Modern Mining March 2019

PRODUCT News

Multotec’s ceramic impellers boost uptime at DRC mine A large order of 24 ceramic impellers des- tined for pumping equipment in a copper mine in the DRC signals the value this tech- nology brings through longer wear life and less plant downtime. pumping applications where particle sizes are less than 6 mm in size,” says Mark Jarrett, Business Development Manager at Multotec Wear Linings. “The ceramic solu- tion is particularly effective in resisting abrasion, and also deals well with high lev- els of either acidity or alkalinity.”

replaced easily without the risk of damag- ing the shaft,”he says.“We can also provide other components – such as the throat bush and the frame plate liner – with ceramic protection for better wear resis- tance and longer service life.” Ceramic impellers are available in vari- ous standard sizes, but there is scope for the development of custom solutions to suit the customers’ needs. They have been successfully applied in mainly gold and copper operations, primarily in the tail- ings and leaching circuits, as well as other aggressive environments. Jarrett highlights that all applications of ceramic solutions must first be thoroughly investigated before the best option is finalised. “Our experienced Multotec technical professionals will conduct a detailed and methodical assessment of the customer’s plant conditions before recommending the appropriate solution,”he says.“We con- sider the key characteristics of the plant process to confirm if the ceramic solution is the optimal one. This includes under- standing the total wear conditions of the plant system.” Multotec Group, tel (+27 11) 923-6000, website: www.multotec.com There is also the possibility of painted parts being scratched or damaged dur- ing transport and installation. When this occurs, it leads to the time consuming task of being returned to the factory for proper powder-coating, further delaying the installation and commissioning process. Indeed, if there is a need to weld again for any reason, then there is a repeat process of grinding and pre-washing before paint- ing again. Kohler highlights that the corrosion- resistant properties of aluzinc allows parts to be kept in stock, ready for quick assem- bly. He notes that this is not possible with mild steel due to corrosion. “By introducing the use of aluzinc in the manufacture of our MCCs, we can reduce the lead time on components by as much as two to three weeks, and this is a time-saving that we can pass on to our customers by delivering more quickly,” he says. Shaw Controls, website: www.zestweg.com/about/shaw-controls

Designed and manufactured in South Africa by Multotec Wear Linings, part of the Multotec Group, the ceramic impellers can be a viable alternative to conventional pump impellers and in the right applica- tion are expected to last up to five times longer. “The impellers will be used in slurry

The ceramic design, in which alumina ceramic components are bonded mechan- ically and chemically onto a stainless steel impeller skeleton, is growing in popularity. Multotec Wear Linings has been supplying ceramic impellers into the market place for many years and some 300 ceramic impel- lers have already been exported by the company into the African market during the past four years. “The key advantage of our ceramic technology is to lengthen the replace- ment intervals for these wear parts,” says Jarrett. “This, in turn, reduces downtime on the plant and raises productivity, invariably delivering positive impacts to the bottom line.” To further enhance the ceramic value-add, Multotec also offers ceramic components on certain other strategic pump components. “Our ceramic shaft sleeve, for instance, also contributes to longer life, and can be aluminium, 43,5 % zinc and 1,5 % silicon. Manufacturers of the product guarantee that it will last for about 35 years before any major maintenance is required. “The powder coating of steel panels complicates the earthing requirement on an MCC, as the paint layer insulates the panel and prevents conductivity,” he says. “This means that technicians and installers must take special care to ensure that proper contact is made between the unit and the earth connection.” For instance, the use of star washers must be strictly enforced among installa- tion staff. Alternatively, certain areas of the MCCs are left unpainted to allow for earth connections. Kohler points out that this does raise the concern that it only takes a small oversight and the earthing will not be fully effective. The use of aluzinc eliminates this issue as there is no longer a paint layer between the earth connection and MCC panel.

Front view of the Multotec ceramic impeller.

Aluzinc replaces steel in manufacture of MMCs The replacement of steel by aluzinc in the manufacture of Shaw Controls motor control centres (MCCs) is giving a range of benefits to the company’s customers, according to Anderson Kohler, the com- pany’s Senior Manager Operations.

“Traditionally, we used only steel for our MCCs, which needs to be powder coated in order to protect it from corrosion,” says Kohler. “This made it necessary to follow quite a long process in completing our products – a process which aluzinc can now simplify and speed up.” The usual process of preparing the MCC panels includes welding, grinding and prewashing before the powder coat- ing painting process can take place. These phases can now be bypassed by using aluzinc which is a material that effectively resists corrosion without a protective coat- ing being applied. Kohler highlights the extended life­ span of aluzinc, which comprises 55 %

52  MODERN MINING  March 2019