Exercise 5-1 Single-stage flotation plant using the Klimpel model.

Draw a flowsheet with a single flotation cell (A bank of flotation cells with one cell). The ore to be treated is from a porphyry copper sulfide deposit with chalcopyrite and pyrite as the main sulfide minerals in a silicate gangue. To keep a focus on the flotation model we will assume that the minerals are perfectly liberated. Therefore there are three minerals, silicates with specific gravity 2.71, pyrite with specific gravity 5.0 and chalcopyrite with specific gravity 4.1 in 3 grade classes. Since the Klimpel model does not allow the kinetic constant to vary with particle size, only one size class is required. Set largest particle size to 5.0E-4 m. Each grade class consists of one pure mineral so check the grade-class set up. Specify a feed rate of 75 tonnes/hr at 28% solids. The composition of the feed is 80% silica, 8.5% pyrite and 11.5% chalcopyrite. Specify 1 mesh size on the feed stream form and clear the default size distribution.

It will be useful to track the grades and recoveries of Cu and Fe in this exercise so edit the output format and request grades and recoveries of individual metals. Chalcopyrite contains 34.6% Cu and 30.4% Fe. Pyrite contains no Cu and 46.7% Fe.

Choose model KLIM for the flotation cell. Choose a single cell of 10 m^3 with 15% air holdup. Set the concentrate percent solids to 55%. This value will fix the water balance around the cell. The kinetic parameters for the minerals are

Mineral	Ultimate recovery %	Kinetic constant 1/min
Silicates	12	0.12 (0.0020 1/sec)
Pyrite	53	0.8 (0.0133 1/sec)
Chalcopyrite	83	2.5 (0.0417 1/sec)

Table 1. Klimpel parameters for the feed.

Run the simulation and you should find that the cell will recover 71% of the copper at a grade of 21% Cu. The concentrate will also contain 29% Fe.

Save this job when you are satisfied with the result.