Alex Stewart International provides metal assaying, lab analysis and lab testing services for ferrous and non-ferrous metals, minor and precious metals including gold and silver bullion, platinum group metals, auto catalysts, jewellery, ores and concentrates, ferro alloys, recycled scrap metal, electronic scrap, metallurgically complex materials and plastics.

Through Alex Stewarts International's global inspection network, we can also provide you with weighing, sampling and inspection services. Our professional and technically knowledgeable team provide a dedicated, high quality service to meet the specific requirements of the metal industry, mining companies, traders, metal producers and refiners, governments, banks and financial institutions and the general public.

Metal Analysis – Non Ferrous and Ferrous Ores and Concentrates
Alex Stewart International provides a complete service of global inspection, weighing and sampling supported by its UKAS Accredited ISO 17025 laboratories in Liverpool England for copper, cobalt, managenese, silver and nickel; additional metal tests for ores and concentrates include zinc, lead, tin and iron all of which are carried out at our laboratories in Liverpool, England. Analysis is performed by classical wet chemistry techniques, combined with state-of-the-art high-tech instrumentation including Atomic Absorption, ICP, Carbon Sulphur and XRF.

Supervsion of loading and discharge, inspection, weighing, sampling and analysis is provided for:

LeadMinor Metals

Ferro Alloys & Minor Metals - Inspection and Analysis

Our strategically located inspection operations cover all major loading and discharging ports and refineries for ferro alloys and minor metals such as cobalt, nickel and manganese. Inspection and analysis locations include all leading South American countries of mining importantance such as Argentina, Bolivia, Brazil, Chile, Ecuador, Peru; African - Rwanda and Zambia; Asia - India, Kazakhstan, UAE; Pacific Rim - Australia, Malaysia, Indenesia, Thailand; also Black Sea and all principal European ports, refineries and warehouses. Services include full inspection, draft survey, transportable moisture limits, shore scale or belt weighing surveillance, stockpile control and sampling.

Inspection, weighing, sampling and analysis for Minor Metals and Ferro Alloys includes:


Geochemical Analysis for Global Mining Exploration Projects
Alex Stewart International provides mining, geochemical, environmental, metallurgical and analytical services to the mining and mineral exploration industry in Africa, Europe, South America and Asia.

Alex Stewart International is able to design, install and staff laboratories at for major exploration projects at mining sites almost anywhere in the world.

Laboratories are accredited to ISO 9001, 14001 and 17025 standards and participate in inter-laboratory tests and international round robins. Alex Stewart Argentina TV Interview at Argentina Mining 2016, Jujuy

Geochemical Analysis

PreparationFire Assay
Trace level analysisDrill core analysis
CalcinationsEnvironmental analysis
Solid and liquid brinesMineral processing
Metallurgical testingSample storage and custody

Classical Geochemistry Methods

Atomic absorption spectrophotometry -AAMulti element emission spectrophotometry by Argon Plasma – ICPMercury determination by cold vaporGravimetric determinations

Precious Metals and Platinum Group Metals Analysis
Alex Stewart International provides precious metal analysisprecious metal inspection, weighing and sampling  services at major precious metal refineries supported by Alex Stewart International's worldwide inspection offices and laboratories in Africa, Americas, Asia, Australia and Europe.

Alex Stewart International are accredited to carry out LBMA and LPPM appointed precious metal inspections at all globally recognized precious metal refineries, including all major and reputable UK, USA, Swiss and Italian precious metal refineries. Precious metal inspection services cover gold, silver and dore bullion, auto catalysts, jewellery, coinage and electronic precious metal scrap, sweeps and slimes which will require accurate weighing, representative sampling and supervision of melting at refinery or bonded warehouse, so that we can then perform laboratory analysis at our precious metal laboratories in Liverpool, Lima and Dubai.

Precious Metal Analysis for precious metals are by classical chemistry methodology, gravimetric titration, fire assay, Atomic Absorption, ICP and XRF and materials include:

Auto CatalystsPGM
Electronic scrapSlimes

Gold and Silver Testing - Accurate Fast Analysis
Our Liverpool Assay Office will weigh, test and analyse any gold or precious metal containing jewellery including earrings, bracelets, necklaces, rings, filings, chains, watches, pendants, coins, sovereigns and krugerands. Tests are determined by rapid XRF which is able to provide detailed analysis by measuring the intensity of the generated gold X-rays by wavelength dispersion analysis. This technique is essentially non-destructive and minimal sample preparation permits very fast turnaround times.

When testing is complete, a full report indicates the percentages of gold content as well as other alloying metals such as copper, silver, zinc, etc. This method is remarkably accurate and can certify the value of your gold or silver before selling on. Having tested for gold, we will then send you an official certificate of its content and correct gold or silver market value at current precious metal market prices.

Scrap & Recycled Metals Analysis - ISRI Standards
Alex Stewart International can provide quantity and quality certification for ferrous, non-ferrous, electronic or plastic scrap material conforms to all contractual terms, conditions and also including all international regulations such as ISRI and GOST.

Digital photographic evidence will be provided for all Pre-shipment Inspection and Proof on Arrival for scrap metal inspections, inspection during loading and sealing of containers. Radioactivity testing and checking for the presence of hazardous or dangerous materials will also be rigorous to protect you from any unnecessary financial or environmental claims. Materials inspected include:

Steel scrap: Radioactive certification, quantity determinations by draft and barge survey, quality assessment to contractual or international (ISRI) guidelines, off grade and dust/dirt assessments, density assessments.Steel products: Pre-shipment quality inspections, tally, loading and discharge supervision, mill test certificate approval, physical and chemical tests.Pig iron: Loading and discharge supervision, weight determination, broken ingot assessment, sampling and chemical analysis.

RoHS and WEEE Screening Tests
Rapid XRF screen testing of electronic components and PCB's is performed in accordance to the Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) Directives. This means that to comply with RoHS and WEEE you must be sure that your products are checked. Our screening tests will verify the percentage of harmful elements in line with the RoHS directive.

Whether your organization is the manufacturer of products, a supplier to the end manufacturer or recycles electronic scrap by testing electronic components, household appliances, telecommunications equipment, toys and other consumer goods you will receive our certificate which confirms whether or not your product contains lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls. If evidence is found then further in depth analyses can be applied. We are available to discuss and help you comply with RoHS and WEEE Directives.

XRF Detection Limit Analysis:

Cadmium 100ppmChromium, Lead, Mercury, Bromine 1000ppm

All analysis can be combined with representative sampling, weighing and inspection services carried out by Alex Stewart International's network of offices in Africa, Americas, Asia, Australia and Europe.


  • ASI Inspections, Loads and Discharge Operations
  • ASI Laboratory, Sample Preparation and Customer Services