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A LIMS Solution for a Mining Laboratory
Data Processing Capability and Workflow Optimization
By Martin Frechette and Patrice Morin |
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Abstract
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Inmet Mining Corp. recently implemented the LabPlus LIMS, developed by LabPlus Technologies, at its Troilus division. It was a turnkey project for the basic LIMS, including configuration, instrument integration and basic reports.
The LIMS enables the laboratory to perform analytical procedure that would be impractical in a non-automated environment due to the numbers of measurements and calculations required.
In addition, with the use of customization tools developed by LabPlus Technologies and MS Office applications, the workflow has been optimized through the elimination and/or automation of repetitive tasks and data manipulation. The relative simplicity of those tools allows the laboratory staff to perform most of this work.
The implementation process, workflow and data processing of the laboratory are presented and discussed.
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Introduction
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The Troilus division of Inmet Mining Corp. faces a major operations challenge from the nature of the ore they mine. Advanced analytical methods are required to assess the value of the different mining zones.
Such analyses, coupled with geological studies, allow exploiting the site in the most effective way.
The other problem faced by the laboratory is the relative remoteness of the site and the technological needs of the processes used. Simply having all the equipment and systems in place involved a great deal of work and when combined with the difficulty of getting specialized services, it could have been a nightmare.
This situation necessitated a very focused approach to the problem, and a turnkey solution providing a Laboratory Information Management System (LIMS) was proposed by LabPlus Technologies to solve the data management issues.
This solution offers an efficient way for the laboratory to perform metallic analysis on a routine basis for all the samples generated from exploitation of the site.
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Metallic Analysis
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Given the nugget effect problem, it was decided to change the protocol to minimize the variability of the sample.
This effect is caused by the presence of gold particles in the ore. By using larger initial samples and reducing the particle size of the ore analyzed, it is possible to get a representative analysis of the fine portion and analyze the whole coarse portion, resulting in a more accurate picture of all the gold contained in the initial sample.
The laboratory had to be optimized for the metallic method. Modifying sample preparation, including the LIMS system, cost half a million dollars. The new protocol involved the production of 80 samples a day, representing 440 assays of gold/copper analysis daily. |
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Sample Preparation
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Once prepared, the laboratory received 10kg samples for metallic analysis.
These samples are dried at 180C and cooled at room temperature. A first mill is then used to reduce the ore to 0.5 mm, for good distribution during splitting. One kg is collected for pulverization in a second mill.
For the metallic method, 5 grams are set aside in a bag for copper analysis. This portion is labeled and bar-coded. The remaining material is screened over a 150-mesh sieve.
This process gives a coarse portion, usually less than 90 grams, which is fully analyzed in 30g segments. One assay is done of the -150 mesh. |
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Sample Analysis
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The average gold content of the coarse and fine portion is calculated. The total gold content of the sample is determined by multiplying the weight of each portion by its gold content and dividing the sum of these two values by the sum of the weights of the coarse and the fine portions. Equation (1) summarizes the calculation:
Where :
AuMetallic is the metallic gold content,
AuC is the average gold content of the coarse portion,
AuF is the average gold content of the fine portion,
WC is the total weight of the coarse portion
WF is the total weight of the fine portion.
This gives a representative value of gold content even if the primary sample was not uniform, due to gold nuggets. |
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LIMS Implementation
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To implement a LIMS as a turnkey system, the needs of the laboratory must be carefully assessed. A visit to the facility at Troilus was made by the sales representative, to explain the approach and make sure that the LabPlus LIMS would fit Inmet's needs. After the LabPlus solution was selected by Inmet, a project leader made a second visit to assess the technical aspects of the project.
As a turnkey system, all analysis had to be configured by the LabPlus Technologies implementation and technical team. Accordingly, a thorough understanding of the laboratory was essential.
This visit allowed most of the information needed for the configuration to be obtained and the basic reports developed. The point was to produce a system that could be implemented quickly by combining the knowledge of the laboratory staff about their process and the knowledge of the LIMS specialists about their system.
The configuration specifications were written first, in order to establish solid basis and allow it to be reviewed by the laboratory staff. Once validated, the system was configured at the LabPlus Technologies facility and tested by Inmet and LabPlus Technologies representatives using a test script. This ensured the basic compliance of the system with the original specification.
The system was then ready for on-site implementation, conducted as part of ten-day stay by two implementation specialists from LabPlus Technologies and laboratory and technical staff of Inmet.
At that point, the data base server had to be integrated in the network, the client station installed, the instruments interfaced and the laboratory staff trained. Inevitably, some last-minute adjustments were also made to the configuration and the reports.
With proper training, the laboratory staff is now able to perform the maintenance and development needed for the LIMS to meet their growing needs in terms of reports and automation. Technical support and on-site visits are also available if needed.
In all, four on-site visits and some eight months were needed to get the system running. |
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Department Collaboration
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In order to increase the efficiently of the sampling process, close collaboration had to be established between the geology department and the laboratory. The driving force behind this collaboration was the potential benefits for both departments. The geologists were already using a computerized system to plan sample collection in the pit. This system could be used to build the list of the samples for later analysis in the laboratory.
The goal was to avoid transcribing information from one system to the other. With the help of a sample-logging tool from the LabPlus system, a sample-logging sheet was developed in MS-Excel and given to the geologists, for building the sampling plan directly in Excel. From that file, the sample can then be pre-logged in the LIMS and listed in the geology software used by the geologists. Each sample to be taken has a bar-coded label printed for it that can be traced back to the sampling plan.
Upon arrival at the laboratory, the sample labels are scanned for confirming receipt. Lost samples can be easily identified.
After completion of the analysis, the results are returned to the geology department with the exact identification of the sample made by the geologist in the first place, assuring accurate data interpretation. The results can then be used in the geology software to compute concentration level curves and orient mining toward the richer zones.
Considering the number of samples involved, optimization of the sample logging process provided one of the major productivity gains in the project. |
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Workflow Optimization
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Once the samples are received at the laboratory, the preparation and analysis process begins. Every phase that involves data collection was studied to improve the effectiveness of data circulation throughout the laboratory.
The goal was to avoid and systematic duplication of data entry from one instrument to another. For instance, all weights collected during sample preparation are sent directly to the LIMS via an interface that connects each scale to a computer. Should the weights be needed for input to another instrument, such as an atomic absorption spectrophotometer, a file is produced that gets the data directly to the instrument rather than having it keyed in manually. This improves both the time needed for the analysis and the accuracy of the results. The same type of interface then transmits the final results to the LIMS database.
The overall data flow eliminates virtually all manual data entry and duplication. The reduced sample time requirement allows for an increase in the number of measurements that can be performed. This is why the metallic analysis could be implemented as the routine analytical procedure for determining the precious metals content of the samples. |
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Reporting
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As more and more data became available in a structured system, the demand for various reports and data interpretation grew. The technology behind the LIMS allows relatively simple report development, using the MS-Access development shell. That kind of report gives a static presentation of results and can be distributed electronically or printed.
Another way of reporting data is using MS-Excel and an add-in tool that connects to the LIMS database and extracts data according to specified criteria. This kind of reporting allows the user to perform further data processing, such as computing statistics or building scenarios. The data integrity is unaffected, as this tool does not update the data in the central database.
This feature also enables the laboratory to develop templates for use by anyone who needs to access analysis results on a frequent basis. For instance, a process operator can display the results of the sampling points he wants without having to call the laboratory. On the laboratory side, no control is lost as the templates can be designed to allow access only to the approved results or based on any other characteristic suitable for external consultation. The same control can be exerted over any other property of the sample, such as its sampling point or analytical parameter. Even user access van be controlled by giving individual users their own accounts in the system. |
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Conclusion
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Implementation of the LIMS and the metallic analysis protocol allowed better identification of key indicators for an effective mining operation. This method provides good quality control of the samples.
Unfortunately, the costs associated with this new procedure are high, involving new equipment and staff training.
The LIMS and other satellite systems allow managing increasing volumes of data in a relatively user-friendly manner, avoiding manual data transcription and performing automated calculations.
In a new implementation, one should consider beginning the project with new computer equipment, to avoid premature replacement and associated problems. A good level of knowledge of the new LIMS software before beginning the configuration process would also be preferable. |
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Authors
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Martin Fréchette:
A B.Sc. in chemistry and an M.Sc. in polymer sciences from the Université of Montréal, Martin Fréchette joined LabPlus Technologies as a member of the LabPlus development team. He has worked on development, documentation, testing, customer training and system implementation.
Patrice Morin:
A 1985 graduate of Valleyfield College in analytical chemistry, Patrice Morin has worked in mine laboratories since October 1986 and for Inmet Mining Corporation - Troilus Division since April 1996 as Chief Assayer. |
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