sorry typo..should be Anthracite is a type of coal, chemical name is silicon dioxide . Wondering how do we proof that is it food grade?
I suggest yr requirement may be based on a misconception.
I do not see any manufacturer of anthracite for filtration claiming their product is "food grade". ? eg -
Kleen Industrial Services is a direct distributor for anthracite products. Kleen Blast Anthracite filter media is produced from the highest quality anthracite available to ensure the physical characteristics of hardness, durability and performance. Anthracite typically produces consistent improvements in turbidity removal because, in part, to more efficient solids loading. Low uniformity coefficient media also produces smaller changes in effluent turbidity during periods of peak influent turbidity. Products meet or exceed the NSF/ANSI Standard 61 for Drinking Water System Components, as well as AWWA Standard B100-01.
Effective Sizes: . 60mm - 1.6mm
Uniform Coefficient: 1.3 - 1.7
Specific Gravity: 1.3
Moh's Hardness: 3
Density: 50 lbs per cubic foot
What is "food grade" anthracite ?
Yr query may be equally directed towards the claimed, attained quality of effluent when the product is implemented in yr filtration system ?
PS - an additional example specification -
anthracite for use in water filtration.pdf 489.64KB
PPS - correction - I did see one supplier of "food grade" anthracite (terminology unexplained) -