Horizontal drilling and blasting

Contents

Contents

Source Data

Introduction

1. Determination of cross section dimensions of the workpiece

2. Calculation of parameters of spur set of charges

Conclusion

List of used literature

Appendix: Workpiece section. TRU passport

Task

The purpose of the course project: to master the skills of calculating the cross section and the bore set of horizontal mine charges when conducting it in a drilling and blasting method in mines and mines that are not dangerous by gas or dust.

Source Data

The equipment - BC20;

The thickness of the support is  40mm;

The permanent presence of people is not provided;

Strength factor - f = 14;

The traffic rate of cars per day is up to 100 cars per day;

Vault - box;

Machine width - d = 2800 mm;

Machine height - h = 2000 mm;

Machine speed - v = 8 km/h;

Tire width - s = 430 mm ;

BV - granulite - AS-8;

Rock structure coefficient - f 0 = 1.3;

Working length - L = 500 mm;

Number of working days per month - tp = 25;

The period of development is t m = 4 months;

Number of working shifts per day - n cm = 4;

The number of cycles per shift is nc = 1.

Introduction

The open method of mining is more common than the underground. But the open way is good at relatively low depths. The underground method is used when, for economic and other reasons, an open method is compared with it, or there is no free territory for building a quarry, or the volume of P.I. is small, but it is valuable and deeply lying, etc. This method is carried out through underground mining.

Underground mining - structures in the bowels of the earth created as a result of mining, regardless of whether they have access to the surface or not.

Using TRU, the workings are usually carried out at a strength factor of f > 4.

Workings with the help of TRU include the following main operations: drilling and loading of holes, their blasting, ventilation, rock harvesting and, if necessary, workings attachment. All these operations constitute one pass cycle.

A pass cycle is a collection of processes and operations repeated during approximately the same period of time, during which the bottom of the work is moved by the same amount.

But in addition to the main operations, there are also auxiliary operations. Auxiliary operations include the laying of compressed air pipes, power and lighting cables, the suspension of ventilation pipes, the equipment of a pedestrian path, if necessary, the laying of rail tracks or the installation of roadways, drains, etc.

In the drilling and blasting method, horizontal workings are usually carried out with a continuous face.

Drilling of drilling holes is one of the main technological processes. In terms of time and labor intensity of work, drilling of holes takes from 25 to 40% of the total duration and labor intensity of the penetrating cycle.

The selection of explosive materials is made taking into account the gas regime of the mine or mine, the strength and water availability of rocks. The explosion of charges can be carried out in various ways: electric, fire, electric fire, capsule-free - detonating cord. All kinds of retardants are used in these blasting methods. In the first method, electric detonators of instantaneous, short-slow and delayed action are used. 

Conclusion

During this course project, I got acquainted with the technique and technology of horizontal drilling and blasting. He mastered the skills of calculating the cross section and the spur set of mining charges when conducting it in mines and mines that are not dangerous by gas and dust. He got a visual idea of ​ ​ the methods and types of placing holes on the face.

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