阅读说明：本技术 一种利用液态二氧化碳相变控制爆堆属性的方法 (Method for controlling explosive property by utilizing liquid carbon dioxide phase change ) 是由 史秀志 喻智 高纯生 胡冬阳 张玉辉 张文渊 陈新 饶帝军 霍晓锋 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种使用液态二氧化碳相变控制爆堆属性的方法,本发明在矿石区域炮孔中安放炸药,在废石区域炮孔中安放液态二氧化碳爆破器,通过爆炸能量的差异,使矿石区域爆破后得到的岩块平均尺寸较小,废石区域爆破后得到的岩块平均尺寸较大,两侧岩块在尺寸上形成明显差异,以便于工程技术人员进行矿石和废石的肉眼识别。同时,废石区域爆破得到的大型岩块将抑制矿石区域小型岩块的运动,有效的降低爆堆中的矿岩混杂程度。本发明为矿体蕴藏条件复杂、品位控制要求高、周边环境复杂矿山提供了降贫减损新方法,为存在特殊爆堆属性需求的露天矿山提供了控制措施。(the invention discloses a method for controlling the property of blasting piles by using liquid carbon dioxide phase change. Meanwhile, large-sized rock blocks obtained by blasting in the waste rock area can inhibit the movement of small-sized rock blocks in the ore area, and the ore rock mixing degree in the blasting pile is effectively reduced. The invention provides a novel method for reducing the lean and the loss for mines with complex ore body storage conditions, high grade control requirements and complex surrounding environments, and provides control measures for open-pit mines with special blasting property requirements.)

1. A method for controlling the properties of pile-up by utilizing the phase change of liquid carbon dioxide is characterized by comprising the following steps:

1) Designing a carbon dioxide blasting experiment in a waste rock area; taking the blasting parameters as independent variables and the blasting attribute parameters as dependent variables;

The blasting parameters comprise liquid carbon dioxide content t, carbon dioxide blast hole pitch a1 and carbon dioxide blast hole row number b1, and the attribute parameters of the blasting pile comprise rock fragment size X ₅₀, blasting pile height H1 and blasting pile depth L1;

2) Establishing a regression equation of the attribute parameters and the blasting parameters of the blasting piles in the waste rock area by using a regression analysis method according to the experimental data obtained in the step 1);

X₅₀＝f(t,a1,b1)

H1＝g(t,a1,b1)

L1＝p(t,a1,b1)

3) designing an explosive blasting experiment in an ore area, and taking blasting parameters as independent variables and blasting pile attribute parameters as dependent variables;

The blasting parameters comprise charging height H, hole distance a2 and blast hole row number b2, and the attribute parameters of the blasting pile comprise rock fragment size X ₅₀, blasting pile height H2 and blasting pile depth L2;

4) establishing a regression equation of the ore region blasting attribute parameters and the blasting parameters by using a regression analysis method according to the experimental data obtained in the step 3);

X₅₀＝f(h,a2,b2)

H2＝g(t,a2,b2)

L2＝p(t,a2,b2)

5) blast zone division

Firstly, determining a rock boundary;

The second step is that: dividing the whole step into explosion areas, wherein the ore area is divided into the rear half part of the explosion area, and the waste rock area is divided into the front half part of the explosion area;

6) Guiding the selection of blasting parameters of the ore area and the barren rock area according to the relational expression between the blasting attribute parameters and the blasting parameters obtained in the step 2) and the step 4) and the blasting attribute parameters expected to be obtained during actual blasting;

Arranging explosive blastholes in an ore area of a boundary of the ore rocks, blasting the explosives, and arranging a liquid carbon dioxide blaster in a waste rock area, and blasting the carbon dioxide; the blasting energy of the liquid carbon dioxide in the barren rock area is lower than that of the explosive in the ore area, and the barren rock area is detonated before the ore area.

2. The method of claim 1, wherein: and (3) constructing a three-dimensional geological model by using geological modeling software, slicing by using the step altitude, and performing color matching by using the mine industrial grade, thereby obtaining the ore rock boundary of the whole step.

3. the method of claim 2, wherein: for radioactive mines, radioactive logging can be performed in the drilled holes after the drilling is completed to obtain the specific ore grade of the drilled hole area, a more precise single-explosion area grade model is established after the drilling and before the explosion, model color matching is performed according to the ore grade, and a more accurate ore and rock boundary can be seen.

4. The method of claim 1, wherein: the survey crew can choose to insert bamboo sticks, fiber bands or wooden piles on the ore rock boundary line for identification, and can also spray fluorescent materials on the ore rock boundary line for identification during shovel loading operation at night.

5. The method of claim 1, wherein: the liquid carbon dioxide blast holes can be arranged along the boundary of the curvilinear ore rock, the explosive blastholes need to be detonated after the liquid carbon dioxide blast holes are detonated, and when the liquid carbon dioxide blast holes are detonated, the explosive blastholes within the range of 20-30m of the periphery of the blast holes are required to complete the detonator ignition process.

6. The method of claim 1, wherein: the blasting network of the ore area adopts a V-shaped blasting network.

7. The method of claim 1, wherein: the detonator in the explosive blast hole is a digital electronic detonator.

Technical Field

The invention relates to the technical field of ore body blasting, in particular to a method for controlling the properties of blasting piles by utilizing the phase change of liquid carbon dioxide.

Background

In view of the advantages of high production efficiency, low mining cost and low labor intensity of blasting, the drilling blasting is a rock breaking method commonly adopted in surface mines at home and abroad at present.

in the working process of explosion energy, rocks around the blast hole are firstly crushed under the action of explosion shock waves with the strength greater than the dynamic compressive strength of the rocks to form a crushing ring, then the explosion shock waves are attenuated into stress waves with lower strength along with the attenuation of the energy, and the strength is continuously reduced along with the outward propagation process of the stress waves. When the stress wave strength is greater than the rock dynamic tensile strength, fissured rings form in the rock. Then, the explosive gas enters the cracks to expand the cracks through the gas wedge effect, and further rock is crushed. In the whole process of the action of the explosion energy, the broken rocks move towards the direction of the free surface and are finally accumulated and redistributed in front of the free surface to form the common blasting pile of the mine.

The blasting is a working object of a mine shoveling and loading process, and the attributes of the blasting (the mixing degree of ore rocks in the blasting and the form of the blasting) have great influence on the subsequent processes, and the influence is mainly shown in the following steps:

1. The degree of mixing of ore rocks in the blasting heap. For a blasting area with both ore and waste rock, the distribution of rock in the blasting pile is different from that before blasting due to the blasting energy, but in many field situations (for example, there is no obvious difference in physical properties such as color, form, density and the like between the ore and the waste rock), engineers cannot effectively identify the ore and the waste rock during shoveling, and only the distribution of the ore and the waste rock before blasting can be used for shoveling. The results thus produced are: a large amount of ores are conveyed to a dumping site for stacking waste rocks, and a large amount of waste rocks are conveyed to a smelting workshop for processing, so that any beneficial return cannot be obtained while money cost, labor cost and time cost are wasted.

For the conditions that the ore body accumulation conditions are complex (the rock mass subjected to primary blasting must contain ores and waste rocks at the same time) and the ore economic value is high (rare and precious metals such as gold, silver, uranium and the like), the degree of mixing of the high-explosive-pile ore rocks caused by the displacement of the ore rocks in the blasting process causes great ore dilution and loss, and the mine economic benefit is greatly influenced.

2. The height of the blasting pile and the depth of the blasting pile. In mine blasting, if protection objects such as transportation railways, highways, buildings to be protected and the like exist in front of an explosion area, the width and depth of a blasting pile need to be controlled, and rock in the blasting pile is prevented from impacting the protection objects.

In the control of the properties of the explosive pile, some research results have been found in papers and patents for solving the problem of explosive pile front, which mainly include: patent CN201010157275.8 (staged mining slope-expanding blasting method for deep concave open pit), patent 201210461737.4 (blasting method for controlling blasting pile forward-impact for open pit bench blasting), patent CN201811444458 (method for optimizing width of blasting pile for open pit bench blasting), paper "analysis of influence factors of shovel loading efficiency of open pit electric shovel" (chemical mining technology, 5 th 1995), paper "prediction method of width of blasting pile for open pit bench blasting" (western prospecting engineering, 2 nd 1995), paper "research and practice of blasting technology for deep concave slope mining open pit (chinese mining industry, 4 th 2005), and the like. Among them, patent CN201010157275.8, patent 201210461737.4 and paper "research and practice of blasting technology of deep concave steep side mining open pit mine" mainly control movement of ore rock in the blasting process by adjusting blasting network in the same blasting area, and further control the forward blasting of blasting pile. In patent CN201811444458 and the thesis "analysis of influence factors of shovel loading efficiency of electric shovel for strip mine" and the thesis "prediction method of strip mine step blasting pile width", the pile forward is effectively controlled by mainly analyzing the correlation between the pile forward and blasting parameters and adjusting the blasting parameters.

These studies all achieve certain effects, but have certain disadvantages: (1) the method mainly aims at the problem of pile-blasting forward rushing, and fails to consider the problem of ore rock mixing in pile blasting; (2) for the problem of controlling the pile-blasting forward by adjusting the blasting network, the design difficulty is high due to the influence of the precision of the detonator and the delay time of the detonator, and a certain risk of failure of the blasting network exists; (3) there was no significant improvement in the negative effects of blasting (vibration, flyrock, etc.).

disclosure of Invention

the present application is directed to solving at least one of the problems in the prior art. Therefore, one of the objectives of the present invention is to provide a method for controlling the properties of a blasting pile by using liquid carbon dioxide phase change, which has the advantages of good control effect of the properties of the blasting pile, safe blasting operation, simple operation, and controllable negative blasting effect, on the premise of comprehensively considering the mixing degree of the blasting pile and the problem of the forward rush of the blasting pile.

In order to solve the technical problems, the invention adopts the following technical scheme:

A method for controlling the properties of pile-blasting by utilizing the phase change of liquid carbon dioxide comprises the following steps:

1) designing a carbon dioxide blasting experiment in a waste rock area; taking the blasting parameters as independent variables and the blasting attribute parameters as dependent variables;

the blasting parameters comprise liquid carbon dioxide content t, carbon dioxide blast hole pitch a1 and carbon dioxide blast hole row number b1, and the attribute parameters of the blasting pile comprise rock fragment size X ₅₀, blasting pile height H1 and blasting pile depth L1;

2) Establishing a regression equation of the attribute parameters and the blasting parameters of the blasting piles in the waste rock area by using a regression analysis method according to the experimental data obtained in the step 1);

X₅₀＝f(t,a1,b1)

H1＝g(t,a1,b1)

L1＝p(t,a1,b1)

3) designing an explosive blasting experiment in an ore area, and taking blasting parameters as independent variables and blasting pile attribute parameters as dependent variables;

The blasting parameters comprise charging height H, hole distance a2 and blast hole row number b2, and the attribute parameters of the blasting pile comprise rock fragment size X ₅₀, blasting pile height H2 and blasting pile depth L2;

4) Establishing a regression equation of the ore region blasting attribute parameters and the blasting parameters by using a regression analysis method according to the experimental data obtained in the step 3);

X₅₀＝f(h,a2,b2)

H2＝g(t,a2,b2)

L2＝p(t,a2,b2)

5) Blast zone division

Firstly, determining a rock boundary;

Secondly, dividing the blasting area of the whole step, wherein the ore area is divided into the rear half part of the blasting area, and the waste rock area is divided into the front half part of the blasting area;

6) Guiding the selection of blasting parameters of the ore area and the barren rock area according to the relational expression between the blasting attribute parameters and the blasting parameters obtained in the step 2) and the step 4) and the blasting attribute parameters expected to be obtained during actual blasting;

Arranging explosive blastholes in an ore area of a boundary of the ore rocks, blasting the explosives, and arranging a liquid carbon dioxide blaster in a waste rock area, and blasting the carbon dioxide; the blasting energy of the liquid carbon dioxide in the barren rock area is lower than that of the explosive in the ore area, and the barren rock area is detonated before the ore area.

Further, a three-dimensional geological model is constructed by using geological modeling software, slicing is carried out according to the step altitude, and color matching is carried out according to the mine industrial grade, so that the ore rock boundary of the whole step is obtained.

Furthermore, radioactive logging can be performed in the drill hole after the radioactive mine is drilled to obtain the specific ore grade of the drill hole area, a more precise single-explosion area grade model is established after the drill hole and before the explosion, model color matching is performed according to the ore grade, and a more accurate ore and rock boundary can be seen.

Furthermore, survey crew can choose to insert bamboo sticks, fiber bands or wooden piles on the ore rock boundary line for marking, and can also splash fluorescent materials on the ore rock boundary line for marking when shovel loading operation is carried out at night.

Further, the liquid carbon dioxide blast holes can be arranged along the boundary of the curvilinear ore rock, the explosive blastholes need to be detonated after the liquid carbon dioxide blast holes are detonated, and when the liquid carbon dioxide blast holes are detonated, the explosive blastholes within the range of 20-30m around the blastholes are required to complete the detonator ignition process.

Furthermore, a V-shaped blasting network is selected as the ore area blasting network.

further, the detonator in the explosive blast hole is a digital electronic detonator.

Principles and advantages

The method utilizes the characteristics of controllable liquid carbon dioxide blasting energy and less disasters, introduces a liquid carbon dioxide blasting method to control the width of the blasting pile in the step blasting and blasting pile attribute control, and simultaneously utilizes the rock blocks crushed firstly to suppress the subsequent rock blocks, thereby reducing the rock and ore mixing degree in the blasting pile.

According to the invention, the explosives are placed in the blast holes of the ore region, the liquid carbon dioxide blasters are placed in the blast holes of the waste rock region, the average size of the rock blocks obtained after blasting of the ore region is smaller, the average size of the rock blocks obtained after blasting of the waste rock region is larger, and the sizes of the rock blocks on two sides form obvious differences through the difference of the blasting energy, so that engineering technicians can conveniently identify the ore and the waste rock by naked eyes.

Meanwhile, the large-size rock mass produced by blasting of the low-energy liquid carbon dioxide blaster can effectively inhibit the movement of the small-size rock mass produced by blasting of the high-energy explosive, the movement of the small-size rock mass towards a free surface is reduced, the depth of the blasting pile is effectively reduced, the mixing degree of ore rocks in the blasting pile is reduced, and the ore recovery rate is improved. In addition, the liquid carbon dioxide blasting device is used for replacing part of explosives to carry out rock crushing, so that the negative blasting effect can be effectively reduced, and the blasting properties such as the height and depth of the blasting pile can be adjusted.

The liquid carbon dioxide blasting network and the explosive blasting network are two sets of networks which are irrelevant to each other and do not interfere with each other, so that the risk of the blasting network on a construction site can be avoided.

Therefore, the patent is scientific, effective, simple to implement, remarkable in effect and has wide popularization and application values.

Drawings

FIG. 1 is a top view of a medium and large scale ore-rock mixed blast zone;

FIG. 2 is a cross-sectional view of a blasting pile of a large-scale ore rock mixed blasting area in the embodiment;

Reference numbers in the figures: reference numbers in the figures: 1-free space in front of the free surface; 2-step; 3-a pre-blasting ore rock boundary; 3-1-ore region; 3-2-waste rock area; 4-actual ore rock boundary in blasting pile; 5-liquid carbon dioxide blast holes; 6-liquid carbon dioxide blaster connecting line; 7-liquid carbon dioxide blaster initiator; 8-blasting explosive holes; 9-hole delay detonator; 10-rows of delay detonators; 11-detonator initiation; 12-small pieces of rock formed by detonation of explosives; 13-large rock pieces formed by liquid carbon dioxide blasters.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention mainly utilizes the characteristics of controllable pressure, lower expansion energy and weak negative effect of the liquid carbon dioxide gas, and uses the high-pressure gas generated by the phase change of the liquid carbon dioxide to crush the rock, thereby intervening and controlling the rock crushing and moving processes. The method is particularly suitable for the ore mining of the surface mine with complex ore body accumulation conditions, high grade control requirements and complex surrounding environment or the surface mine with special blasting attribute requirements. The method specifically comprises the following steps:

(1) Carbon dioxide blasting parameter selection

firstly, designing a carbon dioxide blasting experiment

The independent variables of the carbon dioxide blasting experiment are liquid carbon dioxide content t, hole distance a1 between carbon dioxide blasting holes and carbon dioxide blasting hole row number b1, and the dependent variables are rock fragment size X ₅₀ with the content of 50%, blasting height H1 and blasting depth L1.

Engineering technicians respectively design 15-30 groups of field experiments in the waste rock area according to the requirements.

And secondly, drilling blast holes on production steps of the surface mine according to the designed blasting parameters, filling liquid carbon dioxide into the liquid carbon dioxide blaster, arranging the liquid carbon dioxide in the designed blast holes, connecting with a detonation network, and detonating after the liquid carbon dioxide blaster is checked to be error-free.

Thirdly, shooting the rock fragments generated by carbon dioxide blasting by using a digital camera after blasting, acquiring size distribution data of the rock fragments by using an image processing technology, and taking the size X ₅₀ of the rock fragments with the content of 50% as a measurement standard of the whole rock fragments.

And measuring the height H1 and the depth L1 of the blasting pile by using a length measuring tool such as a distance meter or a positioning tool such as RTK.

And fourthly, mutually corresponding the measured dependent variables (X ₅₀, H1 and L1) of the blasting pile and the independent variables (t, a1 and b1) in the blasting parameters, and then selecting a proper regression equation to express the mathematical relationship between the dependent variables and the independent variables by using a regression analysis method to establish a regression equation corresponding to the waste rock area.

X₅₀＝f(t,a1,b1)

H1＝g(t,a1,b1)

L1＝p(t,a1,b1)

(2) explosive blasting parameter selection

First, designing explosive blasting experiment

The independent variables of the experiment are the charging height H, the hole distance a2 and the blast hole row number b2, and the dependent variables are the rock fragment size X ₅₀ with the content of 50%, the blasting height H2 and the blasting depth L2.

The engineer designs 15-30 field experiments in the ore region according to the above requirements.

And secondly, drilling a blast hole on a production step of the surface mine according to the designed blasting parameters, placing an initiating explosive package, completing the charging work of the blast hole, connecting an initiating network, and initiating after checking.

thirdly, after blasting, shooting the rock fragments in the blasting pile by using a digital camera, acquiring size distribution data of the rock fragments by using an image processing technology, and taking the size X ₅₀ of the rock fragments with the content of 50% as a measurement standard of the whole rock fragments.

And measuring the height H2 and the depth L2 of the blasting pile by using a length measuring tool such as a distance meter or a positioning tool such as RTK.

And fourthly, mutually corresponding the measured dependent variables (X ₅₀, H2 and L2) of the blasting pile and the independent variables (H, a2 and b2) in the blasting parameters, and then selecting a proper regression equation to express the mathematical relationship between the dependent variables and the independent variables by using a regression analysis method to establish a regression equation corresponding to the waste rock area.

X₅₀＝f(h,a2,b2)

H2＝g(t,a2,b2)

L2＝p(t,a2,b2)

(3) Blast zone division

First, determining the boundary of ore rock

And collecting the drilling data of geological exploration holes, supplement exploration holes and the like of the mine, and constructing a three-dimensional geological model by using geological modeling methods such as a kriging method and the like by using geological modeling software such as Datamine and the like. The three-dimensional geological model is sliced according to the step altitude, the three-dimensional geological model of the step is limited according to the coordinates of the boundary points of the explosion area, so that the two-dimensional geological model of the whole step is obtained, the ore and the waste rock are matched according to the ore grade, and the ore and rock boundary of the whole step can be seen.

preferably, radioactive logging can be performed in a drill hole after drilling is completed for radioactive mines (such as uranium mines) to obtain specific ore grades in a drill hole area, a more precise single-explosion area grade model is established after drilling and before explosion, model color matching is performed according to the ore grades, and a more accurate ore-rock boundary can be seen.

second, dividing the explosion area

In the distribution of the ore area and the waste rock area, the ore area is divided into the rear half part of the blasting area as much as possible, and the waste rock area is divided into the front half part of the blasting area, so that blasting instead of grinding in the blasting process is realized.

(4) Blasting

According to the relation between the blasting attribute parameters and the blasting parameters obtained in the steps and the blasting attribute parameters expected to be obtained in actual blasting, the blasting parameters of the ore area and the waste rock area are guided to be selected, specifically:

In a first step, a borehole is drilled. Blastholes are drilled according to the blasting design within the ore rock boundaries (ore regions), and blastholes are drilled according to the liquid carbon dioxide blasting design outside the ore rock boundaries (barren rock regions).

Preferably, liquid carbon dioxide blast holes can be arranged along a curved ore rock boundary, the liquid carbon dioxide content t and the hole spacing a1 in the waste rock area can be determined by using the relation between the hole spacing a1 and the liquid carbon dioxide content t and the average size X ₅₀, the blasting depth L1 and the blasting height H1 to determine the blasting depth L1 so as to obtain a reasonable average size X ₅₀ of the rock mass, and the relation between the hole spacing a1 and the filling height H and the hole spacing a1 in the ore area can be determined by using the relation between the hole spacing a1 and the filling height H and the average size X ₅₀, the blasting depth L1 and the blasting height H1 to determine the blasting depth L1 so as to obtain the reasonable blasting depth L1.

And secondly, respectively placing a detonator, an explosive and a liquid carbon dioxide blaster in blast holes on two sides of the boundary of the ore rock to finish the on-line work. Wherein, the explosive blasthole needs to be detonated after the liquid carbon dioxide blasthole is detonated, and when the liquid carbon dioxide blasthole is detonated, the explosive blasthole within the range of 20-30m around the blasthole is required to complete the detonator ignition process.

preferably, the detonators in the blast holes can be digital electronic detonators so as to reduce negative blasting effects such as blasting vibration.

Preferably, when the blasting operation is performed in the blasting area by using the digital electronic detonator, the digital electronic detonator further comprises a handset capable of realizing identity registration, delay time setting, blasting network inspection and blasting of the digital electronic detonator.

Preferably, the explosive area blasting network can adopt a V-shaped blasting network, and the V-shaped blasting network can effectively utilize free space and is beneficial to rock breaking.

And thirdly, arranging blasting warning to finish the blasting operation. Setting a blasting warning range, and arranging blasting warnings at each traffic intersection; and finishing the detonation operation of the explosive blasthole and the liquid carbon dioxide blasthole by using the detonator.

Fourthly, the rock breaking degree is high due to high explosive energy in an ore area, the average size X ₅₀ of the rock is small, the rock breaking degree is low due to low carbon dioxide energy in a waste rock area, the average size X ₅₀ of the rock is large, and measuring personnel perform boundary marking according to the average size X ₅₀.

Preferably, the measuring personnel can insert bamboo sticks, fiber bands and wooden piles on the ore and rock boundary line for marking, and can spray fluorescent materials on the ore and rock boundary line for marking when shovel loading operation is carried out at night.

And fifthly, commanding the forklift to respectively shovel and load the ore and the waste rock by an engineer according to the ore rock boundary calibrated by the measuring personnel.

The present invention will be further described with reference to specific examples.