Exercise 3-4. Two-stage crushing

Add a second-stage cone crusher to handle the product from the gyratory crusher that was used in example 3-3. Since cone crusher capacity is less than the gyratory you must either use more than one secondary crusher in parallel or, preferably, screen the primary crusher product and send only the oversize to the second-stage crusher.

Change the jobname to exercise 3-4 and edit the system data to name the additional product stream.

Edit the unit parameters for the additional crusher, use the model CRSH, and set the CSS to 35 mm. Leave other parameters at their default values.

Edit the parameters for the screen. Use model SCRN with 45 mm mesh.

Run the simulation and view the flowsheet. Right click on the cone crusher icon to view the report file for this unit. Check the crusher capacity in Technical Notes 5: Crushers. One 7-ft standard crusher would be required to handle the tonnage.

Save this job as exercise 3-4.

Unit number 3 MODSIM model name CRSH
Job name: Exercise 3-4 Two-stage crushing
PARAMETERS:
Fines fraction .2000
Classification function parameters .653 1.600

Tonnage to be processed 819.3 tons per hour

Closed side setting 35.00 mms

Size distribution in feed

Size % passing
mms
.101E+04 100.00
713. 100.00
505. 100.00
357. 99.86
252. 97.66
178. 87.49
126. 66.10
89.2 38.64
63.0 17.90
44.6 5.13
31.5 4.02
22.3 3.12
15.8 2.39
11.2 1.82
7.88 1.38
5.58 1.04
3.94 .78
2.79 .59
1.97 .44
1.39 .33
.985 .25
.697 .18
.493 .14
.348 .10
.000 .00

Top size in feed is approximately 286. mms

Open side feed opening must be at least 358. mms

Size distribution in product
Size % passing
mms
.101E+04 100.00
713. 100.00
505. 100.00
357. 100.00
252. 100.00
178. 100.00
126. 100.00
89.2 100.00
63.0 100.00
44.6 92.03
31.5 64.67
22.3 45.30
15.8 35.18
11.2 28.82
7.88 23.97
5.58 20.01
3.94 16.73
2.79 13.99
1.97 11.71
1.39 9.81
.985 8.22
.697 6.89
.493 5.77
.348 4.84
.000 .00

Select a crusher size and cavity type to suit the closed side setting and
feed opening requirements.

Crusher selected is......

Capacity in tons per hour? ....

Number of crushers required?....

Impact work index of the material is 12.00 kWhr/ton
80% passing size in feed is 155.74 mms.
80% passing size in product is 37.39 mms.
Estimated power requirements 259. kW

NOTES: