

1. Accumulation of small particles

  • Reason     : Presence of particles smaller than 0.3 mm.

  • Solution     : Clean the silicone    thoroughly before use.

2. Wide range of grain sizes.

  • Reason     : The UC value   is greater than   1.7.

  • Solution     : Use silicon dioxide with a  more uniform  particle size.

3. Particle size reduction

  • Reason     : Insufficient transport options.

  • Solution     : Repeat  the analysis  after stabilization.

In conclusion

Particle size analysis of silicon dioxide according to the European standard EN 12904 is     a crucial tool for quality assurance of silicon dioxide used in filtration systems. Precise analysis and correct interpretation of the results can improve the performance of water treatment plants, reduce operating costs, and extend plant lifespan. Due to the sensitivity of silicon dioxide applications in the water treatment industry, regular testing and documentation of the results are strongly recommended.