Study on New Process for Comprehensive Recovery of Lead and Antimony from a Tailings

A cassiterite, multiple metal sulfide ore tailings old abandoned production, in addition to having a poor fine, complicated characteristics, but also vary with the nature of the ore. The tailings contain not only precious metals, non-ferrous metals, ferrous metals, but also a large number of non-metals. Among them, the refractory metal minerals are mostly in the form of continuous, fine or fine particles, including sulfide minerals, oxidized minerals, and vulcanization. The mineral has been oxidized due to long-term accumulation of minerals. For these special complex cases the tailings, the tailings to be comprehensive recovery of valuable substances such as lead, antimony, beneficiation processing to bring a greater degree of difficulty. This study conducted an experimental study on the properties of the tailings sample. Through a large number of experiments, a reasonable beneficiation process and pharmaceutical system were determined, which obtained an ideal beneficiation index.

First, the basic properties of the sample

The chemical composition and lead phase analysis results of the tailings are shown in Tables 1 and 2.

Table 1 Chemical composition analysis results ∕%

Table 2 Lead phase analysis results

It can be seen from Table 1 that the ore sample contains Sn, Zn, As, Pb, Sb, S, etc., wherein the gangue mineral is mainly SiO ₂ , the content is 40.95%, and the Fe and Al ₂ O ₃ contents are 10.62% and 5.60%. It can be seen that the tailings is a valuable secondary resource, and tin, zinc , lead and antimony in metal minerals can be comprehensively recovered. This study mainly recovers lead and lead minerals.

Lead phase analysis results show that the multi-lead mineral galena and jamesonite sulfide ores, etc., in an amount of 0.082%, accounting for 37.27% of lead minerals; pyromorphite, white lead, lead Iron shovel followed; there is a small amount of lead bismuth.

Second, lead bismuth dressing test

The tin and zinc grades in the sample exceed the national industrial grade requirements specified by the state and are the main elements of the mine's main recovery. Secondly, there are elements such as lead, antimony, arsenic and sulfur in the mine. The lead grade of the original ore is 0.22%, and the grade of niobium is 0.15%. After pre-selected tailing, the lead is enriched, the lead grade is increased to 0.33%, the niobium grade is increased to 0.237%, and the lead + niobium grade is 0.567%. This is also a small amount of metal when industrially mined. Therefore, in the secondary development and utilization of tailings resources, in order to maximize the use of limited resources and improve the economic benefits of enterprises, considering the recycling of tin, zinc, sulfur and arsenic, the comprehensive recycling of lead and antimony has a large Economic value.

(1) Lead and sputum rough selection test

The old tailings are lead-bismuth polymetallic sulfide ore. In the flotation of metal sulfide ore, it is difficult to activate lead once it is suppressed, so it should be used in the process of comprehensive recovery of lead, antimony, zinc, sulfur, arsenic and tin. The process of preferential flotation of lead bismuth. In addition to recovering lead bismuth as much as possible, the process can effectively reduce sulfur and arsenic in zinc concentrate. The lead flotation priority flotation indicator is largely determined by the choice of flotation reagents. To this end, through a large number of exploratory experiments, selected agents that can effectively inhibit zinc, sulfur and selectively capture lead bismuth. At the same time, the best pharmaceutical system for rough selection of lead bismuth was determined (see Figure 1).

Figure 1 Lead and flotation flotation rough selection test process

In the rough selection of lead bismuth, in order to effectively suppress sulfide minerals such as zinc, sulfur and arsenic in tailings, ZnSO ₄ , KCN and Na ₂ S ₂ O _{3 are used} as combined inhibitors, which can achieve good suppression effect. The lead bismuth concentrate obtained by the lead bismuth concentrate was significantly improved, the lead bismuth recovery rate was larger, and the zinc and sulphur grades in the lead bismuth concentrate were greatly reduced. The combination of 25 ^#黑药 and 乙硫氮 was used as the combined collector. With 2 ^# oil as a foaming agent, the flotation effect of lead bismuth is better. The specific indicators are shown in Table 3.

Table 3 Lead and sputum rough selection test results

(3) Lead and bismuth selection test

It can be seen from the rough selection test of lead bismuth that the Pb grade of lead bismuth concentrate is 7.47%, the Sb grade is 4.69%, the Pb+Sb grade is 12.16%, and the lead recovery rate is 61.73%. index.

Further flotation of the coarse concentrate, the test found that no matter how to adjust the flotation agent system and conditions, it is difficult to make breakthroughs in the indicators, and even the phenomenon that the flotation concentrate grade is lower than the tailings grade. To this end, a multi-element analysis was performed on the lead-bismuth concentrate, and the results are shown in Table 4.

Table 4 Results of multi-element analysis of lead-bismuth concentrates∕%

It can be seen from Table 4 that lead bismuth concentrate contains 4.62% zinc, 11.58% sulfur and 1.48% arsenic. It is difficult to further suppress the minerals such as zinc and sulfur to float lead bismuth. However, it can be seen that the composition of lead lanthanum concentrate is relatively simple after flotation and enrichment; and the lead bismuth mineral is significantly different from other minerals in terms of specific gravity. In addition to tin, lead bismuth is the mineral with the largest specific gravity and lead lanthanum The tin content in the concentrate is very low, so it is possible to conduct a selective test study by re-election based on the difference in specific gravity. The process is shown in Figure 2, and the ore dressing indicators obtained in the test are shown in Table 5.

Figure 2 Selective test procedure for lead-salt flotation coarse concentrate shaker

Table 5 Selected test indicators for lead-salt flotation coarse concentrate shaker

The test shows that the selection of lead-salt flotation coarse concentrate by re-election is better. The lead bismuth grade of lead bismuth concentrate was increased from 7.47% and 4.96% to 31.10% and 20.52%, respectively, and the operation recovery rate also reached 53.71% and 53.36% respectively. The obtained lead ore in the mine is still high, and the medium ore is re-elected by the wave removing shaker, which can further improve the beneficiation index of lead and antimony. The lead and niobium grades are 29.86% and 15.26%, and the recovery rates are 31.68% and 23.86%, respectively.

(III) Lead and bismuth beneficiation process test

On the basis of lead slag and selected tests, the lead bismuth beneficiation process test was carried out. The process is shown in Figure 3. The test results obtained in the test are shown in Table 6.

Figure 3 lead and lead dressing test process

Table 6 Lead and bismuth beneficiation process test operation index%

The test shows that it is feasible to select the lead-bismuth metal of the old tailings by using the flotation process combined with the flotation process. The effect is good, and the lead grade is 29.43%, and the niobium grade is 19.76%, that is, the Pb+Sb grade. For the 49.19% lead bismuth concentrate, the lead and bismuth recovery rates were 52.52% and 49.18%, respectively. It can be seen that the use of the float-and-weight combined beneficiation process to select lead bismuth can solve the problem that the grade of lead and bismuth concentrate cannot be improved by single use flotation, thereby solving the problem of difficult selection of lead bismuth in tailings.

Third, the conclusion

This study is aimed at the characteristics of a certain polymetallic sulphide ore tailings with deep oxidation, low grade, fine grain size and many valuable components. The effective and reasonable chemical system and test procedure are used to preliminarily float the lead and lead minerals, and then float according to the results. The mineral composition of the coarse concentrate is relatively simple, and the difference between the target mineral and the gangue mineral is obvious. The re-election is used to further select the lead-bismuth mineral, that is, the “flotation-re-election” joint process is successfully used from the old The lead bismuth is sorted out in the tailings, and the process is innovative.

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