In mine production, the depletion rate and loss rate of ore are the two most important indicators to measure the level of mining technology and management. The incorporation of a large amount of waste rock leads to a high depletion rate, which leads to a corresponding decrease in the grade of the ore and increases the mining cost. The loss of the rich ore will also reduce the grade of the ore, which will become a waste rock; the loss of depletion is high, resulting in The direct cost of mining has increased, and the grade of mining has decreased, which has led to a chain increase in production and operation costs in other mines [1-3]. Therefore, it is of great significance to control the depletion rate and loss rate to the smallest possible extent, to improve the economic benefits of mining enterprises, make full use of mineral resources, and extend the service life of mines. Wo vanadium-titanium magnetic iron mines in the years of production practice, we have taken various positive measures to effectively reduce ore dilution losses, with remarkable results. This study analyzes the influencing factors of the depletion rate and loss rate of the mining area, and discusses the reduction measures of the two.
1 Overview of the mining area
The morphology, occurrence and thickness of the Taihe vanadium-titanium magnetite ore body are greatly changed, and the phenomenon of branching and refraction and remnant reproduction is more common. The mining area can be divided into 3 ore belts and 9 ore bodies. The thickness of the ore layer is 100-197m. It is layered, lenticular and medium-coarse gabbro and medium-grain gabbro. The ore body is generally NE. , tends SE, the inclination angle is 40°～60°, thinning from west to east, the thickness of the high and medium grade ore layer is less than 5~10m, and it does not appear continuously. The stone has gabbro and syenite, and the thickness of the stone is 1~6m long. 10 ~ 200m. The natural type of ore is vanadium-titanium magnetite ore. The top and bottom of the ore deposit, the surrounding rock and the stone are mainly gabbro and gabbro veins. The rock is relatively intact, dense and hard, and the joint fissures are not developed.
The boundary between the ore body and the surrounding rock is not obvious, and it is mostly in a gradual relationship. The ore body is often interspersed and cut by the later veins, and the regularity is poor.

At present, the Taihe vanadium-titanium magnetite mining area is open-pit mining, road development, and automobile-tape joint transportation. Mining and stripping adopts down-the-hole drilling rig and cone drilling machine for rock drilling and perforation; medium-deep hole blasting adopts mixed emulsion explosive, which is charged with two explosives mixed vehicles, and one shallow hole blasting adopts 2# rock explosive, detonating tube, non- The electric detonator is detonated; the ore loading is carried out by a hydraulic excavator of 2.1 to 10.0 m3 or an electric shovel, and a bulldozer is equipped for use as a step cleaning, site leveling, ore pile collection and equipment migration, etc. Automobile transportation, according to the production situation of the mine, the combination of tape transportation and automobile transportation; the step height is 12m, the step slope angle is 65°, and the minimum working platform width is 40m.
Most of the mining work line is perpendicular to the ore body or the oblique ore body direction, and its propulsion direction is to advance from the upper plate of the ore body. Due to the complicated geological conditions, large-scale equipment, and standardization of steps, ore mining losses and depletion are very serious (depletion rate is 9.12%, loss rate is 10.27%).
2 factors affecting the rate of depletion and loss rate
(1) The ore body is complex and the geological data is inaccurate. The Taihe iron ore is a magma-differentiated deposit. The ore body is complex in shape, and the shape and thickness of the ore body vary greatly. The multi-stage sub-series are interspersed to destroy the ore body, and the number of ore bodies is large. The in-surface and off-surface minerals are interspersed with each other. Geological data is of poor accuracy. In the process of mining, lenticular, irregular small ore bodies, corner ores are not
The method produces losses, and the veins and stones with a thickness of less than 2 m cannot be removed to cause depletion. The spatial position of the ore body defined by the geological data has a certain difference with the actual spatial position of the ore body. The boundary of the ore is unclear. During the mining process, it is impossible to strictly achieve the detonation and mining according to the boundary of the ore, resulting in ore loss and depletion.
(2) The design of the blasting parameters is unreasonable, the blasting effect is poor, and the direction of mining and excavation is unreasonable. The choice of blasting parameters and stripping method depends on the occurrence of ore body and the scale of production. Due to the irregularity of the ore body, the design of blasting parameters can not fully realize the detonation of ore, the mixing of ore and rock is serious, the mining is difficult, and the loss of depletion is caused. Inevitable. Large mining equipment
Modeling, 12m step standardization operation, single mining and stripping method, unreasonable direction of excavation, and increased depletion loss of ore.
(3) On-site production organization and technical management are not in place. On-site production management is not in place, and it is inevitable that people of all types of work will cause losses and depletion. The technical level of the operators is not high, and the sense of responsibility is not strong. When the operating conditions are poor, the construction work is not strictly carried out according to the design, resulting in the flatness of the steps not meeting the requirements. The ore rock explosion line and the actual access are larger, and the ore is increased. Depletion losses.
3 Measures to reduce the depletion rate and loss rate of ore
3.1 Technical measures
(1) Strengthen basic geological work, accurately delineate ore boundaries, obtain reliable geological data, and reduce the loss of ore and rock in mining. Geological data is the basis for mining blasting design, and its reliability directly affects the loss of ore depletion. Insufficient exploration during the exploration of the Taihe vanadium-titanium magnetite mine, the boundary of the rock, thickness, grade and actuality
Great entry and exit. In order to obtain accurate geological data, according to the geological conditions and output characteristics of the ore body, the production exploration selection uses the platform trough as the main exploration means, and the net degree is 50m × (50 ~ 25) m for encryption exploration, and at the same time In the complex and difficult to control geological conditions, with the advancement of the mining face, timely carry out the geological cataloging and sampling and testing of the mining project, accurately grasp the ore body shape, thickness and grade change law, continuously correct the geological boundary, and improve and perfect Mine geological data lays the foundation for reducing the loss of ore depletion.
(2) Optimize the control of blasting parameters, improve the blasting effect, select a reasonable direction of excavation, and reduce the degree of mineral mixing. In production, pre-blast mining and geological technicians should study the geological features of the block to be inspected in detail and carry out detailed blasting design. In the vicinity of the inflection point where the ore body changes, the steering hole is designed and arranged to ensure that the blasting direction is always perpendicular to the blasthole surface. In order to reduce ore loss, lateral holes are designed in the local convex part of the ore body; at the junction of the rock and rock, unless the free surface is created for the rear blasthole, the position of the blasthole must not exceed the boundary of the ore body, nor should it reach the ore body. Boundaries to reduce the degree of mixing of the ore. In order to ensure the blasting effect, during the construction, the geological surveyor will design the spotholes according to the blasthole design, and measure the elevation of each blasthole point to ensure the blasting parameters are accurate. At the same time, pay attention to observe the rock powder generated by the drilling, if the rock powder reveals If there is a big difference between the mine seeing situation and the design, it should be reported to the blasting designer in time to modify the blasthole design in time. For the completed blastholes, special quality inspectors should be arranged in a timely manner to check one by one. The blastholes with unqualified acceptance should be replenished in time, the bottom of the holes should be blocked, and the bottom holes should be filled with ultra-deep holes. Ensure that the blasting design parameters are accurate and reasonable, improve the blasting effect, and ensure that the mineral rock mixing level is at the lowest level. After the blasting, according to the distribution of the explosive ore in the mining operation, choose a reasonable direction of excavation, and insist on boring from the upper plate of the ore body to minimize the mixing of rocks during the shovel loading and reduce the depletion of the ore.
(3) Integrate equipment resources, reduce the thickness of stone removal, and control the loss of depletion. With the expansion of mine production scale, the mining intensity is getting larger and larger, and the equipment is becoming larger and larger, the stone cannot be completely eliminated.
To this end, Taihe vanadium-titanium magnetite design stone removal thickness of 2m, mining using 4m3 electric shovel to load ore, in recent years, with the expansion of production scale, but also purchased 10m3 electric shovel, in production, only It can effectively remove the stone with a thickness greater than 2.5m, which increases the loss of ore depletion.
In this regard, the new 2.1m3 excavator was purchased, and the equipment resources were integrated in the production organization. As far as possible, the 4,10m3 electric shovel was arranged in the thick part of the ore body to shovel the ore, and the part with more stones was placed. The 1m3 excavator has better effect on removing the stone layer exposed on the face, which can ensure that the 1.5m thick stone is removed without losing the ore. For the case where the upper part of the step is the lower part of the rock or the upper part is the rock of the lower part of the ore, the excavator can be flexibly used to remove the rock by the layered stripping method, thereby reducing the depletion and loss of the ore.
(4) Construction of off-balance sheet mines, severely depleted ore tailing treatment production lines, and recovery of some lost ore. In the production, some ore cannot meet the production index requirements due to the incorporation of rocks, and it will become a waste rock. If it is abandoned, it will cause great loss of mineral resources. To ensure the intensive use of mineral resources, the company has built an annual treatment of 2 million t tables. The ore mine and the depleted ore pre-tailing treatment production line, the part of the ore is pre-tailed to recover the part of the ore, thereby effectively reducing the ore loss rate.
3.2 Management measures
(1) Strengthen the business skills training of operators and improve the operation level. The work of depletion loss control involves many types of work and a wide range of personnel. Dispatchers, downhole drill drivers, shovel drivers, bulldozer drivers, miners, drivers, etc. are closely related to mining. Such personnel lack relevant geological knowledge reserves. And this type of staff is also constantly adjusted, most of the people are not
With the ability to identify ore rocks, through the centralized training, labor skills competition, etc., as much as possible to improve their rock identification skills.
(2) Strengthen the on-site management of mining operations, strengthen the close cooperation between different types of work and processes, and avoid the loss of artificial depletion. In the process of on-site operation, due to the lack of management, the cooperation of various types of work is not good, and the responsibility of employees is not strong. In the production, the mixed rock and mixed phenomenon often occur, and the ore collected is left in the stope and transportation. Big ore
Depletion losses. To this end, before the shovel is installed, the ore grades and waste stones in different areas are marked with brightly colored objects, indicating the reasonable mining and propulsion direction for the shovel workers, avoiding the mixed rock and rock; And the driver is equipped with a walkie-talkie for flexible command, avoiding mixing and chaos; avoiding ore sprinkling during shipment
Falling, causing loss of ore; strictly controlling the reclaiming and use of roads, roads and roadblocks, the ore area is paved with ore, and the rock area is built with rocks to prevent artificially depleted ore loss.
(3) Establish and improve the performance appraisal system for ore depletion loss management, and strictly follow the rules to ensure the quality of ore produced. After years of production practice, the company has established a set of perfect “three-rate” indicator assessment system, strengthening the management of ore loss and assessment of balanced ore distribution, mainly assessing the mining performance of low-grade ore in different mining areas, in the process of mining production. The perforation, blasting, shovel loading and transportation are supervised, and the problems are strictly assessed. The depleted loss of ore and balanced mining are linked with the performance of employees and evaluation, so as to provide institutional guarantee for reducing the loss of ore.
(4) Technical personnel protection. The company has set up a professional team of geological, measurement and mining technicians with practical work experience, responsible for the loss control of ore depletion, and implemented it to specific responsible persons, established and improved technical files and depleted loss statistics, and improved professional statistics. Reporting, strengthening various basic work, promoting ore quality management and depletion loss control work gradually entered the standardization and standardization track.
4 Conclusion
In recent years, the Taihe vanadium-titanium magnetite mining area has adopted practical technical measures and management measures in controlling the loss of ore depletion. By encrypting the exploration network, controlling the blasting effect, reducing the thickness of the stone removal, and flexibly applying the correct mining and stripping method. The measures have achieved good results, and the depletion rate and loss rate of ore mining are controlled within 3%, which has certain reference value for similar mines. However, there is still a certain room for the loss of ore mining losses in the mine. Further strengthening the technology research and development and scientific management, under the economic and reasonable conditions, it is expected to control the mine's ore depletion losses to a smaller extent.
references
[1] Mu Xinhe. Ways to reduce the loss of lean and open aluminum ore [J]. Nonferrous Mining and Metallurgy, 2002 (5): 5-8.
[2] He Mingsheng. Discussion on ore loss and depletion control in Liangshan Mining Open-pit Mine [J]. Mining Technology, 2012 (2): 19-21.
[3] Wang Yubin. Comprehensive measures to reduce mine losses and depletion [J]. Mining Engineering, 2007 (3): 31-32.
Author: Ho rivers; heavy steel Xichang Mines Limited;
Article source: "Modern Mining"; 2016.8;
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