Superphosphate den (SSP/TSP) simulation

phosphate rock + sulfuric and/or phosphoric acid -> superphosphate product (solid), den off-gas (CO2, SiF4, HF, steam)

Governing equations

The exact equations the solver works for a superphosphate den (ssp/tsp) — the same math shown in the app's "Theory" panel, not a black box.

$n$

waters of hydration of the calcium sulfate (0, 0.5 or 2) [-]

$\xi$

apatite attacked [mol/s]

$\eta$

attack efficiency [-]

$F_{ap}$

fluorapatite fed [mol/s]

$F_{S}$

sulfuric acid fed [mol/s]

$F_{P}$

phosphoric acid fed [mol/s]

$F_{cal}$

calcite reacted [mol/s]

$M_{P_2O_5}$

molar mass of P2O5 [kg/mol]

$n_P$

phosphorus in the product [mol/s]

$m_{prod}$

product mass flow [kg/s]

Parameters

phosphate rock attacked by sulfuric acid (single superphosphate) or phosphoric acid (triple superphosphate) to monocalcium phosphate monohydrate. temperature [K] (required, the den product and off-gas); attack_efficiency [-] (required, the largest fraction of the apatite the cure attacks when acid is not limiting); fluorine_to_gas [-] (required, fraction of the released fluorine leaving as SiF4/HF); product_moisture [-] (required, mass fraction of free water in the product); calcite_conversion [-] (default 1); sulfate_hydrate (anhydrite | bassanite | gypsum, default anhydrite). Acid below the stoichiometric demand limits the attack. No energy balance (no heat of formation for Ca(H2PO4)2.H2O is held); grade wt% P2O5, water-soluble P2O5 and acidulation ratio reported