WUQIA Lin Sike beneficiation plant process two types of copper matte zinc ores in Trask Gold Deposit: copper-zinc ore containing pyrite and copper-zinc ores containing pyrrhotite. The treatment of copper-zinc-pyrite ore with a copper-zinc-pyrite ore cannot recover zinc from a qualified zinc concentrate. As a result, 1.3% to 2.3% of the zinc contained in the ore is lost to the abandoned tail. In the mine.
Due to the high mining cost of the Uzelinsk mine and the large amount of ore containing pyrrhotite in the mine, the recovery of zinc from the ore containing pyrrhotite is an urgent problem to be solved by the Uchalinksk mining company.
The copper-zinc ore containing pyrrhotite is characterized by complex material composition, and the sulfide minerals are intergranularly interspersed with each other. In order to dissociate the monomer, the ore needs to be ground to 85%-0.074 mm or more. The content of pyrrhotite is 50% to 60%, and only a small amount of iron sulfide exists in the form of pyrite.
In the world of copper-zinc ore dressing practice, there are no examples of processing high-content pyrrhotite ore. A typical process for treating copper-zinc ore is to activate sphalerite with copper sulfate, but this process is not suitable for ore containing pyrrhotite because the floatability of sphalerite is similar to that of pyrrhotite.
In pyrite-pyrite-a pyrite-like homologue series, pyrrhotite has the worst floatability. Unlike pyrite, pyrrhotite is a softer mineral with a hardness of 3.5 to 4.5, which is similar to the hardness of chalcopyrite and sphalerite.
In the development of ore process with pyrrhotite, we started from two directions: creating conditions for suppressing pyrrhotite and flotation of sphalerite at high alkalinity; looking for pyrrhotite before zinc flotation Separated into separate products.
In the process research of inhibiting pyrrhotite, the following three experiments were carried out: the slurry aeration time test to oxidize the easily oxidized pyrrhotite; the slurry aeration test under the high alkalinity created by the lime; the pre-inflation of the slurry Then test with lime treatment.
The test results show that the optimum aeration time is 5 min. Although the quality of the zinc concentrate is improved to some extent, the loss of zinc in the tailings is still high. It should be noted that the slurry should be inflated prior to the addition of lime, as the aeration of the slurry added to the lime will cause its alkalinity to drop drastically, at which point a negative effect will occur: the pyrrhotite begins to float well and thus sharply Deteriorating the quality of zinc concentrate. For example, after the slurry is aerated for 15 minutes, the concentration of free calcium oxide in the slurry is reduced from 1000 g/m 3 to 280 g/m 3 , at which time the yield of the zinc coarse concentrate is increased by 4 to 5 times.
When zinc is floated after activation of sphalerite with copper sulfate, the pyrrhotite is also activated to enter the zinc concentrate, and the fine selection of the zinc concentrate cannot improve its quality.
From this it can be concluded that the process of pre-suppressing pyrrhotite is not recommended for this type of ore.
During the course of the study, it was found that the presence of pyrrhotite returned in the closed circuit with the main components deteriorated the process, so the process should be as open as possible.
From this inference, an ore beneficiation process with pyrrhotite was developed.
A positive priority flotation process is recommended in the process of extracting pyrrhotite concentrate prior to zinc flotation. At the beginning of the process, copper flotation is carried out in a medium of sodium sulfide and zinc sulphate to separate high grade copper concentrate. The copper is then coarsely selected in an alkaline slurry (200 to 250 g/m 3 CaO). A part of the pyrrhotite enters the copper concentrate in the rough selection of copper, but this condition does not satisfactorily meet the flotation conditions of zinc.
Like pyrite, pyrrhotite is well floated at low alkalinity only in the presence of an activator. Sodium carbonate is used as an activator, which is a less expensive flotation agent with less toxicity. The optimum amount of sodium carbonate in the flotation of pyrrhotite is 2kg/t. At this time, the free Ca0 content in the slurry is reduced to 14~42g/m 3 .
It should be noted that the amount of sodium carbonate is directly related to the alkalinity of the copper flotation slurry. The higher the alkalinity of the copper flotation slurry created with lime, the greater the amount of sodium carbonate used. Therefore, in order to effectively float the pyrrhotite at the recommended amount of sodium carbonate, the alkalinity of the copper flotation must be strictly controlled, and the free CaO content does not exceed 200 g/m 3 in order to minimize the loss of zinc. This is important because the zinc transferred to the copper loop cannot enter the zinc flotation circuit because of the large amount of pyrrhotite present and the zinc is discharged into the tailings dam along with the copper rough tailings.
The comparative test results of separating and not separating pyrrhotite products before zinc flotation are shown in Table 1.
Table 1 Comparison test results of separation and non-separation of pyrrhotite products before zinc flotation
product name | Test conditions | Yield/% | grade/% | grade/% | ||
Cu | Zn | Cu | Zn | |||
High quality copper concentrate | Separating magnetic yellow iron products | 6.7 | 8.55 | 1.02 | 36.5 | 3.8 |
Copper concentrate | 16.03 | 4.50 | 1.71 | 46.O | 15.1 | |
Total copper concentrate | 22.79 | 5.69 | 1.51 | 82.5 | 18.9 | |
Pyrrhotite products | 19.16 | 0.56 | 0.92 | 6.8 | 9.8 | |
Zinc coarse concentrate | 6.66 | 0.41 | 17.56 | 1.7 | 64.6 | |
Zinc flotation tailings | 51.45 | O.27 | O.24 | 9.0 | 4.7 | |
Raw ore | 100.0 | 1.57 | 1.81 | 100.0 | 100.0 | |
High quality copper concentrate | Does not separate pyrrhotite products | 8.60 | 7.76 | 1.16 | 42.3 | 5.6 |
Copper concentrate | 15.83 | 4.03 | 1.74 | 40.4 | 15.6 | |
Total copper concentrate | 24.43 | 5.34 | 1.53 | 82.7 | 21.2 | |
Zinc coarse concentrate | 7.89 | 0.55 | 11.28 | 2.7 | 50.2 | |
Zinc flotation tailings | 67.68 | 0.34 | 0.75 | 14.6 | 28.6 | |
Raw ore | 100.0 | 1.58 | 1.77 | 100.0 | 100.0 | |
In the first case, a zinc concentrate having a zinc grade of 17.56% and a recovery of 64.6% was obtained. In the second case, a zinc concentrate having a zinc grade of 11.286% and a recovery of 50.2% was obtained.
The characteristic of flotation of zinc from ores containing pyrrhotite is that the alkalinity of the slurry is not less than 1000 g/m 3 of free CaO, the amount of copper sulfate and butyl yellow is small, and the flotation is short. The optimum amounts of copper sulfate and butyl xanthate are 120 to 150 g/t and 25 to 30 g/t, respectively. The zinc rough concentrate is not selected and is directly fed into the de-ironing operation (mixed flotation of pyrite and pyrrhotite). The conditions for the de-iron flotation are as follows:
Washing the zinc concentrate with water to 14g/m 3 free CaO;
Treating the slurry with sodium sulfide or sodium hydrosulfide, desorbing the excess collector , so that the remaining concentration of Na 2 S reaches 1000-1100 mg / L;
Treating the slurry with zinc sulfate to a pH of 7.6 to 7.8;
Float with a collector and a foaming agent.
In individual cases, it is reasonable to add inhibitors (25-50 g/t Na 2 S and 50-100 g/t ZnS0 4 ) to pyrite-pyroxite product selection I and select II.
Based on the experimental research results, a process for treating copper-zinc ore containing magnetic pyrite in Uzelinsk was developed. It consists of some new units and a new pharmaceutical system. This process results in a qualified zinc concentrate.
The process includes:
1) Flotation separation of high quality copper concentrate containing 16.6% Cu and 0.69% Zn, and copper recovery rate of 35.7%.
2) Copper was roughly selected to obtain a copper concentrate having a yield of 17% to 20% containing 4.02% of Cu and 1.54% of Zn, and the copper recovery was 47.5%.
3) The copper concentrate is re-ground to 90%-92%-0.44μm, and then copper flotation is performed to separate the pyrite-magnetite tailings.
4) The pyrrhotite flotation is carried out on copper rough-selected tailings to obtain pyrrhotite products with a yield of 16% to 18%, and the grades of zinc, copper and sulfur are 0.62%, 0.92% and 40, respectively. % to 45%, the recovery rates are 6.3%, 8.2% and 20% to 22%, respectively.
5) Zinc flotation to obtain zinc coarse concentrate containing 0.4% to 0.5% of Cu and 20% to 24% of Zn. The recovery rates of copper and zinc are 1.4% to 1.5% and 57% to 59%, respectively.
6) De-iron flotation of zinc coarse concentrate to obtain zinc concentrate in the tank, which contains 0.75%-0.80% of Cu and 48.0%-52% of Zn, and the recovery rate of zinc is 48%-52%.
7) Exhaust the total tailings, which consists of copper flotation tailings, zinc flotation tailings, pyrrhotite products and pyrite-magnesia products (zinc coarse concentrate deferred foam products). The total tailings yield is 89%-90%, including 0.33% Cu and 0.72% Zn. The recovery rates of copper and zinc are 18.9% and 36.1%, respectively.
The mineralization indexes of copper-zinc ore containing magnetic pyrite in Uzelinsk are shown in Table 2.
Table 2 Obtaining the metal balance sheet of the final product
product name | Yield/% | grade/% | Recovery rate/% | ||
Cu | Zn | Cu | Zn | ||
High quality copper concentrate | 3.39 | 16.0 | 0.89 | 35.7 | 1.7 |
Copper concentrate | 4.77 | 14.31 | 3.18 | 44.9 | 8.5 |
Total copper concentrate | 8.16 | 15.01 | 2.23 | 80.6 | 10.2 |
Copper flotation tailings | 12.93 | O.35 | O.79 | 3.0 | 5.8 |
Pyrrhotite products | 16.09 | 0.52 | O.92 | 5.5 | 8.3 |
Zinc concentrate | 1.80 | 0.75 | 52.57 | O.9 | 53.2 |
Pyrite-magnetite products | 3.53 | 0.23 | 3.35 | O.5 | 6.5 |
Zinc flotation tailings | 57.49 | O.25 | O.49 | 9.5 | 16.O |
Total tailings | 90.04 | 0.31 | O.72 | 18.5 | 36.6 |
Raw ore | 100.00 | 1.52 | 1.78 | 100.0 | 100.0 |
The established process has been used in the retrofit design of the second system of the Uchalinksk Concentrator.
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