November 10, 2015
Efforts to protect the environment are increasingly evident in Chinese industries, not least in cement manufacturing where dust presents a major challenge. Atlas Copco’s surface drill rig, PowerROC D55, is making a small, but important contribution to a solution.
The Zhonglian Cement factory in Anyang Henan in central China, produces some 7 000 tonnes of clinker per day. It is a modern, environmentally designed plant where the transportation system, storage facilities and workshops are all carefully enclosed to minimize the presence of dust in the air.
The raw materials come from the surrounding limestone quarry where the same consideration for the environment is practiced. Here, the contractor Anyang Yuhao Blasting Engineering Company is responsible for the drilling, blasting, loading and transportation. Some 20 000 tonnes of rock per day is blasted and excavated per day using two PowerROC D55 surface drill rigs supplied by Atlas Copco in Nanjing.
Yuhao says environmental considerations played a big part in its decision to purchase the PowerROC D55 which has proved to have good dust suppressing capability, which benefits the working environment on the site as well as the individual operators.
Two rigs were put to work at the quarry this year and have been living up to expecations for reliable performance. The five, 5 m long drill rods are perfectly matched to the 20 m benches and the rigs drill 140 mm holes according to a drill pattern of 4 m x 4.5 m. The selected hole diameter of 140 mm greatly reduces the cost for explosives (ANFO), at the same time as it improves efficiency. One kilogram of explosive is normally used to blast five tonnes of stone.
The rigs are in operation eight hours per day. It takes around 30 minutes to drill a hole and about one minute for a rod change. The working pressure is 20 bar and the bit lasts for 2 000–3 000 m.
The life of the quarry is estimated to be 30 years and Zhonglian Cement aims to expand its production line as well as its capacity, which can potentially be increased to 45 000 tonnes per day.
Yanjun Ma, Site Manager, tells M&C: “Before we contacted Atlas Copco, we did a lot of investigations and comparisons. We wanted a reliable partner who could help us to consistently develop and improve our business and we think Atlas Copco lives up to its name and fame.”
Operator Guoqiang Wang says: “I have been an operator for almost ten years, operating different kinds of drill rigs. The PowerROC D55 with its straightforward design and hydraulic control system is really convenient as it enables me to solve most regular problems by myself.
“If I meet a problem that I cannot fix, I call the Atlas Copco service guys and they respond very quickly. These two PowerROC D55 rigs are meeting our production demands of up to 7 000 tonnes per day and perform very well.”