EA026718B1 - Method for selective extraction of marginal minerals in open-pit mining - Google Patents

Abstract

The invention is related to the ore mining industry and is designed to be used in open-pit mining. The essence of the invention consists in selective extraction of marginal minerals using the data of prepared qualimetric maps with transverse pockets and subbenches in accordance with the controlled condition-process criterion- content of useful component in ore or rock, %;- not-go limit according to quality of ore mass, %, on the basis of which a condition specific relationship of separated volumes of oresand rocksis established. Height of a subbenchis determined from the proposed relationships with consideration for geological and geometrical features of bedding and geometry of the contact surfaces of the ore body. The separation process is conducted by way of adherence to specific proportion of their volumes determined by criteria in subbench excavation and batchwise loading of exploded mass to containers of loading and transportation units. Control of the separation process is conducted by adherence to the condition according to which, if, the ore mass will be transported to an excavated ore warehouse or to a concentrating mill, and in reverse cases, if, the rock will be transported to overburden rock dumps. The result of the invention is minimization of quality deterioration, losses and waste generation during mining.

Description

The invention relates to the mining industry and is intended for use in the open development of mineral deposits.

The method for the selective extraction of near-surface minerals is based on the guiding concept of creating selective processes for the separation of ores and rocks, with differentiation of mining elements, which are complex, based on the adaptation requirements for their qualimetric correspondence to geological and geometrical features and parameters of excavation excavation of ore bodies.

The essence of the method is to conduct selective extraction of contour minerals by transverse approaches and sub-accesses according to the controlled qualified air-technological criterion for the separation of ores and rocks by adjusting the specific ratio of their volumes in the capacities of loading and transport mechanisms during accessible excavation and portion loading of blasted ore mass in the working face.

The practice of controlling losses and ore dilution of ores based on the principle of normalizing them taking into account the relationship between them with varying complexity of mining sections (Lomonosov G.G. Formation of ore quality in open mining. M. Nedra, 1976, 226 p. ), taking into account the interconnection of lost ores and diluting rocks and the variability of ore contacts (Kurmankozhaev A. Methods for assessing the quality level and ore losses. Alma-Ata, Nauka, 1990, 190 pp.), as well as by using estimated gradients of quality indicators up to ychi (Sharin VV Perfection of technology and an estimation of the complexity of rural development in the degree of contact zones M., Nedra., 1966); The known method of taking into account gradients reflecting the specific outputs of the quality of lost ores and diluting rocks in the form of qualimetric estimates (Kurmankozhaev A., Ospanov SR. Problems of system technology for qualimetric regulation of the quality of ore products. Almaty, KazNTU, 2005, 316 s), method for optimizing losses and ore dilution based on the relationships between losses, dilution and reserves ready for excavation (Zaraysky V.N., Streltsov V.I. Rational use and protection of mineral resources, M., Nedra, 1987, 292 pp.). These methods made it possible to introduce standard values of losses and ore dilution instead of their design parameters taking into account the relationship between losses and dilution, the complexity of contact zones and other factors affecting their level during mining, which formed the basis for further improvement of the processes of reducing quantitative and qualitative mineral losses during open mining. However, the indirection and insufficiency for their use in regulating the process of separation of ore-rock mass, taking into account the technical conditions of production, the content of the useful component in the mixed ore and rock, along the contact zone of the deposit, remains a significant drawback.

Widespread methods of selective extraction based on the involvement of traditional standards and mining approaches to increase the completeness of extraction of marginal minerals.

The Known Method for the selective extraction of reservoir minerals [RF patent No. 2291300, 01/10/2007, IPC E21C 41/26 (2006.1)], including separate excavation of minerals and a layer of valuable rock, separation of their flows in the face, a strip is taken out by the direct feed of the shearer valuable rock, and in the opposite - a strip of minerals, thereby selective extraction of the interlayer of minerals and their separate delivery to the surface.

However, in the selective extraction of minerals and a layer of valuable rock, there are no mechanisms for the optimal separation of the border of ores and rocks, and no regulatory criteria for breeding exploded varieties of minerals and a layer of rock are taken into account.

The Known Method of extracting minerals from the near-edge zone of the quarry [RF patent No. 2239063, 10.27.2004, Е21С 41/26 (2006.1)] for regulating rock outcrops, including drilling wells at an angle of inclination equal to the angle of inclination of the ledge, the width of the drilled block, taken based on the height of the pile and the slope angles of the ledge and the natural slope of the rock mass and the coefficient of loosening of the ore mass.

However, this method does not take into account the qualitative and conditional indicators of mining near-edge sections of the mineral, zones and separation parameters, the selection process of the blasted rock mass is neglected.

The Known Method for the development of ore bodies in the zones of contact of ore and stripping approaches [RF patent No. 20100827, cl. Е21С 41/26 (2006.1)], which includes dividing the productive layer in the contact zones into two approaches with a height depending on the inclination angle and power of the ore body and mining from the lying side of the deposit at a horizontal distance from the contact corresponding to the minimum area of the lost ore triangle and rocks, wells are drilled depth to the entire height of the ledge, the trench is laid on the side of the hanging side with a depth corresponding to the height of the upper step and after its penetration the lower productive layer to minimize losses.

However, the reduction of ore losses and dilution in the contact zones by rational selection of the heights of the approaches based only on the angle of inclination and power of the ore body without taking into account the complexity of the contact zone, ore and rock contents, the limits of separation of production and opening in the working face is not enough to obtain real results.

- 1,026,718

The closest in technical essence and results is the following known method. Method for the selective extraction of high-quality minerals in a quarry [RF patent No. 02208221 Е21С 41/30 (2006.01)], including drilling wells and calculating their parameters, performing surveying surveys, testing wells, and contouring with high-quality ore, blasting of wells drilled in high-quality ore, crushing of high-quality ore in a clamp and separate breaking of ordinary ore.

However, in this method, selective mining is limited to the extraction of high-quality ore by creating advanced processes for drilling, blasting and excavating the rock mass, ensuring high-quality ore crushing and separate breaking of ordinary ore, but both quantitative and qualitative ore losses are not taken into account, and also did not consider the technical parameters of the supply, the parameters of the process of excavation and the criterion of separation of ores and rocks of excavation of rock mass.

The main disadvantages inherent in the known methods for the selective extraction of marginal minerals include: 1) neglect in them the optimal ratio between losses and dilution of ores, their normative and limit values; 2) adaptive and technological insignificance of the impact of the known normative gradient criteria for excavator parameters and treatment elements of the excavation; 3) the absence of direct criteria comprehensively taking into account the qualitative and geometric characteristics of excavation zones for mixing ore-rock masses.

An object of the invention is to reduce losses, the level of quality reduction and the joy of production.

The algorithm for solving the technical problem is carried out on the basis of an integrated approach that includes selective processes that ensure the efficiency and reliability of the selective extraction of ores from the marginal sections of the deposit with the least loss and dilution of the ores.

The technological content of the method for the selective extraction of near-surface minerals includes a series of separate processes: 1) creating a qualimetric map of the concentration zones of ore and rock mass varieties in the excavation section, 2) differentiation of the open pit ledge into excavation mines taking into account the dimensions of excavation excavation excavation elements, 3) justification conditioning and technological criteria for the separation of ores and rocks in the limit of the face, taking into account the parameters of the loading and transport mechanisms mov, 4) actually combined extraction process separate from the blasted ore rudoporodnoy weight limit of longwall working.

Qualimetric map of the excavation site of the reservoir and its basic parameters

According to horizontal geological and mine surveying plans, which usually use data from detailed and operational exploration, geometrization of the forms and occurrence of ore bodies, and spatial and spatial distribution of component contents, contour minerals are outlined and quickly tested. Based on them, qualimetric maps of mining zones are compiled within the working ledge of the quarry.

The qualimetric map of the extraction zone (or block) is a combined plan that includes the geological and technological components of the excavation, which reflects the estimated indicators of the separation of concentration zones of ore and rock varieties along the contour sections of ore bodies. In the qualimetric map, the calculated average values of the content of the quality-forming component in the ore and rock (c), the thickness of the contour section of the ore body O ”,) of horizontal and vertical contact ore ore Yu and rock It) are plotted. The main initial parameters representing the quantitative and qualitative content of the qualimetric map are the variability of indicators and the complexity of the excavation section of the deposit, the average values of the contents of the component, the thickness of the marginal zone, ore and rock contact irregularities.

The spatial variability of the ore contact reflects the tortuosity of the contour of the ore body relative to the reduced technological plane and is determined by the formula

where θ is the coefficient of variation, dol. units;

1shah, Gshshh »Ar - values, respectively, of the maximum, minimum, average size for contact ore irregularities, representing the magnitude of the deviation of the contact from the smoothed plane of the contact area. The value of the empirical parameter k is determined on the basis of established empirical dependencies.

The complexity of mining the near-contact zone by deposits is determined by the formula 0.5 (1+ (2)

Here, the value of ^{m is} determined taking into account the thickness of the intra-ore interbeds of rocks and non-standard ores. Coefficient ' ^Mg ' ⁷ included in the formula (2), reflects the complexity of the ore body, in terms of operational power of the ore bodies.

When compiling a qualimetric map, data are determined for differentiating the concentration zones of ore and rock varieties by the number of key indicators of mineral quality. The average values of the capacities of contact ore irregularities and the contact zone are entered in the qualimetric maps. To determine them, the density function of the probability-structural distribution is used, according to which the formula for estimating the mean </ ₂ ГГ /? (. Х ₄ - х,.) + Άβιβ (χ „-х„) is derived (3) where _{2 2 =} х _к x ₀ , a,

X = x „-x ₀ ; β distribution parameter;

tag fashion;

^ is the function of the hyperbolic tangent;

Chl, X.

’- the final and initial values of the characteristic.

Based on the qualimetric map, qualimetric estimates of the separation of concentration zones of ore and rock masses are calculated in the form of estimated indicators of the quantitative and qualitative composition of the excavation site.

The quantitative estimated indicator (Kcal) reflects the complexity of the geometry of the occurrence of the ore contact shape along the excavated marginal zone and is determined by the formula (unit) „k, (4) where 'о is the modal value of the contact roughness power along the marginal zone, m; ^t from - the power of the contour area of the ore body, m

A qualitative assessment indicator (Kkach) reflects the degree of conditionality of ore quality in the extraction zone and is determined by the formula (units)

where with

- the average content of the main component in the contact ore, taking into account the quality and the host rock,%;

Co is the industrial minimum content of the main component in the ore body,%.

As can be seen, the Kkol indicator reflects the influence of the variability of the thicknesses of contact ore bumps and is expressed as the ratio of the modal value containing in fractions of the average. The Kkach indicator reflects the degree of conditioning of the contact ore and is expressed as the average content of the contact ore in quality fractions in the contact rock mass, units

The uniform regularity follows from the estimated indicators, according to which the larger their value in the extraction near-contact zone, the easier the uniform contact geometry and the better condition for the quality of the near-ore ore, respectively, and at lower values, the contact geometry is polyhedral and more complex, the conditional insignificance of the near-edge ore prevails. The contouring of the concentration zones of ore and rock masses over the blasted rock mass is carried out according to the calculated values of the estimated indices ^ count and taking into account the degree of transformation of the blown mass. In cases where a contoured contour takes place along the near-contact extraction zone, it represents a concentration zone of conditioned mined ores, and in the opposite cases, a concentration of overburden is taken out to waste dumps. Here, the ratio of the side (or reject) value of quality, the quality of the forming component to its average value over the ore body serves as a reference value for the separation of ore and rock mass.

Differentiation of a ledge into excavation steps One of the conditions for the effectiveness of selective excavation is the validity of the differentiation of the ledge, taking into account the dimensions of the excavation elements of the excavation excavation. It determines the pattern of blasting, the location of blast holes, the front of excavator loading and transportation. In practice, when substantiating the height of the sub-steps, enlarged indicators are used: the effectiveness of the front of the technological scheme for mining the excavator's productivity deposits, the cost of mining operations, the quality outputs, losses and ore dilution. Reducing the optimal height of 3,027,718 stupas worsens the technical and economic indicators of mining, which results in an increase in the cost of the extracted minerals. To conduct selective excavation, without reducing the height of the developed ledge (rock), it is necessary to loosen it so that the rock mass after the explosion can be selectively loaded with minimal loss and dilution of the mineral. The validity of the differentiation of the height of the ledge to the accessible vertical layers for excavation excavation of the blasted ore mass and their dimensional parameters mainly depends on the thickness of the contact zone, the spatio-statistical variability of the distribution of contact irregularities along the contour sections of the ore bodies. Their qualimetric mismatch with the height of the face, the sizes of which are not proportional to each other, reduces their relationship to a minimum.

In practice, the height of the ledge or faces is determined depending on the angle of incidence and the power of the ore body, rarely taking into account the thickness of the contact zone. The main common drawback in these works is the non-use of excavation elements for treatment and excavation, loading and transportation, as well as the level of increasing information on the contacts of the ore body;

Indirection of the influence of the angle of incidence and power of the ore body on the heights of the bottomhole sub-steps, they can be used for an enlarged calculation of the height of the ledges;

the absence of a direct dependence on determining the height of the sub-steps on the complexity of the contact surface, which is a direct source of reducing quality, losses and ore dilution.

The efficiency of dividing the calculated step along the career into sub-steps when conducting selective extraction of the ore-rock mass blown up in a clamped medium depends mainly on the magnitude of the deviation of the geological surface of the ore body from the distinguished technological surface of its mining. This value in geological surveying practice is distributed as the power of near-ore ore roughness and is calculated by the calculation method according to updated data from testing exploration and drilling and blasting wells, production geometrization of the field. Variation of distribution and the convex angle of the contact areas of ore irregularities also influence the choice of thickness of the excavation approach.

Empirical inequality should be taken into account that the rational height of the approach must not exceed the height of the excavator

Differentiation of the set parameters of the step to the excavation elements by cleaning the excavation is based on a direct approach using data from the qualimetric map for the excavation site. A direct method for differentiating the main parameters of the step is to determine the dimensions of the excavation excavation excavation elements in the working face based on the use of quantitative and qualitative estimates of the contouring of ore and overburden masses along the contour excavation zone.

The height of the approach is determined by the recommended model assessment in the form

Where

Η _ν y - the established rational height of the step along the career, m; coefficient of loosening, dollars;

λ - the general evaluation criterion for the differentiation of the ledge on the working elements of the excavator excavation, dol. The value of the evaluation criterion λ allows you to jointly take into account its quantitative (Kkol) and qualitative (Kot) venous indicators

When excavating the near-contact zones of the pit ledges, if the power mode of the ore bump has a high value close to the power of the near-contact zone, then the ratio is close to unity ^K “” ^1.0 . Accordingly, most often the power mode of ore bumps is about half the power of the ore-bearing near-contact zone and rarely with very complex contacts - ® 0.20 - = - 0.35.

Consequently, when differentiating the height of the step into the steps according to the quantitative evaluation criterion,

- 4,026,718% = "1.0 Ku = ^ H _g- at. _t = 0.5 K, = | Υ - at ¥ ^ _t h 0.35

Accordingly, by differentiating the height of the ledge on podustupy the qualitative evaluation criteria, we have W = - "P" ^{to the> th} ™ 1.0 (C ,, · * C _o) to _r = \ in _y -. _W ith K_ "0.5 ( С, „“ 0.5 С _о ) (9) ^ = ^ Н _{у - at} К. ^ 0.3 (С „Д0.3 С„)

It is known that the mode of any indicator of a mineral is, firstly, the most informative, probable and realistically possible value, and secondly, the modal value is determined more reliably and more accurately than the average and other parameters of marginal minerals. Using the properties of the modal power of contact irregularities, the complexity of the geometry of the contact surface and the level of quality of the near-surface mineral determines the validity and reliability of the results of differentiation of the ledge into excavation pits along the career. When determining the values of ' ^{, 0} ' ^t can be used the size of the elementary area of a single contact surface. In cases where it becomes possible to determine the angle of inclination of the contact surface, which occurs when its elements are approximately aged within half the height of the step, the height of the excavation access can be calculated by the formula ^A - & - for complex zigzag contact shapes, ~ - for simple direct forms contacts, where the angle of inclination and the height of the ore contact in the limit of the step Ή quarry,%, m;

With complex observations of ore bodies, a single surface of ore bumps along the marginal area is mainly bell-shaped. When calculating the area with the known formulas of the trapezoid, cone, cylinder, as a rule, unacceptable errors are made. For this purpose, it is recommended to use the hyperbolic cosine function, which satisfactorily describes such bell-shaped curves.

(YU)

Air-conditioning criteria for the separation of ores and rocks in the limit of the face

The solution of the technical problem is achieved by developing a controlled air-conditioning criterion parameterized through standard-forming optimal ratio of ore and rock volumes, which allows to regulate the qualitative and quantitative separation of mining, overburden and waste-forming rock masses during mining of marginal zones of deposits of various complexity. It is based on the principle of the transition from conventional accepted conditioning parameters to controlled conditioning and technological criteria qualified for the conditions of mining near-boundary zones by attracting quality-determining estimates of portioned separation of rock masses taking into account losses and rejection limit on quality, as well as metal content in lost ores and host rocks.

The technological controllability of the conditioning standards is ensured by regulating the established optimal specific ratio of ore and rock volumes, which acts as regulators of the conditioning and technological separation of mining and overburden rock masses.

The conceptual difference between the methodology used and the existing indirect approach to the substantiation of the conditioning parameters using geological and economic indicators of mineral exploration and exploitation, without taking into account the direct foundations of the technological process of separation of ore-rock mass in the limit of the working face when excavating near-surface minerals, is that the rationale for the recommended conditionally -boundary limit is carried out on the basis of a direct method by directly accounting for indicators - pairs meters of technological mixing of ores and rocks within the face.

The developed conditioning and technological criterion is aimed at direct batch separation of ores and rocks directly in the working face during excavation selection and loading of the exploded ore-rock mass under conditions of mining near-edge sections of minerals with sufficient reliability. Analysis shows that the ratio of the volumes of stirred technological mezhΑι do a qualitative lost ^(p nu) and rock impoverishing ^<VT rock masses quantitatively stripping lost from ores (P _t) and admixed thereto host species ^(-) -x rock masses pre- 5 The 026718 specific sizes of the lost ores (P>) and the clogging rocks ° P /, in essence, are evaluation criteria for the separation of varieties of excavated ore and overburden rock masses during mining of marginal areas of minerals. When excavating an exploded variety of rock mass, the parameter of optimal separation of ores and rocks on the basis of the conditioning and technological limit for selective excavation can be only the quantitative ratio of ore-rock mass mixed between sleep

This ratio of the volumes of mixed production and overburden masses may well be visually observed by an excavator during the daytime, since ores and rocks can differ in clear visibility (deposits of mining metals) or substandard signs with a continuous decrease in the content of useful component (deposits of non-ferrous metals). Under certain geological conditions, the use of physical, mechanical, and other properties of rocks gives good results. As, for example, in the development of uranium deposits in radiator buckets, radiometers are installed, which allows you to control the quality of ore for each cycle. The combination of radiometric control and rational methods of excavating selective excavation makes it possible to produce high-quality ore in complex production units.

It is recommended to carry out technological batch separation of blasted near-rock varieties of rock into overburden and ore mass during excavation based on the specific coefficient [{'- 9: “, / which serves as a batch ratio of mixed industrial ore and host rock mixed between each other, regulated in loading and transport mechanisms involving the quality of the elementary block cell of the notch in the mining circuit of the near-contact zone (units).

The regulatory conditional-technological criterion for batch separation of ores and rocks during excavation of ore-rock mass, taking into account the quality-forming and geometric characteristics of the contour area, is calculated according to the proposed model assessment

Where

With ₆ , in - the content of the useful component in ore and rock, respectively, on the marginal zones of the excavation,%;

- the value of the rejection limit on the quality of ore mass established by career,

%

The average content of the useful component in the contact area is determined by the formula

Where

- average capacity respectively of the host rock and the balance ore mixed together during the development of the contact zones of the deposit.

The obtained values ““> can be used to assess the validity of the bolt content of the established GKZ career

Selective process of separation of ores and rocks within the face of the mine Development of selective excavation is carried out from the hanging side of 55555 ore bodies using a transverse approach with a variable width and height of the excavation layer. In this case, the selected contours of ore and rock masses, dispersion over the area of the blasted rock mass, parameters of the collapse, the presence of two or more numbers of contacts between the varieties elongated along the collapse are taken into account. Selective excavation includes geological and geometrical and explosive preparation of contact zones of deposits. The geological and geometrical preparation of the excavation section includes operations for dividing the height into working approaches, forming approaches, blasting schemes in a clamped environment, contouring zones of concentration of high-quality and poor ores. Further, geological and geometrical preparation is completed with the mineral preparation of the extracted ore for pre-dressing and processing. Explosive preparation of the excavation section includes operations to select the layout and location of drilling and blasting wells, their operational testing, the method of blasting in a clamped environment, the height of the blast ledge or approach.

The essence of our own process of selective separation of ores and rocks is the sequential mining of blasted rock with transverse approaches and access vertical layers, using the above formulas for determining their sizes, differentiated by the selected concentration zones of ores and rocks by portioning them in the treatment bottom to bottom, in the forward and reverse directions, using the developed air-conditioning criteria.

The dynamics of the combination of the process is reduced to the sequential conducting of breeding with approaches and approaches by layers with variable heights and differentiated angles of excavation of the blasted rock mass with subsequent excavation and loading in the working face. The vertical excavation excavation of the blasted ore-rock mass along the sub-steps is carried out by separately scooping varieties of ores and rocks by alternately removing layers to a specific area or a large area of collapse. At the same time, it is taken into account that the thickness of the separately removed layer with the top loading is approximately equal (Lomonosov, 1975), ^{+ g} )> ^Η „™” - is the maximum discharge height of the excavator, k + g) the height parameter of the dump truck with an acceptable clearance to the bottom of the bucket.

The technological process of batch separation of the volumes of ores and rocks consists in regulating their ratio when loading containers of loading and transport mechanisms (excavator bucket and vehicles), based on the actual batch value of the conditioning and technological

And _{to the} criterion ^κ · ρ ·

In conditions of extraction of contour sections of minerals from a lying side, if the actual value of the conditioning and technological criterion is above its optimal limit, 0), mixed ore-rock mass in the vehicle’s tanks is transported to mining depots (or to a concentration plant), in the opposite cases ίΆρ · ^< ·) To overburden dumps or to a warehouse of waste-forming ore-rock masses. For control, an additional criterion (γ) is taken into account, taking into account the average quality of the outputs of the mixed ore-rock mass extracted from the marginal mineral ί® ''') relative to the rejection limit for ore quality established by the career. Here ^a <o and for the cases when ^{> |} and vice versa, for cases - ^<1 .

The method provides, eliminates the quality of reducing the smallest losses and clogging of ores during mining, justifies the allowable costs due to an increase in cost due to a decrease in excavator productivity (about 10-30%). This method is very effective in the development of valuable ores, especially in conditions of visual difference between ores and rocks, and is intended for the development of complex ore-bed geometry and contact forms of ore bodies with high mobility of ores and rocks.

Example.

According to exploration and operational testing of the excavated near-edge section of the ore body, its qualimetric map was compiled on a scale of 1: 200. Defined average values of the horizon! ζ) total and vertical thicknesses of common contact ore irregularities at · ”· /, power and quality (ore and rock content), complexity indicators and variability are calculated according to formulas (1-3), estimated indicators ( ^k ” m, K ”,) according to formulas (4), (5), according to which the concentration zones of varieties of ores and rocks are outlined. According to formulas (6-10), the step was differentiated into sub-steps ^, = / КЗ ^ = / (К _ha )

Inequality is used to control

B _{pu <8} H _y p -1

The optimal value of the conditionally-technological criterion for the separation of ores and rocks was calculated according to the developed analytical assessment (11) for the conditions for mining the marginal zones of chromite deposits in the South Kempirsai deposits developed by quarries.

Actual career data for 40 years of the Donskoy GOK: ^с «= 35-50.2%, в = 0, operating loss standards № = 1.5%) and dilution (Κ, -11.5%) and the value of the conditional rejection limit by production quality ^{= 30%} 'TA.

The optimal value of the conditional-technological criterion for the separation of the blasted ore-rock mass during the treatment excavation is determined based on the values of О в, в, п, в, taking into account the optimal value of the rejection limit by the formula (11).

S__0L

Fkp = K p for control

Al or ' ^{R P} "

Initial career data for 40 years of the Kazakh SSR: ^with b = ⁵⁰ > ^2% > ^{c =} °> ₀ = 13.5, k „= 17.5%, π„ = ι, 5%.

When calculating the options: when C _th -35-50.2%, the optimal value of the criterion is ^{= 0.95;} 2) at!%, = 1.09; ₃ ) _with Sat = 35%, = 1.96.

The approved value of the minimum side grade of chromium oxide in ore according to the State Reserves Committee for

- 7,026,718

Kempirsai chromite deposits are assumed to be “ ^30% .

With such a side content of the useful component, the obtained sizes of the conditionally-technological boundary limit for the separation of ore-rock mass (^., = 0, ⁹⁶ ^ ⁹⁷ ) are due to the actually established optimal ratio of ore loss and dilution over a career of 40 years, according to which ore dilution is 7 times higher than their losses (^ ^{/ n} = 1Lraz), when their design content is approximately equal to ^_ GB times).

In addition, the content of chromium oxide in the lost ore ( ^s and ^{> 30%} ) is taken significantly lower than its value in the deposit. According to the values of the three embodiments qr = 0 96 GH = 1 September IV = 196 * d ''>>cr> · conditionally-technological criteria separating ores and rocks during excavation recess exploded rudoporodnoy weight will be equal to the first embodiment ^{of IPS} - at

The "second _PN ~ 1.0977, and the third ^{in the"} w ¹ 86P _PN.

The net output of calculation results obtained are as follows: in the working face at the excavation and loading exploded rudoporodnoy mass during mining deposits the marginal zones to be observed is kriteriynoe technological ratio between the volumes of stirred ores and rocks ⁿ LS & ^pn.

This is done by adjusting the proportion of the mixed overburden in the stirred ore volume to not less than ^{(/ |} - °> ⁹⁶⁷⁷ lsh (in the first embodiment), not less than Ά ~ ^| ' ⁰⁹⁷⁷ ™' (in the second variant), not less than ~ (in the third option) during batch separation of the volumes of ores and rocks during selective excavation and batch loading of blasted ore masses onto loading and transport mechanisms. In conditions of selective extraction, the visibility of ores and rocks, geological surveying support, selection mode, geological and technological elements As a result of the development of excavation space, an explosion in a clamped environment fully ensures the accuracy of controlling the optimal ratio of the mixed volumes of ores and rocks in the tanks of excavator-transport mechanisms, by which the separation of mining and stripping is carried out directly in the working face during excavation and loading, followed by their removal to ore depots (or on OF) or on overburden waste dumps.

Claims (1)

CLAIM The method of selective excavation of marginal minerals in open mining, including drawing up a qualimetric map of ore and rock contours of contact zones, selective working out of their cross-sections and substeps, establishing an air conditioning criterion for separating ores and rocks, characterized by the fact that they make up a qualimetric map of the excavation site, according to it zones of concentration of ore and rock masses are distinguished according to the developed condition-technological criteria for minimizing the quality va othodoobrazovaniya losses during extraction is determined height podustupa and conditioning specific volume ratio of ores and rocks, which regulate conditionally capacitive loading volumes during transport mechanisms podustupnoy excavation and loading rudoporodnoy batch weight.