How buyers compare silica sand grades
How buyers compare silica sand grades by mesh or AFS grain, iron as Fe2O3, and moisture, and which of the three moves a glass, foundry, or ceramic purchase.
A silica sand grade is not a brand name. A glass furnace, a foundry, and a ceramic body can all buy “silica sand” and reject each other’s material. Buyers who compare lots quickly end up on three checks: grain size, iron, and moisture. Everything else on a sheet is context for those three.
Grain size
Grain is the mesh, the sieve band, or the AFS number the plant already qualified. Glass wants a band that melts evenly. Foundry wants a band that packs and vents. Filtration wants a band that holds a flow rate. Construction often wants a clean, graded sand and is less strict on iron.
Ask for the cut, not for “fine” or “coarse”. If two offers do not name the same sieve series, they are not comparable yet. Silica sand from Skylark is graded to the band you send. There is no single mesh on that page pretending to fit every plant.
Ground quartz powder is a different product. It is milled to a mesh for coatings and fillers. Do not treat a 200-mesh powder as a substitute for a foundry sand.
Iron
Iron is reported as Fe2O3. It colours glass and it colours a ceramic body. Flint and clear glass sit at the low end of what the trade calls a silica sand. Foundry and some construction uses can accept more. A percentage without your limit is not a grade.
Compare the method as well as the number. A typical range printed for a grade family, including the typical range on the silica sand page, is not a certificate of analysis. The sheet for the lot is the number you hold the supplier to.
Moisture
Wet sand upsets a furnace charge and a foundry mix, and it means you paid to ship water. Washed sand is dried so moisture stays low. A typical figure for this grade family is below half a percent. Your purchase order should still name the maximum you will accept, because “low” is not a specification.
What to send with the comparison
Put four lines in the inquiry: the sieve or AFS band, the maximum Fe2O3, the maximum moisture, and the quantity. Add packing if you already know it. Destination port is your port, named by you. Skylark does not publish a port list on the site.
Then compare the current sheet with those four lines. A grade that misses grain size will not be saved by a strong silica number. A grade that misses iron will not be saved by a perfect mesh. Buyers who reverse that order spend a trial on sand they should have rejected from the sheet.
