Bias testing of a mechanical sampling system is the only way to determine if a sampling system is collecting a representative sample. ASTM advises that mechanical sampling systems should be tested initially and on a regular on-going basis for bias. Bias testing is statistically significant systematic error. Critical inspections are often used prior to testing to correct any problems that may cause bias.

Bias testing consists of a series of pairs of samples of the same coal. Usually a series of stopped belt reference samples and final save samples are collected and analyzed. The difference between analytical results is determined for each pair. The series of differences is subjected to statistical analysis to determine bias.

Miltech Energy Services, Inc. provides a complete line of bias testing services, including critical inspections, collection, analysis and reporting of bias tests on all types of mechanical sampling systems.

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The Miltech Energy Services, Inc. Analytical Division provides a complete line of laboratory analyses to meet the needs of energy producers and consumers. All analyses are run in accordance with recognized industry standards such as ASTM, ISO or EPA standards. Our laboratory utilizes state of the art equipment and experienced technicians to provide fast and accurate laboratory data on coal, metallurgical coke, petroleum coke, refuse derived fuels, oils and solvents.

Coal testing and analysis usually begins when the coal is still in the ground. Exploration coal core samples are drilled and analyzed for recovery and coal quality well before the mining process. During mining coal channel samples are routinely collected and analyzed for recovery and coal quality to determine the most efficient coal preparation system necessary. During preparation coal samples are collected and analyzed to assure the desired product quality is being achieved. Third party coal sampling and analysis are done routinely at loading and discharge of rail cars, trucks, barges and stockpiles. Finally, coal is routinely sampled and analyzed at the power plant to determine plant efficiency and EPA compliance.

Miltech Energy Services, Inc. Analytical Division provides a complete line of sampling and analysis services as well as inspection, check weighing and barge drafting services.

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The goal of every coal preparation plant operator is to recover every pound of clean coal possible at the desired quality. This is a product of both the cleaning process and the raw feed. Preparation plant testing can be used to determine the optimum parameters within the plant process that obtain the desired product (quality of the clean and at what rate of recovery). Knowing the maximum efficiency of the plant and the process, the operator can balance the efficiency of the mining process (raw feed) with that of the plant to achieve the desired results in the final product.

Usually representative samples of raw feed, product and refuse from all the different circuits within the plant are collected. In the laboratory the samples are subjected to coal washability studies and coal quality analyses at various specific gravity. Coal washability tables are prepared that demonstrate the recovery and quality at the different specific gravities under laboratory conditions. From the laboratory washability tables it can be determined how well the coal preparation process is being managed.

Miltech Energy Services, Inc. provides a complete line of coal preparation plant efficiency testing including collection, sieving, washability studies and coal analyses.

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Miltech Energy Services, Inc. provides quality barge draft surveying of river barges. Miltech's field technicians measure the barge freeboard at ten points prior to loading the barge. The same ten freeboard readings are taken after the barge is loaded. From current barge charts (provided by the barge lines) the light tonnage, loaded tonnage and net tonnage are computer calculated.

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