New Horizons of Donskoy Ore-Mining and Processing Plant
A kilometer under the surface. This is how deep miners of one of the mines of Donskoy Ore-Mining and Processing Plant (Donskoy GOK), a branch of Kazchrome TNC, which is a subsidiary of ERG (Eurasian Resources Group), currently work. With a speed of 100 meters per month, the safest possible way, they are driving minus 480 horizon. In perspective, the pace of work will be even greater through the use of innovative technologies.
Extracting industry is a natural competitive advantage of Kazakhstan. Therefore, improving its efficiency is an important task set by the President of the country Nursultan Nazarbayev in his Message to the people “Kazakhstan 2050 Way: Common Goal, Common Interests, Common Future”. The works currently performed at the “Ten Years of Independence of Kazakhstan” mine of Donskoy GOK significantly contribute to the achievement of such ambitious goals.
The driving technology offered by a German company enables high performance there. It was almost impossible to provide safe and quick horizon driving under such complicated mining and geological conditions using the enterprise’s own efforts (expecially given the deadline provided for the project of the second phase of the mine construction). It was required to find an optimal solution for that. Therefore, three years ago a round table was held at Donskoy GOK including the specialists from the enterprise itself, and some experts from Kazakhstan, Russia, Germany, and other countries. It was when the German specialists presented their options of driving approved by the management of the company.
The technology is almost fully powered so it minimizes the manual labour and enables performing all the stages of the driving cycle with high performance. It means driving a horizon several times faster than if using the old technology and so performing a linkage with the “Ventilating” mine access. That is a final purpose of the horizon driving. Preparatory works with the enterprise’s specialists engaged took nearly a year.
According to the head of the engineering research center of Donskoy GOK Anatoliy Tretyak, during the first months designated for adaptation of the technology to the existing mine engineering and geological conditions, the driving speed was not higher than 40 meters per month. However, after some adjustments made by the center’s specialists to the contractor’s support patterns, there appeared a possibility of increasing it to the designed rate. Besides, it provides stability of the marginal mass (wall) and prevents it from fall-formation. The employees of the enterprise’s engineering department are currently updating the technology for mine workings at Donskoy GOK considering the elements offered by the German specialists. For example, gunite fixation as an advance and protection support installed in the face along the roof to provide advance fortification of the mass.
“565 meters had been driven as of May 22. The speed provided by the agreement is 100 meters per month. At the same time, there are works performed for permanent track laying and hitch arrangement”, says Ravil Nassyrov, Technical Director at Donskoy GOK.
“Sure, we faced some engineering and organization issues during first months. But all of them were successfully solved. In cooperation with Donskoy GOK specialists, we developed a specific procedure for work performance; adjusted the production technology in order to prevent fall formation during driving and provide stable designed speed. As for technology, it is certainly conceptually new for us. If we take into consideration the experience we had before when driving using our own resources, it is much more efficient through high mechanization level. Nearly 10 months have passed since the contractors started their work. So, we see neither visible deformation processes nor breaks in the support on the site where they operated.”
In perspective, the technology will be adjusted so that to provide the speed about 115–120 meters per month. According to the design documentation, in order to connect two mine accesses, crosscut driving will be used, an underground mine opening located at horizon minus 480, i.e. 900 meters deep from the ground surface. The designed mine opening is 4,150 meters long. As the specialists noted the specially developed driving technology had a set of specific features. First, the perimeter blasting technology provides an opportunity of preventing the marginal mass from destroying in case of drilling and blasting operations. Second, the sprayed concrete fixation fortified with steel fiber is installed within two hours after blasting operations to avoid the ambient impact on enclosing strata.
As Alexandr Dashkus, the head of the enterprise’s shaft construction department highlights, “It should be noted that the technology provides maximally efficient and safe driving with mass stability fortified under mining and geological conditions typical for horizon minus 480, i.e. in the mass, which is quite unstable and free-caving. Faster site driving will provide important advantages: after linkage with the “Ventilating” mine access we will provide the horizon ventilation and will be able to control ventilation conditions. And the most important thing is that we will continue further development of the mining operations to prepare the field for extraction.”
Driving is performed by drilling and blasting methods with rail haulage. Clear arrangement and mechanization of operations ensure that the miners underground will not stay outside the fortified area. The crosscut should be fixed with the help of manipulators located on the fortified site. However, in order to achieve maximum performance the project process had to be adjusted at some certain stage. Initially, the designed technology provides only the use of the contractor’s machinery. However, for the purpose of operations at this horizon Kazchrome TNC ordered two storage battery locomotives. The machinery is equipped with acoustic and light warning system.
In perspective, the enterprise’s employees are planned to be trained to use innovative technologies and working methods. “I can say that the workers are quite impressed by the extent to which the equipment is used and the labour is powered. Sure, we welcome it – it is a good experience for us,” – shares his impressions Yerzhan Tuyakov, a master of shaft construction department.
In their turn, the German company’s representatives are sure that after assessing all the required parameters they have chosen an optimal driving technology. The operations at such unique project are planned to be completed in 2017.
Insertion
The “Ten Years of Independence of Kazakhstan” mine is one of the leading workshops of Donskoy GOK, a promising department with young and ambitious team. Its history started in 1999, when the President of Kazakhstan Nursultan Nazarbayev launched he first phase of the first start-up facility of the “Central” mine with the capacity of 100,000 tons of ore per year. And in 2001, the first phase of the mine was commissioned with the designed capacity of 100,000 tons of ore per year. The mine got its name in honour of the anniversary – “Ten Years of Independence of Kazakhstan”. It produced its first million of crude ore in 2007 and since then it has annually been providing outstanding production performance.
