Chromite sand AFS45-55 fine powder ratio

Chromite sand AFS45-55 fine powder ratio

Chromite sand AFS45-55 is a commonly used model in sand casting. Its particle size meets the requirements of AFS Foundry Association. However, in practical applications, the ratio of fine powder under a 100 mesh sieve has a significant impact on the performance of casting sand. In the quality control process of casting grade chromite sand, 4-5 mesh screens are usually used for particle size distribution testing. The particles screened below 100 mesh and above 140 mesh are not further sorted. Recently, a customer has special requirements for the particle size of AFS45-55. Our lab conducted further tests on the particles under 140 mesh, 200 mesh, and 270 mesh sieves. The following are the test results:

1. Five seives test Chromite sand AFS45-55 particle size distribution:
   

   Mesh	Percentage
   +40mesh(425um)	1.80
   +50mesh(300um)	22.50
   +70mesh(212um)	59.20
   +100mesh(150um)	12.00
   +140mesh(106um)	4.30
   Fineness	AFS51.944

   2. Seven seives test Chromite sand AFS45-55 particle size distribution:

   Mesh	Percentage
   +40mesh(425um)	1.90
   +50mesh(300um)	24.85
   +70mesh(212um)	55.92
   +100mesh(150um)	13.21
   +140mesh(106um)	2.35
   +200mesh(75um)	0.95
   +270mesh(53um)	0.82
   Fineness	AFS53.037

Thus, there is a little difference of AFS fineness value with different test process.