The physical and mechanical properties of gneiss vary considerably due to different initial geostresses, which exert a huge effect on the stability of underground engineering. In order to explore the influence of initial ground stress on the properties of gneiss. Changes in the physical properties (e.g., P-wave velocity and volumetric weight ...
The mine has a permit boundary of 116 acres and carries a $116,000 bond. This mine initially used open pit mining methods and then converted to an underground mining method. In 1997, the Beaverhead mine produced 8060 tons of talc and 9364 tons of waste rock. The mine uses an open stope, paste backfill method of mining.
This paper presents a comprehensive investigation into weathered granitic gneiss in Guangzhou, China, including its formation, grading, classification, and the geotechnical characteristics of different weathered states. The granitic weathering profiles are graded into five weathered states: fresh rock, slightly weathered, moderately …
Shale is the most common sedimentary rock, accounting for about 70 percent of the rock in the Earth's crust. Shale is a fine-grained rock made from compacted mud and clay. The defining characteristic of shale is its ability to break into layers or fissility. Black and gray shale are common, but the rock can occur in any color.
Underground mining interferes with the rock mass and also leads to the formation of stresses and strains inside the rock mass, which may result in the occurrence of deformations on the ground ...
Abstract. 70 Mg/day of fine grained waste gneiss in slurry condition, together with 700 m3/day of water from the wet benefication plant flow from the Mikleuśka gneiss …
There are a few upsides and downsides to underground mining. Let's check them in short. Upsides . 1. Underground mining allows a mine operation hidden from the outer world. 2. Underground mining can be as deep as the development permits. 3. Climate change doesn't affect underground mining. Downsides. 1.
Mining of minerals is essential for our day-to-day life so is the groundwater. Mother Earth is the custodian of these two essential commodities, and both are part and parcel of sustainable living for human beings. This chapter of book focuses on the need, quantity, quality, and management of groundwater encountered in mines, from where …
Influence of blasting techniques on open pit economics. The economics of open-pit mining depend heavily on the cost of overburden removal. It is necessary to maintain a pit slope as steep as ...
The +105 m level resource occurs above the upper limit of the historically mined Prieska copper /zinc deposit at about 105 m depth below surface, up to surface. It has a strike length of about 1 ...
In addition, the frictional strength cannot be fully mobilised in gneiss with a high disturbance, which is supported by the unchanged normalised crack initiation stress and the reduction of shear cracks. The internal fracture network reconstructed by CT scanning indicates that the fracture modes of gneiss are determined by the disturbance.
Abstract. This paper aims to study the effect of anisotropy on strengths of several metamorphic rocks of southern (Çine) submassif of Menderes metamorphic massif in southwest Turkey. Four different metamorphic rocks including foliated, schist, gneiss and strength determination in laboratory. L- and N-type Schmidt hammers were applied in the ...
Underground mining, as the name would imply, is the technique of mining into and under the ground for commercial purposes, usually in the pursuit of valuable ores or minerals. In general, the technique is employed when surface mining, or rather 'strip' mining would be prohibitively expensive. For example, there are mines in South Africa ...
The impact of coal mining subsidence on the surface eco-environment can be characterized as the evolution of a complex system. The complexity and stochastic nature of the ecological background conditions (soil quality, vegetation distribution, and geological structure) and coal mining conditions (mining depth, seam thickness, and …
The main underground mining facilities are: shafts, drifts, raise, pump chambers, warehouses etc. ... in gneiss rock type. ... determine their impacts on nearby residents and develop noise control ...
The aim of this paper is to determine whether the foliation in gneiss forms a dominant plane of weakness such that the footwall of a hard rock open pit mine should …
To sum up, the long-term strength of rock is affected by the pore pressure. 5. Conclusions. Granite gneiss, taken from underground oil storage, was tested in a series of triaxial creep tests under different pore pressures. The long-term strength of rock is investigated and studied in this paper experimentally.
Depletion of surface and near surface mineral deposits. •. Deep underground mining lower environmental footprint compared to surface and near-surface mining. •. …
It is of great importance to study the failure process and scale effect of jointed rock mass in the field of rock mechanics and mining engineering. In the present paper, initially the uniaxial compression test on granite was performed and acoustic emission (AE) sequence was acquired during the compression process in laboratory. Results from …
Gneiss with foliation. Gneiss is a foliated metamorphic rock that is a common distribute type of rock high-grade regional metamorphic approaches from pre-current formations that have been initially both igneous or sedimentary rocks.It has a glorious banding which is apparent on microscopic scale and hand specimen. It usually …
Underground observations made revealed that at times, the blast-holes are drilled to a shorter length than specified in the mine standard. The impact of shorter blast-holes is demonstrated using the following simple example. The ideal case (according to mine standard), assuming a 30 m long panel with a 1m stoping width, is as follows:
Environmental hazards are present during every step of the open-pit mining process. Hardrock mining exposes rock that has lain unexposed for geological eras. When crushed, these rocks expose radioactive …
Gneiss is a foliated metamorphic rock identified by its bands and lenses of varying mineral composition. Some of these bands (or lenses) contain granular minerals that are bound together in an interlocking texture. Other bands contain platy or elongated minerals that show a preferred orientation that parallels the overall banding in the rock.
The effects of open-pit mining and mineral processing plants on the environment include land degradation, noise, dust, poisonous gases, pollution of water, etc. (Dudka and Adriano 1997).Figure 1 shows typical pathways of common pollutant transfer from a tailing dam or from a processing plant to a river if the waste management is not …
This chapter describes three major parts associated with mining stability and mine water inrush: The first part discusses the stability issues related to rock burst in deep underground coal mines ...
Underground hard-rock mining accounts for 40 percent of global mining operations but only 12 percent of run-of-mine (ROM) production. 1 Underground mines also tend to be more targeted, more …
There are two potential surface subsidence effects of underground mining, chimney collapse and trough subsidence. Chimney collapse involves the collapse of the ... granite gneiss. The percent of free swell could not have been more than approximatelq 44 percent in this worst-case of conical collapse. It is probable that the pressure of the
Underground Mining. Underground mining has the potential for tunnel collapses and land subsidence (Betournay, 2011). It involves large-scale movements of waste rock and vegetation, similar to open pit mining. Additionally, like most traditional . Read More (PDF) Environmental and social impacts of mining and
Ang Li, Yi Liu, Feng Dai, Ke Liu, Kun Wang, Deformation mechanisms of sidewall in layered rock strata dipping steeply against the inner space of large …
