Experimental study on ore dressing of a polymetallic ore

I. Introduction

Ore a plurality skarn metal deposit, by type silver ore, lead, zinc, and scheelite skarn scheelite ore two kinds. In order to make full use of the national resources and comprehensively recover the various valuable components, the Zhangzhou Nonferrous Metallurgical Research Institute conducted a detailed ore dressing test on the mine. Through a large number of experiments, reasonable process and technical and economic indicators have been obtained, and the concentrates obtained have reached the requirements of grade products.

Second, the nature of the ore

Process mineralogical studies show that the original ore is composed of 31 elements, and the results of multi-element analysis are shown in Table 1. The main valuable element in the ore is silver, and other valuable elements are lead, zinc and tungsten. The main constituent elements are silicon, calcium, sulfur and iron .

The main metal ore minerals galena, sphalerite, pyrrhotite, pyrite, copper ore, scheelite; major gangue minerals include: quartz, fluorite, calcite, diopside, Ca, Fe pyroxene, garnet, feldspar, white mica. The relative content of the main constituent minerals is shown in Table 2.

Silver minerals are: argentite, lead-bismuth needle silver, silver Orthopyroxene lead bismuth, tellurium, sulfur, lead and bismuth silvery silver tin ore.

Small or trace minerals include: Fushan stone, plagioclase, magnetite, antimony tin, sulphur- cadmium , copper, pyrite and beryllium.

The silver in the ore is in three phases: (1) independent minerals, accounting for 78.21%, and the inlaid grain size is fine, -0.005mm is 76.76%, mainly associated with galena; (2) mechanically mixed "immersed" or " Concealed in the galena, accounting for 21.35%; (3) the same type of image in the chalcopyrite, accounting for 0.44%. Because of the complex state of silver, it is quite difficult to sort out individual silver concentrates from ore. It can only be recovered from lead concentrates.

The results of particle size measurement showed that the galena and sphalerite monomer were dissociated later. The dissociation rate of -0.104mm~+0.076mm granular galena monomer is 89.82%; the dissociation rate of sphalerite in the range of -0.104mm~+0.076mm is 92.38%.

Third, experimental research and results

(1) Basis for process selection

Process mineralogical studies have shown that silver is mainly embedded in galena, so the test uses silver-lead concentrate to recover silver. Since the galena and sphalerite monomers dissociated later and the particle size was relatively uniform, the test decided to use a section of grinding. Since the useful mineral galena, sphalerite, and scheelite are all floatable minerals, the test determines that the full float process is adopted. According to their floatability, the preferential flotation process is adopted, that is, the lead float is preferentially, and then the zinc is floated and strengthened. The process of white tungsten flotation is carried out by floating sulfur and floating sulfur tailings. The simplified test procedure is shown in Figure 1.

(2) Selection of flotation reagents

The butyl ammonium black drug has weak ability to capture pyrrhotite and pyrite in the weak alkali slurry, while the other lead ore has strong ability to collect. Therefore, the experiment uses the butyl ammonium black drug as the collector for the floating lead operation. .

Since lime has a certain inhibitory effect on lead ore, sodium carbonate is used as a slurry pH adjuster when floating lead.

The zinc-lead operation inhibitor uses zinc sulfate which has a good zinc-inhibiting effect. The zinc floating operation uses butyl yellow medicine as a collector and copper sulfate as an activator. Sulfur is easy to float under acidic conditions, so sulfuric acid is used as a pH adjuster for floating sulfur. The white tungsten flotation collector selected a mixed collector (MF) with good sorting effect.

(3) Conditional test

1. Grinding fineness test

The grinding fineness test results are shown in Table 3. The test results show that the grades of silver, lead and zinc in the tailings gradually decrease with the decrease of the grinding size.

The test grinding fineness is determined to be -0.074 mm, which is 83.5%.

2. Silver and lead crude sodium carbonate dosage test

The test results of sodium carbonate dosage are shown in Table 4. The test results show that the amount of sodium carbonate is increased, and the grade of lead crude concentrate is also increased, but the effect on the grade of zinc coarse concentrate and the recovery rate of lead and zinc is not significant. Considering that the pH value of the pulp is too high, it will affect the amount of the sulphur activator. Therefore, the amount of sodium carbonate selected is 1kg/t ore.

3, silver, lead crude selection of zinc sulfate dosage test

The test results of zinc sulfate dosage are shown in Table 5. The test results show that with the increase of the amount of zinc sulfate, the zinc content in the tailings is also gradually increased. Based on the comprehensive test results, it is reasonable to select 1kg/t ore.

4, white tungsten rough selection "sodium carbonate method" and "lime method" comparison test

The test results of the "sodium carbonate method" and the "lime method" are shown in Table 6. The test results show that the “lime method” selection index is obviously better than the “sodium carbonate method”, so the white tungsten is selected by “lime method”.

(4) Closed circuit test

On the basis of the conditional test, a full-process closed-circuit test was carried out. The results of the closed circuit test are shown in Table 7.

Fourth, the conclusion

1. The content of silver in the ore is relatively high, reaching 183g/t. Although it is mainly produced by independent minerals, it is difficult to obtain high grade alone because more than 70% of silver is concentrated in galena and the size of the inlay is mostly granular. Silver concentrate, it is reasonable to test the recovery of silver by lead concentrate.

2. The use of preferential flotation process according to mineral characteristics is conducive to improving the quality of silver, lead and zinc concentrates. Since the pyrrhotite content accounts for 18.5% of the original ore, strengthening the sulphur prior to the floating white tungsten can reduce the mixing of sulfur in the white tungsten flotation, which is beneficial to improve the quality of the scheelite concentrate. Therefore, the entire process selection is reasonable.

3, white tungsten flotation adopts "lime method", using mixed collector, which improves the selectivity of scheelite flotation and achieves better sorting effect.

4. The test obtained good technical indicators. Achieving the expected goals provided a reliable basis for the industrial evaluation of the deposit.

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