Gravity Concentration Process Control Metallurgical Plant Operations Training

Objectives:
• Understand the principles of gravity concentration in mineral processing.
• Identify key equipment used in gravity concentration.
• Explain the role of process control in metallurgical plant operations.
• Recognize the importance of safety and quality standards.

Topics:
• Overview of gravity concentration: principles and applications.
• Types of gravity concentrators: jigs, spirals, shaking tables, dense medium separators.
• Introduction to process control: sensors, actuators, control loops.
• Basic instrumentation: flow, density, level, and pressure measurement.
• Safety protocols in plant operations.
• Quality management systems and standards (ISO, SANS).
• Plant layout and material flow.
• Course structure and assessment criteria.

Objectives:
• Describe the physical properties of slurries and their impact on separation.
• Calculate key parameters: density, viscosity, settling velocity.
• Explain particle size distribution and its effect on gravity concentration.
• Understand the principles of hindered settling and stratification.

Topics:
• Slurry rheology: density, viscosity, and yield stress.
• Particle size analysis: sieving, cyclosizer, laser diffraction.
• Settling behaviour: Stokes' law, terminal velocity, hindered settling.
• Stratification mechanisms in gravity concentration.
• Effect of particle shape and liberation.
• Sampling techniques for slurry and solids.
• Laboratory demonstrations: density measurement, settling tests.
• Calculations workshop: mass balance and recovery.

Objectives:
• Explain the operating principles of dense medium cyclones and baths.
• Identify control parameters for DMS efficiency.
• Understand medium preparation and recovery circuits.
• Analyse the impact of medium density and viscosity on separation.

Topics:
• Dense medium separation theory: sink-float separation.
• Dense medium cyclones: design, operation, and control.
• Dense medium baths: Wemco, Drewboy, and others.
• Medium preparation: magnetite/ferrosilicon, density control.
• Medium recovery: magnetic separators, densifiers.
• Control loops: density, pressure, and level control.
• Troubleshooting common DMS issues.
• Case study: DMS plant optimisation.

Objectives:
• Describe the jigging process and stratification mechanisms.
• Identify different jig types and their applications.
• Understand control parameters for jig performance.
• Analyse the effect of water flow, stroke, and ragging.

Topics:
• Jigging theory: pulsation, stratification, and ragging.
• Types of jigs: Baum, Batac, InLine Pressure Jig (IPJ).
• Jig control parameters: stroke length, frequency, water addition.
• Ragging media selection and maintenance.
• Automatic control systems for jigs.
• Performance monitoring: recovery, grade, and efficiency.
• Troubleshooting jig operation.
• Practical example: jig plant data analysis.

Objectives:
• Explain the separation mechanism in spiral concentrators.
• Identify key design features and operating parameters.
• Understand control strategies for spiral circuits.
• Optimise spiral performance through splitter adjustments.

Topics:
• Spiral concentrator theory: film flow, centrifugal force, and particle separation.
• Spiral design: pitch, diameter, number of turns, trough profile.
• Operating parameters: feed rate, density, splitter position.
• Control of spirals: feed distribution, wash water, splitter settings.
• Multi-stage spiral circuits: rougher, cleaner, scavenger.
• Performance evaluation: grade-recovery curves.
• Troubleshooting: surging, misplacement, wear.
• Case study: spiral plant optimisation.

Objectives:
• Describe the shaking table separation mechanism.
• Identify different table types and their adjustments.
• Understand control parameters for optimal separation.
• Analyse the effect of tilt, stroke, and wash water.

Topics:
• Shaking table theory: differential motion, film flow, and particle stratification.
• Types: Wilfley, Holman, Gemini, and others.
• Operating parameters: tilt angle, stroke length, frequency, wash water.
• Control adjustments for feed variability.
• Table deck covers and riffle patterns.
• Performance monitoring: concentrate, middlings, tailings.
• Troubleshooting common issues: poor separation, wear.
• Practical exercise: table setting optimisation.

Objectives:
• Identify key instruments for gravity concentration control.
• Explain the role of PLCs and SCADA in plant automation.
• Understand control strategies: PID, cascade, feedforward.
• Interpret process control diagrams and P&IDs.

Topics:
• Instrumentation: density gauges, flowmeters, pressure transmitters, level sensors.
• Actuators: control valves, variable speed drives.
• Programmable Logic Controllers (PLCs): architecture and programming basics.
• SCADA systems: data acquisition, HMI, alarm management.
• Control strategies: PID tuning, cascade control, feedforward control.
• Process control diagrams: P&IDs, loop sheets.
• Communication protocols: Profibus, Modbus, OPC.
• Practical: SCADA simulation exercise.

Objectives:
• Collect and analyse process data from gravity concentrators.
• Calculate key performance indicators: recovery, grade, efficiency.
• Use statistical tools for process optimisation.
• Implement data-driven decision making.

Topics:
• Data collection: sampling, on-line analysers, plant historians.
• Mass balance calculations: two-product formula, three-product formula.
• Performance indicators: recovery, grade, separation efficiency, Ep.
• Statistical process control (SPC): control charts, capability analysis.
• Optimisation techniques: response surface methodology, design of experiments.
• Software tools: Excel, MATLAB, Python basics.
• Case study: optimising a spiral circuit using data.
• Practical: data analysis workshop.

Objectives:
• Describe safe start-up and shutdown sequences for gravity circuits.
• Identify emergency situations and appropriate responses.
• Understand lockout/tagout (LOTO) procedures.
• Develop contingency plans for equipment failure.

Topics:
• Start-up procedures: pre-checks, sequence, ramp-up.
• Shutdown procedures: normal and emergency shutdown.
• Emergency response: spills, fires, equipment jams.
• Lockout/tagout (LOTO) procedures.
• Alarm management and troubleshooting.
• Contingency planning: backup equipment, bypass circuits.
• Safety drills and role-playing.
• Practical: simulated start-up and emergency response.

Objectives:
• Identify common wear areas and maintenance requirements.
• Develop preventive maintenance schedules.
• Understand condition monitoring techniques.
• Implement reliability-centred maintenance (RCM).

Topics:
• Wear mechanisms: abrasion, corrosion, erosion.
• Maintenance of jigs: ragging replacement, screen decks.
• Maintenance of spirals: splitters, liners.
• Maintenance of shaking tables: deck covers, drive mechanisms.
• Maintenance of DMS equipment: cyclones, pumps, magnetic separators.
• Condition monitoring: vibration analysis, thermography, oil analysis.
• Preventive maintenance scheduling.
• Reliability-centred maintenance (RCM) principles.

Objectives:
• Understand water balance in gravity concentration plants.
• Describe water treatment and recycling methods.
• Explain tailings disposal options and environmental impact.
• Implement water conservation strategies.

Topics:
• Water balance: sources, usage, losses.
• Water treatment: clarification, flocculation, filtration.
• Water recycling: thickeners, ponds, reuse.
• Tailings disposal: conventional, paste, dry stacking.
• Environmental regulations and compliance.
• Tailings dam management and monitoring.
• Water conservation strategies.
• Case study: water optimisation in a gravity plant.

Objectives:
• Apply advanced process control techniques.
• Implement model predictive control (MPC) basics.
• Use expert systems and fuzzy logic for optimisation.
• Integrate control across multiple units.

Topics:
• Advanced process control (APC): overview.
• Model predictive control (MPC): principles and applications.
• Expert systems and fuzzy logic in mineral processing.
• Multivariable control and decoupling.
• Optimisation of integrated circuits: spiral-jig-table combinations.
• Real-time optimisation (RTO) concepts.
• Software implementation: DCS, APC packages.
• Practical: simulation of advanced control.

Objectives:
• Understand quality control (QC) procedures in gravity concentration.
• Implement statistical quality control (SQC) methods.
• Conduct audits and ensure compliance with standards.
• Develop quality improvement plans.

Topics:
• Quality control in mineral processing: sampling, assaying.
• Statistical quality control: control charts, acceptance sampling.
• Quality assurance: ISO 9001, SANS standards.
• Internal and external audits.
• Non-conformance management and corrective actions.
• Continuous improvement: PDCA cycle, Six Sigma.
• Case study: implementing QC in a gravity plant.
• Practical: quality control exercise.

Objectives:
• Integrate all aspects of gravity concentration process control.
• Review key concepts and address gaps.
• Prepare for final assessment.
• Develop a personal action plan for application.

Topics:
• Integration of process control across the gravity circuit.
• Review of key learning points from all days.
• Final assessment: written test and practical demonstration.
• Feedback and discussion.
• Action planning: applying learning to own plant.
• Course evaluation.
• Certification and close-out.
• Networking and resources.