Study on Beneficiation Process of a Tungsten Mine in Jiangxi

Jiangxi Tungsten Mine is a typical native quartz - tungsten, bismuth multi-metal ore types, Gannan areas sorting practice more similar tungsten ore, the general stage of sorting, enhanced classification process, fully embodies the "can receive early harvest, The loss of early throwing" thought. Whether the ore can be applied to the principle flow of the same type of ore is subject to process mineralogy analysis and process testing.

I. Mineralogy characteristics of ore process

(1) Ore chemical composition and mineral composition

The results of multi-element analysis of ore chemistry are shown in Table 1.

Table 1 Multi-element analysis results of ore chemistry

It can be seen that the content of WO _{3 in the} ore is relatively high, which is the main component recovered; the components that can be comprehensively recovered in the ore dressing are Bi, Cu, Mo, and Sn.

Ore mainly metallic minerals are wolframite, scheelite, etc., other metals minerals pyrite, molybdenite, sphalerite, yellow copper ore, bismuthinite like; gangue minerals are quartz, followed by a small amount feldspar, white mica, fluorite, apatite, chlorite, calcite. The veins are rich in polymetallic ore such as tungsten ore, and the ore is not weathered. It is a type of primary quartz-tungsten-bismuth polymetallic ore.

(2) Structure and structure of ore

The ore structure mainly has a self-crystal structure, a semi-automorphic crystal structure and its crystal structure, as well as a metamorphic residual structure, a dissolution structure, an inclusion structure and a metamorphic structure. The ore structure has a cross structure, a symmetrical strip structure, a breccia structure, a complex vein structure, and a comb structure.

(3) Main mineral inlay characteristics

1. Black tungsten ore inlay features. Brownish black, streaked tan, metallic luster, high density. Produced in early quartz veins, mostly in the form of leaf-like and slab-like aggregates, vertical or oblique vein wall growth, a few granular or small blocky distribution, individual appeared in the "tungsten sand package". More symbiotic with scheelite, surrounded by scheelite or pyrite, interspersed, confessed and eroded. The black tungsten ore is generally coarser in grain size, and more than 68.32% of the black tungsten ore is distributed in the 1.6-0.2mm grain size, which is in the coarse-grain range.

2. Inlaid features of scheelite. Light yellow-gray-white, with diamond or rosin luster, generally his shape is granular or small, scattered, sometimes replaced by calcite and chlorite.

3. The characteristics of pyrite embedding. Light brass color, black streaks, strong metallic luster, generally produced as a block or granular aggregate, with the phenomenon of discoloration or dissolution by sphalerite.

4. Molybdenum ore inlay characteristics. Lead gray, metallic luster, low hardness, dirty hands, thin sheets of flexible, oily, mostly phosphorous aggregates or fine granular distribution, more common in tungsten-containing quartz veins, in the granite area It can also be seen in Yingyan, and generally produces more alone, and occasionally sees symbiosis with muscovite.

5. Characteristics of chalcopyrite inlays. Copper yellow, streak greenish black, metallic luster, hardness less than pyrite, often in the form of his block or granular aggregate; mainly produced in tungsten-containing quartz veins, often with pyrite, sphalerite, stibnite Mine symbiosis, sometimes confessed or interspersed with pyrite, sphalerite.

6. Embossing characteristics of stibnite. Lead gray, streaks grayish black, metallic luster, high density, low hardness; often produced in bulk or fibrous aggregates, sometimes seen in the cavity like needles or hair. Often associated with stellite, pyrite, sphalerite, chalcopyrite, etc., and chalcopyrite with each other or interspersed, so it is difficult to distinguish their crystallization.

7, quartz inlay features. It is gray-white-white, strong in oily luster, and has a shell-like cross section, brittle and blocky structure.

8, feldspar inlay features. Gray-light-red meat, with a glass luster, produced in a plate or block form, often with kaolin powder on the surface.

9, the characteristics of the muscovite inlay. It is white-gray-white, glassy, ​​and produces in small pieces.

(4) Determination of the dissociation degree of the black tungsten ore

The ore dissociation degree of the wolframite was measured after the ore was broken to -2 mm, and the results are shown in Table 2.

Table 2 Determination results of dissociation degree of black tungsten ore

It can be seen from Table 2 that the monomer dissociation degree of the wolframite is good, and the whole sample can reach 79.03%.

Second, the ore processing process test research

(1) Selection of mineral processing technology plan

The black tungsten-quartz vein type tungsten ore has a wide variety of metal minerals, and the main useful component is WO ₃ . The content of other elements is relatively low; the tungsten mineral inlay has a relatively coarse grain size; the gangue mineral is mainly quartz. In general, the ore is a simple and easy to choose ore type.

The ore dressing test study draws on the treatment experience of similar ore in southern Anhui. It is planned to use first grading, jigging + shaker rough selection, tungsten coarse concentrate re-flotation desulfurization, magnetic separation to realize hematite and scheelite. The separation of cassiterites ultimately leads to a joint process of high quality tungsten concentrates.

(2) Study on the size of the jigging

The jigger was used to conduct early acceptance studies on coarse-grained useful minerals. First, 12 to 0 mm and 6 to 0 mm were selected for the preferred test. The results are shown in Table 3.

Table 3 Results of the preferred test results for the jigging

It can be seen from Table 3 that the selection of 6~0 mm is better than that of 12~0 mm. When the recovery rate of WO ₃ is not much different, the grade of WO _{3 is} more than 3 times higher, so it is determined that the size of the jigging re-election is 6~0 mm.

(3) Grading and grading re-election test

In order to improve the efficiency of beneficiation, the working condition of the jigging was optimized, that is, the whole grain size was selected as the classification stage, the test process is shown in Figure 1, and the test results are shown in Table 4.

Figure 1 Split-stage jigging re-election test process

Table 4 Jig split grade inclusion test results %

It can be seen from Table 4 that the grades and recovery rates of the coarse concentrates are 31.38% and 31.74%, respectively, which are higher than the grades and recovery rates of the coarse concentrates of the 6~0mm full-grain grades by 18.14 and 11.23, respectively. The percentage point indicates that the efficiency of the ore sorting is significantly higher than that of the full-grain sorting; in addition, the WO ₃ grade and recovery of the re-selected tailings are as high as 0.35% and 68.26%, respectively, and most WO ₃ does not. Get recycled. Therefore, the fine and tailings of the process need to be further selected.

(4) Re-election test of jigging tailings shaker

A full-grain shaker sorting test was conducted on the jigging graded tailings. The results are shown in Table 5.

Table 5 % of the grading selection of tailings full-grain shaker test results

It can be seen from Table 5 and the mineralogical characteristics of the ore process that the shaker must also be graded. The test procedure is shown in Figure 2, and the test results are shown in Table 6.

It can be seen from Table 6 that the jigging rough-choice tailings adopts the step of re-sorting of the grading shaker - the re-spinning process of the first shaker, and the comprehensive yield of 0.83%, the grade of WO _{3 is} 31.85%, and the recovery rate is 51.83%. Shaker concentrate; final total tungsten concentrate yield 1.46%, WO ₃ grade 31.07%, recovery rate 88.97%; tailings WO ₃ grade has been reduced to 0.04%, no further deep selection is necessary, but coarse concentrate needs Further selection to improve the crystal quality of the concentrate.

The analysis of the test process showed that the WO ₃ grade of each grade-level shake was between 30.58% and 33.14%. This result fully indicates that the fractionation grade is characterized by high efficiency and accuracy.

Figure 2 Jigger and shaker classification process

Table 6 Results of jigging and shaker sorting test results %

(V) Re-election of coarse ore concentrate grading and flotation desulfurization test

Because the ore contains a small amount of sulfide ore, the difference between the density of sulfide ore and the density of tungsten mineral is small. It is difficult to remove this part of sulfide ore by re-election, and it is difficult to obtain high-quality tungsten concentrate without removing the part of sulfide ore. The re-election of coarse concentrate was carried out by the fractionation stage suspension and flotation desulfurization test. The test procedure is shown in Figure 3. The test results are shown in Table 7.

Figure 3 Re-election process of coarse concentrate ore flotation and flotation desulfurization

Table 7 Results of re-election of coarse ore concentrate grading and flotation desulfurization test %

It can be seen from Table 7 that with the increase of the dosage of Dinghuang, the grades of bismuth and sulphur in the sulphide ore are all decreased, but the recovery rate is obviously increased; and with the increase of the amount of butyl sulphate, the obtained The WO ₃ grade and recovery rate of tungsten coarse concentrates are not much different. When Taiwan Dinghuang xanthate 70g / t, flotation Dinghuang 50g / t, 2 ^# oil 21g / t, the obtained tungsten concentrate WO ₃ grade reached 57.84%, the operation recovery rate reached 25.87%; the obtained sulfide ore The sulphur-containing strontium was 31.45% and 7.21%, respectively, and the recovery rates were 79.19% and 91.71%, respectively. The recovery rates of raw ore were 4.67% and 12.76%, respectively. Therefore, 70g/t of Dingfu Dinghuang, 50g/t of Dinghuangxuan and 21g/t of 2 ^# oil were selected as the subsequent test conditions.

(6) Semi-selection of tungsten for flotation desulfurization tailings shaker

Due to the high content of tungsten in the sulphur tailings, the re-election test of the sulphur tailings shaker was carried out for this purpose. The sulphur tailings were also divided into two levels for shaker re-election. The test procedure is shown in Figure 4. See Table 8.

Figure 4: Tungsten test procedure for re-election of floating sulfur tailings shaker

Table 8 Tungsten test results of re-election of floating sulfur tailings shaker

It can be seen from Table 8 that the tailings after flotation desulfurization adopts a fractional-stage shaker re-election-shaker-mine re-shake process, which can obtain an operating yield of 50.94%, a WO ₃ grade of 56.68%, and an operation recovery rate. 90.27% of the comprehensive shake; tailings WO ₃ grade has dropped to 6.34%, the operation recovery rate also fell to 9.73%. Therefore, the further deep selection of the tailings is of little significance, but the total coarse ore concentrate of tungsten is only 56.95%, which needs further selection to improve the quality of the concentrate.

The analysis of the test process showed that the WO ₃ grade of each shake was between 56.13% and 57.25%. This result fully indicates that the classification of the grade is characterized by high efficiency and accuracy.

(VII) Strong magnetic selection conditions test of tungsten comprehensive coarse concentrate

After the previous treatment, the ore can obtain more than 56% of the tungsten comprehensive coarse concentrate of WO ₃ grade, but its quality can not meet the requirements of high grade tungsten concentrate. This is because the ore contains a small amount of heavy mineral such as cassiterite. The density of minerals is less different from that of tungsten minerals, and the re-election process does not achieve the purpose of separating from tungsten minerals. Considering that the research object is mainly black tungsten ore, and there is a certain difference in the magnetic properties between the black tungsten ore and the cassiterite, the strong magnetic selection condition test of the tungsten coarse concentrate is carried out, and the background magnetic induction intensity is 1.1T.

Due to the wide range of particle size of the tungsten coarse concentrate selected by magnetic separation, the entrainment phenomenon is easy to occur. For this reason, the magnetic separation condition test under different classification schemes of tungsten integrated coarse concentrate is carried out. The test flow is shown in Fig. 5, and the test results are shown in Table 9.

Table 9 Test results of re-election coarse ore fine-grained magnetic separation conditions

It can be seen from Table 9 that the tungsten coarse concentrate is divided into 4 to 0.83, 0.83 to 0.2, and 0.2 to 0 mm for strong magnetic selection. No matter the concentrate grade or recovery rate is high, the graded particle size is appropriate. The downward shift is conducive to improving the overall concentrate grade, but the 61.63% WO ₃ grade still does not meet the requirements of high quality tungsten concentrate. To this end, the background magnetic induction intensity of the strong magnetic concentrate of tungsten integrated concentrate is reduced by about 20% for selection, and the fine sweeping operation under the original magnetic field strength is added. The test results show that the WO ₃ 64.21% can be finally obtained. The tungsten ore concentrate with an operation recovery rate of 89.48% and a recovery rate of 76.80% of the original ore has obtained good test results.

Figure 5 Test procedure for the magnetic separation condition of tungsten coarse concentrate

(8) Full open circuit process test

In order to verify the repeatability of the conditional test, a full-process open-circuit test was performed on the previous stage process.

The results show that the conditions determined by the conditional test result in the final grade of tungsten concentrate of 64.27% and the recovery rate of 77.65%. The obtained sulfide ore contains é“‹7.58%, sulfur 35.00%, hydrazine recovery rate of 13.77%, sulfur recovery. The rate is 5.40%. Therefore, it is effective to treat the ore according to the (jigging + shaker) classification rough selection-flotation desulfurization-strong magnetic selection process.

Third, the conclusion

(1) The tungsten ore crystal is coarse, the monomer is easily dissociated, and other harmful components are few, which is a simple and easy to choose ore.

(2) According to the mineralogical characteristics of the tungsten ore, the jigging + shaker grading rough selection-flotation desulfurization-strong magnetic selection process is suitable for treating the black tungsten-quartz vein type tungsten ore, which is contained in the original ore. When WO _{3 is} 0.51%, the obtained tungsten concentrate contains WO ₃ 64.27% and WO ₃ recovery rate of 77.65%; the sulfide ore contains 7.58% and sulfur content of 35.00%, and the corresponding recovery rate is 13.77% and sulfur is 5.40%.