First, the nature of the original ore

After an iron ore of a magmatic gasification - mesothermal account multiple metal skarn deposits, ore complicated structure, it has a semi-shape ~ shaped granular structure, a granular structure from the shape, structure and the like account for dissolution; disseminations The structure is dominated. Metal minerals are mainly magnetite, scheelite and cassiterite . The second is black tungsten ore, hematite, limonite, etc. The gangue is mainly fluorite , pyroxene and calcite .

(1) Magnetite: It is self-shaped ~ it has granular appearance, and the particles are closely embedded, slightly oriented, arranged in phase with gangue minerals such as fluorite, forming a strip-like structure. In magnetite crystals, hematite is often replaced along its joints, and some are further metamorphosed to form pseudo-hematite, which is completely replaced by hematite. The particle size distribution is between 0.002 and 0.25 mm, and the particle size is mostly 0.10 to 0.15 mm.

(2) scheelite: semi-self-shaped ~ it is granular, appears in groups, constitutes a cockscomb-like granular aggregate, multi-embedded in fluorite grains or joints, crystals are often wrapped with grain-like, fine-grained magnets The size of the particle size is between 0.02 and 0.04 mm.

(3) cassiterite: It is semi-self-shaped granular, often embedded in ore in the form of loose particles, and the particle size is between 0.03 and 0.10 mm.

The results of multi-element analysis of ore are shown in Table 1. The phase analysis results of tungsten are shown in Table 2.

Table 1 Multi-element analysis results

Table 2 Results of phase analysis of tungsten

It can be seen from the results of Tables 1 and 2 that the main industrial minerals in the ore are iron, white tungsten and cassiterite. Although the content of white tungsten is low, it has reached the industrial requirements for comprehensive recycling.

Second, the test of tungsten selection process

(1) Determination of the principle process

Different process tests were carried out on the magnetic separation tailings to examine the recovery of useful metallic white tungsten. The results showed that the re-election using shaker, jigging, and the strong magnetic process were not satisfactory.

In addition, grinding fineness is an extremely important technical parameter, involving the number of grinding sections, as well as major issues such as investment and operating costs. Process mineralogy analysis and testing of magnetic separation tailings indicate that after a period of grinding (-0.074% to 75%), the tungsten in the magnetic separation tailings has basically obtained monomer dissociation, so the magnetic separation tailings are not Then carry out two stages of grinding.

(II) Comparison test of collector selection

See Table 3 for the comparison test results of collectors. It can be seen from the test results in Table 3 that the GYR and ZL collectors developed by Guangzhou Institute have better collection ability for the mine, and the GYR collection ability is strong, while the ZL selectivity is relatively good.

Table 3 Collector selection test results

(III) Orthogonal condition test

Water glass has a significant impact on the flotation of scheelite. If the amount of water glass is too low, it can not effectively inhibit the calcium-containing gangue minerals. If the amount of water glass is too large, it will significantly inhibit the flotation of scheelite. Sodium carbonate can adjust the alkalinity of the slurry, change the surface activity of the scheelite, accelerate the floating speed of the scheelite, disperse the slime, and combine with the water glass to improve the flotation of the scheelite ore. In order to determine the dosage of the agent more accurately, the orthogonal test was carried out. The determined flotation conditions were water glass dosage, pH value (soda ash dosage), GYR dosage, water glass modulus, and three conditions for each condition. The test points were arranged using an L ₃₄ orthogonal table. The conditional arrangement of the orthogonal test is shown in Table 4, and the test results of the orthogonal test are shown in Table 5.

Table 4 Horizontal corresponding condition table

Table 5 L ₃₄ conditional test arrangement and results

It can be seen from Table 5 that the order of influence of concentrate recovery rate index and concentrate grade index is water glass dosage > GYR dosage > pH value (soda ash dosage) > water glass modulus, taking into account concentrate grade and recovery rate. The optimum test conditions were selected to be about 2000 g/t for water glass, 600 g/t for GYR, 3000 g/t for soda ash, and 2.0 for water glass.

(4) Process determination test

The process test is mainly to consider the number of fine and sweeping, and the number of fine and sweeping is also the main factor affecting the product index. The process test results are shown in Figure 1 and Figure 2.

Figure 1 Selected count test results

Figure 2 sweep test results

As can be seen from Figure 1, the use of GYR as a collector, the number of selections to reach five times, the grade of tungsten can reach more than 62%, but the number of selections can be reduced by appropriate adjustment of the agent. It can be seen from Fig. 2 that the recovery rate does not change much after three sweeps, and the concentrate grade also changes little, so the number of sweeps is determined to be three.

(5) Full-process closed-circuit test

The process flow of the full-process closed-circuit test is shown in Figure 3, and the results of the test are shown in Table 6.

Figure 3 Full process closed circuit test process

Table 6 Full-process closed-circuit test results

Under the closed-circuit test flotation tailings microscope, it is found that the tungsten minerals in the tailings are mainly scheelite, and there are very few black tungsten ore. The particle size is between 0.005 and 0.08 mm, and the monomer dissociation degree is 90.15%. The impurity minerals mainly include fluorite, calcite, pyroxene, a small amount of magnetite, Fushan stone, epidote, quartz , pyrite and the like.

Third, summary

(1) The useful minerals of the mine are mainly scheelite and magnetite. Although the grade of tin contained in the mine is 0.25%, it is difficult to recover; the gangue minerals mainly include fluorite, garnet and pyroxene. The scheelite is unevenly embedded in thickness, and the overall inlay size is fine.

(2) Through rough grinding magnetic separation, the magnetic separation tailings directly floats tungsten, and a tungsten five-purchase process is used to obtain a tungsten concentrate product containing 61.92% of the WO ₃ grade and a recovery rate of 74.82%. The process has high index, and the process is stable and reliable, the pharmaceutical system is simple, and the production is easy to implement.

AWWA C207 Class E Ring

AWWA C207 FLANGES

AWWA refers to The American Water Works Association.