Engineering & Mining Journal

DEC 2018

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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Page 61 of 115

STOCKPILE MANAGEMENT 60 E&MJ • DECEMBER 2018 For more than 65 years, Derrick Corporation has been leading the industry in the design and manufacture of high-frequency vibrat- ing machines and screen surfaces. With a pioneering spirit driving innovative solu- tions, the organization is continuously in the forefront advancing the field of fine particle separation technology. Known worldwide for their high-capacity and superior separation efficiency, Derrick products are used suc- cessfully around the world. Its advanced technology allows processors to screen a wide variety of wet or dry fine materials in the range of 10 mm to 38 µm. A Global Family Focused on Pioneering Separation Technology Derrick's global family, comprised of employ- ees, sales representatives, and distributers, is strategically positioned worldwide to pro- vide superior customer service and technical support to customers around the globe. The company has a reputation for solving tough fine screening problems, increasing efficiency, and ultimately increasing profits for its customers. Combining its large suite of wet and dry screening products with its highly skilled technical staff and an in-house testing facility, Derrick provides its customers with optimize solutions and demonstrates the solution's effectiveness under actual field conditions on full-size machines. Testing is performed using state of the art equipment and each test is video- taped to document test programs. Fine Screening Solutions Derrick has success stories in nearly every mining application that requires fine screen- ing. Its proven fine particle separation tech- nology has been beneficial in coal, copper ore, gold, industrial minerals, fertilizers, iron ore, plastics, silica sand, and many other fine screening applications, creating more efficient processes, saving energy, and increasing profits for the processors. Derrick Corporation, founded in 1951, is a family owned and operated company headquartered in Buffalo, New York. Visit to discover more about its line of fine separation machines and read case studies that demonstrate the impact Derrick has had on the global mining industry. COMPANY PROFILE-PAID ADVERTISEMENT justified in light of the head-grade improve- ment demonstrated in testwork to date, along with the anticipated economic bene- fits delivered by greater production output. The company said approximately 80% of the value of stockpiled sortable frac- tions can be recovered in 20% of the mass, representing a four-times upgrade factor; or, alternatively, 90% of value can be recovered in 40% of the mass, repre- senting a 2.25-times upgrade factor. It plans to install an ore sorting circuit in the existing pilot plant, directly between the crushed ore stockpile and the mill feed hopper. The circuit will divert the feed from the primary crusher ore stockpile conveyor over a screen and through the ore sorting circuit that establishes mill feed stockpiles of upgraded sorted ore, a sepa- rate fines stockpile, and optionally a blend stockpile of fines and upgraded sorted ore. Rejected, low grade ore is conveyed to the stockpile for processing at a later stage. However, not all stockpile improve- ments hinge on high-tech assistance. For example, Teck's Red Dog zinc-lead mine in northwestern Alaska employs a detailed stockpile construction recipe aimed at blending ore to ensure a con- sistent concentrate quality, based on his- torical experience gained through build- ing blended piles from Red Dog's Main Pit deposit. That experience enables the mine to create a workable standard to op- timize its rich and variable zinc grades. At Red Dog, optimizing mill feed cur- rently requires blending weathered, baritic and siliceous ore types from two deposits into stockpiles that meet mill requirements. Ore cuts are run against the models, then ordered and sequenced to meet predeter- mined stockpile criteria. Cuts are orga- nized into roughly 190,000-mt stockpiles that are built in seven lifts on the crusher pad. The stockpiles are designed so the lifts, when mined in strips across the face, create a relatively consistent feed grade profile. The blending process is fine-tuned even further by the dumping sequence. The mine dumps the coarser, often higher-grade ore on odd-numbered lifts, as it has a high- er angle of repose in truck-dumped piles. The finer, more variable sized rock (typical- ly lower grade, baritic ores) is positioned on the even-numbered dozed lifts. This blending concept is adjusted as production blasthole assays and pit progression drives stockpile planning. Piecing It Together Digitalization's potential for improving over- all operational decision-making and risk re- duction has drawn stockpile management into a select group of functions that con- stitute a foundation for future productivity improvements. Skage Hem, vice president, R&D, at FLSmidth, recently explained how the pieces fit together: Noting how digita- lization has the ability to "disrupt conven- tional mining practices in a positive man- ner, in the last decade, data analytics has become increasingly important in order to optimize processes," he said. "Advances in connectivity, software usability and ca- pacity to store large amounts of data have created a range of potential applications for digitalization, all driving productivity. "An example of one of these productiv- ity potentials lies in the interplay between the quality variation of the ore and the wear state of the equipment. By under- standing how these parameters tie in to process performance, energy consumption and wear rates, it is possible to optimize all or some of these variables. Once data is available, it opens up for different types of maintenance schemes and operational strategies. Combining these with selective

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