Development of resource-saving technology for excavation of flat-lying coal seams with tight roof rocks (on the example of the Quang Ninh coal basin mines)

Abstract

It is shown that the creation of the variants of resource-saving systems for the development of long-column mining is one of the main directions for improving the technological schemes for mining operations in the mines of the Kuang Nin coal basin. They provide a reduction in coal losses in the inter-column pillars and the cost of maintaining preliminary workings fixed with anchorage. The implementation of these directions is difficult (and in some cases practically impossible) when tight rocks are lying over the coal seam, prone to significant hovering in the developed space. In the Quang Ninh basin, 9-10 % of the workings are anchored, the operational losses of coal reach 30 % or more; up to 50 % of the workings are re-anchored annually. It is concluded that the real conditions for reducing coal losses and the effective use of anchor support as the main support of reusable preliminary workings are created when implementing the idea put forward at the St. Petersburg Mining University: leaving the coal pillar of increased width between the reused mine working and the developed space and its subsequent development on the same line with the stoping face simultaneously with the reclamation of the reused mine working.

An experiment to determine the width of coal pillar when mining seams under hard-to-cave main roof conditions

“…Under geological and technical conditions, the rock layers in the model were created to simulate the mechanical behavior of coal mining. The boundary pillar of the model has a width of 48 m. According to the similarity theory (Zubov and Le, 2022), the geometry, density, and strength depend on a certain relationship.…”

“…In underground coal mines, the longwall mining system is the main method used in the mining of coal seams. In this method, ensuring roadway stability requires solving many geotechnical problems, which is the key to ensuring safe and efficient exploitation (Zubov and Le, 2022). In the process of implementation, the longwall mining method is applied with two schematics, including (1) one-entry and (2) twoentry of fresh air to the working face.…”

Preservation of the Pillar and the Gate Road by Weakening the Roof of the Overlying Longwall Face With Directional Hydraulic Fracturing

“…При отработке сближенных угольных пластов в услови ях труднообрушаемых кровель их зависание в выработан ном пространстве вызывает не только динамические яв ления при посадке кровли, но и создает резкое увеличе ние затрат на поддержание и безопасное ведение подго товительных выработок, происходящих в зоне их влия ния, например на нижележащих пластах, как это было вы явлено во Вьетнаме [16]. Аналогичная ситуация возник ла в настоящее время на шахте им.…”

Dealing with geodynamic safety challenges in cooperation with a mining company: A case-study

“…Принцип использования разных наборов факторов обеспечил применение нейронных сетей для осуществления прогноза в условиях неравномерного распределения данных о количественных значениях влияющих факторов как для ретроспективного анализа в процессе обучения сети (рис. 14), так и для прогноза [29][30][31].…”