Jiaojia gold ore Ltd. Hope children Mountain mine in Shandong Gold Mining (Laizhou) containing pyrite altered rock ore mineralization based. Mount Hope children V-2 # gold deposits are V pulse number control structure, gold-bearing quartz ore belonging sulfide ore vein type, pyrite and other sulfides in veins filled in fissures faults, veins thickness 0 .2～1.1m, is thin and extremely thin ore body, the ore rock is stable; the surrounding rock of the surrounding rock is all paddy granite , with joint development and moderate stability; grade 20～40g/t; 13°, the ore body inclination angle is about 65°.
The mining of the steeply thin and rich veins is mainly based on the shallow hole retention method and the mining method. The mixed mining of ore and surrounding rock is mainly based on simplifying the mining process and improving the mining strength and quality. The shallow hole retention method is mainly used. This method is mainly applicable to the stable or medium stable mining conditions of the ore, and the mining process is simple and easy to manage; The loss of wood is relatively small, the equipment required is simple, the mining cost is relatively low, and the production capacity of personnel is relatively high; the disadvantage is that the ore is depleted. The mining class focuses on reducing the depletion, mainly by the wall filling method. This method can effectively reduce the depletion of ore and better control the ground pressure. Generally, relatively small mines use the wall-filling method, and the mechanization level is relatively low. According to the stability of the ore and surrounding rock, the mining sequence and the cutting position of the ore should be determined, and the process links are complicated, and the depletion rate index is not ideal [1- 6].
1 minute mining and filling mining method
In view of the mining process of steeply inclined ultra-thin ore bodies, reducing the depletion rate and improving the ore grade, the ground pressure management is the essential problem that needs to be solved at present. In order to solve these problems, the wall-filling mining method is optimized. It is proposed to use the mining and cementing filling method.
1.1 recovery plan
As shown in Figure 1, the stratification height of the sub-collection cement filling mining method is 3m, and the small stratification height is 1.5m. The height of the surrounding rock is 1.5m during construction, and the stone is cleaned and expanded. The ore body collapsed and the height of the ore body was further collapsed by 1.5m. At this time, the stratification height was 3.0m, and the height of the stope was 5.0m. After the ore and the powder ore were all cleaned, the remaining surrounding rock was collapsed. Filling part of the gob is 2.5m in height. After connecting the chute and the drain well, the full tailing sand is used for filling to fill the gap of the dry filling part, and then the thickness of the cement ending sand with the ratio of sand to sand is 1:10. 0.5m cemented surface as a platform for mining. The filling height is 3m, the empty top height is 2.0m, and the working space width is reserved for 1.5m. Rock drilling adopts the shape of "Zigzag". The spacing between holes in the ore is 0.3m, the spacing between rows is 0.8m, the spacing between the surrounding holes is 0.5m, the spacing between rows is 0.7m, the shallow hole falls, and the interval charge is loosely blasted. The caving ore must be loosely blasted by the interval charge. When the surrounding rock is collapsed, the blasthole near the ore body must be air-spaced, the charge is small, and the detonation sequence is the last, reducing the damage of the blasting to the ore body.
1.2 points of cementation filling advantages
(1) The height of the mining layer is 3m and the small stratification height is 1.5m. The ore body and surrounding rock are alternately collapsed, which further reduces the depletion rate and loss rate, improves the recovery efficiency and the ore grade, and increases the economic benefits.
(2) The optimization of rock drilling and blasting construction mode, interval charge, reduction of charge and loose blasting not only effectively control the generation and loss of fine ore, but also reduce the charge and bring direct economic benefits.
(3) Through calculation, the thickness of the surrounding rock is strictly controlled, and the goaf is filled according to the design. At the same time, the full tail sand is used to fill the gap, and then the high-strength cemented surface is constructed. The comprehensive utilization of dry filling and wet filling not only achieves less filling, but also uses low filling ratio instead of high filling, which can reduce the cost and achieve high strength working platform.
(4) The high-strength cemented surface provides a safe and stable working platform for the upper mining, and also provides a solid "ground" for the cleaning of the fine ore at the end of the stratified mining, greatly reducing the loss of ore loss.
1.3 promotion and application
Separate mining and filling mining method has been popularized since the successful experiment of W12050044 in the middle section of Wangjiashan Mine of Jiaojia Gold Mine. The mining method using this method for recovery mining and its benefits are as follows.
(1) The mining of W12230020 is the 23# vein ore body, which belongs to the gold-bearing quartz sulfide vein type. The quartz sulfide is filled with fine veins in the fracture structure and the fracture of the potassic granite. The ore body is fine. Vein filling, the thickness of the ore body is only 0.2m. The original method is to use the upward horizontal layered filling mining method, and it is suspended for 2 years because it is difficult to continue mining. After on-the-spot investigation, the geological profile such as the shape, grade and dip angle of the ore body was analyzed, and it was decided to change the mining process. The mining method was adopted for the mining method. The practice proved that the grade of the ore was increased from the initial 1.65g/t to 7. .55g/t, an increase of 458%, the remaining rich ore body 3054t was fully developed, with an industrial value of 1.38 million yuan.
(2) The W12052036 mining site is the V-2# ore body, which belongs to the gold-bearing quartz sulfide vein type ore body. The sulfides such as pyrite are vein-filled in the fault fissure, and the vein is thin. The surrounding rocks are mainly potassic granites, and the ore is stable. The overall trend is about 13°, the inclination is about 283°, the inclination angle is 64°, the length of the submitted ore is 60.82m, the block height is 19.56m, the average level of the ore body is 0.5m, the ore volume is 1606t, and the average geological grade is 24.71g/t. The amount of metal is 23.62kg. Through the analysis and research of geological data, the ore body is recovered by sub-collection cement filling mining method, and the industrial value is as high as 1.42 million yuan. The main technical and economic indicators are: work class efficiency of 8.5t/class, production capacity of 25.5t/d, loss rate of 4.2%, depletion rate of 3.0%, and mining grade of 23.97g/t.
2 social and economic benefits
(1) Practice has shown that the sub-collection cement filling mining method is an effective method for mining thin-rich veins, which can greatly reduce the depletion loss rate of ore, and the goaf can be filled in time to prevent surface changes.
(2) The collapsed surrounding rock fills the goaf, fills the void with full tailings, and the construction of high-strength cemented surface provides a solid working platform. The combination of dry filling and wet filling more effectively controls the ground pressure and saves filling. The material reduces the cost and avoids the disadvantages of dry filling of the ore into the ore, further reducing the depletion rate and loss rate of the ore.
(3) With the continuous improvement of the mining progress, the thick ore body is reduced, the mining and residual work of the thin or very thin rich ore body is strengthened step by step, and the application scope of the mining method will be further expanded, which will bring significant Economic benefits.
(4) By optimizing the mining process, the industrial value of 2.8 million yuan can be achieved by the end.
3 conclusions
Separate mining and filling mining method can effectively improve ore recovery efficiency, use full tailings filling on the basis of caving stone, and use high proportion of rubber end sand to form a layer of cemented surface with sufficient strength. The depletion loss rate is reduced, and the ore recovery efficiency and the work safety of the operators are greatly improved. The industrial value of the mine has been realized to 2.8 million yuan, which can provide reference for efficient production of similar mines.
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Source: Mining Technology: 2016, 16(4);
Copyright:
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