Particle size distribution Process Flowsheets & Simulations
Explore 2 validated, solved Particle size distribution simulation flowsheets in MaximaLabs — real components: quartz, chalcopyrite, water. Open any one directly in your browser.
Solved via: PENG-ROBINSON.
Closed-circuit crushing and grinding, with the size distribution carried
180 t/h of quartz ore at a 60 mm median goes through a cone crusher in closed circuit with a 16 mm screen, then a ball mill in closed circuit with a 150 micron screen. Every solid stream carries its full particle-size distribution, class by class, so each unit acts on the distribution rather than on a median and a spread. The crusher is Whiten's model: everything finer than its 12 mm closed-side setting passes, everything coarser than its 30 mm open-side setting is broken, and between them a classification function decides. It reduces the circuit feed from an F₈₀ of 90 mm to 13.4 mm for 165 kW, and the screen returns 19% of what it receives to it. The mill is a breakage/selection-function size-mass balance in three mixed stages, not a target size: its product is whatever the breakage of each class produces, fines tail included. The 150 micron screen sends 72% of the mill discharge back, a circulating load of 258% that nobody specified — it is where the recycle settles given the breakage rate and the screen's sharpness. The circuit product leaves at a P₈₀ of 158 microns, and the screen recovers 81% of the true undersize, because a screen with a sharpness of 3 is not a perfect cut. Bounded, and stated. The mill's power is Bond's law applied to the mill's own throughput and its own F₈₀ and P₈₀; Bond's work index is defined on the circuit's fresh feed, so read it as a screening number. The breakage function is Broadbent-Callcott and the selection exponent 1.0 — an ore's own breakage and selection parameters come from its laboratory tests and replace them. Dry circuit: water is not carried.
8 unit ops • PENG-ROBINSON
38 0
View & openGrinding to liberate, flotation to recover: a copper rougher
97 t/h of a 2 wt% chalcopyrite ore in quartz, crushed to a 2 mm median, is ground in a grate-discharge mill and floated in an 8-cell rougher bank. The feed declares its composition by size (psd_minerals) and its texture (150 micron grains), so every unit acts on mineral by size, not on one distribution. The mill is Whiten's perfectly mixed mill with a 0.6 mm grate: nothing coarser can leave, so the coarse fraction is held and ground until it passes. That is why the mean residence time comes out at 643 s against the 300 s the fines see, and the mill holds 17.9 t. The product P₈₀ is 240 microns for 615 kW. Chalcopyrite breaks 1.5 times faster than quartz here, so it ends up enriched in the fines. Liberation is computed, not assumed: at 150 micron grains only 17% of the chalcopyrite sits in fully liberated particles at this grind. The rougher floats every particle type at a rate set by its grade, so a composite floats slower than a liberated grain and drags quartz with it. It recovers 87.0% of the chalcopyrite into 15.4% of the mass, a concentrate grade of 11.3% against 2% in the feed, and leaves 0.31% in the tailings. The sensitivity is the grind-recovery trade. Grind longer and recovery and grade rise together (80% at 100 s, 93% at 900 s) while the mill's power rises with them, which is the decision a concentrator's grind size is set on. Bounded, and stated. Every ore parameter here is illustrative and fitted to no deposit: the selection rate, the grain size and the flotation rate constants are measured per ore (the breakage-fit tool measures the first from a batch test). A composite's flotation rate is taken as proportional to its grade (linear exposure); there is no froth recovery, no size dependence of the rate beyond liberation, and one valuable mineral.
6 unit ops • PENG-ROBINSON
39 0
View & open