Training and Courses

CEMI's various areas of activity include courses on various topics in mining, including Process Simulation, Sampling, Mass and Metallurgical Balance and Mineral and Industrial Mineral Grinding provide participants with a recycling of knowledge in the various areas And provide a critical overview of the various techniques available in the mineral processing area.

The vast experience of CEMI allows a broad approach, developing themes in a constantly updated way with a focus on day-to-day business. Participants acquire theoretical knowledge that can be applied immediately. If there is interest from the participants, the problems faced by your company may be discussed.

In these courses are available the most modern and advanced software that are used as work tools, adding value to the participants.

Short description of the courses:

Mass and Metallurgical Balances

Global or detailed material balances are the fundamental means used to design and evaluate the operations of processing plants. In order to establish flow balances for these plants, it is first necessary to obtain experimental data, such as fluxes, chemical composition and particle size distribution. It is often difficult to calculate accurate balances from these parameters for the following reasons:

• The data are inconsistent and/or redundant due to measurement errors;
• A large number of equations are required to establish a detailed balance sheet in a complex plant.

The objective of this work is to present alternatives for obtaining mass and metallurgical balance through the mathematical treatment of data obtained in the process.

In addition to the theoretical approach, exercises are done during the course using BILCO software, which provides an interactive, fast and accurate means of solving material balance problems in a vast number of applications.

Scope

• Mass conservation and sampling errors;
• Adjustment procedure for material balances:
• The principle of redundancy;
• Lagrangian methods;
• Methods that do not involve derivation;
• Mass balance and consistency of process behavior.
• Sensitivity analysis:
• Proper choice of differentiating property in the process;
• The accuracy of the balance sheet due to different balance sheet strategies.
• Case Study:
• Obtaining balance in a complex process;
• Obtaining balance for circuits in which some samples were not obtained.

Grinding of Minerals and Industrial Minerals

Comminution of solids is an operation that can be used for several purposes. In the beneficiation of ores, comminution is necessary to obtain a granulometry appropriate to the concentration process used.

In the hydrometallurgy, it is not necessary to reach the liberation, if the comminution is extended to a granulometry that promotes adequate exposure of the minerals to be leached.

Comminution is necessary, in some cases, to obtain commercial products, as is the case of the production of aggregates for concrete use.

Another example of an application of the comminution is in the chemical industry, and in particular in the manufacture of cement, where it is required to promote an adequate rate of reaction of the particles, which is proportional to the specific surface, which in turn is inversely proportional to the Diameter of the particles.

In comminution operations, the forces applied to the particles are of compression, friction or impact. When the particle is large, the energy to be applied to the comminution of each particle is raised, although the total energy per unit mass is low; The application of this energy is done in an individualized way. When the particle is thin, the energy to be applied at the commencement of each particle is small, although the total energy per unit mass is high; The application of this energy, in this case, is done in a distributed way.

Thus, crushers have to be structurally reinforced in order to be able to apply high localized forces. The mills must be able to distribute a large amount of energy over a large volume of particles. Crushing is often characterized by the application of a single comminution force. The grinding is effected by the combination of compression and friction (roller mill) or the combination of impact and friction (ball mill).

Scope

• Comminution engineering: energy theory and kinetics;
• Crushing systems;
• Sampling in comminution systems;
• Dimensioning circuits and equipment by simulation;
• Grinding Systems:
• Dry processes: raw materials, cement and others;
• Moist processes: normal and reverse circuit.
• Dimensioning of tubular mills and classification equipment;
• Mechanical elements of tubular mills;
• Optimization of grinding systems:
• Procedures and diagnosis;
• Ball load;
• Classification equipment - sieves, spiral classifiers, hydro cycles, etc;
• Air separators.
• Operation and control of grinding systems;
• Mass balance in commutation circuits.

Sampling

It is necessary to have reliable information about the subject studied. This information is mainly given by measures that are rarely performed on a representation of the studied mass (radioactivity, temperature, etc.), are, in most cases, by sampling. Sampling is the operation that seeks to represent a batch of matter for a generally very small fraction of it.

Numerous factors may disrupt this sampling (systematic deviations, "nugget" effects, dimensions, types of extraction, etc.) and a sampling plan must be adapted to the characteristics of the sampled mass and the units to be sampled, humidity, size, etc.).

Despite the precautions taken, an inevitable error is committed, inherent in the heterogeneity of the constitution of matter. This error is called the fundamental sampling error (EF) and can be quantified with the ECHANT software.

The sampling of a batch of fragmented matter (for example, from a batch of a few hundred kg to a few tens of tons) usually consists of extracting from this batch a sample of a few tens of grams which will be sent for chemical analysis.

It is frequent, when there is commercial interest, that this sample is subject to parallel analyzed in different laboratories, to guarantee a very precise knowledge of its content. But the content of the sample is not considered here, but that of the lot. And the form in which this sample was obtained is often neglected.

Sampling is carried out from a batch of minerals (or mineral matter in general):

• To design or evaluate (in relation to a given mineralogical or chemical content) a sampling plan in several stages;
• Determine its granulometric distribution;
• Determine its content in a critical chemical or mineralogical constituent;
• Determine its moisture content;
• Determine your porosity.

The mathematical treatment made by Pierre Gy in the equiprovável sampling model allowed to define and estimate the variance of the fundamental sampling error, which, among other components of the total error, can be estimated a priori.

Of all the components of the sampling error, it is the only component that does not annul, whatever the properties of matter (in the state of physical fragmentation it is in) and the sampling conditions (a homogenization does not, for example, suppress it or even reduce it).

Scope

• Sampling Concept:
• Sources of errors;
• In situ and incremental sampling;
• Sampling methods.
• Theory of Sampling - Formalism of Pierre Gy.
• Calculation of fundamental sampling error.
• Sampling in the mineral industry.
• Sampling equipment and systems.
• Evaluation of a sampling system:
• Sizing of the sampling system;
• The design of sample tower.
• The sensitivity of mass balances in function of sampling errors.

Mineral Process Simulation Technology

Mineral process simulation technology is becoming more and more consolidated in the day-to-day of the process, operation and design engineers, for a wide range of applications - from circuit diagnostics, plant design and equipment design, optimization, mass balance, to operator training.

The use of simulation tools in real cases in the industry, made by local or contracted personnel, can bring immediate benefits with high rates of return of investments involved, besides a higher level of domain and process knowledge.

Scope

• History and current status;
• Methodologies:
• Direct and Reverse Simulation
• Calibration of the simulator
• Sizing equipment
• Mathematical models: from crushing to hydrometallurgical processes;
• Mass and metallurgical balances;
• Preliminary design of an ore processing plant;
• Advanced design using pilot or industrial plant data;
• Execution of scale-up;
• Process optimization.

Optimizing Process Control

Optimizing control systems continuously determine and implement optimized set points that reflect a selected control strategy while maintaining the required quality of the product and making technical-economic objectives to be achieved. This results in increased capacity, better quality control of the product and/or a decrease in production costs.

After a brief comparison between conventional control techniques and the use of optimizing control systems, a critical analysis is done on model-based control, use of neural networks and expert control with nebulous or fuzzy logic.

What are the objectives of a control system, its structure and where should be applied. Case study. The OCS Optimizing Control System is presented during the course.

Scope

• Conventional control techniques;
• Optimizing control systems;
• Specialist control with nebulous logic;
• Model-based control;
• Structure and objectives of a control system;
• Neural networks;
• Application cases;
• Optimized control system throughout the plant.

Mineral Processing

The course entitled "Mineral Processing" seeks to present all theoretical aspects of ore processing, starting with the characterization of ores, aiming at drawing the attention of the participants to the fundamental points that determine the definition of a particular circuit.

Next, special topics of sampling theory will be presented - fundamental for participants to become aware of the importance of using correct techniques to obtain representative samples of sampled lots for better control of the production process.

The third part of the course refers to a description of the various unit operations in the mineral processing - from the crushing to the hydrometallurgy - and its principles.

The next item deals with the mass and metallurgical balance of a plant. Global or detailed material balances are the fundamental means used to design and evaluate the operations of beneficiation plants. Thus, its calculation principles and the main software used for this purpose will be presented.

Finally, aspects of circuit sizing and optimization will be addressed; Followed by the last topic of the course dealing with the operation and control of mineral processes. This last topic is very important in obtaining optimized operation of mineral processing plants or mills.

Scope

• Technological characterization:
• Mineralogy fundamentals;
• Differentiating properties of ores and their constituents;
• Laboratory analysis;
• Granulometric distribution and chemical contents;
• Definition of mineral processing circuits.
• Theory of Sampling:
• Elements of statistical probability;
• Theory of sampling - Formalism of Pierre Gy;
• Calculations of fundamental sampling errors;
• Evaluation of a sampling system, sampling system design and sampling tower design.
• Mineral processing unit operations:
• Commencement (crushing, grinding, concept of degree of release);
• Classification (sieving, cycloning, etc);
• Concentration (gravimetric processes, magnetic concentration, flotation);
• Solid - liquid separation;
• Pyro and hydrometallurgical processes.
• Mass and Metallurgical Balance:
• Mass conservation and sampling errors;
• Material balance adjustment procedure;
• Principle of redundancy;
• Lagrangian Methods;
• Mass balance and consistency of process behavior;
• Sensitivity analysis;
• Proper choice of differentiating property in the process;
• The accuracy of the balance sheet due to different balance sheet strategies.
• Sizing and optimization of circuits;
• Operation and control of mineral processes:
• Regulating equipment;
• Circuit performance calculations;
• Operational strategies and control according to the variations of the material fed;
• Conventional process control techniques;
• Optimizing process control.

PID Control and Tuning Strategies

Goal

To present in a practical and objective way, notions of reduction of variability, process control theory, methodologies for tuning PID controllers and formulation of control strategies.

Methodology

The course presents the basic concepts of process control in a totally innovative way. The understanding and fixation of the concepts are obtained with practical exercises developed in a digital control system similar to the existing ones. The processes are simulated and the graphical displays and the responses of the controls are very close to those found in the practice of operating a real plant.

Target Audience

Engineers and technicians of process and control, operators, instrumentalists, involved with activities of design, coordination, operation and maintenance of control systems.

Scope

1. Process Variability and its Control

• Motivation. Control Objectives;
• Concept of variability: measurement, causes and consequences;
• Method for reducing variability;
• Evaluating opportunities and estimating benefits;
• Diagnosis of variability. nonlinearity, dead time, interactions, noise, valves;
• Variability monitoring, indices for monitoring.    

    2. Basic Concepts of Process Control

• Elements of a control mesh and type of variables;
• Process characterization. Gain, Time Constants, Dead Time;
• Analysis of the stationary and dynamic characteristics of the systems;
• The concept of dynamic stability of systems.

    3. PID Controllers

• Effects of Proportional, Integral and Derivative Control Actions;
• Type of PID algorithms and their characteristics;
• Control actions for typical applications;

    4. Tuning PID Controllers

• Identification of the process. Methods and procedure. Open mesh / closed mesh / relay;
• Tuning criteria;
• Most commonly used parameters calculation methods (Ziegler-Nichols, CC, CHR, ITAE, IMC, Lambda, BCS);
• Integrating Systems. Adjustment of level controllers with the aim of disturbance attenuation;

    5. Typical PID Control Strategies

• PID Control with Variable Gain;
• Relationship control;
• Cascade Control;
• PID Gap / Dead Band;
• Control with restrictions ("override");
• Selective control ("split-range");
• Position Control (Mid Ranging);
• Dead time compensator (Smith's predictor);
• Anticipatory control ("Feed-Forward");
• Reverse response compensator;
• Control with decoupling.

Course	Workload
Mass and Metallurgical Balance	12 horas
Grinding of Ores and Min.	20 horas
Sampling in the Mineral Industry	12 hours
Process Simulation Technology	20 hours
Optimizing Process Control	20 hours
Mineral Processing	20 hours
PID Control and Tuning Strategies	20 hours

 

 

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