COMMINUTION AND CRUSHING whether the yearly ball consumption could be further reduced .”
Alcón clearly states that all of these challenges are positively impacted by many factors , among which , is the quality of Metso ’ s grinding balls . “ Since the start of the operations here , we haven ’ t seen any broken balls and the shape of the balls produced by Metso are close to being perfect ,” he says . “ These clearly influence the grinding efficiency and energy consumption in a positive way . Over the years , Metso has always partnered with us to find better solutions to these challenges . They bring us the best benefits when comparing grinding media and mill linings from other suppliers . Today our whole plant is running at over 95 % availability , which is above international standards , and we ’ re sure that is partly the result of working together with Metso .”
Reducing grinding consumption while simultaneously improving grinding efficiency and reducing energy consumption are common issues in the mining industry . “ Our grinding balls can help improve each of these in a significant way ,” says Santiago Fernandez , Manager of Metso ’ s Forjas del Guadalquivir operations and manufacturing facilities . “ This , in combination with our proximity to Cobre Las Cruces , has benefited our valued customer . Thanks to lower inventory levels , lower ball consumption and more recovery , they are able to better use their financial resources .”
In addition to the grinding media , CLC is also using Metso ’ s Poly-Met™ mill lining , which they are very satisfied with , according to Rafael Sánchez , Maintenance Supervisor at the CLC plant . “ We are able to change the plates and lifter bars inside the whole mill in only two days ; and since we are using the Poly-Met lining , we only need to do this every 7 to 8 months . This previously was needed every 4 to 5 months . This reduces our plant downtime and , consequently , also the costs involved . Since we changed to the Poly-Met mill lining , our costs decreased by around 15 % due to the longer wear life and fewer liner changes . The Metso grinding balls also have a positive influence on the changing schedule , as the quality of the balls definitely increases the lifetime of the linings ,” he stipulates . “ Together with the Metso crew we ’ re now looking into increasing the lifetime of the mill linings even further by eventually switching to a thicker size . Many factors influence the time between changes ( quality of the grinding media and mill lining , mill speed , mill lining design , etc ) but we have no doubt that we ’ ll find the right balance with Metso ’ s help ,” he concludes .
When it comes to grinding media ; design , raw material and manufacturing rigidity are critical for maximum performance . ME Elecmetal states : “ The worldwide success of the ME Elecmetal
ME Elecmetal points out that balls that break prematurely or wear into ovoid shapes in SAG mills clog grate slots , creating significant reduction in throughput and increased downtime , resulting in revenue loss . When balls maintain the round shape they more successfully pass through slot openings allowing designed throughput to be more easily achieved
Grinding Media division is built on these three factors , as well as world class logistics and robust application engineering support . Since the introduction of SuperSAG ® and Ultragrind ® media for SAG and ball mills in 2010 , ME Elecmetal has grown to be a leading supplier of high quality grinding media solutions world-wide , expanding on its reputation as the premier supplier of cast grinding mill liners , crusher products and solutions in the mining industry .”
The ME Elecmetal SuperSAG ® ball was developed in response to the need for SAG mill balls that did not spall and break , causing production , maintenance and consumption problems . The design of the new ball used high quality ‘ clean steel ’ bars made from virgin steel , instead of melted steel scrap , as raw material , and saw attention to advanced forging techniques , and uniform , precision heat treatment . The result was a ball with improved ‘ toughness ’ to resist spalling and breakage from the high impacts in modern SAG mills , and improved resistance to abrasion wear because of increased ‘ hardness .’
The company states : “ The improved performance of this SuperSAG ball led to a paradigm shift in the SAG milling community , from accepting breakage and spalling as normal and desirable to expecting SAG balls to remain competent and spherical from the time they are introduced into the mill until they are worn enough to pass through the slots in the discharge grates of the SAG mill . Maintaining the round shape for the complete life cycle of the ball is important for SAG mill productivity . Balls that break prematurely or wear into ovoid shapes in SAG mills clog grate slots , creating significant reduction in throughput and increased downtime , resulting in revenue loss . When balls maintain the round shape they more successfully pass through slot openings allowing designed throughput to be more easily achieved .”
In several instances , primary grinding ( SAG ) balls that maintain roundness are used to supplement ball charging in secondary ball mills ,
saving a portion of the costs of new balls . SAG balls that do not break maintain maximum size during their lifetime in the mill , thereby bring maximum crushing force to bear on the ore . The result is often higher productivity .
“ The same principles used in developing the SAG mill ball line was used in developing the ME Ultragrind ® ball mill balls . These balls range in size from 40 to 100 mm . They have proven to be highly effective in ball mill circuits around the world , and are often bundled with SuperSAG ® media products to provide comprehensive grinding media solutions in many of the world ’ s leading mining ventures .”
ME Elecmetal ’ s modern grinding media production facility opened in China in 2012 , with present full production capacity approaching 400,000 t annually of forged grinding balls used for SAG , ball and regrind mill applications . Recently the company has also noted a demand for high quality media in Africa , and the construction of one more manufacturing facility is presently underway in Zambia . The ball production facility is Quality Management System certified ISO 9001:2008 , Environmental Management System certified ISO 14001 , and Occupational Health and Safety Management Systems certified OHSAS 18001 .
Overall , the range of ME Elecmetal grinding media spans from 22 mm to 160 mm , with surface , volumetric and centre hardness characteristics exceeding those of the competition .
“ Each batch of the media produced is subject to the rigorous testing procedure that includes chemistry composition verification , a hardness test and a drop test .”
The ME Grinding Media Application Team is also an integral part of the ME FIT System , which stands for Fully Integrated Technology . “ ME Elecmetal is the first company to offer this integral system which brings together our array of products and services . The ME FIT System is an optimised mill liner and grinding media system integrating consulting , products and services , people , logistics , and manufacturing all into one . Our approach is to provide concrete ,
MARCH 2017 | International Mining