Exercise 3-3. Gyratory crusher

The next three exercises step you through the method to develop a crusher circuit to produce 1200 tonnes/hr of 80% passing 10 mm aggregate.

Start a new MODSIM job.

Select a single gyratory crusher for the flowsheet and add a feed stream and a product stream.

Edit the system data and select one mineral of specific gravity 2.7.

Set the largest size to 1.2 m with 25 size classes.

Double click on the number of the feed stream to specify feed stream data. Name the feed stream, show 20 size classes, and use Rosin-Rammler distribution with D63.2 = 40 cm, lambda = 1.4. Remember to click the clear button to generate the R-R distribution.

Name the product stream before accepting the system data.

Edit the unit parameter and select model GYRA for the gyratory crusher.

Select the following parameters: OSS = 15 cm, WI = 12 kWh/tonne. Average ore type.

Edit the output format and select tonne/hr for solid flowrate.

Run the simulation.

View the particle size distributions in the feed and product streams.

View the flowsheet. Right click on the crusher icon to view its report file. Note that the output includes a table of size distributions for the crusher feed and the crusher product. An estimate of the power required is also calculated using the crushing work index and the d80 sizes of feed and product. You should investigate how the size distribution of the crusher product varies as the open side setting is varied.

Unit number 1 MODSIM model name GYRA
Job name: Exercise 3-3

Tonnage to be processed 1500. tons per hour

Open side discharge setting 15.00 cms

Size distribution in feed

Size % passing
cms
101. 97.41
71.3 89.45
50.5 74.94
35.7 57.34
25.2 40.81
17.8 27.59
12.6 18.03
8.92 11.52
6.30 7.26
4.46 4.53
3.15 2.81
2.23 1.74
1.58 1.08
1.12 .67
.788 .41
.558 .26
.394 .16
.279 .09
.197 .06
.139 .04
.985E-01 .03
.697E-01 .02
.493E-01 .01
.348E-01 .01
.000 .00

Top size in feed is approximately119.08 cms

Dimension A of crusher must be at least148.85 cms

Minimum head diameter required to handle the tonnage.....
"Fall through" material in feed 22.38 percent.
Scalping of the feed is recommended.

Size distribution in product

Size % passing
cms
101. 100.00
71.3 100.00
50.5 100.00
35.7 99.91
25.2 98.40
17.8 91.46
12.6 76.85
8.92 58.11
6.30 43.95
4.46 35.02
3.15 27.47
2.23 21.28
1.58 16.32
1.12 12.43
.788 9.41
.558 7.10
.394 5.34
.279 4.00
.197 3.00
.139 2.24
.985E-01 1.67
.697E-01 1.25
.493E-01 .93
.348E-01 .70
.000 .00

Impact work index of the material is 12.00 kWhr/ton
80% passing size in feed is 561.95 mms.
80% passing size in product is 134.43 mms.
Estimated power requirements 251. kW

Power requirement to allow for 35% surge capacity 338.6 KW.

Crusher selected.....

Crusher capacity from manufacturer's tables.....tons per hour.

Number of crushers required......

NOTES: