Crystallization + granulation finishing — a PENG-ROBINSON process flowsheet
A continuous MSMPR crystallizer, cake filter, and dryer feed a granulator that grows the dried crystals into free-flowing granules — the finished-product train after the mother liquor and dryer vapor leave.
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- Rigorous PENG-ROBINSON thermodynamics, solved by the same engine every simulation runs on.
- 4 unit operations modeled: CR, FIL, DRY, GRAN.
- Focus areas: Crystallization, Granulation, Solids mass balance.
- Verified fast convergence — a real, measured solve time, not an estimate.
- Thermodynamics
- PENG-ROBINSON
- Components
- water, glycine
- Unit operations
- CRFILDRYGRAN
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Read the step-by-step guideReproduce this exact result from Python — the real client.get_example() → run_and_wait() path, not a mockup.
from flowsim.sdk import FlowSimClient
client = FlowSimClient()
example = client.get_example("crystallization-granulation")
sim = client.create_simulation(example["title"], example["flowsheet"])
result = client.run_and_wait(sim["id"])
print(result["status"]) # "converged"
streams = client.streams(sim["id"])Related models
Crystallize → thicken (dewatering)
An MSMPR crystallizer precipitates the salt, then a gravity thickener dewaters the crystal slurry into a dense underflow while a clarified overflow leaves the top — the solid-liquid separation a hydrometallurgy plant runs before filtration.
Solids train (crystallize → filter → dry)
An MSMPR crystallizer feeds a cake filter and dryer — the crystal size and cake moisture propagate on the stream's solids payload (pharma / minerals workflow).
DAP granulation loop: pre-neutralizer, ammoniating granulator, scrubbers
Diammonium phosphate at the scale of one Jorf Lasfar (JESA) granulation train: 40.2 kg/s (145 t/h) of wet-process phosphoric acid is neutralised by ammonia in two steps and granulated in a loop that recycles four times its own product. The acid carries the composition Handley (IFA, 1984) gives for a commercial merchant-grade acid, per 100 g: 54.82 g H₃PO₄ (39.7% P₂O₅), 3.90 g H₂SO₄, 5.68 g of metal and fluoride impurities (carried as one inert lump) and 35.60 g water. It is pumped first through the tail-gas scrubber and the pre-scrubber, which take back the ammonia the reactors do not absorb, then into the pre-neutralizer, which holds a mole ratio NH₃:H₃PO₄ of 1.44 at 114 °C (near the ratio of highest ammonium phosphate solubility, so the least water keeps the slurry fluid) and boils off water with its own reaction heat. The slurry is sprayed onto the rolling bed of the ammoniating granulator, where sparged ammonia lifts the ratio to 1.845. New solid layers onto the recycled granules (an equal-thickness growth law on the full size distribution), the bed is dried to 3% moisture, a double-deck screen splits it at 3.35 and 1.70 mm, the oversize is crushed, and fines, crushed oversize and 73% of the on-size go back to the granulator. The rest is cooled and sold. The 73% is the split that puts the loop at the recycle ratio Handley reports, 4: a plant sets its recycle to absorb the slurry's water, so here it is an input, not a prediction. Solved: 33.7 kg/s of product (121 t/h), 18.7% N and 47.6% P₂O₅ on a dry basis, above the 18-46-0 commercial grade, which is set by the acid's sulfate and impurities rather than by the 21.2-53.8 of pure DAP. Consumption per tonne of product is 0.227 t NH₃ and 0.474 t P₂O₅. An 18-46-0 product carries 0.219 t of NH₃ as nitrogen and 0.46 t of P₂O₅ per tonne by its grade alone; the difference is this product's richer grade and the ammonia lost at the stack. The recycle ratio is 4.0, and the loop converges on its own tear machinery (six tears, Wegstein). The pre-neutralizer releases 19.1 MW of reaction heat and evaporates 7.3 kg/s of water; the granulator releases 6.9 MW and evaporates 5.2 kg/s; the dryer takes 1.7 kg/s more for 7.1 MW. 0.029 kg/s of ammonia leaves the stack, 0.4% of what is fed, which is what two scrubbers at 90% recovery each give.
Crystallization with agglomeration (distributed CSD)
An MSMPR crystallizer solved with the rigorous distributed population balance (not just moments): the full crystal-size distribution is computed on a size grid, and an agglomeration (aggregation) kernel combines fine crystals into larger ones — coarsening the mass-weighted mean size (d43) and broadening the distribution (CV rises above the growth-only MSMPR value of ~1.0) while conserving mass exactly. The distribution, its coefficient of variation, and d43 propagate on the solid stream into the filter and dryer — the gPROMS/gCRYSTAL capability the moment model structurally cannot provide.
Grinding-circuit hydrocyclone classifier
A hydrocyclone classifies a mineral slurry by particle size — the unit that closes every closed-circuit grinding loop (mill → cyclone, coarse underflow recycled to the mill). A quartz slurry (200 µm mean, spread by a log-normal PSD) is split about a 100 µm corrected cut size (Plitt 1976): the coarse solids report to the thick underflow and the fines to the dilute overflow, split by the short-circuit recovery. The underflow comes out much coarser (~300 µm mean) than the overflow (~80 µm), and the solids mass balance closes exactly. Honest scope: the d50c is the real Plitt correlation, but the partition sharpness and water recovery are screening params.
Cobalt/nickel solvent extraction (D2EHPA)
A laterite leach liquor (Co/Ni/Mg in dilute sulfate solution) meets a D2EHPA-in-kerosene organic phase across a 20-stage countercurrent extraction circuit run at pH 5.2 — the real industrial operating window (e.g. Bulong, Murrin Murrin, Western Australia) that exploits the ~1 pH-unit gap between Co and Ni's D2EHPA extraction isotherms: Co extracts into the organic while Ni (and Mg gangue) are rejected to the raffinate. The loaded organic then meets fresh dilute-acid strip liquor across a 10-stage strip circuit at pH 1.0 (well below Co's isotherm), reversing the equilibrium to recover a concentrated cobalt strip liquor and regenerate barren organic. Real pH-isotherm chemistry throughout, not a fitted shortcut K_D.