Lead-zinc ore beneficiation test plan example

A lead-zinc-fluorite ore beneficiation test program

(--) Analysis of ore properties research data

According to Table 3-9, chemical multi-element analysis and simple and easy selection of lead-zinc fluorite ore with coarse-grained unequal-grained inlays. The results of 3-10 phase analysis showed that the main recoveries were lead, zinc and fluorite. Other yuan cables contain little suspension and no industrial price. Lead and zinc are mainly found in galena and sphalerite. The lead and zinc oxidation rates are all below 10%. Metallic mineral grains embedded in a coarse ranging from only a small amount of lead and zinc in a star-like points disseminated in phyllite. Most are irregularly granular, followed by cubes of self-shaped and semi-self-shaped cloth, and most of them appear alone, in the form of coarse or medium-fine particles in quartz . The ore is dominated by a block structure. Therefore, the embedding characteristics and mosaic structure and structure of the ore are beneficial to crushing, grinding and sorting, and are simple and easy to select ore.

(ii) Selection of test plan

According to the nature of the ore studied, the following three options were selected:

(1) Priority flotation process

According to the results of ore properties, the ore is a simple and easy-to-select sulfide-lead fluorite ore with coarse-grained granules. The structure, embedding characteristics and embedding relationship of galena and sphalerite are favorable for sorting. It is easy to dissociate during grinding, no need for fine grinding, and the floatability of top lead ore is very good. Natural The sphalerite is easier to float, which is a favorable condition for preferential flotation. Fluorite can be recovered by flotation from sulfide ore flotation tailings.

(2) Lead-zinc mixed flotation process

The main contradiction between lead-zinc mixed flotation is the separation of lead and zinc. When mixing concentrates, it is necessary to remove excess chemicals and the handling procedures are complicated. If the hybrid flotation indicator is close to the priority flotation indicator, the priority flotation process should be considered first.

(3) Combined process of heavy medium jigging flotation

The ore is a coarse-grained unequal-grained inlay, such as galena particles generally 1 to 5 mm, up to 20 mm; sphalerite particles are generally 2 to 10 mm, up to 22 cm, plus The proportion is large, so re-election can be considered. For the analysis of specific gravity components, the heavy liquids HgI2 and KI have a specific gravity of 2.65. The sorting of the ore size of 25~3 can discard the waste tailings which account for 25~32% of the original ore. The grade of abandoned tailings: Pb0.01~0.2 %, Zn 0.17~0.14%, CaF21.1~4.2%. It indicates that the ore can be used for heavy media dressing and tailing. Through microscope observation, gravity analysis, etc., it is proved that qualified concentrate can also be obtained under the rented granularity. Therefore, it is decided to test according to the following two schemes:

1) Heavy medium dressing is carried out at the level of -25+3 mils in the ore to discard some of the waste rock.

2) Sort out qualified concentrates by jigging and remove some of the abandoned tailings. When the jigging test is carried out, the raw ore may be directly jigging; the heavy products obtained by sorting the raw ore through the heavy medium may be further jigging.

The results of the jigging test show that it is easier to obtain high-grade lead concentrate (78%), and it is difficult to obtain high-grade zinc concentrate. The qualified fluorite concentrate and the waste tailings with a useful metal content below 0.2% are Impossible, at the same time, the maximum size of the ore should not exceed 12 mm.

The results of mineral monitoring indicate that the main reason for the inability to obtain high-grade zinc concentrate is that the dissociated sphalerite is not well separated from barite and fluorite; the reason for not being able to obtain waste tailings is due to the tail. The gangue in the ore contains flat grains and star-shaped inlaid galena and sphalerite accounted for about 10~15%, and most of them are connected with quartz, even if it is ground to 0.5~1 mm, It is also not easy to dissociate, so it is impossible to use the jigging method to throw tailings. The jigging can produce part of the concentrate, and the tailings that cannot be discarded can be tested by flotation. A reasonable solution should be to recover the coarse-grained lead and zinc concentrate from the heavy product sorted by heavy medium (specific gravity 2.65), and then the re-election tailings and the unreselected fine-grained materials are sent to flotation. The test results show that the re-floating combined process is similar to the single flotation process, but it can throw away 25~32% of abandoned tailings before grinding, reduce grinding costs and reduce production costs.

Compared with the two schemes of preferential flotation and mixed flotation, the two indexes are the same, the grinding fineness is also the same, and the operation of the former is relatively easy to control, so the priority flotation process is recommended.

The original test report finally recommended two options for the design department to consider:

1) Heavy medium-jigging-flotation combined process

2) a single flotation process (priority flotation) process;

In fact, the main advantage of the re-floating combined process is that it can reduce the processing capacity of the grinding and floating section, the index is not improved, and the grinding size required for flotation is coarse, and the over-grinding problem is not prominent, so it is not necessary to use the hopping method. For the recovery of coarse concentrates, a simpler heavy medium-flotation combined process and a single-flotation process can be considered. Due to the small amount of tailings lost by re-election, and the lack of experience in heavy-weight dressing in China at the time, the design department did not adopt the re-floating joint process, but chose a single flotation process. Years of production practice have proven that the process is basically reasonable.

From the domestic situation, the selection of lead-zinc ore is usually based on flotation, generally using mixed flotation, preferential flotation process, and a few plants adopting floatable processes. Individual selection plants use a re-election-flotation joint process. At present, almost half of the mixed flotation and priority flotation processes in China. Most of them are one-stage grinding, and some factories use crude concentrate regrind or remix and regrind.