Test and practice of comprehensive recovery of flotation tailings in Chehe Concentrator

Car River mineral processing plant is currently processing 92 lean ore mining giant, is a low-grade ore cassiterite multi-metal sulfide ore concentrator re-election - flotation - re-election process principle of recovery of useful minerals, mineral products as the main cassiterite, iron and zinc concentrate by flash Jamesonite lead concentrate. Among them, lead, zinc and sulfur minerals adopt mixed flotation-separation flotation process, and sulfur and arsenic minerals are mainly enriched in lead-zinc separation tailings. Separation tailings have an average sulfur content of 28.00%, arsenic content of 3.50%, and tin content of 0.26%. The tailings amount is nearly 300,000 tons per year, of which the metal sulfur is about 80,000 tons, the arsenic is about 10,000 tons, and the tin is about 800 tons. In order to make more rational use of resources, improve the economic benefits of enterprises, reduce tailings emissions, and reduce environmental pollution, Chehe Concentrator has built a comprehensive recovery workshop for sulfur and arsenic to synthesize sulfur, arsenic and tin minerals in lead-zinc separation tailings. Recycling.

The comprehensive recovery project of sulfur and arsenic started construction on March 20, 2008. The main project was completed in September 2008. At the beginning of October of the same year, the main equipment passed the no-load linkage test. The production began on November 1, 2008, and several production and commissionings were carried out, but there is a certain gap between the commissioning results and the design indicators. In view of the problems found during production commissioning, the necessary technical transformation was carried out on the original design process. After the transformation, good indicators were obtained: sulfur concentrate grade 40.08%, sulfur recovery rate 48.17%, low tin concentrate grade 5.03%, tin The recovery rate is 1.07%, which meets the design requirements, and can reduce tailings emissions by about 100,000 tons per year, and the added economic benefit is 6.86 million yuan.

First, the nature of the ore

The main metal minerals of lead-zinc separation tailings (sulphur-arsenic workshop) are pyrite and arsenopyrite. The secondary metal minerals are pyrrhotite, iron sphalerite, brittle sulphide ore, cassiterite; gangue minerals. It is quartz and calcite . The mineral composition and multi-element chemical analysis and particle size analysis results are shown in Table 1, Table 2 and Table 3, respectively.

Table 1 Lead and zinc separation tailings mineral content %

Table 2 Multi-element chemical analysis results of lead-zinc separation tailings

Note: The unit of Ag content is g/t.

Table 3 Results of particle size analysis of lead and zinc separation tailings

It can be seen from Table 1 and Table 2 that the sulfur minerals in the lead-zinc separation tailings are mainly pyrite and pyrrhotite, and arsenic mainly exists in the form of arsenopyrite. It can be seen from Table 3 that the fractional yield of -0.074 mm in the separated tailings accounted for 51.94%, and the distribution rates of sulfur and arsenic metals accounted for about 30%, which indicated that the fineness of the separated tailings was suitable.

Second, the preparation of the test plan and analysis of test results

Because part of the pyrite and arsenopyrites in the Dachang mining area are similar, the crystal lattice of the pure minerals of pyrite contains 0.54%~0.70% of arsenic (ie, the arsenic content of sulfur concentrate is ≥0.54%), and Chehe ore dressing The plant has many kinds of ore minerals and complex nature. The main process has a mixed flotation-separation process. After activation of copper ions, the sulfur and arsenic minerals are very close to each other, and the subsequent separation of sulfur and arsenic is very difficult. . In the Dachang mining area, some ore dressing plants used to produce sulfur concentrate products, but all of them contained 2.00% to 5.00% of arsenic. The products have not been sold.

The Chehe Concentrator Laboratory uses flotation-magnetic separation-re-election (Scheme 1) and magnetic separation-flotation-re-election (Scheme 2) to carry out comprehensive recovery of sulfur and arsenic minerals from lead-zinc separation tailings. the study. Scheme 1 Sulfur and arsenic minerals are first mixed flotation, mixed flotation tailings are selected by shaker to obtain low-grade tin concentrate, sulfur and arsenic separation is obtained by FN arsenic-suppressing sulfur to obtain sulfur concentrate, and sulfur-arsenic separation tailings are magnetic The magnetic separation sulfur concentrate is selected, and the magnetic separation tailings are enriched by the re-selection shaker to obtain the final high-grade arsenic concentrate, and the magnetic separation sulfur concentrate and the flotation sulfur concentrate are combined as the final sulfur concentrate. Scheme 2 is to obtain magnetically selected sulfur concentrate by magnetic separation, and the subsequent process is consistent with Scheme 1. The test indicators and dosages are shown in Tables 4 and 5, respectively.

Table 4 Sulfur and arsenic comprehensive recovery test indicators %

Note: Test protocol 1 is flotation-magnetic separation-reselection; scheme 2 is magnetic separation-flotation-reselection.

Table 5 dosage of different test protocols g/t

As can be seen from Table 4, the sulfur concentrate of Scheme 1 contains S 43.22%, As 0.96%, sulfur recovery rate 81.18%, arsenic recovery rate 10.55%, tin concentrate 9.53%, tin recovery rate 20.62%; comparison scheme 2 sulfur concentrate The S content is 1.65 percentage points higher, the As content is also 0.26 percentage points higher, the sulfur and arsenic recovery rates are 0.46 percentage points higher and 2.77 percentage points higher, the tin concentrate grade is about 1 percentage point higher, and the tin recovery rate is equivalent. The arsenic concentrate of Scheme 1 contains As 17.16% and the arsenic recovery rate is 88.15%. Compared with Scheme 2, the arsenic concentrate contains 3.41% lower than As, and the arsenic recovery rate is also 2.77% lower. The test index of Option 1 is slightly better than that of Option 2.

It can be seen from Table 5 that because Scheme 2 preferentially magnetically selects and recovers magnetic concentrate, it reduces the amount of minerals entering the flotation, reduces the interference of pyrrhotite on subsequent sorting, and greatly reduces the difficulty of flotation agent consumption and separation. 2 The cost of mineral processing is much lower than that of Option 1.

Third, the design process and process indicators

According to the laboratory small-scale test comparison, considering the cost of mineral processing chemicals, the design and site of the Chehe Concentrator will use the magnetic separation-flotation-re-election process to treat the total recovery of tin, sulfur and arsenic minerals from lead-zinc separation tailings. The design process is shown in Figure 1.

Figure 1 design process

Design process index: 0.26% for tin ore, 28.00% for sulfur grade, 3.50% for arsenic; 39.00% for sulfur concentrate, 1.00% for arsenic, 48.00% for raw ore (65.50% for ore recovery) ); the arsenic concentrate grade is 20.00%, the recovery rate of raw ore arsenic is 45.00% (the recovery rate of ore is 60.00%); the low tin concentrate grade is 5.00%, and the recovery rate of raw ore tin is 1.00% (the recovery rate of ore is 10.00%) ).

Fourth, production commissioning results

The comprehensive recovery project of sulfur and arsenic in Chehe Concentrator The main equipment passed the no-load linkage test in early October 2008. On November 1st, trial production began, and process production commissioning was started from November to April 2009. Due to market factors, arsenic is not recycled. The production quality process during production commissioning is shown in Figure 2.

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