On determining the parameters of face blocks during mining operations with backhoes

The backhoe hydraulic shovels (backhoes) have been widely used in open-pit mining operations in the Kuznetsk coal basin since the early 2000s. Now their number is growing every year, both because new operations begin on new sites, and because of the backhoe advantages. However, up to now parameters of their operation, more particularly the parameters of the face blocks, are often taken according to the actual data, i.e. based on the accumulated experience of the mining companies, and are not calculated using the approved scientifically validated methods. In the given article the authors give some preconditions for creation of a uniform methodology to calculate parameters of the face blocks depending on mining-geological and miningtechnical conditions. It is noted that the manufacturers of excavation equipment quote the data corresponding to the maximum possible parameters of the equipment operation, in particular the height of the excavated layer, as a result of which it is rather difficult to apply this in practice. Preliminary conclusions about the need to take into account the diversity of the above conditions and their interrelation with the parameters of a particular model of the excavation and loading equipment have been made.

About scientific and practical conference explosives of the Urals

The article reviews the results of the VIII Scientific and Practical Conference with international participation "Technology and Safety of Drilling and Blasting Operations in Surface and Underground Mines of the Urals" which was held at the Ekaterinburg-EXPO Exhibition Center and the Uralasbest Industrial Complex as part of the IX Urals Mining Industry Forum and the URAL MINING' 21 Exhibition dedicated to the Year of Science and Technology in the Russian Federation and the 30th Anniversary of the Urals Mining and Industrial Association. The article also informs about the winners of the Ural Mining Award 2021 and about the research and engineering reports and presentations made during the conference and dedicated to blasting operations. Results are summarized of the visiting seminar at the Uralasbest Industrial Complex, where the Chief Engineer of Promtekhvzvzryv Company N.A. Chistyakov and General Director of the Urals Explosives Association G.P. Bersenev conducted tours to the open-pit mine, the 'Poremit' Plant - the first emulsion explosives production facility in the Urals, a bulk explosives storage, the museum and training center of the Urals Asbestos Mining and Processing Complex. Following the tours of the training center site of the Processing Complex, the second part of the conference was held, during which a number of reports were delivered. Upon completion of the seminar, the Urals Explosives Association awarded honorary certificates and valuable gifts to specialists of the Promtekhvzvzryv Company for their contribution to improvement of drilling and blasting technology and organization of labor on blasting sites. The article is concluded by a summary of the Conference's decisions.

A method to improve the quality of rock preparation for extraction with emulsion explosives in open-pit mines with high benches

Increasing the production capacity of open-pit and strip mines while ensuring the efficiency of the mining enterprise can be achieved through enhancing the quality of rock preparation prior to excavation. The use of emulsion explosives and the transition to the high-bench technology can reduce the cost of mining operations by optimizing the drilling and blasting parameters. The article reviews methods to improve the efficiency of rock preparation for extraction based on the applicable scientific and methodological principles and it proposes a method to regulate the density of emulsion explosives. Schemes are presented for calculation of drilling and blasting parameters when implementing technical measures aimed at improving the blasting quality through rock preparation for extraction in conditions of overburden and mining operations with bench height of 15 m and higher. Parameters of drilling and blasting operations on high benches are justified with differentiation of the charge density along the length of the blast hole by controlling the delivery of the gas-generating additive. A simulation has been performed and the results of pilot tests of the emulsion explosive charge density control at the Ural deposits are presented.

Integrated Parametric Graph Closure and Branch-and-Cut Algorithm for Open Pit Mine Scheduling under Uncertainty

Open pit mine production scheduling is a computationally expensive large-scale mixed-integer linear programming problem. This research develops a computationally efficient algorithm to solve open pit production scheduling problems under uncertain geological parameters. The proposed solution approach for production scheduling is a two-stage process. The stochastic production scheduling problem is iteratively solved in the first stage after relaxing resource constraints using a parametric graph closure algorithm. Finally, the branch-and-cut algorithm is applied to respect the resource constraints, which might be violated during the first stage of the algorithm. Six small-scale production scheduling problems from iron and copper mines were used to validate the proposed stochastic production scheduling model. The results demonstrated that the proposed method could significantly improve the computational time with a reasonable optimality gap (the maximum gap is 4%). In addition, the proposed stochastic method is tested using industrial-scale copper data and compared with its deterministic model. The results show that the net present value for the stochastic model improved by 6% compared to the deterministic model.