Injectors for Pumped Sidestream Flows

The Multi Mix injector uses the energy of turbulent eddies generated by slurry flow over the injector head to create sized oxygen bubbles, which are then dispersed within the slurry.

A unique feature of the Multi Mix injectors is the ability to varying the system pressure and with it the pumping energy requirements. The Multi Mix injector operates at a significantly lower pressure than "high shear" type oxygen injectors / mixers. For ores with a high oxygen demand, a secondary mixing device may be installed downstream of the injector to increase the system pressure and thereby oxygen mass transfer. Similarly, the secondary mixing device may be installed when oxygen mass transfer efficiency outweighs energy utilisation.

The energy utilisation by a Multi Mix injector may be tailored to suit the specific requirements for each gold ore.

The injector is installed within a housing supplied by Multi Mix, as depicted in Figure 1. The injector is fabricated from 316 stainless steel and all wetted services are lined with a wear resistance ceramic and custom-made Linatex sleeves. The injector design and fabrication ensures a long service life and minimal maintenance. The injector is designed such that it seals automatically when gas flow stops. The self-sealing mechanism, in combination with a small flushing water flow, prevents slurry clogging the injector head.

The Multi Mix injectors offer the following benefits:

• High gas utilisation efficiency

• Elevated dissolved oxgyen concentration achieved in gold ore slurries.

• Low feed pump power requirement resulting in low operating costs.

• Low installation costs.

• Long service life, typically greater than six months.

• Minimal maintenance - one person can remove an injector head and install a new unit in approximately 15 minutes. A crane is not required.

• Installation tailored for each application.

Several Multi Mix injector models are available to suit a variety of slurry flow rates: