Surface mining is a technique used by a few cement companies to exploit limestone deposits, where the cost of mining is relatively low.
The eco-friendly operation of surface miners has made them a very popular and safe option of open cast mining of coal and limestone, as they eliminate hazardous drilling and blasting processes. The small product size also ensures smooth transport of material with lighter vehicles without the need of primary crushing. Envisaging future potential of such eco-friendly mining equipment, L&T introduced its first indigenously designed and developed Surface Miner KSM304 in 2004 and has now made significant contributions in about 60 successful installations across the country.
This range includes models with capacities of 50 tonne and 100 tonne, with drum width varying from 2.2 m to 4 m. L&T has been continuously improving its products and services for better productivity and operational efficiency to meet the increasing demands of limestone and coal mining.
The journey of the L&T surface miner in limestone mining was initiated in 2005 immediately after the successful performance of KSM304 in coal. The initial trial was conducted at Hirmi Cement Works´ (presently UltraTech Cement) open cast limestone mine where experts from various cement industries were invited to witness the smooth operation of L&T surface miner KSM304 on massive hard limestone deposits (hardness up to 60 Mpa).
L&T KSM304 passed the test very convincingly with satisfactory performance. The result was encouraging enough for L&T to venture into the new application of surface miner in limestone mining.
L&T surface miners were supplied to Togo (West Africa) for limestone mining. The deposits in Togo were medium hard and a little sticky, so surface miners were supplied along with rear loading conveyors for discharging the cut material to the dumper, immediately after mining. The machines have clocked more than 10 years now and continue to meet the expectations of the user.
L&T KSM304 also made its entry in the costal belt of Gujarat where the limestone deposit was comparatively soft in nature. The machine (L&T KSM 304) was supplied to Sanghi Industries Limited where the performance exceeded customer requirements. The long mine face (Jadua mines) at Sanghi was apt for the L&T KSM304, which was operated continuously on comparatively softer limestone deposits without any interruption and delivered much higher productivity (1100+ TPH). L&T Surface Miner KSM223 also carried out limestone mining at Rajula (Gujarat) in 2008. The machines continue to meet the expectations of the user for around a decade now.
L&T Surface Miners also operate in very hard limestone deposits. Accordingly, L&T KSM 304 was supplied to the Middle East in 2006 and the machine was operated at Doha (Qatar). The impact of hard rock cutting could not shake the sturdy design of KSM 304. Although productivity came down with higher pick consumption as expected for the harder deposits, the L&T KSM 304 was economical in operations, despite operating in the desert.
L&T Surface Miners have become popular in Indian coal mines with their presence in Odisha (MCL), Chhattisgarh (SECL), Jharkhand (CCL), West Bengal (ECL) and Andhra Pradesh (SCCL), along with a few captive coal mines.
L&T Surface Miners have proven their performance across various mineral applications (deposits varying from soft, medium to hard) over more than a decade in India, Africa and the Middle East for mining and construction projects.
This article has been authored by Sanjib Roy (AGM -Crushing Technology) and Subhankar Bhattacharya (Manager-BD-Surface Miner), Larsen & Toubro Limited, Kansbahal Business Unit.