The Influence of Geology and Ore Deposit Occurrence Conditions on Dilution Indicators of Extracted Reserves

Abstract

The development of iron-ore deposits is accompanied by the excavation formation of considerable dimensions in the underground space and to ensure high technical and economic indicators of extraction, especially when developing high-grade iron ore, it is necessary to take into account the nature of the geological structure of the massif on the indicators of their dilution. It is established that when the chambers are worked out on a junction with hanging wall waste, the indices of ore dilution with the adjacent strata are 1.7 times higher than on a junction with the foot wall of the deposit. The tendencies and causes of variability of volume of extracted ore dilution with the adjacent strata in diff erent geological structure parts of the ore deposits are revealed, the ore basin across the pitch is characterized by a general evolving trend of the rock strength of the hanging wall and ore basin angle of incidence decreasing and increasing the thickness of the deposit from the northern side to the southern one. It has been established that the concentration of hanging rocks caving and extracted ore dilution indices is enhanced by changing their morphological composition, reducing the strength and stability of these rocks, reducing the ore basin angle of incidence, and increasing the ore deposit thickness. The obtained results allow us to lay the foundations for optimizing the parameters of the development system and the rational procedure for breaking up ore reserves in the chambers under the changing mining and geological conditions of fi eld development.

The study of the stress-strain state of the massif in mining uranium at “VOSTGOK” deposits

“…The stress-strain state was calculated for roofs of 10 to 14 m thick. For calculating the stress field characteristics ANSYS 18 was used [8][9][10].…”

Geomechanical problems of stability of natural-technogenic ore deposits

“…Найбільше засмічення руди у камерах сягало 12% в південній частині рудного покладу. Встановлено [13][14][15], що в 80% випадках руйнування порід висячого боку під дією гірського тиску спостерігаються в центральній і південній частині рудного покладу при заміщенні кварцитів гематит-мартитового складу при міцності f = 14 на кварц-хлорит-серіцітових сланців зниженої міцності f = 8 і стійкості, зменшення кута падіння з 70 до 65 о і при збільшенні горизонтальної потужності рудного покладу з 70 до 100 м.…”

Development of resource-saving technology when mining ore bodies by blocks under rock pressure

“…Kryvyi Rih iron ore basin accounts for over 32.2 bn t of iron ores with iron content in the massif of 24-65% that are mined by underground and open-pit methods. Iron ores with the useful component content of 60-65% are mined applying bulk-caving methods on the compensatory area or open stoping and further caving of enclosing rocks [1][2][3][4].…”