How to optimize the design of v-ti magnetite processing plant?

In recent years, with the development of technology in the mineral processing field, it is inevitable to encounter some new situations and problems in the design practice of the mineral processing plant, especially in the process of designing the mineral processing plant of vanadium-titanium magnetite. Generally, the particle size of the first-stage grinding product is designed to be 0~3mm for magnetic separation of coarse-grained tailings. In the design process of vanadium-titanium magnetite concentrator, continuous coarse-grained tailings must be given priority in order to reduce energy consumption and product production costs.

This text discusses the design of 0~300mm magnetic separation tailings process parameters and the combination with industrial test parameters, semi-autogenous grinding process of vanadium-titanium magnetite and traditional crushing-grinding The comparison of the process, the design of the equipment selection and configuration of the crushing operation and ore washing operation in the crushing system, the selection and configuration of the equipment of the grinding and classifying system?and the design of the combination with the beneficiation test, the comparative design of different feeding methods of the ball mill, and the magnetic field in the design The thinking and practice of the relationship between the determination of the size of the dressing field and the strength of the laboratory test field, etc., summarizes how to implement large-scale tailings in the mineral processing field, higher grinding efficiency, coarse-grained tailings, and prevention of excessive Grinding, high recovery rate, multi-element semi-raw ore beneficiation process, the previous separation process provides the best conditions for the next separation process, etc., so as to reduce the production energy consumption and production cost of the concentrator.

1 0~300mm magnetic separation throwing process parameter design and combination with industrial test parameters

The goal of efficient bulk magnetic separation tailings throwing process parameter design must be to achieve the maximum tailings throwing rate under the condition that the grade of tailings is lower than the qualified tailings throwing.

1.1 Design qualified tailings grade

First of all, when determining the grade of qualified tailings, the most important principle is that the tailings of this grade must be processed under the existing technical and economic conditions. Secondly, when determining the qualified tailings grade and selecting the best conditions for design according to the industrial condition test parameters, the qualified grade of the newly added tailings must be considered. That is, in the industrial test under the two conditions, the raw ore grade is basically the same, but the tailings production rate and tailings grade are different, and the tailings production rate and tailings grade are used to calculate the relative new tailings grade of the industrial test under the two conditions, If the cost of concentrate obtained by beneficiation and processing of new tailings of this grade is lower than the selling price under the existing technical and economic conditions, the various parameters under the corresponding conditions cannot be the best object for design selection.

1.2 Design reasonable tailing magnetic separation field strength and material layer thickness to achieve maximum tailing rate

The field strength of tailing magnetic separation is designed to increase 1000 Oe~1500Oe on the basis of the field strength and size parameters of industrial tests, so as to ensure that large magnetic ores do not enter the tailings to the greatest extent. Material layer thickness design. The thickness of the material layer is a key measure to improve the tailing effect. First of all, consider the effective width after deducting the material-free width on both sides of the tail-throwing belt in actual production, and in order to prevent the superposition of materials as much as possible, at least ensure that the thickness of the superimposed layer under any large material is less than 20mm, and reduce the large material to the center of the belt. For the superposition caused by concentration, the material gap of the throwing tail belt should be made as wide as possible. The buffer roller of the receiving belt under the leak is a flat idler, and the other rollers of the receiving belt under the leak can be grooved rollers, but both sides The angle between the inclined roller and the horizontal line should be less than or equal to 10°. Generally, when the average material thickness on the effective bandwidth of the 0~300mm large block magnetic separation tailing belt is designed according to 30~38mm, it can ensure that there is basically no superposition of materials, and can maximize the efficiency of large block magnetic separation throwing tails.

2 Comparison of vanadium-titanium magnetite semi-autogenous grinding process and traditional crushing-grinding process

The advantage of the traditional crushing-grinding process is its low cost. The same level of large-scale equipment, the traditional crushing-grinding process. The vanadium-titanium magnetite is crushed from 0~300mm, and the ore is ground to 0~3mm. Compared with the semi-autogenous grinding process, the lump ore of 0~300mm is directly ground to 0~3mm, the power consumption per unit product is about 30% lower, and the ball consumption per unit product is about 70% lower. If it is considered that various coarse-grain tailing operations can be embedded in the traditional crushing-grinding process of vanadium-titanium magnetite, the energy consumption and steel consumption of the traditional crushing-grinding process are lower. Although the semi-autogenous grinding process is short and requires less personnel, the traditional crushing-grinding process is generally more cost-effective under the current single labor cost of 150,000 yuan/year. The advantage of the semi-autogenous grinding process is that the process is short, the floor area is small, the demand for employees is small, and the dust pollution is small. The small dust pollution is mainly due to the fact that the semi-autogenous grinding process has relatively few dust-producing points.

The traditional crushing-grinding process needs some innovative design ideas in environmental protection to solve its serious dust pollution problem. The disadvantage of the semi-autogenous grinding process is that the cost is high and the particle size of the product is easily polarized, which is not conducive to the recovery of titanium minerals in the subsequent vanadium-titanium magnetite magnetic separation tailings. Therefore, in general, the semi-autogenous grinding process or the traditional crushing-grinding process should be adopted in the design of the vanadium-titanium magnetite ore concentrator, which needs to be based on the requirements for the floor area of the concentrator, the salary level of personnel, the production cost requirements, environmental protection requirements and environmental protection investment. Design after comprehensively weighing the pros and cons.

3 Selection and configuration of crushing system ore washing operation and intermediate crushing machine operation equipment

Most of the failures in the application of ore washing operations are due to being too optimistic about the operating rate of single machines such as screening machines, magnetic separators, pumps, and pipelines for ore washing, and ignoring the negative impact of the series connection of ore washing equipment on the operating rate. When the ore washing equipment is connected in series, the operation rate must be estimated by multiplying the operation rate of each series equipment by using the idea of probability and mathematical statistics in mathematics. Otherwise, the ore washing operation will become the bottleneck of the crushing process and limit the efficiency of the entire concentrator. In the process design of the main equipment selection process for the medium crushing operation, when the cone crusher is used as the medium and fine crusher, it is necessary to pay attention to the reasonable cooperation of the three parameters of the cone crusher, the ore discharge port, the eccentricity, and the processing capacity, so as to facilitate the crushing process. The efficiency of the follow-up fine crusher is brought into play. Designing a smaller ore discharge port is beneficial to the reduction of the crushing discharge port of the follow-up fine crusher, and is conducive to improving the actual processing capacity of the fine crusher. However, it is generally necessary to select a medium or small grade of eccentricity, and at the same time design a lower processing capacity. Otherwise, the load of the secondary crushing machine will be too large, which is not conducive to the stable operation of the secondary crushing machine equipment.

4 Selection and configuration of grinding and grading system equipment and combination with beneficiation test

In the design of the grinding and grading system, the surplus part of the grinding capacity should be designed in the form of an overall backup of the grinding and grading system as much as possible. In actual operation, except for the standby grinding and grading system, the grinding load of the running mill should be as high as possible, because in practice, the over-grinding problem caused by the large volume of the mill is not conducive to Individual metal recovery in certain polymetallic associated mines. Vanadium-titanium-magnetite is used to recover ilmenite from iron beneficiation tailings. When the volume of the mill is large and the throughput per unit volume of the mill is less than 7t/h, even if the filling rate of steel balls is reduced to a low level, due to the overflow type grading function of the mill, the new-400 mesh content is more, and the difficulty of subsequent ilmenite recovery will be greatly increased.

The ability to configure equipment such as graded cyclones, sieves, and pumps needs to have a certain degree of matching with the volume of the mill during design. case of low capacity. When the capacity of the grading equipment is insufficient, the grinding products will be forced to be distributed in two poles, which is not conducive to energy saving and efficient sorting. When calculating the volume of the ball mill required by the volumetric method, the influence of the particle size composition of the laboratory product and the actual ball mill product or the average particle size on the design selection should be considered. For example, through laboratory jaw crushing, laboratory vertical crushing, and ball mill in actual production to produce the same 0~3mm product, there will be large differences in its -200 mesh content and average particle size, volumetric method selection When calculating the equipment type and quantity of relevant mills, it is necessary to consider the relative influence of the different -200 mesh content and average particle size. If necessary, the designer can propose experiments to supplement the data of the beneficiation test.

5 Comparative design of different feeding methods of ball mill

There are three ways of feeding the ball mill: drum feeding, feeding trolley feeding, and chute feeding. Among them, the basic principle of the feeding trolley feeder is the same as that of the slide tube feeder, except that the diameter of the feeding tube of the general slide tube feeder is smaller than that of the feeder trolley feeder, and its feeding flow rate is faster. Big ones, but the flow rate of the two feeding methods of feeding trolley feeding and slide tube feeding is greater than that of drum feeder. When designing and selecting the feeding mode of the mill, its influence on the grinding efficiency needs to be considered. Drum feeding has the smallest flow rate and the highest grinding efficiency, but the equipment maintenance workload is the largest. Feeding trolley feeding, tube feeding, especially tube feeding has the largest flow rate, which wastes part of the mill volume and reduces the grinding efficiency. The lowest, but the maintenance workload is small.

When choosing a drum feeder in the design, when the throughput per unit volume of the mill needs to be at a high level, it is recommended to use a larger drum feeder than the conventional model to reduce the ore dumping at the feeding head of the ball mill. However, practice has proved that the ore dumping at the feeding head of the ball mill will not negatively affect the grinding efficiency of the mill when the capacity of the classifying cyclone feed pump is slightly surplus.

6 Design of the relationship between the required field strength and laboratory test field strength in magnetic separation production

There is a difference between the required field strength in magnetic separation production and the optimal magnetic separation field strength obtained by laboratory tests. In the process of designing a mineral processing plant, if this problem is ignored, the recovery rate of magnetic separation will be seriously reduced. For example, in a newly-built concentrator, the first magnetic separation 1700Oe, the second magnetic separation 1600Oe, and the fine magnetic separation 1500Oe are designed in strict accordance with the best field strength of the magnetic separator recommended by the laboratory 3%, the loss of nearly 6% of the total tailings iron powder to the tailings pond, the loss is serious, after industrial tests, the magnetic field strength is increased to 3000Oe, and the final tailings magnetic iron content in the tailings pond is reduced to 1 %the following. The main reason for the above phenomenon is that the gap between the bottom box of the magnetic separator of the laboratory test equipment is 10mm~20mm, which is significantly different from the bottom box gap of 45mm~70mm of the actual production magnetic separator on site, and the actual production slurry flow rate is significantly higher than Laboratory magnetic separator, so the design must be calibrated based on the actual field strength of the magnetic separator obtained from laboratory tests.

7 Conclusion

Mineral processing plants are basically one of the enterprises with high energy consumption. Reducing the energy consumption of mineral processing plants is of great significance for carbon peaking and carbon neutrality. It is very important to consider measures to reduce energy consumption and cost in the design stage of the concentrator, especially for the design process of the concentrator such as vanadium-titanium magnetite with low grade raw ore and coarse mineral embedding particle size.