Specific Features of Geotectonic Development and Ore Potential in Southern Altai (Eastern Kazakhstan)

Purpose. The solution to one of the important problems of the underground mining method is to substantiate cost-effective, technologically feasible and safe variants for mining steeply dipping low-thickness ore bodies. Methods. Mining systems are substantiated on the basis of a detailed analysis of the developed and existing experiential variants for mining steeply dipping ore bodies, identifying production and economic disadvantages, as well as their causes. Findings.As a result of the research, the pillar raise performance in the mining system with ore shrinkage has been substantiated. The main parameters of the proposed variants for mining systems with ore shrinkage, intended for expansion-type supports and borehole breaking, have been substantiated. A design has been developed of fastening the material-running raises (MRR) and ventilating raises (VR) on the working and ventilation horizons to ensure their performance in the mining system with ore shrinkage. Originality. For the first time, dependences of dilution and labour productivity on the ore body thickness and the type of ore breaking for blast-hole stoping and borehole breaking for a single and “twinned block” have been obtained. In addition, a certain dependence of the loading and delivery performance on the average fractional composition, as well as on the delivery distance, has been obtained. Practical implications. The research is characterized by scientific innovations created for the first time, which are able to ensure the efficiency and safety of mining operations, while creating the ability to manage the loss of minerals and dilution in the block, as well as reaching their calculated optimal ratio in order to achieve the most cost-effective production rate.

Section: Introductionmentioning

confidence: 99%

Substantiation of mining systems for steeply dipping low-thickness ore bodies with controlled continuous stope extraction

Rysbekov¹,

Bitimbayev²,

Akhmetkanov³

et al. 2022

“…The low-thickness ore bodies tend to have a complex structure with possible swells and twitches. When mining low-thickness ore deposits with a sublevel caving system with end ore drawing, the probability of a decrease in the mineral content increases [15], [16]. For example, the actual ore dilution at the Akbakai deposit of JSC AK Altynalmas reaches 70% or more.…”

Section: Introductionmentioning

confidence: 99%

Reduction of ore dilution when mining low-thickness ore bodies by means of artificial maintenance of the mined-out area

Mussin¹,

Imashev²,

Matayev³

et al. 2023

Purpose. The research purpose is to study the effectiveness of artificial maintenance of the mined-out space based on the use of cable bolts to reduce the dilution coefficient when mining low-thickness ore bodies. Methods. Geotechnical mapping of the rock mass according to the Q, RMR, RQD and GSI rating classifications is conducted, as well as a linear survey of the fracture system in the hanging wall and footwall rocks is performed using a rock compass and the GEO ID application. Numerical analysis by the limit equilibrium method in the Unwedge software package is applied to determine the safety factor of a mass divided by fractures into wedges. Using a Schmidt test hammer, the uniaxial compressive strength of the mass rocks has been determined. The full-scale studies have been conducted using cable support in the conditions of the Akbakai deposit. Findings. It has been revealed that the footwall rocks are in a stable state, while the safety factor of the hanging wall rocks is 0.98, which requires artificial maintenance using cable bolts. The cable support parameters are calculated taking into account nonuniform distribution of horizontal and vertical stresses in the rock mass. It has been determined that when strengthening the hanging wall with cable bolts in inclined veins with a dip angle of up to 40º, the average ore dilution is 66.1%, and that of previously mined without fastening is 68.7%. In similar experiments in steep-dipping veins with a dip angle of more than 60º, dilution decreases from 62.8 to 48.7%. Originality. It has been revealed that in the conditions of the Akbakai deposit, cable fastening of the hanging wall rocks is effective at an ore deposit dip angle of more than 60º, at which the mined ore dilution coefficient decreases. Practical implications. The research results can be used to increase the stability of hanging wall rocks when mining low-thickness ore bodies with a sublevel caving system.

“…The need to improve existing methods and ensure the sustainability of existing and planned open pits is studied in detail in [29]- [36]. The rationale for conducting research work is the need for mineral raw materials, which increases from year to year, leading to the need to increase the production capacity of mining industries [37]- [39].…”

Section: Introductionmentioning

confidence: 99%

Substantiating the rock mass control parameters based on the geomechanical model of the Severny Katpar deposit, Kazakhstan

Tolovkhan¹,

Demin²,

Amanzholov³

et al. 2022

Purpose. The research purpose is to develop a geomechanical model for ensuring the safety of mining operations by determining the optimal slope angles and probabilistic assessment of the stability of the open-pit walls. Methods. Three-dimensional geomechanical models for surface mining of deposits have been developed based on calculations of the stability factor (safety factor SF) of the open-pit walls in the Rocscience program to determine the rock mass stress-strain state at the end of mining using the finite element method. The geological wireframe model (GWM) has been built on the basis of the available geological sections, horizon plans and the results of the engineering-geological surveys using the Surpac geoinformation system. Findings. Strength reduction factor (SRF) has been determined taking into account the physical-mechanical properties of rocks that constitute the near-wall mass. An assessment of the stability of walls according to the selected geological sections is given, taking into account the projected contour of the Severny Katpar open-pit walls. The calculation of the projected contour stability of the open-pit walls by several different methods has revealed that the open-pit walls are generally stable. The open-pit parameters at the end of mining have been determined. Originality. For the first time, it has been determined that in the Southern and South-Western area of the Severny Katpar open-pit wall in the horizons +700…+400, there is a decrease in SF from 1.18 to 1.41 due to the predominant occurrence of siltstones and tectonic disturbances of the walls. Practical implications. The mathematical calculation results of the stability of the projected contour walls in the Severny Katpar open pit have been generalized. In addition, a geological and structural wire-frame model of the deposit has been developed, which makes it possible to ensure the safety of mining operations in the open pit.