Laboratory and Processing Services

Flotation at the mineral processing laboratory in Outokumpu. Photo: Jari Väätäinen, GTK

The GTK geolaboratory is a leading European facility hosting chemical, isotope, mineral research and mineral processing laboratories and a pilot plant. The applications were originally developed for earth science applications, but currently increasingly modified for environmental and process technological research and monitoring.

The geolaboratory of GTK is accredited and fulfills the requirements of ISO 17025 quality standard. In addition to analytical methods, the accreditation covers also the most important environmental sampling methods. Additionally, the laboratory also compiles the guide CAN P 1579 (Guidelines for Mineral Testing Laboratories). All customer tailored analytical methods are validated against international standards to guarantee the traceability of the results, which are controlled and maintained by a comprehensive laboratory information system in order to provide complete chain of custody. As part of the quality system the laboratory regularly participates in inter-laboratory and proficiency testing schemes. The laboratory promotes the international quality assurance development through international organizations such as Eurolab, Eurachem and IAG (International Association of Geoanalysts). GTK laboratory experts are widely used as quality assessors by the accreditation bodies and as consultants to develop quality systems in partner laboratories

The mineral processing laboratory and pilot plant facilities, in the scale and variety GTK has them, are rare in the world. A full study including mineralogical work, bench scale tests and a pilot campaign can be undertaken in our premises for the client’s ore evaluation projects. The capacity of the pilot plant (from 0,5 up to 5 t/h) fulfills the requirements of testing the workability of the complete continuous beneficiation process. A properly conducted pilot scale research is the most reliable method for assessing the commercial exploitability of the mineral deposit. Besides, as a part of the feasibility study, basic engineering can be conducted for the planned processing plant with a fixed throughput, including the equipment sizing, cost estimation and preliminary layout design. The required data for engineering purposes is collected during laboratory and pilot plant studies.

On bench scale, we have facilities to perform grindability tests, including those specifically developed for autogenous grinding. Flotation and magnetic or gravity separation methods can be used for beneficiation studies, complemented with dewatering tests on the products. Hydrometallurgy, such as pressure oxidation and leaching, may be applied to minerals which respond poorly in beneficiation. The latest field of our research includes bio-processing applications for extraction of metals and minerals.

Pilot scale campaigns have been carried out using ore batches of, say, 25 to 3,000 tons, the most common sample size in grinding-flotation studies being 100 to 300 tons. Our pilot plant is equipped with a versatile selection of process units in crushing, homogenization, grinding, classification, magnetic separation, gravity concentration, dense media separation, flotation and dewatering. Modern instrumentation connected to a process computer is used for process control and data collection.

The developed mini-pilot facility, built inside a sea container, can be used to treat samples of just few tons in a continuous process. This unit may be moved to handle the ore at a mine site, or to operate parallel to an existing process in a concentrator. Fresh feed capacity of the mini-pilot is normally around 10 to 50 kg/h.

Chemical analyses, provided by Labtium Oy, an independent spin-off company, include element and other inorganic determinations on rock, mineral, soil, water and air filter samples, and on plant and animal tissues. Specialized applications involve analysis for base-line and exploration geochemical surveys, environmental studies and monitoring, with a particular emphasis on the mining environment. For exploration and mining, the laboratory provides a full spectrum of analytical services for gold and other precious metals, from cyanidation tests to complete PGE determinations down to geochemical background levels. These services are also often used by the material and process industries, and in the engineering, business and health sectors.

The mineralogical research facilities include a variety of instrumentation for identifying, characterizing and analyzing solid materials, e.g. natural minerals including ore and industrial minerals, metals, alloys, diamond indicators and environmental samples.

Current facilities include two electron microprobes (EPMA), a low vacuum scanning electron microscope (LV-SEM), an X-ray diffractometer (XRD) and an IR-spectroscope. The Cameca SX-100 EPMA has 5 wavelength dispersive spectrometers (WDS) for accurate quantitative analysis and element mapping (Be to U) and an energy dispersive spectrometer (EDS) for element analysis and mapping. The EPMA unit is also equipped with a cathodoluminescence (CL) detector to complement the secondary (SE) and back-scattered electron (BSE) analysis. The LV-SEM methods are used for electron optical imaging and EDS elemental analysis and mapping.

Identification of minerals and other solid crystalline materials is performed by X-ray diffraction (XRD). Other well-used methods are IR spectroscopy, DTA-TGA and naturally, optical polarizing microscopy.

GTK has built a leading edge diamond exploration facility, unique inside the EU. This facility is specialized in heavy mineral surveys and diamond prospectivity evaluation and is used to provide and produce customized, high quality research services to companies within Finland and abroad. GTK mineralogists provide expert service also in evaluating and validating lapidary materials, like gold and platinum nuggets, precious and semiprecious stones and, interestingly, also meteorites.

The isotope geological laboratory facilities enable to provide high quality U-Pb analyses for dating and uses Sm-Nd, Rb-Sr and Pb-Pb methods as well as analyses of stable isotopes (C, O and H) to study the genesis of rocks and other materials and to investigate geological processes and environmental changes. Larger scale rock age dating projects have been carried out for institutional and private sector clients. The stable isotope research is increasingly focused on ground water research and monitoring as part of the water supply industry and nuclear waste disposal studies.