Method for separating tin and enriching tungsten from high-tin tungsten ore

Abstract

The invention discloses a method for separating tin and enriching tungsten from high-tin tungsten ore, and belongs to the technical field of extraction metallurgy, the method comprises the following steps: heating the high-tin tungsten ore material for high-temperature vacuum melting, cooling the obtained sublimate to obtain a condensate rich in tin, and obtaining the tungsten ore with lower tin content as the residue; according to the method, the high-tin tungsten ore is subjected to vacuum melting, tin oxide in the high-tin tungsten ore is vulcanized and sublimated under the high-temperature condition, the condensate rich in tin is obtained through cooling, tin in the high-tin tungsten ore is effectively separated and recycled, and tungsten in the ore material is enriched; the method is simple, the high-tin tungsten ore is used as the raw material, no additive is needed, the problem that tin in the high-tin tungsten ore is difficult to treat is solved, enrichment of tungsten in the high-tin tungsten ore and utilization of metal are promoted, benefits are increased, and no pollution is caused to the environment.

Description

Technical Field

[0001] The invention belongs to the technical field of extraction metallurgy, and in particular relates to a method for separating tin-enriched tungsten from high-tin tungsten ore. Background Art

[0002] Tungsten is an important strategic metal, widely used in cemented carbide, machinery manufacturing, electronics, space navigation and other fields. In tungsten deposits, tungsten is mainly enriched in the form of tungstates, among which the most economically important minerals are tungsten ore and scheelite. In recent years, with the increasing depletion of high-grade tungsten ores, the treatment of tungsten ores with complex composition and low grade, such as tungsten ores with high tin content, has attracted more and more research attention. The tin content needs to be strictly controlled during tungsten smelting, so some tin will enter the tailings during tungsten flotation. For example, about 1,500 tons of tin are discharged into the tailings every year in Shizhuyuan tungsten mine, causing an annual loss of about 80 million US dollars. In industry, the traditional alkaline leaching method is generally used to treat tin-containing tungsten ores. During the leaching process, tungsten enters the leaching solution, and a large amount of tin remains in the decomposition slag. The national standard requires that the tin content in ammonium paratungstate be below 2ppm, so it is also necessary to thoroughly remove the tin from the sodium tungstate leaching solution. In addition, the tin content in the decomposition slag is low, and it is difficult to recycle it economically. It is often disposed of by outdoor storage or landfill, which causes great pollution to the environment.

[0003] In order to reduce the leaching rate of tin during alkaline leaching, the existing technology uses oxidative roasting or reduction smelting to treat tin-containing tungsten ore. However, the sodium tungstate solution leached from the oxidative roasting slag still has a high tin content, which must be removed in subsequent treatment; reduction smelting mainly adds reducing agents and sulfiding agents, and tin-iron alloy phases are easily generated during the reduction process, which inhibits the volatilization of tin and results in a high tin residual rate in the tungsten ore. Summary of the invention

[0004] In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides a method for separating tin-enriched tungsten from high-tin tungsten ore. The high-tin tungsten ore is heated and subjected to high-temperature vacuum smelting. The obtained sublimate is cooled to obtain a tin-rich condensate, thereby achieving the separation of tin and the enrichment of tungsten.

[0005] In order to achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0006] A method for separating tin-enriched tungsten from high-tin tungsten ore, comprising the following steps:

[0007] The high-tin tungsten ore is heated and smelted in a high-temperature vacuum. The sublimate is cooled to obtain a condensate rich in tin, and the residue is a tungsten ore with a lower tin content.

[0008] Preferably, the element composition of the high-tin tungsten ore includes: O 33.98wt%, W 9.41wt%, Sn8.74wt%, Fe7.49wt%, Al 6.58wt%, F 5.41wt%, S 4.98wt%, Zn 3.69wt%, Ca2.98wt%, Mn 1.66wt%, and the rest are unavoidable impurities.

[0009] Preferably, the temperature of the vacuum melting is 1100-1300° C., the heating rate is 5-30° C. / min, the vacuum degree of the vacuum melting is 5-10 Pa, and the time of the vacuum melting is 0.5 h-3 h.

[0010] Preferably, the apparatus used for vacuum melting is a vertical vacuum furnace.

[0011] Preferably, the cooling rate is 5-10°C / min.

[0012] Preferably, the cooling is performed under a vacuum atmosphere.

[0013] The present invention uses tungsten ore with a tin content of 8.74wt% as a raw material to extract, separate and recover tin, thereby improving the utilization rate of metal resources in high-tin tungsten ore, solving the problem of difficult tin treatment in tungsten ore, and promoting the enrichment of tungsten in tungsten ore. No additives are required, the treatment cost is lower, the operation process is simple, and there is no pollution to the environment.

[0014] The invention subjects high-tin tungsten ore to vacuum smelting, controls the temperature and vacuum degree of vacuum smelting, causes tin in the tungsten ore to volatilize through sulfidation, and obtains a condensate rich in tin after secondary temperature-controlled cooling, thereby effectively separating and recycling the tin in the tungsten ore, improving the utilization rate of metal resources in the mine, solving the problem of difficult tin treatment in the tungsten ore, and promoting the enrichment of tungsten in the tungsten ore, without any additives, lowering the treatment cost, and having a simple operation process without pollution to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the structure of a graphite crucible and a condensation plate used in an embodiment of the present invention;

[0016] Figure 2 This is a physical picture of the residue after vacuum smelting of the high-tin tungsten ore obtained in Example 1 of the present invention;

[0017] Figure 3 This is the XRD pattern of the condensate obtained in Example 1 of the present invention;

[0018] Figure 4 This is a physical picture of the residue after vacuum smelting of the high-tin tungsten ore obtained in Example 2 of the present invention;

[0019] Figure 5This is a physical picture of the residue after vacuum smelting of the high-tin tungsten ore obtained in Example 3 of the present invention. DETAILED DESCRIPTION

[0020] In order to further illustrate the present invention, the method for vacuum separation and recovery of tin from high-tin tungsten ore provided by the present invention is described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0021] In the present invention, unless otherwise specified, all raw materials are commercially available products well known to those skilled in the art.

[0022] In the present invention, the element composition of the high-tin tungsten ore includes: O 33.98wt%, W 9.41wt%, Sn 8.74wt%, Fe 7.49wt%, Al 6.58wt%, F 5.41wt%, S 4.98wt%, Zn 3.69wt%, Ca 2.98wt%, Mn1.66wt%, and the rest are unavoidable impurities.

[0023] In the present invention, each element in the high-tin tungsten ore exists in the form of SnO2, FeWO4, MnWO4, Al2O3 and FeS2.

[0024] Example 1

[0025] Take a certain amount of high-tin tungsten ore in a beaker, place the beaker in a drying oven at 150℃ for 2 hours to remove the moisture in the high-tin tungsten ore, weigh 20g of the dried high-tin tungsten ore and place it in a graphite crucible. Add a graphite condensation plate and a crucible cover to the graphite crucible. Figure 1 As shown, a double-layer condensation tray is set with the steam ports of the double-layer condensation tray staggered. The crucible is moved into the vacuum furnace, the vacuum furnace cover is covered, the vacuum furnace and cooling water control switches are turned on, the vacuum pump is started, the air pressure in the vacuum furnace is evacuated to below 10Pa, and then the vacuum furnace is controlled to heat up to 1100℃ at a heating rate of 10℃ / min, and kept at 1100℃ for 2h. After the vacuum smelting is completed, the vacuum furnace heating switch is turned off, and the material is cooled to room temperature at a rate of 10℃ / min. After turning off the vacuum pump and cooling water switch, the exhaust valve is opened, and the crucible is taken out. The condensate in the condensation tray is rich in tin, and the residue is low-tin tungsten ore enriched in tungsten. Figure 2 This is a physical picture of low-tin tungsten ore with tungsten enriched in the residue; the composition of the condensate and the residue is shown in Table 1.

[0026] Table 1

[0027]

[0028] It can be seen from Table 1 that the treatment method of this embodiment can reduce the tin content in the tungsten ore to 0.79 wt %, and the tin content in the condensate reaches 76.20 wt %.

[0029] Example 2

[0030] Take a certain amount of high-tin tungsten ore in a beaker, place the beaker in a drying oven at 150℃ for 2h, remove the moisture in the high-tin tungsten ore, weigh 20g of the dried high-tin tungsten ore and place it in a graphite crucible. Add a graphite condensation plate and a crucible cover to the graphite crucible. Figure 1 The crucible is moved into the vacuum furnace, the vacuum furnace cover is closed, the vacuum furnace and cooling water control switches are turned on, the vacuum pump is started, the vacuum pump pressure in the furnace is evacuated to below 10Pa, and then the vacuum furnace is controlled to heat up to 1200℃ at a heating rate of 10℃ / min, and kept at 1200℃ for 2h. After the vacuum melting is completed, the vacuum furnace heating switch is turned off, and the material is cooled to room temperature at a rate of 10℃ / min. After turning off the vacuum pump and cooling water switch, the crucible is taken out after opening the exhaust valve. The condensate in the condensate tray is a condensate rich in tin. The XRD pattern of the condensate is as shown in Figure 3 As shown, the main components are Sn, SnS, and ZnS; the residue is low-tin tungsten ore enriched in tungsten, as shown in the actual picture Figure 4 The compositions of the condensate and the residue are shown in Table 2.

[0031] Table 2

[0032]

[0033] It can be seen from Table 2 that the tin in the tungsten ore can be reduced to 0.07 wt % and the tin in the condensate can reach 46.08 wt % through the treatment method of this embodiment.

[0034] Example 3

[0035] Take a certain amount of high-tin tungsten ore in a beaker, place the beaker in a drying oven at 150℃ for 2h, remove the moisture in the high-tin tungsten ore, weigh 20g of the dried high-tin tungsten ore and place it in a graphite crucible. Add a graphite condensation plate and a crucible cover to the graphite crucible. Figure 1 The crucible is moved into the vacuum furnace, the vacuum furnace cover is closed, the vacuum furnace and cooling water control switches are turned on, the vacuum pump is started, the air pressure in the vacuum furnace is pumped down to below 10Pa, and then the vacuum furnace is controlled to heat up to 1300℃ at a heating rate of 10℃ / min, and kept at 1300℃ for 2h. After the vacuum melting is completed, the vacuum furnace heating switch is turned off, and the material is cooled to room temperature at a rate of 10℃ / min. After the vacuum pump and cooling water switch are turned off, the crucible is taken out after opening the exhaust valve, and the condensate is obtained in the condensation tray; the actual picture of the residue is as shown in the figure Figure 5 The composition of the condensate and residue is shown in Table 3.

[0036] Table 3

[0037]

[0038] As can be seen from Table 3, the treatment method of this embodiment can reduce the tin in the tungsten ore to 0.083wt%, while the tin in the condensate is 0.68wt%. This is because the smelting temperature is too high, and the tin volatilizes violently, taking away part of the tungsten ore powder into the condensate tray. Under the condition of 1300°C, the temperature of the condensate tray area is high, and the desublimation temperature of the tin-containing sublimates is not reached, and it is difficult to collect the tin condensate, so the material in the condensate tray is mainly tungsten-containing material. It can be seen from Examples 1, 2, and 3 that the optimal temperature for vacuum smelting of high-tin tungsten ore is 1200°C.

[0039] Example 4

[0040] Take a certain amount of high-tin tungsten ore in a beaker, place the beaker in a drying oven at 150℃ for 2h, remove the moisture in the high-tin tungsten ore, weigh 20g of the dried high-tin tungsten ore and place it in a graphite crucible. Add a graphite condensation plate and a crucible cover to the graphite crucible. Figure 1 The crucible is moved into the vacuum furnace with a device, and the vacuum furnace cover is covered. The vacuum furnace and cooling water control switches are turned on, and the vacuum pump is started. The air pressure in the vacuum furnace is evacuated to below 5Pa, and then the vacuum furnace is controlled to heat up to 1200℃ at a heating rate of 5℃ / min, and kept at 1200℃ for 0.5h. After the vacuum smelting is completed, the vacuum furnace heating switch is turned off. When the material is cooled to room temperature at a rate of 5℃ / min, the vacuum pump and cooling water switch are turned off, and the crucible is taken out after opening the exhaust valve. The condensate in the condensate tray is tin-rich condensate, and the residue is tungsten-enriched low-tin tungsten ore.

[0041] Example 5

[0042] Take a certain amount of high-tin tungsten ore in a beaker, place the beaker in a drying oven at 150℃ for 2h, remove the moisture in the high-tin tungsten ore, weigh 20g of the dried high-tin tungsten ore and place it in a graphite crucible. Add a graphite condensation plate and a crucible cover to the graphite crucible. Figure 1 The crucible is moved into the vacuum furnace with a device, and the vacuum furnace cover is covered. The vacuum furnace and cooling water control switches are turned on, and the vacuum pump is started. The air pressure in the vacuum furnace is evacuated to below 8Pa, and then the vacuum furnace is controlled to heat up to 1200℃ at a heating rate of 30℃ / min, and kept at 1200℃ for 3h. After the vacuum smelting is completed, the vacuum furnace heating switch is turned off. When the material is cooled to room temperature at a rate of 8℃ / min, the vacuum pump and cooling water switch are turned off, and the crucible is taken out after opening the exhaust valve. The condensate in the condensate tray is tin-rich condensate, and the residue is tungsten-enriched low-tin tungsten ore.

[0043] It can be seen from the above examples that the separation effect is better as the vacuum melting time is prolonged.

[0044] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for separating tin-enriched tungsten from high-tin tungsten ore, characterized in that: The following steps are involved: The high-tin tungsten ore is subjected to high-temperature vacuum smelting, and the resulting sublimate is cooled to obtain a tin-rich condensate, and the residue is a tungsten ore with a lower tin content.

2. The method for separating tin-enriched tungsten from high-tin tungsten ore according to claim 1, characterized in that: The mass fractions of the elements in the high-tin tungsten ore are: O 33.98%, W 9.41%, Sn 8.74%, Fe 7.49%, Al 6.58%, F 5.41%, S 4.98%, Zn 3.69%, Ca 2.98%, Mn 1.66%, and the rest are unavoidable impurities.

3. The method for separating tin-enriched tungsten from high-tin tungsten ore according to claim 1, characterized in that: The temperature of the vacuum melting is 1100-1300° C., the heating rate is 5-30° C. / min, the vacuum degree of the vacuum melting is 5-10 Pa, and the time of the vacuum melting is 0.5h-3h.

4. The method for separating tin-enriched tungsten from high-tin tungsten ore according to claim 1, characterized in that: The cooling rate is 5-10°C / min.

5. The method for separating tin-enriched tungsten from high-tin tungsten ore according to claim 1, characterized in that: The cooling is performed in a vacuum atmosphere.

Images