AFS/GFN
Average fineness is controlled together with the full sieve distribution, not treated as a single isolated number.
Silica application consulting
Foundry silica sand process consulting
Foundry performance depends on more than chemistry. Grain distribution, fines, clay, moisture and repeatability influence mould behaviour, finish and operating stability.
Discuss this applicationReference image: Joe Clark / U.S. National Archives, public domain. Cropped and converted to WebP.
01AFS/GFN
02Grain character
03Deleterious fines
Specification lens
What must be controlled
The target is not simply “high silica.” The useful specification is the combination of mineral, process and end-use behaviour that the customer actually needs.
Grain character
Shape, angularity and surface condition influence binder demand, permeability and mould strength.
Deleterious fines
Clay, silt, LOI and unwanted fines are managed to protect gas evolution and mould performance.
Moisture & temperature
Dryer discharge, cooling, storage and packing controls preserve consistency at the foundry.
Process architecture
Indicative equipment train
The correct foundry grade is application-specific. AFS/GFN without sieve distribution, grain shape and clay data is not sufficient.
- 01
Feed control
Scalping, washing and feed blending to stabilize incoming variability
- 02
Scrubbing
Attrition or washing duty selected to remove adherent clay without unnecessary grain damage
- 03
Grading
Hydraulic classification, cyclones and multi-deck screens for the required sieve envelope
- 04
Thermal finishing
Dryer and cooler with moisture and temperature monitoring
- 05
Final control
Screening, blending bins, dust collection, sampling and protected packing
Consulting approach
A decision path for foundry silica sand
Silica sand processing and quality guidance for foundry moulding applications, including grading, AFS control, clay, moisture and consistency.
Technical cautionThe correct foundry grade is application-specific. AFS/GFN without sieve distribution, grain shape and clay data is not sufficient.
- 01
Start at the moulding line
Understand casting size, process, binder system, defects and the foundry's accepted sand window.
- 02
Build the sieve envelope
Use retained percentages and grain shape alongside AFS/GFN to define the target product.
- 03
Tune washing and classification
Remove harmful fines while preserving useful fractions and commercial recovery.
- 04
Close the feedback loop
Link dispatch certificates and retained samples with foundry performance and complaint analysis.
Intended outcome
A controlled foundry-sand product built around the customer's moulding system and operating window.
Technical enquiry
Discuss your material and target specification
Share the source location, available test results, present process and required application. The first discussion will identify the questions that need evidence.