Vibratory Separator,Vibratory Sieve,Vibrating Sifter Sieve,Vibratory Sieving Xinxiang Zhenying Mechanical Equipment Co., Ltd , https://www.beltconveyor.nl
1. Photoelectric beneficiation and heavy medium cyclones replace some manual hand selection.
2. The anti-repair type 2 jig began to replace the Su Xiu “Mhanoba†jig to process the ore of +4.5 m/m.
3. The centrifuge is used to treat fine mud.
4, the groove shaker has been widely promoted.
5. Black tungsten flotation begins to be used for production.
6. White tungsten flotation creates the experience of selection at room temperature.
The most common types of deposit industry in China are black tungsten- quartz mineral system (including Yunying rock type, feldspar -quartz type, quartz type) and white tungsten-quartz mineral system (including skarn type and quartz type). There are five types.
Quartz vein black tungsten deposit
The largest amount of burial is also the main source of tungsten production in China. Therefore, the experience in mineral processing is quite rich. The main experience is introduced below.
First, the beneficiation method
Since the black tungsten ore generally has a relatively large particle size, the difference in the specific gravity of the black tungsten mineral from the gangue mineral is also large, so it is usually selected by the re-election method. Since almost all of the plurality of tungsten ore deposit metal, more symbiotic minerals, crude concentrates obtained by reselection, since a large proportion of the associated minerals such as cassiterite and various sulfides along, or along part into the fine tungsten Mines, resulting in very low concentrate indicators, can not meet the smelting requirements, so coarse concentrates still need to use the combination of particle floatation, magnetic separation, electric selection, flotation, metallurgy and other processes to obtain a variety of qualified products. At the same time, it also solves the problem of comprehensive utilization.
Second, the beneficiation process and equipment
The mineral processing process consists mainly of rough selection, re-election and selected sections.
Rough selection
Including washing, crushing, deliming, hand-selecting operations.
China's black tungsten ore is mostly in the presence of thin veins, with many branches, complexes, and sharp changes. The depletion rate is high. A large number of waste stones need to be pre-selected before re-election. The main method currently adopted is: large-scale selection will be carried out. The raw ore is washed and sieved by hand, and the large waste rock of +250m/m is discarded. The -250m/m is broken to -150m/m and the third grade is used for backhand selection, of which 150~40m/m is high, and -40m/m is low; In the small and medium-sized factories, due to the small upper limit of the size of the ore, the general hand picks up +80m/m waste rock, and the -80m/m is divided into three levels for backhand selection. Some of the fine grain grades are selected by the forehand. Some plants choose photoelectric mining for 50~20m/m grain size ore, select waste rock, and manually select and remove tungsten and a few stones. Some mines insisted on testing, and finally successfully tested the heavy medium cyclone and the heavy medium vortex sorter. The former has been used for production, and the latter is currently in the trial production stage.
The content of -0.074 mm slime in each tungsten ore original ore is generally about 0.5% to 7%. If the slime cannot be effectively removed, it will make the selection difficult, and metal loss will occur when the hand is selected. Therefore, pre-washing before the hand selection is an indispensable operation.
The re-election section is the main part of the process, including rod grinding, jigging and rough selection.
The characteristic of the process is to implement the principle of “less grinding, multiple selection, early harvest, early loss and narrow classificationâ€. It adopts “three-stage jigging, multi-stage bed selection, tail-tail re-grinding, and the process of sorting or selecting the rich and poor in the shaker in the shaker.†The process adapts to the characteristics of tungsten ore and avoids over-grinding. The rough selection section has been strengthened. In order to strengthen the processing of coarse grade and slime, some of the selection plants used the anti-repair-II jig to process the original ore of +4.5m/m, and the selection index exceeded the “Mhanopur†jig, many Tungsten ore in the rough selection section before the selection of the opponent's selection of sieved products under the sieve to recover a part of the concentrate with a jig, improving the overall plant yield.
Selected section
It mainly includes combined operations such as Taifu, Taiwan Washing, Grinding, Magnetic Separation, Electric Election, Flotation, and Metallurgy.
China's tungsten ore is almost all polymetallic deposits, and it is found that the fine concentrates need to be selected to obtain qualified tungsten concentrates. Larger selection plants have selected sections. In addition, there are several fine factories that focus on the processing of fine concentrates from nearby small mines and folk songs.
The selection method is mainly to desulfurization by platform floatation and flotation, and re-election to further improve the grade. Magnetic separation separates the wolframite from cassiterite, white tungsten, strontium oxide or the like. Electro-optic or floating, flotation separation of white tungsten and cassiterite. Sulfides such as copper , molybdenum , niobium, lead , and zinc are separated by flotation and recovered into individual products. Ore dressing plant individual portions still need to arsenic removal by firing, tin, phosphorus acid leaching off so as to achieve the standard product. Some of the selection plants still have a synthetic white tungsten section to carry out hydrometallurgical treatment of refractory semi-finished products. The selection process of each factory varies with different raw materials. The selected qualified concentrates also often contain some rare elements and precious metals. For example, the wolframite may contain antimony, bismuth and antimony . Zinc concentrate may contain indium and cadmium . Molybdenum concentrate may contain antimony . Gold-bearing concentrate may pyrite. All should be determined by quantitative analysis in order to pay attention to recycling during the smelting process.
The method and sequence of separation of sulfide ore depends on the type of sulfide minerals in the coarse concentrate and its inlaid particle size. Common sulfide minerals in tungsten coarse ore are: molybdenite, stibnite, chalcopyrite, sphalerite, galena, pyrite, and arsenopyrite. Generally, molybdenum ore first floats out of the sulfide mineral mixed concentrate. There are three recovery schemes for stibnite: direct preferential flotation from crude tungsten concentrates; preferential flotation in self-sulfurized ore concentrates; other sulfide minerals in self-sulfided mineral concentrates and stibnite as tailings It usually contains more gangue and wolframite, which need to be removed by shaker selection and magnetic separation. The order of separation is: molybdenum ore, stibnite, galena, chalcopyrite, sphalerite, pyrite. The volcanic ore bismuth ore is very similar in floatability, and is generally mixed for smelting and then separated. The fine particles are floated and the coarse particles are floated.
The outstanding problem in the current selection is that the fine recovery rate of the fine mud concentrate is low. Some of the high tin fine mud concentrates have a large loss of dry magnetic separation and chlorination roasting, and sometimes there is no qualified product.
The selection of foreign black tungsten ore, according to the information has been introduced, generally using the platform floating, flotation, magnetic separation and other means. For difficult-to-select low-grade concentrates, water-smelting treatment is often used.
Third, the determination of the test plan
According to the material composition characteristics of tungsten-tin quartz vein ore, with reference to the selection scheme of the same type of ore, especially the rich experience of tungsten ore beneficiation in China, the test plan is determined as follows according to the policy of strengthening comprehensive utilization.
(1) Determination of mineral processing method
According to the results of the study of the composition of matter, the main symbiotic minerals in the ore are black tungsten ore, cassiterite, scheelite, chalcopyrite, sphalerite, and their specific gravity is more than 4, and the size of the inlay is coarser. The longest crystal of the black tungsten ore is more than 20 cm, and the maximum particle size of the single crystal of the cassiterite is 2 to 3 cm, generally 1 cm, so it is suitable for the re-election method. The re-election method is a common and effective method for tungsten-tin ore.
Since the symbiotic minerals are relatively large in weight, they are mostly enriched in the coarse concentrate during the re-election process. From the multi-element chemical analysis of crude concentrate (Table 1), phase analysis (Table 2), it can be seen that the associated useful minerals are high and the grade is high. If the coarse concentrate is not selected, it is impossible to obtain qualified products, and the national resources are also Not fully utilized. In order to make full use of national resources, rough concentrates must be selected to separate their useful minerals and remove their harmful impurities.
Table 1 Multi-element analysis results of coarse concentrate
Table 2 Results of crude mineral phase analysis
The selection of the selection method is mainly based on the difference in physical and chemical properties of the symbiotic minerals in the coarse concentrate, and the separation is carried out by various methods using this difference. The use of one method alone or a combination of several methods depends on the type of tungsten concentrate and the type, content and nature of the impurities contained therein.
From the multi-element analysis of crude concentrate (Table 1) and the results of phase analysis (Table 2), it can be known that the main useful minerals in coarse concentrate are wolframite, scheelite, cassiterite, chalcopyrite, sphalerite, etc. The main harmful impurities are arsenic, sulfur and the like. There is a wealth of experience in the selection of this type of concentrate, and the combined method is generally used: de-sulfurization by flotation and flotation, and re-election to further improve the grade. The magnetic separation method separates black tungsten from cassiterite and white tungsten. Separation of scheelite and cassiterite by electric separation or particle floatation and flotation. Sulfides such as copper, zinc and arsenic are separated from each other by flotation and recovered into individual products.
(II) Determination of the rough selection process
According to the ore dressing experience of similar ore, it is determined that the rough selection section adopts stage grinding, stage selection, enhanced hand selection, reuse of jigging, coarse grain acceptance, sand mud sorting, medium mine re-grinding and re-election, and single treatment of fine mud. Re-election process.
1. Ore preparation
Hand selection and washing
Hand selection
Due to the side curtain arrangement of the veins, the phenomenon of sharp-cut side, branching compound, bending torsion and expansion and shrinkage is more significant, resulting in the depletion rate of the ore ore being as high as 60.05%, and the ore grade WO 3 0.542%, Sn0.223. %. The large amount of surrounding rock is mixed into the ore, which increases the difficulty of beneficiation. Therefore, it is necessary to pre-select the surrounding rock. At the same time, the useful minerals have relatively coarse crystals, which should also be selected in advance. Because they differ from the vein quartz and surrounding rock in color and gloss, they are suitable for hand selection. After hand selection, the sample depletion rate was 41.9%, and the grade was WO 3 0.765%, Sn 0.314%.
Washing
According to the -20 mm raw ore sieve: -0.074 mm, the content is 4.95%, WO 3 0.478%, Sn 0.761%, Cu 0.173%, Zn 0.769%. Useful minerals have a high level of material, such as adhesion to the surface of surrounding rock and coarse ore particles, which will cause metal loss during hand selection. At the same time, the original color and luster of minerals and surrounding rocks are not obvious, making it difficult to carry out the selection, so it is necessary to wash the mine before the selection.
Heavy medium dressing
The results of the heavy liquid separation test indicate that the ore is not suitable for heavy medium beneficiation. The reason is that the specific gravity of the surrounding rock (2.73~2.86) is larger than the specific gravity of the gangue (2.60~2.65), and it is impossible to select the surrounding rock. The continuous body smaller than the surrounding rock or the proportion of the surrounding rock will float together with the surrounding rock, causing a large amount of metal. loss. Only hand selection can be considered.
Heavy medium ore dressing has a high degree of mechanization, high labor productivity, and high sorting effect, but it is not suitable for the sorting of ore and large surrounding rock with a specific gravity ratio of surrounding rock to the gangue, especially the ore contains more light weight. It is even more unacceptable when it comes to associated minerals.
2. Determination of the selected granularity
According to the separation of raw ore monomer: 20 ~ 12 mm, only black and white tungsten has 12% monomer, 20 mm is too thick. 12 to 6 mm, black and white tungsten monomer up to 30%, tin stone up to 12%, this particle size is suitable.
3. Number of grinding sections and particle size
According to the original ore monomer dissociation table, most of the useful minerals of the 0.5-0.3 mm class have been separated, so the final grinding particle size is set to 0.5 mm. If the -12 mm ore is ground to -0.5 mm at a time, the grinding ratio is large and it is easy to be crushed. Therefore, it is divided into two sections. The first section is ground to 2 mm, the second section is grounded to -0.5 mm, and a section is selected. (Most of the domestic tungsten preparation plants are two-stage grinding, inserting a section of the selection, implementing less grinding and multiple selection, and receiving early harvest).
4, mud processing
Mud (-74μ) domestic tungsten selection plants are mostly divided into primary and secondary, respectively, centralized treatment.
The rough selection test process is shown in Figure 1. 
(3) Determination of the rough selection process
1. Main basis for drafting the selection process
(1) Requirements of production department and design department. In the coarse concentrate, 12 to 6 mm is used for hand-selected tungsten block test. The coarse concentrate is crushed to 6 mm, 6 to 2 mm for jigging and enrichment, and the jigging concentrate is magnetically selected to obtain black tungsten concentrate.
(2) The types of symbiotic minerals in the coarse concentrate and their mutual symbiotic relationship are the main basis for determining the selection process. According to the multi-element chemical analysis, phase analysis and rock and mineral identification of coarse concentrates, it is known that the symbiotic minerals of this ore are more and more complex and need to be treated by a joint method.
(3) Types and forms of impurities in coarse concentrates. The main impurities in this coarse concentrate are arsenic and sulfur, which should be removed as much as possible. Among them, a variety of symbiotic minerals should be selected as separate products to ensure the quality of tungsten-tin concentrate and comprehensive utilization of raw materials.
(4) User requirements for final concentrate quality.
(5) Select the exploration test results and draw the following conclusions through experiments:
Desulfurization
The coarse grade (3 to 0.5; 0.5 to 0.2 mm) is floated with a table, and the fine grade (-0.2 mm) is floated.
Selected granularity
3 mm, 2 mm is not available, refer to the current factory to take 2 mm.
Magnetic separation of black tungsten
The coarse-grained coarse ore concentrate and the sweeping concentrate should be separately magnetically selected. The black tungsten can be qualified after the magnetic separation of the coarse-grained concentrate. After the magnetic separation of the concentrate, the black tungsten is unqualified, but the amount is small and can be incorporated. .
Electro-selection separation of cassiterite and white tungsten
The effect of +1 mm is not good, they are all broken to -1 mm, and then graded and selected. The obtained tin concentrate needs to be magnetically selected and floated to obtain a qualified tin concentrate.
2. The principle of the selected test principle is shown in Figure 2.
3. Discussion on several issues in the selection process
Granular floating bed desulfurization
The useful minerals are mainly cassiterite, white tungsten and a small amount of black tungsten, which are mostly continuous, and the gangue accounts for the majority. Grinding, grading, re-election of degaussing stones, desulfurization, electric separation, magnetic separation and recovery of tungsten and tin. According to the dissociation degree of the main mineral monomers, the grinding fineness should be 0.5 mm, and the classification should be carried out in bed.
-0.2 mm sulfide treatment
Including flotation desulfurization tailings, -0.2 mm desulfurization tailings after granulating ore grinding, -0.2 mm grain size after +1 mm magnetic separation tailings, etc., direct flotation separation of scheelite The result was unqualified. After the use of the shaker to lose the gangue, no classification, a coarse two fine magnetic selected black tungsten concentrate, tailings and then separated stellite. Before the separation, the tailings sieve is divided into two grades, +0.074 mm into the electricity, and -0.074 mm into the flotation. However, the +0.074 mm elective tailings must be further stripped of tin to obtain a white tungsten concentrate. How to achieve another 0.074 mm screening industry has yet to be resolved.
Copper, zinc and arsenic separation
Mixed sulphide ore obtained by flotation and -0.2 mm flotation, mainly composed of chalcopyrite, sphalerite, arsenopyrite, pyrite, containing a small amount of tungsten-tin minerals, few gangues, and copper-zinc minerals the Lord.
The crystal size of copper minerals is generally 0.16 mm, and many chalcopyrites are malformed with 0.018 mm irregularly dispersed in sphalerite. According to the separation of 0.3-0.15 mm monomer of the original ore: 67% of chalcopyrite; 90% of sphalerite. The suitable grinding fineness is determined to be 80% to 85% to 200 mesh.
Principle process: priority float copper, then zinc-arsenic mixed float and then separated.
Tungsten ore dressing test plan selection
China is the country with the largest number of tungsten selection plants in the world, so it has accumulated a lot of experience in tungsten beneficiation , especially since the Cultural Revolution has adopted many new technologies and equipment:
element
WO 3
Sn
Cu
Zn
As
S
Mn
V 2 O 3
content(%)
9.25
3.26
1.3
3.74
14.85
14.93
0.85
0.06
element
TiO 2
Cd
Al 2 O 3
element
Au
Ag
content(%)
0.32
0.16
4.09
content
(g / ton)
0.032
138.44
project
Tungsten
White tungsten
Black tungsten
meter
content(%)
0.056
4.524
4.450
9.030
distributed(%)
0.60
50.10
49.30
100.00
project
Colloidal tin
Yanxi Mine
锡石
meter
content(%)
0.054
0.097
3.180
3.331
distributed(%)
1.60
2.90
95.50
100.00
project
Copper sulphide
Copper oxide
Copper sulfate
meter
content(%)
1.164
0.0051
0.0033
1.1724
distributed(%)
99.28
0.44
0.28
100.00
project
Zinc sulfide
Zinc oxide
Zinc sulfate
Zinc ferrite
meter
content(%)
3.47
0.328
0.0096
0.00625
3.8701
distributed(%)
89.66
8.48
0.25
1.61
100.00
Figure 1 Test procedure for rough selection of a tungsten-tin quartz vein ore
(For some reason, the chart is unclear, you can call for free if you need it)
Figure 2 A tungsten-tin quartz vein ore selection test principle process
(For some reason, the chart is unclear, you can call for free if you need it)