Silica Sand Washing — Attrition Scrubbing & Hydraulic Classification (2D)

Process Controls

Washing intensity (attrition) 38%

Water-to-sand ratio (classifier current) 34%

Feed rate (throughput) 52 t/h

Live Readout

SiO₂ in product

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Fe₂O₃ impurity

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Sand yield

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Grains processed

Avg. attrition time

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Product grade

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How it works

Every grain entering the plant carries a real composition — a random 0.6–3.2% Fe₂O₃ (iron-oxide staining) and 2–9% clay, the rest quartz (SiO₂). Nothing is faked at the readout: the panel numbers are the live average of grains that have actually finished the process.

Attrition (top band): a rotating scrubber paddle abrades the loose coatings off each grain. Clay erodes fastest (it is a weak surface film); iron-oxide staining is chemically bonded and erodes slower — which is why 100% SiO₂ is never reached, only approached:

dClay/dt  = -0.45·(intensity/100)·clay
dIron/dt  = -0.10·(intensity/100)·iron
SiO2      = 1 - clay - iron  (renormalised)

Higher feed rate pushes grains through the attrition band faster, so each grain spends less real time being scrubbed — more throughput, slightly less cleaning, exactly the trade-off real plants face.

Hydraulic classification (lower column): an upward water current (set by the water-to-sand slider) fights each grain's own settling velocity, which follows a simplified Stokes' law from its size and the density its remaining iron/clay coating gives it:

density  = 2.65·SiO2 + 2.30·clay + 5.20·iron
v_settle = k·(density − 1)·radius²
v_net    = v_settle − v_current

Grains that out-settle the current sink to the underflow (product, tan). Fine clay and iron debris — small and light — mostly cannot out-settle the current and are carried to the overflow launder (waste, top right). Push the current too hard and it starts sweeping away small clean grains too, trading purity for lost yield — again, an emergent trade-off, not a scripted one.

Clean sand grain Dirty / coated grain Iron-oxide fines Water current