Leaving no cargo unturned

Whether performed automatically or manually, sampling occurs through extracting a quantity of commodity smaller than the original quantity, and sending it for laboratory analysis or screening purposes. However, the quality control of dry bulk commodities in general, is more than just filling a number of sample bags and can only be accurately performed by experienced and highly-educated surveyors. RC Inspection considers the sampling and sample preparation procedures to be of extreme importance and always sets its goal to obtain the desired end result with the first consideration being the accuracy of the sampling procedures.

Each commodity has its own individual characteristics based on the different possible global origins or composition. Due to this, each commodity has to be sampled, inspected and prepared in its own specific way in order to obtain the most reliable end results. A good example can be given when looking at biomass commodities. In order to be of any value, biomass samples need to be unbiased, accurate, precise and representative of the main lot or consignment of the biomass. Since biomass is highly variable in size, configurations and moisture content is prone to fractionation and stratification, which can complicate the sampling procedure.

These services are all performed according to the international ISO Standards for sampling and sample preparation. Sampling and the visual inspection of the cargo are complicated processes and will become more complicated and important in the near future, due to the heterogeneity of the cargoes based on the origin of the commodities and their characteristics. The surveyors need to know the visual characteristics of each different commodity to be able to perform accurate inspection, sampling and sample preparation. Throughout the visual inspection, the condition and the appearance of the cargo is important as it may have an impact on the quality, due to possible contamination and/or free water.

When samples are taken from a stationary source, such as a stockpile, it may be impossible to obtain an accurate sample due to the fact that the material in the center of the stockpile may be inaccessible when conventional sampling techniques are used. When samples are taken from a moving stream, such as a conveyor belt, the requested increments have to be collected at the place of the stockpile. The sampling must be performed where the cargo is leaving the conveyor belt system in order to obtain the most representative increment-samples. Sampling from a moving conveyor belt, is banned at all European terminals due to safety reasons.

Poor sampling and sample preparation will lead to non- representative analytical results. This is best disregarded because the obtained samples will have no reliable value at all.

The used sampling equipment is evaluated according to its effectiveness in obtaining a representative sample according to the accepted standard. To ensure quality sampling, RC Inspection uses ISO-approved shovels.

When a cargo is reloaded from the stockpile, the vessel, river barges, containers and/or trains, have to be visually inspected before loading operations start, in empty condition to protect the quality of the cargo. The surveyors have to inspect for the presence of traces of previous cargoes, contamination, free water and possible damages.

UMPIRE ANALYSES

Sampling and analytical results do not always guarantee 100% accurate results, as these depend heavily on human input and this may introduce human error inaccuracies. Sampling from a single spot is generally less likely to be representative of the main body of the dry bulk than a gross sample, which is a mixture of multiple spot samples.

When errors like these occur during sampling and analysis performed by other parties, RC Inspection is nominated to perform umpire analysis. For these samples also count that the analytical results will be unreliable when sampling and/or sample preparation has not been performed accurately at load- port and/or at disport. All requested analysis are carried out in

the laboratory according to the relevant ISO and/or ASTM standards under full accreditation according to the ISO 17025 norm.

As a result of the management’s longstanding personal experience, RC Inspection recognizes the importance of extensive knowledge and experience, as well as the ISO standards in order to perform highly representative inspection and sampling services, including the sample preparation of the obtained bulk samples.

This has led to the managing experts of RC Inspection developing special internal procedures for sampling, inspection and sample preparation for all kinds of dry bulk commodities.

The surveyors are all well informed and instructed according to these internal procedures, which is necessary to guarantee high quality services.

These procedures are recognized by the fact that RC Inspection recently obtained accreditation according to the ISO 17020, accredited by the RvA, under registration number I 308.

This accreditation has been valued upon the following services:

 

  • Visual cargo inspection, sampling, sample preparation, barge gauging/draught survey for loading and discharging operations for hard coal, pet coke, ferro alloys and ores.
  • Storage facilities and transshipment equipment for solid fuels and metals/minerals
  • Loading Compartment Inspection (LCI) for feed transport

 

This accreditation guarantees the clients that the policies, practices and procedures of the company can be ensured with consistent high quality and expertise in the knowledge of the commodities and the provided services worldwide. 
 
 
 
SGS Australia continues coal sampling and analysis at Origin Energy

Origin Energy operates Eraring Power Station, Australia’s largest power station. It is located on the shores of Lake Macquarie near Newcastle, NSW. It is one of the most efficient and lowest carbon-intensity black coal-fired power stations in Australia with a capacity of 2,880MW. The station was initially put into operation in 1983. Several upgrades have been carried out, with the most recent being in 2012.

Coal is delivered to the power station by overland conveyor, trucks and rail. Commercial sampling is carried out using a number of mechanical sampling systems. SGS Australia was contracted in 2009 to conduct technical audit inspections and bias tests on the existing mechanical sampling systems.

WHAT IS A TECHNICAL AUDIT OF A MECHANICAL SAMPLING SYSTEM?

 

  • Critical review by qualified and experienced sampling engineer/inspector
  • Compliance check against relevant sampling standards
  • Comparison against best sampling practices
  • Reporting including recommendations for improvements v Should be done before any bias test
  • Should be done periodically

 

WHAT ARE THE BENEFITS OF A TECHNICAL AUDIT?

 

  • Assurance that sampling is compliant for both internal and external purposes
  • Minimizes risk of biased sampling
  • Increased confidence in lab results
  • Improved reliability/availability of systems
  • Regular, scheduled audits allows system to be monitored for changes in operation or performance 

 

Following those inspections and bias tests, SGS Australia was awarded contracts to design, supply and install two mechanical sampling systems to replace existing in-coming systems and a new plant feed sampling system. The total value of this work was in excess of A$5 million.

Each in-coming sampling system is based on cross belt primary sampler, double roll sample crushers and cross belt secondary samplers. Final samples are collected and stored in a rotary sample collector with six sealed sample canisters. A facility is also provided to take uncrushed sizing samples using a cross belt sampler. Manual and automatic operation of the sampling systems is available using a HMI Touch Screen.

The installation of the plant feed sampling system was partly prompted by the need to meet the requirements of the National Greenhouse and Energy Reporting (NGER) Regulations and better monitoring of coal usage. That system samples coal from two parallel plant feed conveyors. The sampling system is similar to those installed for the in-coming coal stream but includes two cross belt primary samplers feeding to a common crushing and secondary sampling system.

All installed sampling systems were successfully bias tested after commissioning.

SGS continues its involvement with the power station through the daily collection and analysis of the sampled coal using its state-of-the-art coal testing laboratory located at Newcastle.

With more than 80,000 employees, SGS operates a network of over 1,650 offices and laboratories around the world. SGS offers a full range of coal testing services including exploration, laboratory and production services, as well, as inspection and sampling. With core services and industrial expertise to help you improve your operational efficiencies, SGS’ global technical leadership helps minimize operational and financial risk.

SGS has a coordinated Global Mechanical Sampling Capability with centres of MSS excellence in Australia (covering Australia, Southern Africa, and Asia), Italy (covering Greater Europe, Russia and Northern Africa), India, China and USA (covering Canada, the USA, Mexico and South America).These centres of excellence are all ready and able to meet the local needs of our customers who require mechanical sampling systems for any bulk material. The systems are designed and supplied at mine, port, or delivery sites as required.

SGS co-ordinates this capability from the SGS Australia office. 

 
Alex Stewart Agriculture Ltd. — serving the grain trade market  

Grain and oilseed inspection and analysis are core businesses of Alex Stewart Agriculture Ltd. Alex Stewart is a superintendent and analyst member of the Grain and Feed Trade Association (GAFTA).

Alex Stewart works with many leading grain traders by providing trustworthy professional inspection and laboratory services globally. In addition, ASA can arrange fumigation services in most areas of the world to ensure that its customers’ cargoes are treated as with the greatest care. Upon nomination,Alex Stewart’s mission is to protect customers’ interests at loading and/or discharge ports worldwide. ASA is also able to provide collateral management services such as supervision of long term storage of grain or control of transportation between storage facilities.

The head office of Alex Stewart Agriculture
Ltd in the UK also provides consultancy services. Strategically and commercially located operations
offices offer support and advice regarding ports and silos worldwide and will provide information concerning the latest industry standards in sampling and analysis.

AGRICULTURAL LABORATORIES

Huson & Hardwick and A. Norman Tate Laboratories are GAFTA/FOSFA (Federation of Oils, Seeds and Fats Associations) registered analytical laboratories that specialize in the analysis of oilseed and edible oil, grain, barley, rye and wheat, animal feed, sugar and food products operate from Alex Stewart’s head office in England. They are able to perform a full range of commercial and shipping sample including protein, fat, fibre, ash, moisture analysis via classical wet chemistry and hi-tech instrumentation including NIR (near infrared), ICP (inductively coupled plasma) and HPLC (high performance liquid chromatography); also infestation, foreign matter and admixture, hazardous contents, fuzarious grains, nutritional values, toxic contents (eg. arsenic, mercury & lead) mycotoxins and pesticides.

DRY BULK COMMODITIES CERTIFIED BY ALEX STEWART

Fertilizer

Alex Stewart Agriculture’s highly experienced and knowledgeable inspection team has built a trusted reputation within the international fertilizer-trading arena. The fertilizer division offers first class inspection and analytical services for bulk, bagged and liquid fertilizer with the aim of protecting client’s interests at production site, during transportation, or at store. ASA has fertilizer laboratories in the UK, Belgium, Ukraine, Russia, South Africa, China and India. Its offices in the UK, Belgium and the Ukraine are all members of the International Fertilizer Association.

Animal feed

The Alex Stewart Group provides a fully comprehensive package of inspection and analytical services. Its GAFTA/FOSFA- registered and approved laboratories strategically located around the world perform a full range of analysis for soya, oilseeds – sunflower and rape, and fish meal including infestation, foreign matter and admixture, hazardous contents, fuzarious grains, toxic contents (e.g. arsenic, mercury & lead) mycotoxins and pesticides.  

Grain and wheat

Grain inspection and analysis is a core business of Alex Stewart Agriculture and is a superintendent and analyst member of the Grain And Feed Trade Association (GAFTA), working with many leading grain traders by providing monitoring, testing and consultancy services globally. In addition fumigation services can be offered as ASA works closely with fumigation companies to ensure that cargoes are loaded and stored in appropriate condition and quality is not affected during transportation. Grain inspection services also extend to provide collateral management services such as supervision of long-term storage of grain or control of transportation between storage facilities.

QUALITY INSPECTION SERVICES

Warehouse inventory control and collateral management: ASA can provide a diverse range of services, from stock audits and control procedures, to security advice and commodity/store condition surveys.

 

  • pre-shipment inspection and analysis: the Alex Stewart inspection team will check that the customer’s product is within specification and fit for the intended use.
  • quality control: checking that cargo conforms to contractual specifications, checking cargo for signs of contamination, odour, colour change, moisture levels, friability, protesting/rejecting inferior cargo on sight, granule sizing, radioactivity testing and laboratory analysis.
  • vessel hatch inspection: service includes checking hatch condition ensuring that they are free from loose rust and paint flake, free from previous cargo, checking that hatches are tight fitting, checking hatch open and closing operation is functional and timely, inspecting hatch rubber condition, hatch hose water testing, checking that holds are water-tight.
  • vessel hold cleanliness: detailed inspection ensures that holds are clean, dry, free of loose rust and paint flake, free from previous cargo, free from infestation and odour and in every respect fit to receive the designated cargo.
  • continuous supervision: ASA guarantees continuous supervision of customers’ cargo loading and/or discharge (24 hours), representative sampling/sealing as per contract.
  • quality control inspection: packaging reporting when applicable.  
  • weight verification: gross, tare & net weighing.
  • weighbridge control: test weight checking, scale calibration and certification check, recording truck movements across scale ensuring that all cargo is weighed.
  • bagging supervision and tallying: full tally and checking for bag strength and durability (laboratory testing is available) and verifying markings.
  • continuous information updates: ASA’s busy administration centre is in contact with all of its inspectors operating in the field and provides its customers with up-to-date, hour-by- hour detail of all loading and discharging operations.
  • documentation: Alex Stewart Agriculture uses state-of-the- art technology to supply standardized reports and certificates; certification and reporting can be tailored to suit customer requirements. Photographic reports by conventional and digital camera can also be supplied for evidence purposes.
  • damaged cargo assessment: establishing possible source, cause, and severity.
  • loss prevention: supervision of reconstitution of acceptable cargo.
  • container services: supervision of stuffing and unstuffing, container sealing, container condition surveying (on/off hire, damage assessment).
  • transportation services: whether the commodity is manufactured, stored, shipped, railed, trucked or containerized, ASA can assist customers in their trading activities.
  • consultancy: ASA offers consultancy services to assist customers on methods concerning material handling, weighing, transportation, sampling and analysis. Local knowledge and years of experience are primary assets of its business. 

 

KEY AGRICULTURAL GAFTA/FOSFA SUPERINTENDENT OPERATIONS WITHIN ALEX STEWART AGRICULTURE
Argentina, Australia, Belgium, Brazil, Bulgaria, Chile, China, Egypt, Estonia, Germany, Italy, India, Indonesia, Kazakhstan, Latvia, Malaysia, Netherlands, Peru, Philippines, Romania, Russia, Spain, Thailand,Turkey, Ukraine, UK, Uruguay & USA. 

 
Exposing the risks of sampling, inspection and analysis   

How much can you determine about a cargo on the basis of the test certificates issued at the time of loading? How accurate are the test certificates? Are the cargo characteristics and properties reported in the shipping documentation believable?

These are the questions that Masters ask themselves when reviewing cargo documents prior to loading their ships with mineral ore cargo. If the test certificates are accurate, all of the following applies:

 

  • the cargo must have been properly sampled to obtain test samples that are truly representative of the entire cargo;
  • the cargo must have been visually inspected for irregularities with respect to moisture content and/or other potential contamination at the port prior to loading; and
  • the samples must have been tested in a Competent Authority laboratory, within the appropriate time intervals to be considered valid, and analysed using appropriate test standards.

 

The International Maritime Solid Bulk Cargoes (IMSBC) Code regulates the safe transportation of these mineral ore cargoes.The IMSBC Code details the sample preparation methods to be employed, all the necessary test equipment, and how to analyse results for compliance with internationally and nationally accepted standard procedures. Yet despite the provisions of the Code, there are many non-compliant laboratories issuing invalid cargo certificates and many non- representative samples sent for testing.

Section 4 of the IMSBC Code describes the assessment of consignments for safe shipment.

The ‘provision of information’ (Section 4.2 of the Code) states the cargo must be tested and certified by a Competent Authority in order to demonstrate its safety to the Master at the loading port. However, the laboratory technicians who test  the samples in order to certify the safety of a consignment are not the ones who supervise the collection of test samples. The laboratories work independently of the parties that collect the samples for the testing and analysis, therefore it is imperative that shippers (and their representatives) give clear instructions to obtain suitable samples.

Section 4.4 of the Code describes the cargo sampling procedures.The opening statement in this section stresses the importance of samples being representative of the entire consignment: “Physical property tests on the consignment are meaningless unless they are conducted prior to loading on truly representative samples.” This point is emphasized because the material characteristics of a cargo can be tested accurately in a lab, but the condition of the cargo to be shipped is likely to be affected by outside conditions such as weather, handling and storage prior to loading. The Code also advises on carriage precautions such as hold cleanliness and weather precautions, loading rates, ventilation, trimming and carriage as all these aspects can adversely affect the cargo’s mechanical behaviour during a sea voyage.

Test certificates are only valid for a relatively short time.What is often the case at the port quaysides is that cargoes are standing by waiting to be loaded in all weather conditions without adequate protection from the elements. Often the sampling is carried out well in advance of loading (such as at the mine prior to a long road, rail or barge journey to the port that can take days) so that aside from the changes that the material characteristics undergo due to exposure, the test certificate has expired by the time it is loaded on board a vessel.

Guidance is provided on the sampling procedures and the number of sub- samples to be obtained according to the total consignment size. It has often been the case in cargo disputes that there are more samples taken from some stockpiles and not enough from others. How is the Master or the laboratory technician to know how representative the samples are if the sub-sets are biased towards one stockpile over another?

When there are disputes regarding the moisture content of a cargo, for example, is it extremely important to draw samples
at varying depths of the stockpile to gain representative samples that override any variations in moisture distribution throughout the consignment. Section 7 of the Code describes the risks associated with liquefaction and the precautions to take to minimize this risk. When a Group A cargo (defined as likely to liquefy in the IMSBC Code) has a moisture content greater than the certified Transportable Moisture Limit (TML) value, the cargo is not suitable for transport by sea. Historically many Group A cargoes have been wrongly declared; either by the shipping documents wrongly declaring the cargo as Group C (not likely to liquefy) in the absence of proper test certification, or by improper sampling and testing procedures leading to invalid certificates.

The laboratory test procedures undertaken for bulk cargoes that may liquefy are described in Appendix 2 of the Code. These tests originate from the soil mechanics laboratories of geotechnical engineers. All laboratory analysis starts with visual inspection of the samples to determine their appearance with respect to moisture condition, particle size distribution and variability. The next steps in the analysis are sample preparation, TML testing and analysis of the test results. Soil mechanics is a complex science requiring a sound understanding of the cargo’s behaviour and the test methods at each stage of the laboratory analysis, yet many certificates are produced by inexperienced or uninformed organizations. It is often the case that the best test method for a particular cargo is not the test carried out by the laboratory for the production of the test certificate. This can alter the test conclusion.

There are cases where the general description of the cargo on the shipping documentation is questioned. To resolve a cargo dispute, sampling and testing must be undertaken to support the veracity of the shipping documents (as it is the mechanical properties that determine the appropriate description and Group for the cargo). Many misunderstandings regarding the Code continue today, despite the on-going efforts at the IMO to regularly update and amend the provisions within the IMSBC Code.

Cargo sampling and testing procedures require experienced operators that understand the importance of employing the utmost care to prevent changes in cargo quality and characteristics. Cargoes will remain potentially hazardous until shippers and receivers alike demand the best sampling, storage and handling procedures are employed. Only high quality analysis on representative samples will result in test certificates from Competent Authorities that Masters, shippers and receivers can trust.

Author: Dr Aime Harrison, a Geotechnical Civil Engineer at London Offshore Consultants. She has been a Technical Expert on the subject of mineral ore cargo liquefaction at the IMO and the amendments to the IMSBC Code since 2011. 

 
 
Mechanical Part-stream Sampling – new bulk material sampling device from SAI and PSI 

Sampling Associates International (SAI), in partnership with Precision Samplers, Inc. (PSI), has developed a new device to sample bulk materials from moving
conveyors. This device is called a

Mechanical Part-stream Sampler (MPS) and has already been installed at multiple export terminals in the United States. While the initial installations have been to sample coal, the MPS can be customized to sample any bulk material.

The genesis of the MPS came from the need to sample bulk materials from a moving conveyor when a traditional mechanical sampling system is offline. In most cases when a mechanical sampling system is unavailable, the ‘back-up’ method is to collect sample increments manually by inserting a sampling device by hand into the material on a moving conveyor. However, as loading efficiencies are achieved by greatly increasing the

speed of modern conveyor belts, the historical ‘back-up’ method is no longer safe. The MPS design, which has a patent pending, solves this problem by eliminating the need for sampling technicians to be exposed to moving conveyors.

The MPS can also be a safe and effective method to sample bulk materials on conveyors where a full mechanical sampling system is not available at all because it is not economically justifiable.

The main features of the MPS (see photographs) are:

 

  • It has all stainless steel construction for long- term corrosion prevention
  • There are two alternating sample scoops to reach both sides of the conveyor
  • The scoops are designed to reach deeper than a human with a shovel can
  • The scoops operate in the same direction of the material flow
  • The frequency of sampling is programmable based on the lot size and flow rate calculations; and
  • It has a very small footprint on the conveyor belts.

 

In the sampling world, those samples that are collected by a device that takes a full cross section increment from either a conveyor belt, or a falling stream at a transfer point, are called Probability Samples. This is because every particle in the consignment has a non-zero chance of being selected for the sample. This is the best sampling method for any bulk material and known as Full- stream Cut Sampling.

The MPS does not collect a Full-stream cut, it collects a Part-stream cut (hence its name). Because there are particles in the consignment that have a zero chance of being selected for the final sample, it is called a Judgment Sample. There are many types of Judgment samples such as sampling from the tops of barges, or rail wagons, but the MPS provides the best possible Judgment sample.

The main benefits are as follows. First, Mechanical Part- stream sampling is much safer than manual belt sampling. No human is exposed to the moving conveyor parts or harsh weather. Secondly, it removes the human element in the timing of the sample increments and the selection of material into the sample. By customizing the scoops to reach deep into the material, the particles with a non-zero chance of being selected for the sample are minimized.

When an MPS is paired with a full mechanical sampling system, an important benefit is that the terminal can keep loading when the sampling system is offline for any reason. In addition, the MPS frees the sampling technicians from collecting the samples so that they can concentrate on repairing the sampling system and getting it back on line.

Bulk materials with wide variation in the particles of different sizes may not be suited for sampling with an MPS. However, the initial installations in the USA show excellent comparative results.