UA48832A - A method of mining the steep ore deposits with inclusion of barren rocks - Google Patents

Abstract

A method of mining the steep ore deposits with inclusion of barren rocks with thin unstable ores by a system of roof falling includes of carrying out of horizontal and vertical preparatory and cut workings, the falling of ore deposit by a boring-blast method and the draw of broken ore through the draw workings in the block’s bottom. The stock of extraction block, containing quasi-spherical inclusions of the barren rocks, is worked in turn by falling and drawing ore on the areas between barren inclusions by the minimum width for the selective winning.

Description

Description of the invention

The invention relates to the mining industry. It can be used in the method of development of 2 steep-sloping ore deposits with weak unstable ores containing inclusions of hollow rocks by a system of underground collapse.

There is a well-known method of development of steeply sloping ore deposits containing the inclusion of empty rocks, by a system of underground collapse with mass chipping) of ore and its release under the collapsed rocks. The ore is collapsed by a massive explosion of well charges. The ore mass, a mixture of ore and loose rocks, is released to the rolling 70 horizon through the output workings (V. R. Chernokur, G. S. Shkrebko, V. M. Shelegeda. Dobmcha rud s podztazhnym obrusheniem - M.: Nedra, 1992 - p. 127 -129, Fig. 7.9).

The disadvantages of this method include: a decrease in the quality of the ore mass due to the admixture of waste rock inclusions into the ore; additional losses for drilling, release, transport and lifting of loose rocks to the surface; 19 large losses of ore, on the lying side.

The closest known technical solution is the method of developing steeply sloping ore bodies containing sheet-like inclusions of hollow rocks, a system with massive collapse of ore and overlying rocks, which provides for the separate extraction of ore reserves and inclusions of hollow rocks from sub-floor upper workings to the cleaning space (Patent 37982А, Е21 С41/16. (USA). The method of development of steeply sloping ore bodies containing inclusions of empty rocks. Mo4)

Disadvantages of this method include additional costs for drilling and blasting of empty rocks; additional costs for directed movement of crushed rock in the cleaning area, clogging of ore with loose rocks; limited conditions of use. "

The purpose of the present invention is to improve the method of development of steep ore bodies, which allows the inclusion of hollow rocks due to changes in the technology of working out the ore reserves of the purification block and the parameters of cutting of hollow rocks, which ensures an increase in the quality of the ore mass, a reduction of ore losses and ore mining costs.

The goal is achieved by the fact that the ore reserves of the cleaning block, separated by layer-like inclusions from hollow rocks lying along the stratum formation, are worked out selectively within the extraction area, which is limited by the inclusions of hollow rocks, while the minimum permissible width of the extraction area is determined by the condition of "Ko y, (1) " where tr, - the minimum permissible width of the ore deposit section for selective excavation, which is limited transversely to the extension by inclusions of empty rocks, m;

Co is a coefficient characterizing the conditions of ore removal by deep wells (for the conditions of Kryvbas "is taken equal to 0.3 - 0.4),

A - the height of the collapsing ore layer, m. t s Inclusion of empty rocks is worked out only in the lower part of the cleaning block in the form of a cutting from the lying "side, in the area with parameters determined according to the conditions of пеп - 875 В8594-125.1й3, t sh" because vip! VO? - V. 3 vipt, paroebpri t

Go) vip, - 0) at 50 | | | sho de spr the width of the cutting of empty rocks at the base of the ore massif, which is worked out, m; that) IP - natural logarithm;

Z - the specific economic effect per 1 m of length along the extension, which takes into account the difference from the loss due to the cutting of empty rocks and the profit from the reduction of ore losses in the "dead" zone of the lying side, (for the conditions of Kryvbas it ranges from 90-10 thousand hryvnias). Npr - cutting height of bare rocks, m;

Wu - angle of release of collapsed ore, degree, (taken equal to 787);

A - angle of dip of the deposit, degrees.

The number of extracting areas in the cleaning block limited by crosswise extension of hollow rock inclusions, 60 is determined by the condition m- M 9 p 65 where M is the number of extracting areas of the cleaning block limited by crosswise extension by hollow rock inclusions;,

M - capacity of the ore deposit, m; n - the number of plastid inclusions of hollow rocks.

The minimum permissible capacity of layer-like inclusions of hollow rocks that retain stability in the period

The extraction of ore reserves that remain in the produced space is determined by the condition ty2Mu.Ke (5)

De tru - the minimum permissible capacity of spherical inclusions of hollow rocks, which retain stability in / the period of extraction of ore reserves and remain in the produced space, m;

MU - the line of least resistance in the case of ore cutting in the well, m;

Ke is the reserve factor, taken as 1.3-1.5.

The compensation chamber is formed in a vaulted shape, which ensures a stable condition with a significant area of exposure of the ore massif. 75 The parameters of the vault-shaped compensating chamber, which are as close as possible to the maximum allowable contour of stable equilibrium based on the parabolic law of vault formation, are determined; according to the dependences v2-2оР ОЙ, (6) pk2-2ОРЕОВ ОО (7)

Where are the E-vertical and horizontal semi-axis of the curve, as close as possible to the contour of stable equilibrium of the parabolic form, m; ri; The radii of the horizontal and vertical maximum permissible exposure of the compensating chamber: of parabolic form, m (for the conditions of Kryvbas R, - 1.5 m, re - 37, bm). "

After the transformation, expressions (6) and (7) will have the form

When changing the value of x from 0 to v, the curve of the function decreases, then the first derivative will have the form " и 2к-по) cookie х т (есте) 2 соц 2 " where с,к are real numbers; - с г-smallest odd real number. и Then the second derivative will be и? oso ok- V nt ni-2yuhu

U t i" (82 -x732 the curve will be convex for all values of the derivative -v " x " in

Proceeding from the parabolic shape of the vault, we have z» x2--2RDu-pyu) 13) ug--2Рейспю 14) 60

After the transformation and in lower he (B-R. b5 x-av Ryba (| ov ov, - 09) he (5-1 ov,y

The coordinates of a smoothly enveloping curve that has the shape of an ellipse similar to a parabolic vault with radii P, and P are determined by the formula з З (7 70 у щ- з ' where y, x are the current coordinates of the parabola, m;

After substituting formulas (8) and (9) into expression (17), we get

Z (18) : y - (viv; R) 31 4 VR v.Y y y . and we

Thus, an increase in the quality of the ore mass with an increase in the volume of the compensation chamber, a reduction in ore loss on the lying side and a reduction in the cost of ore extraction due to leaving the main part of void rock inclusions in the produced space is ensured.

The essence of the proposed method is explained in fig. 1-5. d In fig. 1 presents a technological diagram of the preparation and processing of the block in areas located between inclusions of empty rocks at the stage of formation of the 1st stage of the compensation chamber of the Moi area in the hanging side of the deposit.

In fig. 2 - the stage of the formation of a compensation chamber in the Mo2 area of the lying side and the drilling of the ore massif of the extraction area Mo 1. c zo In Fig. 3 - the stage of the release of collapsed ore in the Mo1 area and the drilling of the ore massif of the Mo 2 section.

In fig. 4 - a scheme for determining the parameters of the cutting of hollow rocks in the lower part of the cleaning block. and)

In fig. 5 - a scheme for determining the parameters of the vault-shaped compensation chamber. co

The claimed method of development is carried out as follows. Round-fall deposit of useful deposit 1 with capacity M, which lies at an angle A and contains a layer-like inclusion of empty rocks 2 with capacity t dpso is worked out by extraction sections З and 4, with a capacity of Three Tra"... Tr - which are separated by an ore-free "layer 2. Within of the extracting area by successive blasting of inclined wells 5, the first row of the compensation chamber 6 is formed. After the release of the reflected ore through the discharge funnels 7, vertical fans of deep wells 8 are drilled and by their successive blasting they form the second row of the compensation chamber 9. Vertical fans of deep wells 10, located crosswise, are used to drill 70 remaining array. Collapsed ore 11 is released through funnels 7. In a similar way, the second extracting area 4 on the lying side of the deposit is mined 7. The main part of the ore-free layer 2 is left in the produced space. To reduce the loss of ore 12 on the lying side of the deposit, a cutting of empty rocks is made from the lying side at the angle of release of collapsed ore Vu to the width of epr, HEIGHT E.g. The compensation chamber 9 within the extraction block 13 will be formed not of a rectangular shape 14, but of a vaulted shape 15. Leaving a layer of empty rocks 2 in the produced space, reducing ore losses due to the cutting of the rocks on the lying side to the width of Fpro Ta g" increasing the volume of the compensation chamber ensure an increase in quality ore and reduction of ore losses and reduction of mining costs.

Со The stated minimum permissible for selective mining width of the ore section of the deposit, limited (ee) cross-extending by inclusions of empty rocks tr; determined from the condition of flow of collapsed ore

Experimental studies of the release of collapsed ore showed that favorable conditions for the movement of mine ore under the collapsed rocks are provided if the condition

Co.)

Ka - le. 0.3-0.4, What p r» where Ko is the coefficient; which characterizes the conditions of ore striking with deep wells (for the conditions of Kryvbas it is taken to be equal to 0.3 - 0.4);

Three - the minimum permissible width of the section of the ore deposit for selective excavation, which is limited across the extension by inclusions of empty rocks, m; 6o0 AN - the height of the collapsing ore layer varies from ZO to 45 m.

Thus, the minimum strength of an ore site during selective mining is determined by the condition of tri-Kosa (20) 65 for the conditions of Kryvbas is tri-13.5-15mM.

The declared minimum permissible power of layer-like inclusion of hollow rocks t, which ensures their stability during the period of mining of ore areas and remains in the produced space, is determined under the condition of explosive destruction of the ore massif by well charges

MpigKemu (21) where tdi is the minimum permissible capacity of spherical inclusions of hollow rocks, which ensures their stability during the period of mining of ore areas and remains in the produced space, m;

Ke - the stock factor is taken as 1.3--1.5; 70 MU - the line of least resistance during well-hole ore chipping, m

For the conditions of Kryvbas, the minimum thickness of layer-like inclusion of hollow rocks during selective excavation is t (1.2-1.3).(2.5-3.5)-3.0-4.55M.

The declared optimal width of cutting of hollow rocks on the lying side at the level of the release horizon of collapsed ore /5 is determined from the ratio of loss from ore loss in the dead zone, figure VHDE (Fig. 4) with partial extraction of hollow rocks in the cutting zone, figure ABV (Fig. 4) and profit from the selective extraction of ore of higher quality due to leaving in the produced space a layer of rock with an area of ВЕЖЗ

The efficiency of selective mining is estimated by the expression з-Ор«(Ц-Ср)уО тс (22) where З is the specific economic effect per 1 m of length along the extension, which takes into account the difference from the loss due to the cutting of empty rocks and the profit from the reduction of ore losses in " dead" zone of the lying side, thousand hryvnias;

Or, Op - the specific volume of ore extracted in this area and the volume of cuttings of empty rocks, t;

Ts - selling price of 1 ton of commodity ore, UAH;

Si Su - specific costs for extraction of 1 ton of ore and 1 ton of waste rock, respectively, UAH. "

The calculations were made for the processing of iron ores with an iron content of 58 - 62965, in the conditions of Kryvbas, taking into account the surcharge for improving the quality of the ore mass by 195 and additional costs for chipping, releasing transport, lifting 1 ton of waste rock, it was possible to establish the empirical dependence of the economic effect on the width of the cut of hollow rocks, is approximated by the expression со 3-5В1Z ovidlayerovet) (23) со where Z is the specific economic effect per 1 m of length along the extension, which takes into account the difference from the loss due to со trimming of hollow rocks and the profit from reducing losses in the "dead" zone of the lying side (days of conditions of Kryvbas Czech Republic varies from 90 to 10,000 hryvnias); e - the base of the natural logarithm; "pr 7 The width of the cutting of empty rocks at the base of the ore massif, which is "worked out, m.

After logarithmization and transformation of the expression (23), the width of the cut yG/r is determined by the formula - с хз» ер - В5 ОВБ, 4 - 1253009 where Ип is the natural logarithm; road 75 For the considered conditions of Kryvbas, the distance varies from 10 to 15 m.

Accordingly, the cutting height of the hollow rocks at the angle of ore release, according to fig. 4 is determined by the expression (ee) so non vipvvoe - V, ) vip: 25) pr t vip, - o (95) do) de Nar - height of cutting of bare rocks, m; I, - the angle of release of collapsed ore, depending on the physical and mechanical properties, varies from 75 to 81 7;

A - angle of dip of the deposit, degrees.

Under the conditions typical for Kryvbas, I, - 782, and - 557, the cutting height of rocks on the lying side will be 20 - 25 m. c The declared number of extracting areas, which are located across the extension of the deposit and are developed using the same technology, is determined by the condition

M (26) in M - t 1 where M - the number of removal areas within the cleaning block, which are located across the extension of the deposit;

M - the thickness of the ore deposit (varies from 25 to 135m) m; 65 p - the number of layer-like inclusions of hollow rocks located along the layering of the ore (practically varies from 1 to 5)

For the conditions of Kryvbas, the number of extraction sites varies from 2 to 6.

The parameters of the vault-shaped compensating chamber, which is as close as possible to the limit contour of stable equilibrium, are determined on the basis of the indicators of stability of the horizontal | of vertical exposures P, and Re, which represent, respectively, the radii of the horizontal | vertical maximum permissible exposure of the compensating chamber of a parabolic shape, their value is established experimentally. For conditions

Kryvbasu R, ranges from 1 to 3, Re - from ZO to 50m. Accordingly, the parameters of the semi-axes of the vault-shaped chamber according to (8) and (9) are Пп, - 25.0 m. in - 9, Ohm.

The coordinates of the curve that is as close as possible to the contour of the stable equilibrium of the coimpensation chamber with a 70 parabolic vault shape are determined for the conditions of Kryvbas by expression (19) after substituting the specific values of the stability indicators Р Ре х2 у - Б250 4 1--- - | mm

Its to where y, x are the current coordinates of the parabolic curve, as close as possible to the contour of stable equilibrium, m;

The parameters of the compensation chamber of a rectangular shape are determined according to the instructions of the NDGRI (Determination and control of permissible sizes of structural elements of development systems at the Kryvbass - Kryvoi mines

Horn of NIGRY, 1987 - 75s) When the chamber has been standing for 3 to 5 months, its volume is 5400 - 3100m3 under the conditions of Kryvbas.

The cross-sectional area and volume of the vault-shaped chamber in similar mining and geological conditions is 7,800 m?, which is 1.5--2.0 times greater than the parameters of the rectangular chamber. Increasing the volume of extraction of clean uncontaminated ore from the block from 15-20 to 42905, due to the increase in the parameters of the compensation chamber, allows to improve the quality of mined ore by 4 - 5965.

The application of the proposed method of selective extraction of deposits with the inclusion of empty rocks by a system with massive collapse of ore and overlying rocks ensures obtaining a specific economic effect according to (9) in the amount of 90 - 10 thousand. UAH on them the length along the extension. If the length of the treatment block is 25 - 30 m, the economic effect of excavating one block will be 2.25 - 2.85 million hryvnias.

F s ormula of the invention so 1. The method of development of steep-sloping ore bodies containing inclusions of hollow rocks with weak unstable ores, a system of underground collapse, which includes horizontal and vertical preparatory and cutting operations, collapse of the ore massif by drilling and blasting and release of reflected ore so 3z5 Due to the output workings in the bottom of the block, which is distinguished by the fact that the reserves of the cleaning block, which contain "I layer-shaped inclusions of empty rocks, are worked out sequentially by collapse and release of ore in the areas between the ore-free inclusions at the minimum width for selective mining, which is determined by the condition ri ra Ko "p, " where tr is the minimum permissible width of the section of the ore deposit for selective excavation, which is limited across the extension by the inclusion of empty rocks, m; - с Ko - the coefficient characterizing the conditions of ore removal by deep wells (for the conditions of Kryvbas "" is taken as equal to 0.3 - 0.4); " A - the height of the ore layer that collapses, m. 2. The method according to item 1, which is distinguished by the fact that the ore-free spherical inclusions remain in the produced space if the condition of round 2 of MU.Kuz is observed, where three is the minimum permissible power of spherical inclusions of hollow rocks that maintain stability in

Go) the period of extraction of ore reserves and remaining in the produced space, m;

MU - the line of least resistance in the case of ore cutting in the well, m; so Kz is the reserve factor, taken as 1.3-1.5.

Ha 50 Z. The method according to item 1, which differs in that the inclusion of hollow rocks is partially removed in the form of a cut at the angle of release of the collapsed ore, the width and height of which are determined according to the conditions and: я 58594-19518а 3 ипи! VI? -Vv |; all"

Vr - yiv YZB- "А Я 6 4. 2 4 - з" vip (Yev - is) where Yy - the width of the cutting of empty rocks at the base of the ore massif, which is worked out, m;

IP - natural logarithm; 60 - the specific economic effect per 1 m of length along the extension, which takes into account the difference from the loss due to the cutting of empty rocks and the profit from the reduction of losses in the "dead" zone of the lying side (for the conditions of Kryvbas varies from 90 to 103 thousand UAH);

Npr - cutting height of bare rocks, m;

Dr 7 Angle of release of collapsed ore, degree (taken equal to 787); bo gu - angle of fall of the deposit, degrees.

Claims (1)

4. The method according to claim 1, which is distinguished by the fact that the number of areas in the cleaning block that include rock layers is determined by the condition М М---ч1 and where M is the number of extractable areas of the ore deposit, limited by the cross-section of empty rock inclusions; M - the thickness of the ore deposit, m: n - the number of layer-like inclusions of hollow rocks. 5. The method according to claim 1, which differs in that the compensation chamber has a vault shape, the parameters of which are determined by the formula оо а х у- «р/р; VE) CI rt "I! ra. Y 4 B/Р R, where y, x are the current coordinates of the parabolic curve as close as possible to the contour of stable equilibrium, m; рі, Рв - radii of the horizontal and vertical maximum permissible exposure of the compensation chamber of parabolic form, m (for the conditions of Kryvbas, r, - 1.5 m, Рв - 37.6 m). « with Zo so (ee) (ee) « - with . and? sh" (ee) (ee) (95) Ko) 60 b5