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
Issue link: https://emj.epubxp.com/i/938385
HYDROCYCLONES FEBRUARY 2018 • E&MJ; 31 www.e-mj.com up to 10 in. internal diameter have been produced for special applications." Ridd went on to explain that operators often do not use full liners inside hydro- cyclones, but only in those sections where wear is greatest — typically the inflow. "We can cater for full liner requirements or small segments depending on the ap- plication. We use our own proprietary bonding system to join the alumina com- ponents together to form highly complex internal shapes and geometries that meet specific customer requirements," he said. "Even where liners are produced up to 1.2 m (4 ft.) long, the bonding ensures that any joints are stronger than the ce- ramic material itself, so the liner is less likely to break under vibration or impact." Ridd noted that while confidentiality restrains the company from identifying specific mining-sector users of its lin- ers, its long-standing relationship with National Oilwell Varco (NOV) provides a comparable illustration. NOV is a major provider of equipment and components used in oil and gas drilling and produc- tion operations, and of oilfield services. Maximizing oil recovery requires the effective removal of sand and other abra- sive waste materials from the well, using hydrocyclones for de-sanding. Morgan reports that its linings have provided ero- sion resistance and enhanced structural integrity, while its bonding technology has provided NOV with flexibility in the custom development of the hydrocyclone inlet and outlet profiles. In addition, this joining technology has meant that its lin- ers last longer than others used in the in - dustry, the company claimed. R&D; Brings New Chinese Designs A key feature of recent years has been the emergence of Chinese companies into the international mining equipment market. Established in 1989, Haiwang Hydro- cyclone Co. told E&MJ; it has an annual output of more than 20,000 cyclone sets, for use in a range of industries, and that as well as supplying the domestic market, its cyclones are now sold and serviced by agents in more than 10 other countries. Haiwang provided E&MJ; with details of two applications of its equipment, the first of which concerned the design of new cyclones to operate with low circulat- ing loads in primary closed-circuit grind- ing (ball mills and conventional hydrocy- clones) in iron-ore operations. With the high-specific gravity and degree of libera- tion of iron ore, there can be problems of low classifying efficiency and recirculat- ing high-SG particles for regrinding when using conventional hydrocyclones for classification. These problems reduce the system capacity and increase the energy consumption per ton, while overgrinding leads to the production of excessive fines, low recovery and greater losses to tailings. In response, Haiwang has developed and patented two new cyclone systems, which, it said, have proved effective at an iron-ore operation in Australia. Com- pared to the original hydrocylones used, the qualitative classifying efficiency of the new separation equipment rose from 40% to 61.50%, while fine particle re- covery was 23.25% higher at 72.25%. Meanwhile, overgrinding was reduced, with the production of minus-10 µm par- ticles in the tailings being reduced from 31.2% to 22.5%. Haiwang pointed out that on the basis of an operation with 5,000- mt/h tailing capacity, a cut of 435 mt/h of minus-10 µm particles equates to 3.445 million mt/y less fines being sent to tailings. Other benefits claimed for the new cyclones include a 600-mt/h increase in raw ore capacity and 200 mt/h of concen- trate (equivalent to more than 1.5 million mt/y), with lower energy and maintenance labor costs. Haiwang stated its new cy- A cluster of the new units designed by Haiwang Hydrocyclone for improving the separation efficiency and fines recovery in iron-ore processing plants. The three-product dense-medium cyclone designed by Haiwang Hydrocyclones for cleaning run-of-mine coal containing high waste and middlings.