Exploration and discussion on the selection process of kaolinite ore in a gold mine

Due to the special nature of Erdaogou gold ores and restricts the choice of equipment, for lack of the original design We conducted a preliminary exploration and discussion, the aim is to have the mine kaolin mine to find a savings in equipment, infrastructure investment to meet the on-site production The rationalization of the way out.

First, the nature of the ore

(1) Material composition and embedding characteristics of ore

The Erdaogou gold deposit is a medium-temperature hydrothermal fissure filling and dissemination type deposit, and the ore type is medium sulfide polymetallic ore. Metallic minerals include pyrite, yellow copper ore, arsenic tetrahedrite, sphalerite, galena, bornite, copper blue, the main gangue minerals are quartz, feldspar, kaolin clay, hornblende, chlorite , calcite and so on.

(II) Particle size analysis of natural gold

Table 1 Natural gold level measurement results

Under the microscope, the packaged gold accounted for 30%, the intergranular gold accounted for 65%, and the cracked gold accounted for 4.9%, mainly composed of intergranular gold.

(3) Metal minerals

Pyrite: It is self-shaped, semi-self-shaped, and it is granular in shape. It has a crushed structure and is filled with beryllium ore in its intergranular and fissures. The particle size is generally 0.05-0.2 mm, the maximum is 1 mm, and the smallest. 0.01mm, closely related to gold minerals.

Chalcopyrite: It is irregularly shaped and its granular shape is produced. It is mainly composed of 0.1mm or more. The chalcopyrite is floating in the sphalerite and distributed in a line shape. The size of the floating drop is generally 0.005-0.05mm. There is a round granular distribution in the pyrite, and it is closely related to the pyrite.

Arsenic bismuth copper ore: irregularly shaped, interbedded with intergranular and fissures to replace pyrite, chalcopyrite, sphalerite, widely distributed, and the particle size is generally 0.025-0.3mm.

Sphalerite: It is self-shaped and it is granular. The pyrite is often distributed in the crystal, and the particle size is about 0.02-0.8mm.

Galena: mostly produced in cubic form, with coarse particles and less granularity.

Second, ore chemical analysis

(1) Multi-element analysis of mineral samples (see Table 4)

Table 2 Multi-element analysis results of ore samples

Observed by the microscope, the natural gold particle size is different, the distribution is not uniform, mainly medium and fine grain gold.

(2) Phase analysis

Table 3 Analysis results of copper ore phase of ore

Third, due to the high content of kaolin in the ore, the impact of reaching the standard is reached, and the following technological exploration and discussion are proposed:

(1) Using the cyclone group on the original basis, the slurry entering the leaching 1# tank is subjected to secondary grading in advance, that is, the underflow product of the two products of one stage is returned to the 2# ball mill and regrind, and the overflow product ( -200 mesh content of 95%) to the second stage classification. The underflow products (concentration of 40%-60%) of the two products classified in the second stage are directly sent to the slurry tank after chip removal, and the overflow product is sent to the thickener after dedusting. After concentration, the concentration is 20%-33. % of the slurry is fed to the slurry tank. The qualified slurry adjusted to a concentration of 38%-42% is sent to the 1# leaching tank by a sand pump. (See Flowchart 1)

(2) Adding a cyclone group to the tailings filtration workshop to improve the problem of low concentration of filtered pulp, thereby reducing the amount of flocculant used, and solving the low filtration capacity to prevent the thick mixer from running out of confusion. The processing capacity of the carbon slurry is up to 200 tons/day. (The process is shown in Figure 2)

Fourth, the discussion and analysis of the problem

(1) Due to the high kaolin content, we found that the processing capacity was 7-8 kt/hr through the previous production debugging. The 1# thickener overflow was mixed and even uncontrollable, and the 2# thickener was also the same. Once, the return water can not be used, and the technical indicators are not satisfactory.

(2) The equipment and facilities on site are in place, and if they are changed, they will invest a lot of manpower, material resources and a long time.

(3) Comprehensive manpower and capital investment, the above-mentioned process improvement plan is proposed. The two sand pump points in flow chart 1 are selectable points, and only one place is selected.

V. Program Discussion

(1) The purpose of adding the cyclone to the secondary grading and tailings filtration workshop is to increase the concentration of the slurry, improve the sedimentation effect of the thickener, and reduce the input amount of the flocculant, thereby ensuring the smooth and smooth flow and laying the foundation for reaching the standard.

(2) If, as shown in Process 3, it is necessary to increase the sand pump, cyclone and slurry tank, the cost of mineral processing will increase, but such a configuration will have a significant effect: the flocculant dosage can be up to 40 g/t. The thickener discharges smoothly, the mixing time of the flocculant is reduced, and the sedimentation area of ​​the thickener is sufficient because the solid particles in the cyclone overflow are reduced. See flowchart four

(3) Equipment configuration: see Table 1

(IV) Feasibility analysis flow chart four

Table 1

Table 2 According to 240 tons / day

Table 3 is based on 240 tons / day

Table 4 374.4/1.56 by 240 tons / day

(V) Comparison of economic analysis:

1. The amount of flocculant used in the previous test and the unit cost are shown in Table 2; the amount and cost of the improved flocculant are shown in Table 3; the increase due to the new equipment is shown in Table 4.

2. Through Table 2 and Table 3, we can see that the unit cost of using flocculant before the change is 2.52 yuan/ton, and the unit cost of the improved flocculant is 0.96 yuan/ton, so the improved flocculant is used. The unit cost is 1.56 yuan/ton less than the unit cost of using flocculant before the change.

3. New costs: electricity cost is 1.343 yuan / ton; operating expenses are 0.08 yuan / ton; new equipment based on one-year service time unit cost is 0.33 yuan / ton (according to 240 tons / day, 24 hours / day , 28 days / month, December / year); new costs (unit costs) totaled 1.753 yuan / ton.

4. Comparison by 2 to 3: The unit cost before the change is only increased by 0.193 yuan/ton, but with the extension of the service time of the new equipment, the unit cost before the change is basically the same.

6. Comprehensive review

1. The feasibility of the modified process requires further industrial test identification. Specifically determine whether the grading combination at the 1# thickener can operate normally according to the results shown in the fourth process; the relationship between the slurry concentration required by the tailings filter and its utilization coefficient; the underflow of the cyclone, the diameter of the overflow and the concentration of the slurry. relationship.

2, the economic comparison shows: Although the addition of new equipment, increased power and material consumption, but the change will not be much more expensive than before the change.

3. If the industrial test is successful, it will provide reference for other plants of the same type.

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