Measurement And Control Solutions

The Measurement and Control division has developed a range of specific Advanced Process Control Solutions that are implemented on Mintek’s process control platform, StarCS. Advanced stabilisation and optimisation control has been developed for Milling, Flotation, Smelting and Gold Leaching.

LeachStar

LEACHING CONTROL

LeachStar is Mintek’s advanced control suite, specifically designed for gold circuits. It incorporates leading technology to optimise the performance of the various process units found on gold circuits, including thickeners, leaching circuits and carbon circuits.

The LeachStar suite of controllers increases plant performance and improves safety by deploying:

  • Advanced signal fault detection.
  • Safety checks, ensuring safe control of cyanide in particular.
  • Advanced control techniques, especially designed for each process unit.

The LeachStar suite comprises of the following controllers:

  • Thickener Control
  • Cyanidation Control
  • Adsorption Carbon Movement Control
  • Cyanide Destruction Control

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THICKENER CONTROL

When thickeners are located between unit operations, such as between milling and leaching, they present an opportunity to be used in an integrated control strategy. It is possible to significantly stabilise individual thickeners as well as downstream circuit operation by employing an effective thickener control and optimisation solution.

The LeachStar Thickener Controller is aimed at providing the following benefits:

  • Reduction in flocculent consumption.
  • Improving the clarity of the thickener overflow water.
  • Ensuring stable thickener operation by minimising bed slides or high rake torque scenarios.
  • Stabilising the flow rate and density of the underflow, thereby improving the performance of downstream processes.

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CYANIDATION CONTROL

Cyanide is a significant operating cost. It’s effective use requires a dosage rate related to the operating conditions on the plant, and the pH of the solution must be held in the correct range.

Furthermore, cyanide represents probably the most significant health and safety risk on gold circuits. Safe control of the cyanide dosage is imperative.

Mintek also supplies the Cynoprobe Cyanide Analyser for online measurement of free and WAD Cyanide.

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ADSORPTION CARBON MOVEMENT CONTROL

Carbon- in- pulp plants offer the potential for excellent recoveries of gold, but the operating conditions must be correct. Upsets to the plant must be detected early enough so that appropriate action can be taken.

Apart from the cyanide and pH controllers already mentioned (and applicable to adsorption control) the LeachStar control suite also includes a carbon management strategy that efficiently moves carbon upstream.

To support the Carbon Movement Controller, Mintek also supplies the Carbon Concentration Meter (C² Meter) for the online measurement of adsorption carbon.

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CYANIDE DESTRUCTION CONTROL

Environmental legislation dictates maximum permissible levels of WAD (Weak Acid Dissociable) cyanide in the tails stream from treatment plants. In some cases it is required to employ a cyanide destruction process to adhere to environmental legislation.

Mintek also supplies the Cynoprobe Cyanide Analyser for online measurement of free and WAD Cyanide.

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