DEVELOPMENT OF COAL DEPOSITS USING LAYER-BY-LAYER MILLING MACHINES

Abstract

Among important issues of mining production are
improving the quality of mineral resources, reducing the losses during its extraction, the full use of extracted resources, minimizing the recycled waste. The use of traditional mining technologies in the development of complex structure deposits with loosening the rock mass by explosive method and excavating the rock mass by single-bucket excavators often does not allow to conduct the selective excavation and leads to mixing the mineral with the empty rock. Layer-by-layer milling machines allow selective extraction of minerals from complex rock masses, which helps to increase the extraction coefficient and improve the quality of the extracted minerals. The disadvantage of the technology with the use of layer-by-layer milling machines in the development of coal deposits is a significant yield of small fractions of coal. The presence of a large amount of fines in the mined coal determines the loss of the mineral during loading, transportation and storage due to spillage and blowing, as well as reduces its quality and market value. The paper offers an improved design of the layer-by-layer milling machine equipped with
transport and sorting unit, which consists of a scraper conveyor, a sizing grill on elastic supports and vibrator. Also, the layer-by-layer milling machine is equipped with a storage device for coal fines and a pneumatic conveying system. In the process of mining the rock mass the coal entering the transport and sorting unit is divided into the coal fines directed by the pneumatic conveying system
into a sealed bunker of a special vehicle and the over-sized product transported to the dump truck by means of a discharge conveyor. As a result of separating the coal fines directly during the excavation and loading process, the dust and coal losses during its transportation will be significantly reduced, which will have a positive effect on environmental situation in mining operations.