RU2392054C1 - Method for softening and disintegration of shallow deposit clay sands - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to mining and may be used for development of natural and technogenic high-clayey gravel deposits of minerals with an increased content of fine-grained and disperse-grained gold. The method for softening and disintegration of shallow deposit clay sands involves deposit opening, digging a water supply trench slanted towards the deposit stratum drop and a water collection trench of a depth with a difference of bottom marks in the trenches from 1.5 to 3 m, filling the water supply trench with water with simultaneous water-filling of the deposit area under development to a depth sufficient for mounting and installation of equipment in a floating state and subsequent maintenance of the level for primary softening of clay sands by way of supply of water through an adjustable shutter, mounting the delivery hydrotransportation installation, process of natural filtration of water into the bulk. One mounts an ultrasonic installation and a mechanical installation. Successively one intensifies filtration of water into the compacted sand strata by way of ultrasonic impact on the sands along the surface of the site being developed by means of radiation in the interval of low ultrasonic frequencies ensuring maximum amplitude of displacement of compacted sand particles and radiation intensity parameters creating stress-strain tension, resistance to rupture and shear exceeding the normative data for deposit frozen sands strength. One performs intensification of disintegration of water-saturated sand surfaces with ultrasound at the same radiation frequency but reduced parametres of ultrasonic radiation intensity corresponding to the averaged equilibrium density and compressibility of water saturated sands. Then one performs hydrodynamic activation by way of mixing the hydromixture with an element of the mechanical installation and supply of the hydromixture with the help of the delivery hydrotransportation installation to the concentrating installation.

EFFECT: improved efficiency of destruction and disintegration of deposit clay sands.

2 dwg, 2 tbl

Description

The invention relates to the mining industry and can be used in the development of natural and industrial high-clay alluvial mineral deposits with a high content of fine and fine gold.

There is a method of destruction of a rock massif, according to which the rock is subjected to rock-cutting tool and ultrasonic vibrations at the point of contact of the latter with the mass, preliminary determine the direction of maximum compressive stress in the mass, and the direction of ultrasonic vibrations is oriented perpendicular to the direction of maximum compressive stress ahead of the rock-cutting tool [1 ].

The method is intended for the destruction of rocks of the ore type and cannot be used for the destruction of medium and high plasticity clay sands of placers.

A known method of controlling the process of transformation of gold-bearing rock, including softening the rock by mechanical action, followed by periodic initiation of elastic vibrations in the ultrasonic range with a constant frequency in the sand-clay rock-water system, the initiation of elastic vibrations is carried out at constant external pressure, various time intervals and capacities, and upon preliminary selection of a controlled range of particle sizes, the optimal exposure time is determined at which stability of the clay particles precipitate in a system with a constant volume is studied, then conditional transformation coefficients are calculated, a graph of the variation of the indicated transformation coefficients versus time is built, from which an increase in the controlled initial value of the specific surface of softened particles is determined by an order of magnitude, which reduces the ultrasonic radiation power by half [2] .

This method does not include the intensification of volumetric areas of compacted and water-saturated sands and can be used to activate the hydraulic mixture and its control.

The closest in technical essence is a method of softening and disintegrating clay sands of alluvial deposits, including opening the placer, digging a water trench with a slope in the direction of falling of the field and a catchment trench with a depth of the bottom marks in trenches from 1.5 to 3 m, filling the water with water trenches with simultaneous filling of the developed placer section with water to a depth that provides installation and installation of equipment in a floating state, and maintaining this level in subsequently for primary softening of clay sands by means of water supply through an adjustable shutter, the process of natural filtration of water into the massif, installation of a pressure hydrotransport installation. At the end of the pressure pulp line, a vortex generator and hydrodynamic cavitator are installed [3].

The disadvantage of this method is that the main process of disintegration is carried out by acting on the hydraulic mixture. However, at the first stage of natural filtration of water into the massif, the process is not initiated and therefore develops rather slowly, since the clay filtration coefficient is from the fourth to sixth order of smallness - 0.0005-0.000005 cm / s.

The technical result of the proposed method is to increase the efficiency of destruction and disintegration of clay sands of placers by intensifying the natural process of filtering water into compacted and water-saturated layers and disintegration of hydraulic mixtures with clay particles.

The technical result is achieved due to the fact that in the method of softening and disintegrating clay sands of fine-grained placers, including opening the placer, driving a water trench with a slope in the direction of falling of the field and a drainage trench with a depth with a difference of bottom marks in trenches from 1.5 to 3 m, filling the water trench with water while filling the developed placer section with water to a depth that provides installation and installation of the equipment in a floating state, and maintaining this level subsequently, for the initial softening of clay sands by means of water supply through an adjustable shutter, installation of a pressure hydrotransport installation, the process of natural filtration of water into an array, the installation of an ultrasonic installation and a mechanical installation is carried out, and the water is filtered into the compacted sand layers by ultrasonic exposure to sand the surface of the developed area by radiation in the range of low ultrasonic frequencies, providing maximum amplitude In order to displace particles of compacted sands and radiation intensity parameters that create compressive-tensile stresses, tensile and shear stresses that exceed the normative strength data of frozen placer sands, they intensify the disintegration of water-saturated sand surfaces with ultrasound with the same radiation frequency, but with lower ultrasonic radiation intensity parameters corresponding to averaged equilibrium density and compressibility of water-saturated sands, then produce a hydrodynamic act the initiation by mixing the slurry with an element of a mechanical installation and the flow of slurry through the installation of pressure hydrotransport to the concentration plant.

The combination of new essential features allows us to solve a new technical problem - to intensify the production process by intensifying the natural process of filtering water into compacted and water-saturated layers of clay sands and disintegration of hydraulic mixtures with clay particles.

Figure 1 - General view of the development system of the placer, ensuring the implementation of the method; figure 2 - obtained by calculation, the graphical dependence of the amplitude of the bias | u | particles in the sound wave from the frequency f of ultrasonic radiation during the deformation of the sand | S | = 10 ^-5 m, curves 1, 2, 3 were obtained for weakly plastic, medium plastic and highly plastic sand of the Amur Region placers, respectively. The graph gives a visual representation proving the preference for a lower frequency of 25 kHz radiation when exposed to sands with different degrees of plasticity, at which the maximum particle displacement amplitude.

The implementation of the method is as follows. The placer is opened, the water trench 1 is drilled with a slope of 2 in the direction of 3 fall of the reservoir and the drainage trench 4 with a difference of bottom marks 5 in trenches 1 and 4 from 1.5 to 3 m. The water trench 1 is filled with water while filling the developed section 6 placers with water to a depth of 7, providing installation and installation of equipment 8 in a floating state. Subsequently, the level is maintained for the primary softening of clay sands by means of a water supply using an adjustable shutter 9. Installation of a pressure hydrotransport installation 10 is carried out. After water arrives at the developed section 6, the process of natural filtering of water into the array takes place. The ultrasonic unit 11 and the mechanical unit 12 are installed. The water is subsequently intensified in the compacted sand layers by ultrasonic exposure of the sands along the surface of the developed section 6 by radiation in the range of low ultrasonic frequencies, providing the maximum amplitude of the particle displacement of the compacted sand, Fig.2. Given the strain | S | according to the formulas

,

,

,

,

,

,

where u is the particle displacement in the sound wave (the absolute value of the particle displacement vector), m; Λ is the wavelength, m; V _p is the velocity of the longitudinal wave in isotropic solid space, m / s; λ and µ are elastic constants, Lamé constants, radiation intensity parameters are calculated that create compressive-tensile stresses, tensile and shear strengths that exceed the standard strength data for frozen sand placers, table. 1. The initial parameters of sound intensity during deformation | S | = 10 ^-4 m create compressive-tensile stresses, tensile and shear resistances that exceed the normative data on the strength of frozen placer sands (Instruction for the development of frozen permafrost underground method RD 06-326-99, approved By the resolution of the Gosgortekhnadzor of Russia dated November 18, 1999, No. 84, introduced from June 1, 2000).

Table 1 The calculated parameters of the ultrasonic effect on the compacted areas of placer sands with a radiation frequency of 25 kHz Intervals of wave resistance of sand (ρ · V _p ) · 10 ⁶ , kg / m ² · s Lame constants (λ + 2µ) · 10 ⁹

, м/с |S|=10^-5 мThe amplitude of the vibrational velocity during deformation

, m / s | S | = 10 ^-5 m The initial intervals of sound intensity I _y · 10 ^-2 during deformation | S | = 10 ^-5 m, W / cm ² The initial intervals of sound intensity I _y during deformation | S | =
10 ^-4 m, W / cm ² The initial intervals of sound intensity I _y · 10 ² during deformation | S | =
10 ^-3 m, W / cm ² 3.98-4.18 7.96-8.36 2 7.96-8.36 0.796-0.836 7.96-8.36 5.2-6.0 13.06-15.06 2.5 16.3-18.82 1.63-1.882 16.3-18.82 7.2-7.3 21.69-22.05 3 32.53-33.1 3.253-3.31 32.53-33.1

The disintegration is intensified by ultrasonic installation of 11 water-saturated sand surfaces with ultrasound with the same radiation frequency, for example 25 kHz, but with reduced parameters of ultrasonic radiation intensity corresponding to the averaged equilibrium density and compressibility of water-saturated sand layers, tab. 2.

table 2 The calculated parameters of sound radiation on water-saturated gold-bearing sands of placers taking into account the average equilibrium density and compressibility of the medium Initial calculated interval values Estimated speed of sound at equilibrium equivalent density value V _e · 10, m / s the amplitude of the displacement of particles in the sound wave | u | · 10 ^-7 , m

м/с
при деформации
|S|=10^-5 м,amplitude of particle vibrational velocity

m / s
during deformation
| S | = 10 ^-5 m, Lame constant (λ + 2µ) · 10 ⁹ , kg / s ² · m sound intensity I _e · 10 ^-2 under deformation | S | =
10 ^-5 m, W / cm ² sound intensity I _e at deformation | S | = 10 ^-4 m, W / cm ² The porosity of 26%, the layer depth of 0.01 m, the average water content of 15% and _a = 0,15, a _m = 0,85 1,771-1,758 1,127-1,119 1,769-1,757 5.78-5.95 5.11-5.23 0.511-0.523 1,968-1,908 1,253-1,215 1,967-1,907 7.46-8.00 7.34-7.63 0.734-0.763 2,082-2,075 1,326-1,322 2,082-2,075 9.53-9.61 9.92-9.97 0.992-0.997 Porosity 26%, layer depth 0.04 m, average water content 1.5%, and _c = 0.015, a _m = 0.985 1,966-1,964 1,252-1,252 1,966-1,966 7.63-8.00 7.50-7.86 0.750-0.786 2,382-2,362 1,517-1,505 2,382-2,363 11.77-13.33 14.02-15.75 1,402-1,575 2.837-2.842 1,807-1,81 2,837-2,842 19,23-19,61 27.28-27.86 2,728-2,786 The porosity of 33%, the layer depth of 0.01 m, the average water content of 25% and _a = 0,25, a _m = 0,75 1,677-1.659 1,068-1,057 1,677-1,659 4,899-5,00 4.11-4.15 0.411-0.4) 5 1,799-1,743 1,146-1,11 1,799-1,743 5.88-6.25 5.29-5.45 0.529-0.545 1,863-1,850 1,186-1,178 1,862-1,849 7.14-7.14 6.65-6.66 0.665-0.666 The porosity of 33%, the layer depth of 0.04 m, the average water content of 3% and _a = 0,03, a _m = 0,97 1,944-1,934 1,239-1,232 1,945-1,934 7.41-7.69 7.21-7.44 0.721-0.744 2,324-2,297 1,481-1,463 2,325-2,297 11.11-12.49 12.91-14.34 1,291-1,434 2,698-2,700 1,718-1,720 2,697-2,700 17.24-17.54 23.25-23.68 2,325-2,368 The porosity of 40%, the layer depth of 0.01 m, the average water content of 30% and _a = 0,30, a _m = 0,70 1,638-1,62 1,043-1,032 1,637-1,620 4.54-4.63 3.72-3.75 0.372-0.375 1,737-1,667 1.107-1.062 1,738-1,667 5.32-5.52 4.62-4.60 0.462-0.460 1,752-1,745 1,116-1,111 1,752-1,744 6.10-6.14 5.34-5.35 0.534-0.535 The porosity of 40%, the layer depth of 0.04 m, the average water content of 4% and _a = 0,04, a _m = 0,96 1,921-1,917 1,223-1,221 1,920-1,917 7.19-7.52 6.9-7.21 0.69-0.721 2,280-2,236 1,452-1,424 2,280-2,236 10.63-11.77 12.12-13.16 1,212-1,316 2,618-2,618 1,667-1,667 2,617-2,617 16.13-16.39 21.11-21.45 2,111-2,145

By comparing the numerical values of the compressive-tensile stress of water-saturated sands, at an ultrasound frequency of 25 kHz and sound emission intensity from 0.372 to 2.786 W / cm ² , with the standard ultimate compressive-tensile strength for placers (Instruction RD 06-326-99 No. 84 of 18.11 .99 g) it has been analytically established that the normal component of stress will exceed the ultimate tensile strength by 3 to 14 times depending on the layer depth and water content, and the ultimate shear resistance under pressure of freezing surfaces at temperature D - 4 ° C (2.5 kgf / cm ² for CH and n II-6-66 B, Table 3 in Appendix B..) - from 2 to 9 times. This will ensure the activation of the filtration process and the destruction of bonds in the water-saturated layers of clay sands. Then hydrodynamic activation is made by mixing the hydraulic mixture with the element 13 of the mechanical installation 12 and supplying the hydraulic mixture through the installation of pressure hydraulic transport 10 to the concentration plant 14.

The solution of this problem in conditions of instability of the valuable component content, high clay content and an increased content of fine gold of complicated forms and types (flattened and spliced) at the objects will allow at the stage of excavation of placer sands with different types of plasticity to effectively transform the structural and mechanical bonds of the clay component and its subsequent destruction without loss of gold, including its small particles with sizes from 0.5 to 0.002 mm in an environmentally friendly way, will reduce the destructive effect of mining of production on the ecosystem, will preserve the unique natural complexes of the region.

Information sources

1. A.S. 1666707, Russian Federation. The method of destruction of the mountain range / L.M. Zinker et al. - 30.07.1991 - Bull. Number 28.

2. Pat. 2276727, Russian Federation. The method of controlling the process of transformation of gold-bearing rocks / N.P. Khrunina, Yu.A. Mamaev. 05/20/2006 - Bull. Number 14.

3. Pat. 2288361, Russian Federation. The method of softening and disintegration of clay sands of placer deposits / A.M. Pulyaevsky et al. - 11/27/2006 - [Electronic resource]. - Access mode: www.fips.ru.

Claims (1)

A method of softening and disintegrating clay sands of shallow-lying placers, including opening the placer, digging a water trench with a slope in the direction of falling of the reservoir and a catchment trench with a depth of the bottom marks in trenches from 1.5 to 3 m, filling the water trench with a simultaneous filling of the water trench with simultaneous placers to a depth that provides installation and installation of equipment in a floating state, and maintaining this level in the future for primary clay softening sand with the help of water supply through an adjustable gate, installation of a pressure hydrotransport installation, the process of natural filtration of water into an array, characterized in that they install an ultrasonic installation and a mechanical installation, sequentially intensify the filtration of water into compacted sand layers by means of ultrasonic action on the sands along the surface of the developed plot radiation in the range of low ultrasonic frequencies, providing the maximum amplitude of the displacement of the particles of compacted p creep and radiation intensity parameters that create compressive-tensile stresses, tensile strength and shear resistance, exceeding the normative data on the strength of frozen placer sands, intensify the disintegration of water-saturated sand surfaces with ultrasound with the same radiation frequency, but with reduced ultrasonic radiation intensity parameters corresponding to the average equilibrium density and the compressibility of water-saturated sands, then hydrodynamic activation is carried out by mixing hydraulic mixtures setting mechanical element and applying the slurry by setting the pressure hydrotransportation to the processing unit.

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