Mining operations include: mining, transportation and ground pressure management. (1) Falling mine This program is commonly used in free space blasting. Blasting horizontal flat deep holes to achieve. Deep hole drilling equipment: YQ-100 or economy-100 type diving holes or drilling rigs . The minimum resistance line is W=3.3~3.6 meters. Medium and deep hole rock drilling equipment: 01-38 type, YG-80 type rock drilling machine . For the blasting method, there are two types: 1 Free space blasting - the blasting with a compensation ratio of ≤20~30% is called free space blasting. The ore after blasting can get enough space and can be freely loose, but the ore must be blasted in free space when it is quite stable, otherwise it is enough Large compensation space will not be available. 2 Extrusion blasting - extrusion blasting comes from production practice When the compensation ratio is ≤10~20%, the blasting is called extrusion blasting. The blasted ore does not have enough free and loose space, but squeezes and collides with each other to improve the blasting effect. For the sublevel caving method with horizontal deep hole falling ore, since it is a horizontal falling mine, in order to protect the stability of the bottom structure, free space blasting is often used. * The sublevel caving method is the same as the horizontal drop method. Not a blast. (2) Mining. (ie ore transport) The mining work includes three aspects: mining, primary crushing and antimony mining. 1) Mining – For this method of mining, 70 to 80% of the ore that has fallen off the ore is released under the upper covered rock. As the ore is released, the upper cover rock also moves down, and the ore is in direct contact, causing ore loss and depletion. It is generally controlled by planned ore mining. (mine mining problems, special lectures) 2) Secondary crushing of large blocks - secondary crushing refers to the handling of card leakage, suspended roof and broken large ore during the ore mining process. How to deal with the problem of large block leaks and suspended ceilings is a problem to be studied. 1 The solution to the card leakage is to use a wooden pole or a bamboo pole to carry the medicine pack up and float it in a suitable position for vibration blasting. Or use a mining mine rocket to blast. (According to the use of the Gongchangling Mine, the effect is good, but the cost of the rocket is high, it is only very difficult, and it is used as a last resort. Generally, it is handled by the method of blasting the wooden package.) 3) Mining operations. (Carrying and moving) - stop mining, generally using electric shovel, the way to improve the efficiency of smelting mine is: improve the quality of falling mine; reduce the bulk output rate; thereby reducing the time taken by secondary crushing, increasing pure Yankuang time. (3) Mining site pressure management The caving method is to realize the ground pressure management by caving surrounding rock. Therefore, the ground pressure management of this kind of mining method should firstly pay attention to the formation of the covered rock layer. The methods for forming a covered rock layer are: 1) If the upper part is mined in the open air, the slope of the open pit can be collapsed, or the original stripped rock can be used to fill the gob. 2) When mining steeply inclined ore bodies (70 to 80° or more), it is possible to blast the surrounding rock of the adjacent mining area or the lower disc. When the angle is small, it usually falls off the surrounding rock. 3) When mining the gently inclined ore body, it is necessary to replenish the roof in time to supplement the thickness of the covered rock layer. 4) The natural collapse of the surrounding rock – the ability to naturally collapse is a more economical way to save money. (5) Ventilation in the stope The section caving method has poor ventilation conditions (because the goaf has collapsed) and therefore the ventilation and ventilation systems should be properly selected. (1) Use push-in ventilation as much as possible to reduce air leakage. (2) It should be ensured that the wind speed in the electric ramp reaches 0.5 m / s. (Excessively large and too small are not conducive to mining. If it is too small, the smoke is slow. If it is too large, it will easily blow dust.) (3) In the electric ramp, the main airflow direction should be opposite to the direction of the antimony ore. The key area of ​​ventilation is the electric ramp. (4) The use of all intra-pulse acquisition systems should be avoided. (Because it is difficult to form a complete ventilation system) (5) Focus on ventilation at the level of electricity. The ventilation system of the ramp is directly linked to the total ventilation system of the mine. The basic trend of applying a sub-column sublevel caving ventilation system is to avoid lifting and transporting lanes, adding dedicated lanes, and establishing an independent ventilation system for the new block or the mining area directly sent to the electric ramp. In this way, the purpose of increasing the effective air volume of the electric bypass can simplify the ventilation management and improve the ventilation conditions. (6) Evaluation of the sublevel caving method for horizontal deep hole mining (1) Main advantages: 1 Rock drilling and charging conditions are good; 2 granulite is well ventilated indoors; 3 Adjacent ore blocks are less restrained by each other, and there is a certain flexibility in production connection. (2) Main disadvantages: 2 When the ore is relatively broken, the drilling of the rock drilling patio is difficult and the deformation of the blasthole is serious. 3 large output rate is high, affecting the production capacity of the ore block; 4 The mining workload is large and it is difficult to achieve mechanized operation. (3) Applicable conditions Generally used to mine harder ore. There are very few methods for applying mines in China. (The surrounding rock of the upper plate can be naturally collapsed in a block shape, the ore is stable and steeply inclined above the medium, the ore body, the surface is allowed to fall. The value of the ore grade is low and the ore body) (4) Development trend: From the development of underground mines in the Soviet Union, the sublevel caving method with bottom pillars will be reduced from the current proportion of 13% to 3% (to 1990), due to the sublevel caving method without pillars. Caused by a large number of adoptions. 2T Wheel Loader,Strong Wheel Loader,2T Mini Wheel Loaders,2T Small Wheel Loader Taian zhengtai construction machinery Co., Ltd , https://www.taztmachine.com
2 Deal with the ceiling method. Due to over-squeezing during ore mining, or the bonding of fine ore, etc., during the ore-out, a cantilever may appear in the upper part of the funnel. There are two ways to handle the overhang: (a) It is generally to strengthen the ore discharge of the adjacent funnel, which is the balance of the arch. (b) The bombardment with the medicine bag is an arch. When handling the arch, care must be taken to prevent the dome from suddenly falling.
1 The stability of the bottom column is more stringent. When blasting, the impact on the bottom column is relatively large. If the reinforcement is not good, it often causes serious damage to the electric stern.