Introduction. Drilling and blasting operations are first in the workflow and significantly determine the economic efficiency of the entire mining and primary processing workflow in the enterprise. The cost of drilling and blasting operations is a significant part of total production costs of large mining companies. In this context, mining engineers today are facing a crucial technological problem, i.e. the reduction of the off-gauge fraction yield after the explosion. Research aims to develop the models which forecast the granulometric composition of the rock mass taken down as the original factor in reducing the economic waste of the entire workflow. Methodology. The parameters which influence the results of rock mass fragmentation and the techniques of rock mass granulometric composition forecasting in the course of drilling and blasting were analyzed. Results. The present paper gives a brief overview of the global mineral output; provides information on the extraction of key types of minerals (mineral fuel, ferrous metals, non-ferrous metals, precious metals, and construction materials), as well as revenues derived from their sale. On the example of domestic companies, approaches to the issue of forecasting the off-gauge fraction yield after the explosion. Summary. Direction for future actions in creating the model forecasting rock mass yield of a certain fraction after the explosion.

No abstract

Vancouver, February 27, 2020 -B2Gold Corp. (TSX: BTO, NYSE AMERICAN: BTG, NSX: B2G) ("B2Gold" or the "Company") is pleased to announce its operational and financial results for the fourth quarter and full-year ending December 31, 2019. The Company previously released its gold production and gold revenue results for the fourth quarter and full-year 2019, in addition to its production and budget guidance for 2020 (see news release dated 1/15/2020). In 2020, the Company is forecasting total gold production of between 1,000,000 and 1,055,000 ounces. All dollar figures are in United States dollars unless otherwise indicated.

Purpose. To improve rock classification in terms of explosivity relying upon the detailed analysis of characteristics of rating classifications available in the Russian Federation and in the world. Methods. Complex approach has been applied involving comparison of sizes of particle-size fractions determined in terms of both national and the world standards; information gathering and processing as for the available classifications intended to identify difficulties of rock explosivity; compilation of comparative systematic of classifications or methods being considered.Findings. Both national and the world rock classifications in terms of explosivity have been considered. While comparing national classifications as for the difficulties of rock mass failure (i.e. explosivity), a comparative table has been compiled where the most popular rock classifications are compared. Analysis of the world practices, concerning compilation of rock classifications in terms of explosivity, has shown that their approaches differ from Russian ones slightly. In the first instance, they are empiric dependences being calculated for each rock mass type separately in any single case. It has been determined that geomechanical classification of D. Lobshir (MRMR) is the most popular and rating world system to evaluate rock explosivity. It has been demonstrated that while compiling such classifications, foreign scientific writers put an emphasis on physical and mechanical indices of rocks (i.e. density, fissility, compression strength, tensile strength etc.) as well as on mine engineering ones (i.e. line of the least resistance, well diameter and depth, stope height etc.) which determines essential reliability of calculation of drilling-and-blasting parameters.Originality. The research is the first stage of the development of the unified transition classification from Russian explosivity scales to the comparable world methodic practices as for rock mass explosivity.Practical implications. To perform rapid transition from one explosivity classification to the other. The findings are recommended to be used while projecting drilling and blasting operations in the context of any types of minerals and in the context of academic activity.

No abstract