Control strategies for grinding circuits

Posted on Friday, 15 January 2021 at 12:00

Mineral processing plants are using advanced systems to control their operations. Instrumentation is a key part of it, since those instruments obtain real-time data on the processes to be used in control loops. The instruments data can for example be used to control valves, pumps and to add dilution water to slurries. In this blog we will discuss the most common control variables found in the (re)grinding circuit and discuss strategies and systems that are being used at the Maria Dama gold processing plant in Colombia.

Recently, Maria Dama started to use the SCADA control system. SCADA is the Data Acquisition and Monitoring System that is responsible for acquiring variables and data from field devices, which are sent to servers and converted into process information. The real-time information is visually available in the monitors at the site control room, so that process engineers and operators can take actions over their operations. A relevant operation is grinding, where they can easily see the tons of ore processed per hour for example. Density, flowrate and the pressure are usually monitored in the cyclones. All the information received helps operators to make faster decisions and analysis over the process behavior in order to achieve a high performance and efficiency of the plant.

Benefits of advanced process control:

  • Total control of the plant through monitoring
  • Analysis and evaluation of the process performance
  • Enhanced problem solving

Below you can find a piping and instrumentation diagram (P&ID) showing an overview of control variables in a typical (re)grinding circuit.

Gran Colombia Gold is using Rhosonics density meters at different operations. At the segovia plant, one SDM is installed with a wafer in the four inch pipe in the underflow of a thickener. The slurry density is measured and controlled when being transferred to an agitator tank where it is conditioned. From there it is subsequently pumped to a filter press that recovers a large percentage of water to deliver a compacted paste for disposal (dry tailings). The second SDM is installed with a wafer in an eight inch pipe at the hydrocyclone feed. The slurry density between the ball mill and the cyclones is also measured and controlled based on targets set by the plant process engineers.

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Tags: Grinding circuit, Density meters, SDM Density Meter, Densímetro não radioativo para polpa, Densimetro no nuclear para pulpa, Non-nuclear, Non Nuclear Density Meter, Mineral processing industry, Processamento mineral, Processamiento mineral, No-核密度计