Metallurgical Laboratory

A metallurgical laboratory must offer extensive professional experience in both the metallurgical and chemical disciplines. The personnel have to provide a strong working knowledge of the industrial area as well as the requirements necessary for the successful results of the tests.

Process development testing is the sequel too a comprehensive preliminary investigation of mineral recovery processes. Tests are conducted in the laboratory to study, supplement and develop initial investigation and to supply sufficiently comprehensive engineering data to design, construct and operate a profitable industrial plant. The metallurgical lab has an important role before the industrial operation and during the operation.

With the initial work the number of batch test required can vary from a few on the simple ore to perhaps hundreds for complex ores. The complexity of the tests and the possible effects on the final product require an exhaustive analysis. The tests procedure should be planned in each advance and a preliminary flowsheet can be obtained if there are not problems at this stage. For example the process development for new projects involving flotation normally consists of bench scale studies followed by pilot plant testing and subsequent scale up to the industrial plant. The bench scale studies permit determination of basic parameters for the process. These parameters include such items as mineralogical and liberation characteristics, a preliminary treatment flow-sheets, flotation kinetics, reagent types and dosages, etc. The studies are also used to estimate the variability of the ore body by testing samples of different characteristics obtained from different zones within the deposit. The preliminary flotation tests are usually done using drill core samples obtained from the exploration program, as these tests require small amounts of sample, usually from 1 to 4 kg of ore. Operationally, they are simple and inexpensive tests, and they are usually carried out in open circuit.

To evaluate the process selected on a continuous basis, pilot scale tests are performed which allow mass, metallurgical and water balances to be obtained along with more detailed information for the project engineering studies. These tests are expensive and demand considerable operational effort and of course personnel very skilled. Continuous pilot plants also consume great quantities of ore. As these tests are conducted during the feasibility phase of the project, it is often necessary to develop a drilled program exclusively for obtaining the bulk ore samples, making the investment in terms of cash outlay and project schedule even greater.

When the plant is working, the metallurgical laboratory is involved in typical task such as assure a good performance of the ball mills taking samples and determining is the ground ore is within the operative conditions. If the plant has a good level of instrumentation, the lab has to assure the optimal performance of the instruments. For example, the courier requires to be checked periodically because operators are used follow the results reported by the courier and most the time bad results are justified considering the information obtained with the measurement instruments. Other task is to verify the metallurgical performance of the ore that will be sent to the plant.

As can be seen, the metallurgical lab has duties that many times are not considered with the real importance.