a lead-zinc mining process

A lead-zinc ore mining scale of 2000t / d, mining main targets # 1, # 2 and 5 # 3, etc. ore, wherein ore # 1 based ore, the mining area is divided into seven middle. Due to the development of joints and cracks in the ore body and surrounding rock, the roof is broken and the stability is poor. People and equipment cannot work in the stope. In the middle section of the first mining, the mining method is used in the middle and deep hole stratified collapse mining and retaining method, but the mining effect is not satisfactory, and there are problems such as the mining column not recovering. In order to ensure the economic benefits of the mine, it is necessary to find a new mining process.
1 mining method selection
The main body of 1# is a steeply inclined medium-thick large ore body with high ore value, complete development of joints and fractures of ore, and poor stability of ore. According to the relevant characteristics of 1# main ore body, two schemes are selected for economic and technical comparison. Scheme I is the caving method, and scheme II is the upward approach filling mining method.
1.1 Option I: analysis of caving mining technology
(1) Advantages. 1 The production process is relatively simple, easy for construction personnel to control; 2 low production cost; 3 large production volume, low investment, high return [2].
(2) Disadvantages. 1 Depletion, high loss rate, large waste of resources in actual mining, the loss rate can reach more than 20% of the content, in addition, due to the large amount of waste rock mixed into the ore, the difficulty of beneficiation is increased; 2 mining will lead to surface Collapse will not only affect the flora and fauna of the subsidence area, but also damage the surrounding environment and not meet the relevant requirements of ecological civilization construction. Because the mine is located in the rainy southern area, the terrain around the ore body is in danger, the surface There is a large amount of covering soil. As the depth of the caving increases, in the case of rainy days, the rain will flow into the mining area along the covering soil, which will have certain impact on the underground operation and even cause unsafe accidents. 3 In recent years, the mine The total mining stone volume reached 1.04 million tons, forming an area of ​​about 270,000 square meters. According to the current mining situation, if the caving method is used for mining, not only the first mining area is difficult to select, but also the waste of resources will be increased.
1.2 Scheme II: Analysis of the upward approach mining method
1 Relative to Scheme I, Scheme II has a small exposure range, which is convenient for construction workers to reduce the loss of ore resources; 2 The depletion rate index is significantly low, which can effectively reduce the cost of ore dressing and achieve efficient use of resources; 3 The ore recovery rate is high, gold The genus has a high recovery rate. The technical and economic indicators of the two programs are compared in Table 1.

It can be seen from Table 1 that Scheme II is more economical and reasonable and can be used as the final mining scheme.
2 mining process
(1) Nugget layout parameters. The stope is arranged along the direction of the ore body, with a length of 40m, and the width is basically consistent with the thickness of the ore body. Each stope is arranged along the cutting lane and the ore body. The inlet specification (width × height) is (3.5 ~ 4) m × (3 ~ 4) m. The size of the return air well is 2.0m×2.0m.
(2) Precision cutting. The cutting is carried out by means of pulsed external mining, and the mining and cutting engineering includes segmented roadway, cutting roadway and filling return air well.
(3) Mining process. It is carried out by means of one by one, and the constructor should divide it into multiple ways according to the actual width inside the ore block. After the completion of the roadway mining work, it should be filled immediately. After the relevant requirements of the filling strength are met, the second stage of the recovery and filling work can be carried out [3].
(4) Rock drilling and blasting. Use a single-arm rock drilling rig to drill horizontal holes, strictly control the hole depth and pore size, and use a cylindrical modified ammonium explosive to blast.
(5) Ventilation of the stope. Fresh airflow flows from the middle section of the transportation lane, enters the ramp road, and then reaches the section of the section and alleys. After relevant treatment, it reaches the roadway. Sewage winds from the stope to the filling and returning to the wind well are treated and then arrive at the upper return airway. After the blasting work is finished, the construction personnel can enter the work surface to carry out the work after the smoke in the site is cleaned.

(6) Roof management. During the ventilation process of the stope, the construction personnel should thoroughly inspect the condition of the roof to see if there are any undesirable phenomena such as ore falling off. The unsafe hidden dangers can be completely checked before the operation can be carried out. The anchorage of the roof should be reinforced to improve its stability. Sex.

(7) Mining in the stope. Use a scraper to transport the caving ore out.

(8) Filling. Filling with 1:6 filling material, the ratio of lime sand in different areas is also the same. The upper 0.5m space uses 1:4 lime sand than the filling surface and top filling, two steps and points 2.5 to 3.5 m in the lower part of the layer contact road is filled with cement with a ratio of 1:15. The construction should be carried out in strict proportion to ensure the smooth implementation of the construction process.
(9) Transfer layer. Before the final filling after the stratified recovery is completed, the cutting cross-section and the layered communication path should be increased by 1.5 m and then filled. After the padding reaches the standard scale, it continues to increase to a new height, and thus a layered layering work can be completed.
3 Conclusion
The specific application of the mining process was discussed. The mining method of the upper-direction filling method was selected for the actual situation of a lead-zinc mine, which achieved good application results and provided reference and reference for similar mining.
references
[1] Hu Daoxi. Application of the approach to the filling method in the official set of iron ore Lee [J] and the layering. Metal Mine, 2011 (4): 21-23.
[2] Xiong Guoxiong, Zhao Xiongwen, Lu Bo, et al. Application to the intake passage in the copper filling Method Green Mountain Mine [J]. Modern Mining, 2012 (11): 4-6.
[3] Li Li, Li Zhanjin, Yang Ligang. Optimization research and application of high efficiency approach mining method for unstable ore body [J]. Mining Research and Development, 2014 (4): 1-3.
Article source: "Modern Mining"; 2016.11;
Author: Tan Chun theory; Yunnan Jinding Zinc Industry Co., Ltd;
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