White silver-copper ore processing plant was built in 1958 to open, put into 1960, with the development of production, in addition to the original design copper concentrate and concentrate output, but also output of the zinc concentrate. According to the original design, the copper concentrate grade is 18.8%, and the recovery rate is 88.23%. After 1979, the concentrate grade exceeded 20% and stabilized at around 22%; the recovery rate also increased to over 92%, stabilizing at 94% to 95%.
2 ore properties
Silver copper deposit is a copper pyrite-type multi-metal mine. The ore has complex and diverse ore types, including both lump ore and disseminated ore; both primary and secondary mines; both sulfide ore and oxidized ore. The grade changes greatly and the options are complex. With the development of mining in the lower part, the original ore is gradually exposed, and it has now transitioned to the primary sulfide ore.
The ore is from open pit mines. The three types of copper-bearing pyrite ore, disseminated copper-sulfur ore and massive copper-zinc-pyrite are selected in three systems.
The minerals of the lump ore and the mined ore are basically the same, and only the content of the sulfide and the copper grade are different. The sulphide content of lump ore is 92%-95%, of which pyrite accounts for more than 90%, and the sulphide content of dip mine is 24%-27%. The copper grade of the lump ore is also higher than that of the dip mine.
All types of ore gangue minerals substantially the same, mainly quartz, sericite, chlorite, gypsum and the like.
The structure of the ore is also different depending on the type of ore. The original lump ore is a massive structure with uneven grain size of copper minerals. The secondary lump ore has a loose block, strip shape, and porous structure.
3 Production technology progress
The original design of Baiyin Company's concentrator used 576 sets of 6A flotation machines. During the use process, many problems were found. After years of improvement, the work results were not satisfactory. In June 1989, the upgrade of sulfur-selective 6A flotation machine was completed. Transformation work. As of April 1992, renovation work 6A flotation machine is fully completed, including Sulfur systems were installed JJF-16 flotation machine 60, JJF-8 flotation machine 12, JJF-4 flotation machine 26 sets, Ended the history of using the 6A flotation machine and achieved significant economic benefits. Production practice shows that the JJF flotation machine can improve the beneficiation technical indicators whether it is copper or sulfur.
The ore dressing plant used high-calcium and high-medicine, one-time rough selection, three times of selection, and tailings not sulfur selection process. The process is stable, and the separation of copper and sulfur is relatively thorough, but the dosage of the agent is high, the amount of lime is large, and the calcium in the equipment and pipeline is severe, which affects the efficiency and indicators of the equipment. Moreover, the valuable pyrite is not recycled, which is detrimental to the benefits and the environment. Therefore, the process of low-calcium low-drug, tailings plus acid or sulfuric acid-selective sulfur was explored, and gradually stabilized. The free calcium oxide in the copper selection operation was less than 200g/m3, and the technical indicators increased year by year. Significantly lower. In 1999, when the ore contained 1.005% copper, it achieved advanced indicators of 23.75% concentrate grade and 95.24% recovery rate.
　　 4 Production process and process
A crushing and screening
The crushing and screening adopts a three-stage open circuit, and the second and third sections have a pre-screening crushing process.
The original ore is transported to two coarse ore deposits with a volume of 400 m3 and then processed into two parallel crushing systems. The final crushed ore size of the design is 95%, which is 95%, and actually reaches -25mm, which accounts for 80%.
B grinding process
The ore coming out of the powder mine is passed through a fan-shaped gate to enter the grinding flotation system. The material composition and structural characteristics of various ores vary, requiring different flotation conditions. The following is introduced separately for the bulk copper-sulfur system, the disseminated copper-sulfur system and the bulk copper-zinc system.
a block copper sulfur system
The original design process (see Figure 25-5-25) is stage grinding and stage flotation. The coarsely-selected concentrate is selected three times to obtain copper concentrate, and the flotation tailings is sulfur concentrate. After the plant was put into production, it was basically produced according to the process, and it was not until 1969 that it was changed to a two-stage grinding process (see Figure 25-5-26).
Figure 25-5-25 Original design flow of the silver plant
Bulk copper desulfurization system, for a period of grinding with a lattice-type ball mill φ2700mm x3600mm diameter of 2400mm closed double spiral classifier, classifier overflow and overflow ball mill φ2700mm x3600mm second stage of discharge pumped into the combined diameter of 500mm or 7500mm The cyclone, the cyclone grit and then into the second section of the grinding, overflow into the rough selection. One section of grinding fineness -0.074mm accounted for 50%, the concentration was 45% to 50%, the second section of grinding fineness -0.074mm accounted for 80%, the concentration was 45%; flotation was performed by one rough selection, one sweep, three selections Process. Using lime as a pyrite inhibitor, the free calcium oxide content in the pulp is 800-1000g/m3, the copper is added with butyl xanthate and pine oil, the tailings are sulfur concentrate, and the flotation is all used by Wimco 16m3. Flotation machine.
Figure 25-5-26 Flotation process of bulk ore and dip mine in Baiyin Constituency
Original claim finely ground ore, the recovery rate is almost proportional to the fineness of grinding, but disseminated ore different particle sizes, a suitable grinding fineness is also different. It is not difficult to see from Table 25-5-39 that under the same grinding fineness, the recovery rate of the medium-grained ingot is the highest, and the fine-grained inlay is the worst. Secondly, the copper recovery rate of all types of lump ore increases with the fineness of grinding. Generally speaking, the medium-grained inlaid lump ore requires grinding fineness of -0.074mm to account for more than 70%, and the coarse-grained inlaid lump ore requires -0.074mm to account for 75% to 80%, while fine-grained inlaid lump ore is required. It is -0.074mm and accounts for over 95%. The original lump ore is relatively easy to select, the production index is high, and the range of adaptation to calcium oxide content is also large, generally controlled in the range of more than 600g/m3, the amount of yellow drug must be compatible with the content of calcium oxide, and master the "high calcium and high drug." The principle of low calcium and low drug. The flotation process of secondary lump ore is the same as that of the original lump ore, except that the secondary lump ore should not be ground too fine, otherwise it will cause secondary copper to be pulverized, generally grinding to -0.074mm accounted for 85%. The calcium oxide content should not be too high, and its adaptation range is 200 to 400 g/m3 or more. The secondary block ore has a high copper grade and requires a large amount of chemicals. Due to the complex nature of secondary ore, its selection index is lower than that of primary ore.
Table 25-5-39 Relationship between the height of copper minerals and the mineral processing index of different grain size blocks
b Dip-dyed copper-sulfur system
The dip-dye ore design uses a mixed-first flotation process to comprehensively recover copper and sulfur products. Due to the complicated process, including four-stage grinding and grading, one concentrating operation, using five kinds of chemicals, the consumption quota is high, so it cannot be realized in production. After the production, the copper is recovered according to the production process of the lump ore, and sulfur is not recovered.
c bulk copper and zinc system
The grinding process of the bulk copper-zinc-pyrite system is also the same as that of the massive copper ore. The second-stage grinding fineness is -0.174 mm, accounting for 90%. In the flotation, a process such as copper and zinc can be used to separate the zinc from the flotation tailings, and the zinc tailings are selected as sulfur concentrates (see Figure 25-5-27).
Figure 25-5-27 Block copper-zinc ore grinding process
C product dehydration
The copper concentrate pump is sent to two sets of 30m diameter transmission type thickeners, and then filtered by a disc filter. The dryer is dried by a simple dryer. The dry product with moisture of 5% to 7% is sent to the smelter with a belt conveyor. Fine mining warehouse.
The dehydration process of zinc concentrate is the same as that of copper concentrate, and the dried products are stacked and sold separately.
Desulfurization of sulfur concentrates is treated in the following three ways:
(1) a concentrated after drying a filter, into the smelter acid system.
(2) After being filtered by a cyclone filter, it is stacked in the open air and naturally dried, and then loaded with a grab crane.
(3) Directly pumping the concentrate sedimentation tank, naturally drying after sedimentation, and the product is loaded with a forklift truck for export.
These three methods are flexible according to production needs.
D tailings treatment
The first tailing dam has a volume of 17 million cubic meters. It expired in April 1980 and stored 29 million tons of tailings. The second tailing dam has a volume of 20 million cubic meters. When the tailings are sent to the first tailings dam, In the early stage, a 254mm Bagel pump was used for pumping, and a 254mm Bagel pump was used for pumping. In the second stage, it was sent to the second tailing dam for three-stage pumping. The dam method adopts the surrounding section to deposit the natural accumulation, and uses the bulldozer to cooperate with the dam. The first tailing dam is led by the open channel and sent back to the plant for pumping. The second tailing dam uses the overflow well to divert water. The return water utilization rate is 60% to 70%.
E process flow chart
The current production process of the Baiyin Copper Mine Concentrator is shown in Figure 25-5-28.
Figure 25-5-28 Process of Baiyin Copper Mine Concentrator
F production indicators
Due to the complex nature of the ore, the mineral processing index of the plant is also different. The flotation conditions of various ores are shown in Table 25-5-40. In 1984, the annual average production indicators are shown in Table 25-5-41. In recent years, due to large fluctuations in raw ore grades, production is not stable enough. In general, the copper concentrate grade can reach about 20%, the recovery rate is over 90%, the zinc concentrate grade is about 40%, and the zinc concentrate recovery rate is about 50%.
Table 25-5-40 Flotation conditions of copper-sulfur ore in Baiyin Concentrator
1 Dip mining ore flotation conditions, referring to the conditions for single copper recovery;
â‘¡ Secondary vanadium ore by means of lead-free.
Table 25-5-41 Production Indicators of Silver Concentrator (%)
Bench Milling And Drilling Machine
Drilling Machine refers to the machine tool that mainly uses the drill bit to process holes on the workpiece. Usually, the rotation of the bit is the main motion, while the axial movement of the bit is the feed motion. Drilling machine structure is simple, processing accuracy is relatively low, can drill through holes, blind holes, replacement of special tools, can be expanded, countersink, reaming or tapping and other processing. In the process of machining, the workpiece does not move, so that the tool moves, the tool center to the center of the hole, and the tool rotation (main motion). Drilling machine is characterized by the workpiece fixed, the tool does rotary movement, and along the main axis of the feed, the operation can be manual, can also be motor.
The role of drilling machine:
Drilling machine is a universal machine tool with a wide range of applications. It can be used for drilling, reaming, reaming, countersink flat and tapping.
When drilling machine is equipped with process equipment, boring can also be carried out, drilling, reaming and reaming can also be carried out on the drilling machine with universal workbench.
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