Collaborative effort with local companies SARCO and K5 Heavy Engineering key to meeting contract dates.

NCP International Ltd has successfully delivered three large components that make up a ball grinding mill used in the mining industry, to a gold mine in Kazakhstan, a transcontinental country located mainly in Central Asia, and partly in Eastern Europe. Kazakhstan borders Russia in the north and west, China in the east and Kyrgyzstan, Uzbekistan and Turkmenistan in the south.

NCP International Ltd, based in Grand Baie, Mauritius, only received the order in November 2021 when their client had a catastrophic failure of the mill head at the mine due to a slurry wash.

NCP International Ltd, has successfully delivered three large components that make up a ball grinding mill used in the mining industry, to a gold mine in Kazakhstan

“In an ideal world, mechanical products and components would continue operating without interruption. Nowadays you can implement failure analysis programmes and data being received from Industry 4.0 initiatives is preventing disasters but because of the mechanical compensation of the metal structure, as well as the wear and tear of the mechanical components and materials, as well as the environment that they are operating in, you are still going to have unexpected breakdowns and malfunctions of equipment. Process and machine improvements and process condition monitoring have also lessened these incidents,” explained Wesley Keudel-Schaffer, Senior Project Engineer at NCP International Ltd.

“Our client mines gold and any stoppage time results in sizeable losses. Equipment failure can become very costly because of the length of time it takes to replace the equipment. In our client’s case it was the ball grinding mill, an integral and large part of the process of extraction of the gold resources from the alluvial deposits.”

12 week delivery
“From the time of signing the order we had 12 weeks to complete the design and manufacture and this we have done thanks to the collaborative effort with our South Africa partners – SARCO and K5 Heavy Engineering – on this project.”

SARCO (South African Roll Company) were contracted to manufacture the patterns and castings

“In this project we had to supply two feed heads and one discharge mill head for the ball grinding mill, all of them large individual components. The three components for the mill head weigh in at 32 tons each once machined and cast weight was 42 tons.”

“The mill heads were manufactured new as direct replacement of parts on an existing ball mill. The mills in Kazakhstan were standing whilst the new parts were being manufactured, so you can imagine the pressure we were under. The one mill head that was needed urgently to get the mill up-and-running again was flown directly from Johannesburg to Kazakhstan on a large four-engine cargo aircraft.”

SARCO participation
“SARCO (South African Roll Company) were contracted to supply the patterns and castings and K5 Heavy Engineering completed the machining and finishing of the components. K5 also fabricated a specific transport frame to allow for the mill head to be lashed for transport in the plane,” explained SP van der Walt, Sales and Marketing Manager at SARCO.

“The mill heads are cast in ductile iron and the pattern making and castings were completed in six weeks from order. The machining and finishing took another six weeks, including the December 2021 break, with another two weeks allocated for transport planning and finalising arrangements.”

The three components for the mill head weigh in at 32 tons each once machined and cast weight was 42 tons. The pattern sizes were 4 600mm by 1 650mm, pour time was 114 seconds and SARCO used two furnaces to melt the required amount of metal and used a single 40 ton bottom pour ladle

“Spheroidal graphite iron is relatively easy to cast, but casting it in sections above 75mm needs more accurate control. Through trial and error (calibration of the process) and the help of Magma software we found controlling the metallurgical melt was important to ensure good spheroidal graphite. The most important factors to control were time and temperature. Magnesium treatment and inoculation need tight control. Adding a chill effect in certain areas is very important to keep good feeding, control and treatment throughout the casting process.”

“The pattern sizes were 4 600mm by 1 650mm, pour time was 114 seconds and we used two furnaces to melt the required amount of metal and we used a single 40 ton bottom pour ladle. Additionally, we did in mould heat treatment, which took eight days to achieve the desired strip temperature,” explained van der Walt.

“The mill head was machined on the Farrell vertical boring machine (VBM) at K5 Heavy Engineering, one of the largest VBM’s in the southern hemisphere,” continued Keudel-Schaffer.

“Included in the supply was a new trunnion liner fabricated and machined in line with the supply of the new mill head.”

K5 Heavy Engineering completed the machining and finishing of the components. K5 also fabricated a specific transport frame to allow for the mill head to be lashed for transport in a large four-engine cargo aircraft

“The mill trunnion liner fits inside the bearing to protect it from wear caused by the ore being washed over the liner and through the bearing as it is fed to or discharged from the mill. In some cases the trunnion liner on the feed end of the mill may have a worm to assist the ore into the mill.”

“The completion of the project was at the end of February 2022.”

One of the world’s largest gear driven mills ever manufactured for Red 5’s King of the Hills (KOTH) gold project in Australia
“We are also very proud that NCP International Ltd recently successfully completed the supply of one of the world’s largest gear driven mills ever manufactured for the KOTH gold project in Australia. NCP International Ltd was awarded this contract by Engineering, Procurement and Construction (EPC) firm MACA Interquip and has delivered on all contractual commitments made during the lead up to the order placement.”

“The mill installation and commissioning was planned and commenced in March 2022. Installation has run to schedule with NCP International Ltd providing the onsite mill installation supervision services. NCP International Ltd will supply the client full aftermarket sales service, on-site service and technical support through our local partners.”

“NCP International Ltd is pleased to have successfully completed this mill supply following two other successful mill installations into the Australian market.”

For further details contact NCP International Ltd on TEL: 010 745 7079 or visit www.newconcept.co.za