Capabilities

 

Analytical

The assayers at Autec have extensive experience in mineral analysis and are able to provide rapid and reliable assays for pilot plant, bench scale and research test work.

The assayers at AuTec have extensive experience in mineral analysis and are able to provide rapid and reliable assays for pilot plant, bench scale and research test work.

AuTec has been a regular participant in the biannual Geostats round robin gold assay program sponsored by Barrick since 2006. The AuTec Assay Lab prides itself on passing every single time and achieves this through its dedicated assay staff and excellent quality control program. The AuTec assay lab is consistently in the top tier of all (127 worldwide) participating labs in the Geostats lab proficiency testing program.

Besides providing analytical support for testwork programs carried out at AuTec, the assay group also assists with check assays for Barrick mines and external clients for quality control, and continues to provide consulting services for mine site assay lab commissioning and trouble-shooting.

Assay Capabilities 
Fire Assay for Au/AgAAS/ICP-OES/Gravimetric finish
Wet Assay for base metals (ICP-OES)/AA finish
Aqua regia and 4-acid digestion (HF + HNO3, HCl, HClO4)
Carbon and Sulfur Analysis

  • Speciation by classical methods and Leco finish

  • Sulfur speciation by difference
    • Direct analysis for total sulfur, sulfate sulfur and elemental sulfur
    • S2- = (Stotal – SSO4 – S0)


  • Carbon speciation by difference
    • Direct analysis for total carbon and organic carbon
    • Cinorg = (Ctotal – Corg)


Ion Chromatography Anion AnalysisS2O32-, S3O62-, S4O62-, S5O62-, S6O62-, SCN-, SCN-, CNO-, CI-, SO3-, SO42-
Classical Titration Methods

  • Ferrous/Ferric solution determination

  • Free acid determination


    Site support and quality control
    AuTec staff were tasked with the commissioning of the assay lab at Pueblo Viejo, one of Barrick’s newest operations and one that performs strongly on QA/QC comparisons
    AuTec personnel helped set up the fire assay protocol at the Turquoise Ridge lab.
    Third-party clients have requested site visits by AuTec personnel to assist with mine site lab procedures and quality control

    Relevant Equipment

    Classical Method Equipment Direct Analysis of Mercury Ion Chromatography (IC) Carbon and Sulfur Analysis Wet Assay Equipment Fire Assay for Au/Ag
     

    Mineralogy

    AuTec has a state-of-the-art mineralogy facility. Our ability to run mineralogical analyses concurrently with process development is extremely valuable and provides a tremendously improved depth of understanding. Mineralogical analyses ahead of metallurgical testwork allow refinement of test programs, and mineralogical analyses in conjunction with testing allow for understanding of results, which allows for better direction of the test program.

    AuTec has a state-of-the-art mineralogy facility. Our ability to run mineralogical analyses concurrently with process development is extremely valuable and provides a tremendously improved depth of understanding. Mineralogical analyses ahead of metallurgical testwork allow refinement of test programs, and mineralogical analyses in conjunction with testing allow for understanding of results, which allows for better direction of the test program.

    Key mineralogical data includes modal mineralogy with trace and accessory minerals, grain size distributions, liberation and locking association data for all minerals of interest which can include both ore and gangue minerals. Mineral data can be accompanied by colour mineral images, mineral maps of particles and solid samples and corresponding electron backscatter images to give examples of textures.

    Examples of mineralogy applications
    modal mineralogy of ore, flotation products, roaster products and leach residues for research and process development samples, and for operation trouble shooting
    metal and deleterious element deportment
    gold deportment augmented by diagnostic leaching
    mineralogy for exploration purposes, including mineral maps for solid samples from hand specimen and drill core, and gold deportment
    analyses focusing on acid rock drainage potential
    regular analyses of mine production composite samples to track changes in ore body mineralogy
    environmental and occupational health samples analysis to check for deleterious minerals (e.g. deleterious elements, fibres, coatings)

    Relevant Equipment

    FEI Quanta 600 TIMA (Tescan Integrated Mineral Analyzer) Energy Dispersive X-Ray Microanalysis Stereomicroscope CLEMEX (Image Analysis System) X-Ray Diffraction (XRD) Sample Preparation
     

    Sample Preparation Capabilities

    AuTec is well equipped to handle a wide variety of ore samples with large-scale and laboratory-scale drying, crushing and splitting equipment. AuTec has the capability to prepare homogeneous sub samples from large bulk samples in order to perform a wide range of analytical, mineralogical, comminution and metallurgical test work.

    AuTec is well equipped to handle a wide variety of ore samples with large-scale and laboratory-scale drying, crushing and splitting equipment. AuTec has the capability to prepare homogeneous sub samples from large bulk samples in order to perform a wide range of analytical, mineralogical, comminution and metallurgical test work.

    Using a range of crushers, splitters and screening equipment, AuTec can reduce sample particle size, split into representative sub samples or size fractions. Equipment sizes range to allow AuTec to hand large samples of run-of-mine ore down to small samples of a few hundred grams.

    The following chart shows the mass of sample required to get a representative split at varying passing sizes:

    samplepreperationchart

    Relevant Equipment

    Pulverizer Ro-Tap Gilson Macro and Micro Rotary Splitter Small Rotary Splitter Large Rotary Splitter BOYD Crusher Jaw Crusher Cone Crusher Kue Ken Crusher
     

    Comminution

    AuTec is capable of performing a wide range of comminution test work including abrasion index for determining wear rates, Bond and modified Bond ball mill work index for determining grind ability characteristics, JK Tech Rotary Breakage Testing to determine impact breakage data for the design of AG/SAG mills and crushers

    AuTec is capable of performing a wide range of comminution test work including:

    • abrasion index for determining wear rates
    • Bond and modified Bond ball mill work index for determining grindability characteristics
    • JK Tech Rotary Breakage Testing to determine impact breakage data for the design of AG/SAG mills and crushers

    Bond Abrasion Work Index (Ai)

    The Bond Abrasion Work Index (Ai) is used to determine the steel wear rates within grinding circuits. The Ai is determined by placing sample of a fixed particle size (+½” – ¾”) in a rotating drum with an impact paddle. The paddle is made from a 500 Brinell hardness standard alloy steel. The abrasion index is determined by the weight loss of the paddle. This test requires a minimum of 1.6 kg of sample at the required particle size.

    Bond Ball Mill Work Index (BWi)

    The Bond Ball Mill Work Index (BWi) test is used to determine the net power requirements to grind a specific ore reducing its feed size (80% passing, F80) to a product size (80% passing, P80). The normal finishing size of this closed circuit dry grindability test is typically 150 microns, but other sizes can be selected based on process requirements. The method uses a standard Bond ball mill and grinding media. This test requires a minimum of 6 kg of sample with a feed size of 100% passing 3.36 mm. There is a modified version of the Bond Ball Mill test. The modified test requires calibration against the standard test but can be used to profile large ore bodies.

    JK Rotary Breakage Testing (A x b JKDWT)

    The JKRBT was developed by JK Tech to allow for a rapid and accurate method to generate impact breakage data. The JKRBT has been shown to provide statistically similar results to the JKDWT in far less time, allowing for the tests to be carried out at a lower cost.

    The full RBT requires between 60 and 100 kg of sample with a minimum top size of 63 mm. This ensures adequate sample is provided to acquire the necessary number of particles. The full RBT test is carried out at the following 12 impact energy levels and particle size combinations:

    Particle Size0.10 kWh/t0.25 kWh/t1.00 kWh/t2.50 kWh/t
    45 × 37.5 mm
    31.5 × 26.5 mm
    22.4 × 19 mm
    16 × 13.2 mm

    The RBT lite test procedure uses a single size fraction and four energy levels to deliver A×b values. The standard RBT lite procedure is carried out at the following energy levels (with their corresponding RBT operating RPM). The size selected also allows for a rapid determination of the t10 with a 1 mm screen.

    0.20 kWh/t0.50 kWh/t1.00 kWh/t2.00 kWh/t
    11.2 × 9.5 mm1351203027613756

    Full-scale results can be estimated based on calibration samples from the ore body. This approach uses a small number of samples that are subjected to the entire test and a larger number of samples to the abbreviated test after which a calibration is applied based on the variation of impact breakage properties by particle size.

    For the RBT lite, JKTech consultants carry out the calibration of the results based on the full DWT.

    Relevant Equipment

    JK Rotary Breakage Tester Bond Abrasion Mill Bond Ball Mill
     

    Mineral Processing

    AuTec has a fully equipped mineral processing laboratory, providing ore characterization, physical separation based on size, specific gravity or magnetic properties, laboratory scale and pilot scale flotation testing and on-site support.

    AuTec has a fully equipped mineral processing laboratory, providing ore characterization, physical separation based on size, specific gravity or magnetic properties, laboratory scale and pilot scale flotation testing and on-site support.

    Comminution, Sorting and Classification
    Many mineral processing projects require initial detailed characterisation and physical pre-treatment. At AuTec we are able to do detailed analyses of the sample characteristics to determine the most relevant treatment methods.

    Technical capabilities
    Batch and continuous fine and ultrafine grinding
    Sorting to reject gangue material by heavy liquid or sizing
    Size-by-size analysis using screens and cyclosizer
    Size-by-size analysis using screens and cyclosizer
    Desliming by Mozley cyclone (1” & 2”)
    Evaluation of plant grinding pulp chemistry and media on flotation and leaching

    Gravity Concentration and Magnetic Separation

    Pre-concentration by separation of gravity recoverable gold or heavy minerals can have a significant economic benefit, as can separation of minerals based on their magnetic properties.

    Technical capabilities
    Gravity Recoverable Gold (GRG) testing
    Gravity concentration of gold and heavy minerals
    Medium and high-intensity magnetic separation

    Flotation

    In recent years, our capabilities in flotation have increased tremendously. Flotation as a form of pre-concentration is becoming more and more important as we are forced to deal with lower grade ores. Flotation can also be used to remove deleterious species which can interfere with metal recovery. At AuTec, we have experts in all areas of flotation, including column flotation and reagent optimization. We are also able to produce large quantities of concentrate in our mini-flotation pilot plant.

    Technical capabilities
    Conventional Denver flotation – batch testing from 0.5 kg to 30 kg
    Column flotation – Lab Column (75 mm diameter, 2000 mm high) with cavitation tube air injection system to produce fine and ultrafine bubbles
    Mini-Flotation pilot plant (10-20 kg/h) for continuous flotation, plant simulation, flowsheet development, reagent optimization (lab or on-site testing).
    JK Floatability Index Testing
    Production of large quantities of flotation concentrate for POX, roasting or leaching testwork

    On-site Technical Support

    Our mineral processing team has been involved in on-site technical support at a number of mine sites, including Buzwagi and Golden Sunlight.

    Technical capabilities
    Process Optimization - Production improvements and troubleshooting
    Training Site Personnel - Flotation plant operation and laboratory testing
    Commissioning and Start-up – Flotation and SOP development
    JK Flotation Tools for Flotation Plant Surveys - Gas dispersion, mass balance, and simulations

    Relevant Equipment

    Mini-Flotation Pilot Plant Column Flotation Conventional Flotation Other Separation Techniques Gravity Concentration Shaking Tables including Gravity Table Size Classification Magotteaux Mill Fine and Ultrafine Grinding Crushers
     

    Hydrometallurgy

    AuTec has strong capabilities in hydrometallurgy, with an experienced team offering expertise in a range of hydrometallurgical processes, including atmospheric and high pressure leaching, bio-oxidation, cyanide and thiosulfate leaching, and precipitation processes for water treatment or metal recovery.

    AuTec has strong capabilities in hydrometallurgy, with an experienced team offering expertise in a range of hydrometallurgical processes, including atmospheric and high pressure leaching, bio-oxidation, cyanide and thiosulfate leaching, and precipitation processes for water treatment or metal recovery.

    Pressure Oxidation (POX)
    Pressure oxidation (POX) is a well-established process for pre-treatment of refractory gold ore and base metal sulfide concentrate. AuTec has batch, semi-continuous and continuous pressure oxidation testing capabilities available for process improvement, feasibility, prefeasibility or concept testing. With our advanced chemical and mineralogical analysis tools and improved capability in integration of upstream and downstream unit processes, AuTec is ideally suited to carry out pressure oxidation piloting.

    Examples of POX projects
    El Indio mine feasibility study (arsenide type refractory copper/gold ore)
    Turquise Ridge (Getchell) feasibility study (arseopyrite/pyrite type refractory gold ore)
    Porgera (JV) mine scoping tests, prefeasibility and feasibility study, and on-going operation support (pyrite type refractory gold ore)
    Pueblo Viejo scoping tests, prefeasibility and feasibility studies (pyrite type refractory gold ores with economic content of copper)
    Alkaline and acid pressure oxidation testing on Goldstrike gold ores
    Feasibility study on thiosulfate leaching of Cortez preg-robbing gold ore (stainless steel autoclave)
    Testing on different pressure oxidation processes

    Technical Capabilities
    Bench top pressure oxidation testing (2 L scale)
    Continuous pressure oxidation pilot testing (30 L scale) with full automated control and data collection (Delta V system)
    Flowsheet development and collaboration with Engineering teams to provide design data
    Semi-continuous pressure oxidation testing (4 L scale)
    Site-support for process commissioning


    Cyanidation
    Cyanidation is the most common method of leaching in gold processing, and AuTec is well equipped to investigate cyanidation of gold ores and concentrates, directly or after pre-oxidation.

    Technical Capabilities
    Cyanide leaching and preg-robbing amenability tests
    Bottle roll cyanidation at ambient temperature or heated
    Intensive cyanide leaching (Gekko reactor)
    Continuous carbon-in-leach cyanidation circuits for prefeasibility or feasibility design
    Cyanide column leaching
    Cyanide destruction testing


    Thiosulfate Leaching
    AuTec and its predecessor groups have been studying thiosulfate leaching for many years, and AuTec was instrumental in testwork leading to the design and commissioning of the full scale thiosulfate leach facility at Goldstrike. In the thiosulfate leach process, thiosulfate is used as an alternative to cyanide, to enable gold recovery from preg-robbing ores. The gold-thiosulfate complex does not adsorb onto carbon as does gold-cyanide, but is instead loaded onto resin, in a resin-in-leach process.

    Elution is a multiple-stage process that produces a gold-bearing pregnant solution for electrowinning. Loaded resin received from the RIL undergoes washing, copper elution, gold elution, and resin regeneration. After the gold has been removed from the resin, the barren resin can be reused for in the leach.

    Technical Capabilities
    Bench top leaching and elution testing
    Continuous pilot plant
    Demonstration plant
    Flowsheet development
    Site-support for process commissioning of the full-scale TCM Leach process at Goldstrike


    Precipitation

    Precipitation is a process widely employed in hydrometallurgy for recovery of metal values or for removal of impurity elements from process solutions. AuTec has done frequent investigations of precipitation for flowsheet development purpose, including using limestone/lime/soda ash and sulfide.
    Some examples of precipitation projects are:

    Ammonium sulfide precipitation of gold from thiosulfate leach solution
    Copper sulfide precipitation from Pueblo Viejo POX leach solution
    Iron removal as hydroxide precipitate and zinc recovery as basic zinc sulfate by limestone/lime neutralization in Pueblo Viejo flowsheet.
    Iron removal and arsenic fixation by neutralization for treatment of Donlin Creek POX solution and CIL tailings
    Recovery of copper from El Indio effluent by lime neutralization and sulfide precipitation
    Limestone/lime neutralization for treating combined tailings and process effluents


    Bio-oxidation
    AuTec carries out bio-oxidation tests using mesophilic or thermophilic mixed cultures, to test the amenability of ores and concentrates to biologically mediated oxidation. Direct recovery of metals such as copper, and second stage recovery of gold using either cyanide or thiosulfate lixiviants, is determined. Amenability tests as well as larger scale stirred tank tests or column leach tests can be accommodated.

    Relevant Equipment

    Batch Autoclave Continuous Autoclave Hot Cure Bottle Rollers Batch reactors Intensive Cyanidation Filter Press CCD Shaker Column Leaching Continuous Precipitation Continuous Sulfide Precipitation
     

    Pyrometallurgy

    AuTec is capable of carrying out batch roasting tests under a wide variety of gas compositions and temperature profiles. AuTec also has relationships with external laboratories that are capable of running continuous roasting testwork at sizes ranging from 2” through to 6”. Up-stream and down-stream testing from continuous roasting campaigns are typically handled in-house.

    AuTec is capable of carrying out batch roasting tests under a wide variety of gas compositions and temperature profiles. AuTec also has relationships with external laboratories that are capable of running continuous roasting testwork at sizes ranging from 2” through to 6”. Up-stream and down-stream testing from continuous roasting campaigns are typically handled in-house.

    It is also possible to test carbon activation using the batch roaster in a modified form.

    Relevant Equipment

    Carbolite HTR 11/150 1100 °C Rotary Reactor
     

    Environmental and CN Detox

    AuTec aims to provide environmentally sustainable metallurgical solutions. We offer acid rock drainage testing and relevant mineralogical analyses, leachability testing and water treatment, including cyanide destruction test in the laboratory or on-site.

    AuTec aims to provide environmentally sustainable metallurgical solutions. We offer acid rock drainage testing and relevant mineralogical analyses, leachability testing and water treatment, including cyanide destruction test in the laboratory or on-site.

    Cyanide Destruction

    AuTec is capable of conducting on-site tests to optimize or troubleshoot cyanide destruction circuits. The personnel at AuTec have experience with various cyanide destruct methods using sodium metabisulfite (SMBS), Caro’s acid, and peroxide. The on-site capability of conducting tests has several advantages. Shipping of cyanide containing solutions or slurries to external laboratories can be difficult due to the toxicity of cyanide. Another issue is the possible change in solution chemistry during shipping. Performing tests on-site avoids both of these problems and ensures that the solution chemistry remains the same as per plant conditions.

    AuTec has a cyanide destruct kit which includes 2 L tanks, agitators and stands that can be shipped and assembled on site. The requirements for on-site tests are process air for tests involving SMBS, power (120 or 240 V) and access to on-site assay lab services for quick turnaround of samples. The equipment can be shipped to site and assembled by our personnel immediately after their arrival.

    Other Environmental Work

    AuTec can assist with the technical evaluation of water treatment processes. For example, the removal of metals and sulfate from process and waste water by the high density sludge and ettringite processes has been tested at AuTec. AuTec has also been involved in investigating fouling of reverse osmosis membranes from water treatment processes.

    Static acid base accounting tests to estimate the potential for acid rock drainage are carried out, and simulated small scale leachability tests (such as a simulated TCLP test) can be done.

    AuTec was also involved in development of a process to oxidise arsenic using a carbon-catalyst, as a precursor to the precipitation of arsenic in a stable form (like scorodite). This process offers a significant economic advantage to other methods of oxidation, such as by using peroxide.

    Relevant Equipment

    Continuous Acid Rock Drainage (ARD)/Effluent Treatment Environmental Equipment
     

    On Site Services

    AuTec staff have carried out a significant number of projects on-site throughout the world. These projects have included commissioning of new plants or processes, troubleshooting of existing processes, and operational surveys with an aim to improve metallurgical performance.

    AuTec staff have carried out a significant number of projects on-site throughout the world. These projects have included commissioning of new plants or processes, troubleshooting of existing processes, and operational surveys with an aim to improve metallurgical performance.

    AuTec’s assayers, technicians, and metallurgists strive to deliver high-quality support and pride themselves on being flexible and able to meet tight deadlines and changing priorities.

    Some examples of on-site services include
    Quality control consulting for analytical services at a third-party gold mine, Mexico
    Start-up support for the TCM leach process at Goldstrike, Nevada
    Start-up support and on-going assistance at Pueblo Viejo, Dominican Republic
    On-site testwork and troubleshooting support for cyanide destruction at Hemlo, Ontario
    Mill survey at Golden Sunlight, Montana to characterize ore and process possibilities