Industrial Products for Advanced Control of Mineral Processing Plants - Advanced Control and Supervision of Mineral Processing Plants - page 288

ternatives, some with broad-ranging industrial applications and others conceived
exclusively for the mining sector. Among these solutions, particularly the ones in-
tended for use in crushing, grinding and flotation, new sensors and analyzers, as well
as environments and systems for the development and implantation of advanced
control strategies are outstanding.
The rest of this chapter provides an overview of products offered in the market,
focusing on the benefits they provide. Unlike other more complete analyses such
as that by Hodouin et al. [2] and Jamsa-Jounela [3], we will confine ourselves to
a limited number of products and mention research findings just to clarify major
tendencies.

7.2 Advanced Sensors

The possibilities for developing control strategies in an industrial process are highly
dependent on what sensors are available. In the case of mineral processing, sensors
exist for measuring a variety of process variables such as those listed below:

• feeder frequency, conveyor load and crusher chute level (crushing);

• tonnage, water flow rate, mill speed, pulp level, pump speed, pulp volumetric

flow rate, pulp density, cyclone and mill pressure, and the power draw of mills,
screens, pumps and cyclones (grinding);

• pulp flow rate, cell and column pulp levels, air flow rate, reagent flow rate, wash

water flow rate and pH (flotation).

To these instruments, which may be categorized as basic given the measurement
principles they utilize, we add two more advanced ones that are also widely used:
pulp particle size distribution sensors in grinding and grade analyzers in flotation.
The last few years have seen a significant increase in the availability of indus-
trial sensors for mineral processing, some of which incorporate highly sophisticated
technologies. These include units that take granulometric size measurements on
crushing or grinding belt conveyors, determine mill operating states and charac-
terize the surface froth in flotation cells.

7.2.1 Size Distribution Sensors

The first development of size distribution sensors based on image processing date
back to 1985 [4]. Currently, there are various products that integrate hardware and
software to determine size distribution using this technique, such as Split-Online
(Split Engineering) [5] and VisioRock (Metso Minerals) [6]. KnowledgeScape [7],
Tata [8] and WipWare [9] also incorporate developments in this method.
Split-Online is an automated digital image analysis system designed to operate
continuously and monitor locations suitable for permanently installed cameras. This