Engineering & Mining Journal

APR 2019

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 46 of 83

SHAFT SINKING APRIL 2019 • E&MJ 45 support the weight of the formwork and the concrete cast behind it. The support ring is equipped with hydraulically ex- tendable drawers, which ensure the seal- ing to the face of the shaft. This system has worked well so far, due to the very smooth face, and the sealing work nor- mally required with conventional support rings was completely eliminated. Another major hindrance is the geolo- gy. The consistency of the material being removed is heavy and thick with clay. This has led to blockages in the opening of the buckets, which are shaped like milk cans and coated with a non-stick material, pre- venting them from emptying during tip- ping. Measures taken to enable faster emp- tying have thus far included wetting the bucket with solution, reducing bucket fill levels and modifications inside the bucket to allow the contents to drain more evenly. A series of tests was carried out involving plates attached to chains on the bottom of the bucket, and installations in the cen- ter of the bucket, which were intended to promote the breaking up of the material. Unfortunately under the given conditions, these variants proved to be unsuccessful. At present, tests are also being carried out with chemical liquids, which are sprayed on to the bottom of each partial cut and introduced at the bottom of the cyclone before the bucket is filled. Challenges like these are overcome by innovative thinking, something with which Deilmann-Haniel is familiar. Despite the adverse geological conditions to which SBR is exposed, the engineers at Deilmann-Haniel, in collab- oration with Herrenknecht, have planned and built a sinking system that is second to none. Current Situation and Future Advance The battle for every centimeter of cutting power from the machines is a lengthy one. As the learning curve of using this new technology begins to flatten, the geo- logical conditions remain and continue to challenge the crews. The bottom of shaft No. 2, which has a one-month lead time compared to shaft No. 1, was already at a depth of approxi - mately 75 m by mid-January. Due to op- timization and improvements, excavation started roughly one month ahead of the contractual schedule. During the first four weeks of the sink- ing operation, individual daily outputs of almost 3 m were already achieved, and there is no reason to doubt the planned 3 m/d will be reached regularly after the learning phase. Mining is unpredictable, and new technology adds another dimension of consideration, but there are many reasons to feel optimistic and positive about the progress so far this year. With world-class experience at the helm, and exception- al quality equipment in the ground, the outlook for the Nezhinskiy project looks bright. The project is currently proceed- ing ahead of an ambitious time schedule and there are still 1,250 m to go. This article was adapted from an article that originally appeared in the February 2019 edition of ADVANCE, the Redpath Group's Global Newsletter. Frank Otten, project leader for Deilmann-Haniel, and Jochen Greinacher, managing director for Deilmann-Haniel, are credited for their contribution. TAILINGS FLOTATION CELLS THICKENER UNDERFLOW CONCENTRATORS CENTRIFUGE AND CYCLONE FEED Series 5200 Control Pinch Valve Series D Slurry Knife Gate Valve Series DX Slurry Knife Gate Valve Series 75 Manual Pinch Valve Red Valve | 412.279.0044 The Best Choice for the Toughest Mining Applications. Since 1953, Red Valve Company has been the world's leading manufacturer of slurry valves for the mining industry. Built to last, Red Valve products are the industry's first choice for isolation and modulating valves througout a mining operation. Our global representative network stands ready to work with you.

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