Disintegration Of Rocks Research Articles

Impact disintegration of rocks by single and twin indentors within the framework of a hydrodynamic model

Impact disintegration of rocks by single and twin indentors within the framework of a hydrodynamic model

Zonal disintegration of rocks around underground workings, Part 1: Data of in situ observations

Zonal disintegration of rocks around underground workings, Part 1: Data of in situ observations

Localization of rock disintegration at different scale levels

Localization of rock disintegration at different scale levels

Petrochemistry and origin of megacrysts in Upper Cenozoic basalts, Thailand

The Upper Cenozoic alkali basaltic rocks (basanite, nepheline hawaiite and nephelinite) from Thailand contain megacrysts of clinopyroxene, olivine, garnet, ilmenite, spinel, magnetite, anorthoclase, plagioclase and nepheline in addition to typical spinel lherzolite xenoliths. The host rocks are relatively primitive liquids formed by the melting of heterogeneous upper mantle garnet peridotite with a variable garnet/clinopyroxene ratio in the residue. Phase equilibria and major and trace element distribution indicate that megacrysts of clinopyroxene, olivine, and garnet are either high-pressure cognate phenocrysts or the remains of the disintegration of coarse-grained mafic rocks. The megacrysts of plagioclase, anorthoclase, nepheline, zircon, corundum and magnetite probably crystallized from more fractionated and felsic liquids and were later incorporated into their present hosts. They could also be either relict phenocrysts or the remnants of coarse-grained pegmatitic rocks.

Laboratory simulation of rock weathering by salt crystallization and hydration processes in hot, arid environments

AbstractThe results of a series of experiments are reported in this paper which were designed to differentiate between the forces of crystal growth and hydration in salt weathering, using a single salt‐hydrate system (sodium sulphate), five contrasting rock types, and several diurnal temperature‐relative humidity cycles which permitted or inhibited these processes and simulated ground surface climates in hot, arid environments. It was shown that hydration of sodium sulphate is an effective mechanism of rock disintegration but that it is significantly less destructive than crystal growth pressure. Crystallization of thenardite (Na2SO4) is, in turn, more effective in rock weathering than the crystal growth of mirabilite (Na2SO4.10H2O). In general, rates of disintegration were most rapid where the diurnal temperature range was extreme and relative humidity lowest.

An Experimental Study of the Effect of Humidity and Temperature Variations on the Granular Disintegration of Argillaceous Carbonate Rocks in Cold Climates

An Experimental Study of the Effect of Humidity and Temperature Variations on the Granular Disintegration of Argillaceous Carbonate Rocks in Cold Climates

An Experimental Study of the Effect of Humidity and Temperature Variations on the Granular Disintegration of Argillaceous Carbonate Rocks in Cold Climates

An Experimental Study of the Effect of Humidity and Temperature Variations on the Granular Disintegration of Argillaceous Carbonate Rocks in Cold Climates

Energy capacity of the disintegration of rocks as a subject for control by the mining industry

1. The proposed allometric model in the form of a nonstationary field of energy capacity of disintegration of rocks can serve as an effective means for optimizing the principal technological operations in the extraction of industrial raw material. 2. The model of the energy capacity of disintegration of rocks can serve as the basis for a comparison of different methods of disintegration of rocks and for a quantitative expression of their effectiveness, i.e., enables us to express, the efficiency of different rock-disintegrating mechanisms. Furthermore, it can also serve as the basis for choosing the optimal technological policy—for example, the number of disintegration stages—in the overall technological line.

軟岩の膨潤・スレーキング特性 Ｉ 簡易試験による評価

Some simple and rapid tests were tried out, which were the tests to get water absorption of rock fragments (WSL) and of the commuted and desiccated powder of the same rock (WA). The extent of slaking (rapid disintegration of soft rock in process of water absorption) is observed during the WSL-test.The extent of slaking is ranked in 5 grades (A-E) in observation and closely related to the following index of slaking (ISL).ISL= (WSL-WSAT) / (WA-WSAT) WSAT means saturated moisture content of intact rock before slaking or swelling.The maximum swelling strain (or expantion: ΔV/V0) or pressure (PSW) is sufficiently estimated from the values of WA and γd (dry density) or WSAT which are able to measure simply. WA represents the latent possibility of expantion of the constituent particles upon removal of the cementation of rock fragments regardless of the clay mineral composition.The maximum value of ΔV/V0 in an intact rock is corresponded to the ΔV/V0 of the artificially compacted rock after commuting, and the ΔV/V0 of the intact rock in any drying and wetting process can be estimated from this maximum ΔV/V0 multiplied by the ISL. ΔV/V0-WA-γd diagram and the photographs illustrating the typical features of slaking in each grade are prepared in this paper to estimate ΔV/V0 and ISL easily.

Enhancement of cavitation damage and its uses in rock disintegration : Mazurkiewicz, M; Summers, D A in: Sixth International Symposium on Jet Cutting Technology, University of Surrey, 6–8 April 1982, p27–38. Publ Cranfield: BHRA, 1982

Enhancement of cavitation damage and its uses in rock disintegration : Mazurkiewicz, M; Summers, D A in: Sixth International Symposium on Jet Cutting Technology, University of Surrey, 6–8 April 1982, p27–38. Publ Cranfield: BHRA, 1982

Symmetry in rock disintegration phenomena

Symmetry in rock disintegration phenomena

Weathering and Disintegration of Rocks At Oakwood Lake, South Dakota (39Bk7)

Weathering and Disintegration of Rocks At Oakwood Lake, South Dakota (39Bk7)

Quantitative evaluation of energy cost of rock disintegration

In the evaluation of energy cost of disintegration during the destruction of rocks, variation of lump size is a practical measure of the effect of the work of destruction. But current estimate methods are not practical, as they require averaging of lump size, and of the hierarchicity of the process. A system of assumptions and a scheme of experiments is studied to verify the applicability of theory. A calculation based on Rebinger's concept is derived. The work of destruction, of energy loss due to interaction with the environment, and of the labor of transporting lumps are averaged into equations. The approach described makes it possible to construct a statistically stable correlation between grain size and geometric and energy characteristics of disintegration processes, taking into account the distribution of energy costs with respect to forms of action of the explosive on the percussive destruction of rocks.

Energy methods and discontinuous methods in the mechanics of rock disintegration

1. We have formulated the variational equation for the principle for virtual velocities for a von Mises-Schleicher rock mass which crumbles as a result of shear and is irreversibly condensed as a result of pressure. The volumetric plastic deformation has been selected as the parameter for strengthening in the principal relations. 2. We have proposed a method for the solution of the variational equation by successive approximations, the method being based on step-by-step fixing of the volumetric deformation and reduction of the variational problem to linear algebraic systems. 3. For a crumbling rigid-plastic solid of the von Mises-Schleicher type we have established that the surface of discontinuity of the velocities may be either a figure obtained by impressing some surface on a rotating logarithmic spiral or else a plane. 4. In the case of different models of crumbling rock, we have established kinematic relations in the zones of discontinuity of the velocities for the upper-bound method.

Distribution of Uranium as Function of Sediment Particle Size: ABSTRACT

Uranium concentrations as a function of size were determined for 100 samples from the Estancia Valley, New Mexico, 100 samples from northeast of the Grants mineral belt, and 46 samples from the Black Hawk mining district, southwestern New Mexico. For the Estancia and Grants samples, statistical analysis shows uranium concentrations in stream sediments size fractions greater than 0.125 mm to be nearly independent of particle size whereas uranium concentration increases with decreasing particle size less than 0.125 mm. The standard deviations of uranium concentrations from both areas vary only slightly for all size fractions. For the Black Hawk mining district the uranium concentrations are strongly dependent on sediment particle size with uranium increasing rapidly with de reasing particle size. A correlation coefficient of 90% is calculated for increasing uranium content with surface area of sedimentary particles. In contrast, a much lower correlation coefficient for uranium-to-surface area is observed for the Estancia and Grants samples. We propose that the observed statistical differences are related to the fact that the stream sediments of the Black Hawk mining district represent control by mechanical disintegration of igneous and metamorphic rocks with little effect of chemical weathering, whereas the sediments of the Estancia Valley and Grants area are more chemically mature. The data imply that the nature (maturity) of the sediments sampled must be considered when sampling on a large grid, such as one sample/10 km2, or else risk false ano alies (positive or negative) or masking any anomalies which may be present. End_of_Article - Last_Page 566------------

On the problem of the disintegration of rock by an explosion under the influence of a free surface

On the problem of the disintegration of rock by an explosion under the influence of a free surface

Tunnel-driving techniques until the year 2000 : Holdo, J Consult Engr, V44, N5, May 1980, P57–62

The author surveys the various methods of rock disintegration at present being studied in research laboratories throughout the world. Many methods have been proposed including jet piercing, fusion, electronic heating, pressure waves from spark discharges, ultrasonics, laser techniques, plasma rays and water jets. He suggests that there will be no completely new and revolutionary principle for tunnelling and an evolution of current equipment is more likely. The penetration rate of drills has greatly increased since 1920. Greater automation is forecast to aid with the moving and aligning of drilling booms. Similarly, the equipment for charging explosives, scaling and spraying concrete could be automated and remotely controlled. The continuous working method of full-face boring machines can also be automated, provided tool lives are adequate. Even when an operator is necessary, he could be installed in a protected, air conditioned cab. Remote control will also have increased applications in loading work. The operation of large diesel powered rubber-tyred loaders could be electronically controlled and supervised from a central control room. The control installation would be similar to that of a modern underground transit system. Eventually very few personnel will be required in the drift or tunnel. (TRRL)

Mathematical representation of disintegration of rock with hierarchical defect structure

Mathematical representation of disintegration of rock with hierarchical defect structure

Application of the Sonic Test to Experimental Freeze-Thaw Studies in Geomorphic Research

Frost action is normally regarded as the primary mechanism responsible for rock disintegration and the production of fines in cold climates. However, the results of previous studies aimed at establ...

Problems of disintegration of rock by drivage machines. Part 3. The use of knowledge of rock properties to calculate the disintegration output (in Czech) : Vasek, J Uhli, V25, N9, Sept 1977, P369–376

Problems of disintegration of rock by drivage machines. Part 3. The use of knowledge of rock properties to calculate the disintegration output (in Czech) : Vasek, J Uhli, V25, N9, Sept 1977, P369–376