Atlas Copco ROC L8 – The only choice of Zhujiang Cement
Two ROC L8 have good performance in Zhujiang Cement, which was bought in 2003 and 2008. As its advantage, Atlas Copco became the only brand here for drilling equipment. Nearly eight years, the characteristics of high efficient and low fault make ROC L8 got high praise ofZhujiang Cement.
Located at Langtou Village, Tanbu Town, Huadu District, Guangzhou, Zhujiang Cement owns two mines – a limestone mine and a sandstone mine. The limestone mine is the major source of raw materials for the cement production of the company. Planned in 1986, the mine has a designed reserve of 60.29 million tons, with a mining depth of -50m and an annual production capacity of 1.7 million tons. With the constant growth of production, the annual production has been increased to 2.35 million tons and the mine reserve became obviously insufficient. In this case, a supplementary exploration was conducted in 2003. The mine depth was increased to -110m and the available reserves of the limestone mine reached about 90 million tons.
The limestone mine consists of two production zones – the mining zone and the rock breaking zone. In the mining zone, major operations include drilling, blasting, loading and transport, and machinery maintenance. The sandstone is mined directly using excavators as the layers are loose. So the sandstone mining is included in the rock breaking zone. In the mining zone, only limestone is mined. The rock breaking zone consists of two lines – the limestone breaking line and the sandstone breaking line. The rocks are crushed here and delivered to the prehomogenization storage in the plant through a 9.38km-long conveyor belt. The two Atlas Copco ROC L8 rigs work here in the mining zone.
The limestone mine of Zhujiang Cement is located in a valley between two mountains. In order to adapt to the existing terrains, a sunken-style open-cut mining is adopted. The rock layers at the mine have strong cleavage lines and the ore bodies are in the rigid and half-rigid states. At specific mining sites, the ore bodies are in different strata. The side slopes have distinct joint fissure, which are good to slope stability.
The blasting operations are conducted through blasthole drilling. Burden 4.5m, hole spacing 8.5m, hole diameter 140mm. Hole depth consists of two ranges. Between -40m and -20m bench elevations, there is one bench every 15m and the overdepth is 1.8m. Below -40m, each bench is 20m high and the overdepth is about 2m. The hole inclination is 80°.
The drilling tools that the two rigs use are COP54 140mm drill bit. The rigs have smooth feed as they are equipped with aluminum alloy boom and hydraulic steel wire driving system. The hydraulic double drill steel support can control the deviation within 1% during the drilling of a 15m-deep hole. So the rig has high drilling accuracy and greatly improves the blasting performance.
As of September 2010, the first rig has drilled for 6,400h and the average penetration rate is 42m/h and the second one for 1,700h with the rate of 48m/h.
The high productivity of ROC L8 was proven again during the Guangzhou Asian Games. Starting from October 2010, Zhujiang Cement had to ta ke measures to eliminate emissions and reduce pollution in order to improve the air quality in Guangzhou. Under this special circumstance, the two ROC L8 rigs played a crucial role in guaranteeing the smooth implementation of production tasks. Between September 1 and 22, the two rigs helped mining 700,000 tons of limestone, while the normal monthly output was then only 200,000 tons. During the period, one ROC L8 worked 4 hours per day and the other 7.5 hours per day.
“The second reason why we bought another Atlas Copco rig is its low failure rate. When using these two drilling rigs, we follow the standards, so the failure rate is low and the maintenance costs are also low. But actually, the rigs themselves have a very low failure rate. Atlas Copco provides satisfactory services. And the general performance of the rigs is good,” said Mr. Huang Honghui.
“Secondly, the most difficult problem we come across during mining is that there are many water-eroded caves and holes. Very often, the rig is confronted with caves instead of rocks when drilling a deep hole. And even the drill could be jammed,” said Huang. “During drilling, we usually try to keep away from unstable rocks, such as water-eroded caves and cavities. We have to change the drilling positions if we fail to avoid such conditions. However, the Atlas Copco rigs have an advantage. They have the function of automatic anti-jam protection. In case of a jam, the sudden torque increase will be shown on the control panel display in the cabin, and the jam won’t become worse and it is unlikely that the rig becomes stuck. This again shows the good performance of Atlas Copco products.”
“There is another important thing – service,” said Huang. “After the purchase, Atlas Copco provided prompt and complete training for our operators. The operators can work independently after being trained. Meanwhile, Atlas Copco responds very quickly to service needs. Their highly skilled technicians can always solve our problems in a timely manner. At the limestone mine of Zhujiang Cement, only four operators work with the two ROC L8, two for each, and they also carry out blasting operations. But all of them do a very good job.”
The year of 2011 is the first year of the “12th Five-Year Plan”, and Zhujiang Cement will embrace its new chapter of development. However, Zhujiang Cement limestone mine will unswervingly aim to “build safe, superior, low-consumption, efficient, and environmental-friendly production-based mine”, which coincides with the objective of Atlas Copco equipment. If the mutual selection is based on the mutual trust, their brilliance will undoubtedly result from their common development. In the future, as a manufacturer of mainstream mining equipment, Atlas Copco will continue to contribute its part to the development of Zhujiang Cement !
For further information, please contact:
Marketing Communication Specialist
Atlas Copco Mining and Rock Excavation Technique
Phone: +86 10 6528 0517
Atlas Copco is an industrial group with world-leading positions in compressors, expanders and air treatment systems, construction and mining equipment, power tools and assembly systems. With innovative products and services, Atlas Copco delivers solutions for sustainable productivity. The company was founded in 1873, is based in Stockholm, Sweden, and has a global reach spanning more than 170 countries. In 2010, Atlas Copco had about 33 000 employees and revenues of BSEK 70 (BEUR 7.3). Learn more at www.atlascopco.com.
Atlas Copco’s Mining and Rock Excavation Technique business area provides equipment for drilling and rock excavation, a complete range of related consumables and service through a global network. The business area innovates for sustainable productivity in surface and underground mining, infrastructure, civil works, well drilling and geotechnical applications. Principal product development and manufacturing units are located in Sweden, the United States, Canada, China and India.