阅读说明：本技术 一种利用含水硅酸钠从含钨原料中提取钨的方法 (Method for extracting tungsten from tungsten-containing raw material by using hydrous sodium silicate ) 是由 孙伟 胡岳华 刘航 陈攀 韩海生 杨磊 于 2020-11-25 设计创作，主要内容包括：本发明公开了一种利用含水硅酸钠从含钨原料中提取钨的方法,将含钨物料与含水硅酸钠混合研磨后,先进行焙烧脱水,再进行高温烧结,所得烧结料采用水浸出,得到钨酸钠溶液。该方法对含钨原料中的钨含量要求极低,WO-3品位低至0.5％仍然可完成高效分解和提取,可处理低品位黑/白钨矿精矿、钨冶炼渣、含钨催化剂、含钨废合金等,极大程度上降低了传统钨提取方法中对含钨物料中钨含量的高要求。(The invention discloses a method for extracting tungsten from a tungsten-containing raw material by using aqueous sodium silicate. The method has extremely low requirement on the content of tungsten in the tungsten-containing raw material, and WO 3 Can complete high-efficiency decomposition and extraction with the grade as low as 0.5 percent, can treat low-grade black/white tungsten ore concentrate, tungsten smelting slag, tungsten-containing catalyst, tungsten-containing waste alloy and the like, and greatly reduces the tungsten content in tungsten-containing materials in the traditional tungsten extraction methodHigh requirements are imposed.)

1. A method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate is characterized in that: mixing and grinding tungsten-containing materials and aqueous sodium silicate, roasting for dehydration, and then sintering at high temperature, wherein the obtained sintered materials are leached by water to obtain a sodium tungstate solution.

2. The method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate according to claim 1, characterized in that: the mixing proportion of the tungsten-containing material and the hydrous sodium silicate meets the following requirements: the molar ratio of sodium to tungsten is > 2 and the molar ratio of silicon to calcium is > 1.

3. The method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate according to claim 1, characterized in that: the tungsten-containing material and the aqueous sodium silicate are mixed and ground to a particle size of less than 74 mu m.

4. A process according to any one of claims 1 to 3 for the extraction of tungsten from a tungsten-containing feedstock using aqueous sodium silicate, characterised in that:

the tungsten-containing material is at least one of scheelite concentrate, wolframite and wolframite bulk concentrate, wolframite middling, wolframite smelting slag, waste tungsten catalyst and tungsten-containing waste alloy;

the hydrous sodium silicate is at least one of sodium metasilicate nonahydrate, sodium metasilicate pentahydrate and water glass.

5. The method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate according to claim 1, characterized in that: the roasting dehydration conditions are as follows: the temperature is 50-300 ℃, and the time is 5-20 minutes.

6. The method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate according to claim 1, characterized in that: the conditions of the high-temperature sintering are as follows: the temperature is 600-1000 ℃, and the time is 10-200 minutes.

7. The method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate according to claim 1, characterized in that: the sintered material is ground to a particle size of less than 45 μm.

8. The method for extracting tungsten from tungsten-containing raw materials by using aqueous sodium silicate according to claim 1, characterized in that: the leaching conditions are as follows: the water temperature is 15-95 ℃, the liquid-solid ratio is 1-10 mL:1g, and the leaching time is 10-200 minutes.

Technical Field

The invention relates to a tungsten extraction method, in particular to a method for extracting tungsten from a tungsten-containing raw material by using hydrous sodium silicate, belonging to the technical field of tungsten ore smelting.

Background

To extract the tungsten element from the tungsten-containing material, the tungsten element is usually enriched by a physical separation method and then decomposed and extracted by a decomposition reagent. For example, in a traditional dressing and smelting process, raw ore containing wolframite/scheelite is subjected to physical separation processes such as gravity separation, magnetic separation, flotation and the like to obtain wolframite/scheelite concentrates, the wolframite/scheelite concentrates are sent to a wolfram smeltery, and then tungsten elements in the wolframite concentrates are converted into sodium tungstate/tungstic acid/phosphotungstic acid and the like through processes such as alkaline leaching, acid leaching, sodium salt roasting, water leaching and the like, and the tungsten elements are separated from calcium, iron and manganese, so that the primary extraction of the tungsten is realized. The method is a continuous idea for extracting tungsten from tungsten ore dressing middling, tungsten smelting slag, waste tungsten catalysts and tungsten-containing waste alloys.

However, such conventional tungsten extraction schemes have a number of disadvantages:

for refractory tungsten ores such as low-grade tungsten ores, micro-fine tungsten ores and complex accompanying tungsten ores, the beneficiation method can also enrich tungsten in the refractory tungsten ores, but the enrichment degree is low, for example, the tungsten element content of a certain micro-fine tungsten ore can be enriched from 0.3% to about 5% through flotation, but the product cannot be sold, because the requirement of a tungsten smelting plant on the tungsten content is not met.

The tungsten smelting plant has higher requirement on the tungsten content in the tungsten raw material, and WO in the standard tungsten concentrate is added according to the tungsten concentrate quality standard YS/T231-₃The content of WO in the tungsten fine mud is required to be higher than 50 percent₃The content is higher than 30%, and the traditional tungsten metallurgy decomposition process is applied to WO₃The minimum requirement of the content is also more than 20 percent. With the large consumption of rich ore, the beneficiation process does not support the enrichment of tungsten in refractory ore to metallurgical grade.

With the industrial development, a large amount of non-traditional tungsten resources emerge, and the tungsten resources have various characteristics, such as fine granularity, low grade and existence of a large amount of amorphous substances of tungsten smelting slag; tungsten in the waste tungsten catalyst and the waste tungsten alloy does not exist in a mineral form, the difference of the tungsten content is great, and the traditional smelting process cannot digest non-traditional tungsten resources.

Therefore, a method for decomposing low-grade tungsten-containing materials with high quality and low price is urgently needed to solve the problems.

Disclosure of Invention

Aiming at the defect that the traditional tungsten ore smelting method in the prior art is difficult to extract tungsten resources in non-traditional low-grade tungsten ore, the invention aims to provide the method for efficiently converting tungsten ore which is difficult to leach into sodium tungstate which is easy to leach by decomposing tungsten-containing raw materials at high temperature by using hydrous sodium silicate and realizing tungsten resource recovery.

In order to realize the technical purpose, the invention provides a method for extracting tungsten from a tungsten-containing raw material by using hydrous sodium silicate.

The key point of the technical scheme is that hydrous sodium silicate is used as a tungsten ore decomposition reagent, the hydrous sodium silicate is dehydrated at a lower temperature, and is decomposed into high-activity nano-scale sodium silicate particles in the dehydration process, the surface area of the hydrous sodium silicate particles is extremely large, the contact area of the hydrous sodium silicate particles and tungsten-containing raw materials is greatly increased, and the hydrous sodium silicate particles can be tightly attached to the surface of tungsten-containing materials, so that the high-activity nano-scale sodium silicate particles can better act on the tungsten-containing materials compared with common sodium silicate particles, and tungsten ores in the hydrous sodium silicate particles can be efficiently converted into soluble sodium tungstate. When the tungsten-containing material contains calcite, limestone and dolomite, calcium oxide is generated in the roasting process, the calcium oxide can be combined with sodium tungstate in the water leaching process to form calcium tungstate secondary precipitation, the leaching rate of tungsten is reduced, and calcium and the like can be generated into stable substances such as calcium silicate, sodium calcium silicate and the like in the roasting process by the silicon part in the hydrous sodium silicate, so that calcium and the like are fixed, the formation of secondary scheelite is avoided, and the efficient recovery of tungsten in the tungsten-containing material is realized.

As a preferred scheme, the mixing proportion of the tungsten-containing material and the hydrous sodium silicate meets the following requirements: the molar ratio of sodium to tungsten is > 2 and the molar ratio of silicon to calcium is > 1. Sodium in the hydrous sodium silicate mainly realizes the conversion of tungsten ore in tungsten-containing materials, and silicon is mainly used for fixing calcium and the like to prevent the secondary generation of calcium tungstate, so that a better tungsten extraction effect can be obtained by controlling the tungsten-sodium ratio and the silicon-calcium ratio.

As a preferred scheme, the tungsten-containing material and the aqueous sodium silicate are mixed and ground to have the particle size of less than 74 mu m. Sufficient contact between the tungsten-containing material and the aqueous sodium silicate particles can be achieved after grinding.

As a preferable scheme, the tungsten-containing material is at least one of scheelite concentrate, wolframite middling, tungsten smelting slag, waste tungsten catalyst and tungsten-containing waste alloy.

As a preferable scheme, the hydrous sodium silicate is at least one of sodium metasilicate nonahydrate, sodium metasilicate pentahydrate and water glass. Aqueous sodium silicates such as Na₂SiO₃·9H₂O、Na₂SiO₃·5H₂O, NaO nSiO, etc. can remove crystal water at high temperature to obtain high-activity nano-grade sodium silicate particles.

As a preferable scheme, the roasting dehydration condition is as follows: the temperature is 50-300 ℃, and the time is 5-20 minutes. The preferred temperature is 150 to 250 ℃. The crystal water of the hydrous sodium silicate can be effectively removed at the optimal temperature, and the high-activity and high-specific surface area sodium silicate particles are obtained, thereby being beneficial to the subsequent sintering process.

As a preferred scheme, the conditions of the high-temperature sintering are as follows: the temperature is 600-1000 ℃, and the time is 10-200 minutes.

As a preferred solution, the sinter is ground to a particle size of less than 45 μm. The sintering material is ground to a proper granularity, so that the leaching efficiency of the sintering material is improved.

As a preferred scheme, the leaching conditions are as follows: the water temperature is 15-95 ℃, the liquid-solid ratio is 1-10 mL:1g, and the leaching time is 10-200 minutes. Stirring conditions can be properly increased in the leaching process to improve the leaching efficiency.

Compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:

according to the technical scheme, the hydrous sodium silicate is used as a reagent for decomposing tungsten ore, the processes of low-temperature dehydration and high-temperature sintering are combined, the tungsten ore in the tungsten ore can be fully converted into sodium tungstate which is easy to dissolve in water by using sodium resources in the hydrous sodium silicate, calcium and the like in the tungsten ore are fixed by using silicon resources in the hydrous sodium silicate, and secondary generation of calcium tungstate is prevented, so that efficient recovery of tungsten in tungsten-containing materials is realized.

According to the technical scheme, the water-containing sodium silicate can be decomposed into high-activity nano-scale sodium silicate particles in the low-temperature dehydration process, the surface area of the nano-scale particles is extremely large, the contact area of the nano-scale particles with a tungsten-containing raw material is greatly increased, the nano-scale particles can be tightly attached to the surface of the tungsten-containing material and can better act on the tungsten-containing material, and the tungsten ore in the tungsten-containing material is promoted to be efficiently converted into soluble sodium tungstate.

The technical scheme of the invention adopts the water-containing sodium silicate as a commodity reagent, has low cost and is beneficial to large-scale production and application.

Drawings

FIG. 1 shows a variation process of a dehydrated material of a mixture of hydrous sodium silicate and a tungsten-containing material;

FIG. 2 shows a principle flow of a tungsten concentrating mill;

FIG. 3 is a process flow diagram.

Detailed Description

For the convenience of clear understanding of the technical solutions of the present invention, the following detailed descriptions of the present invention are provided with reference to the following examples, which are not intended to limit the scope of the claims of the present invention.

Example 1

The principle flow of a certain black/white tungsten concentrating plant is shown in figure 2, the black and white tungsten concentrate of the concentrating plant reaches the concentrate standard, but the grade of tungsten middling products cannot meet the metallurgical requirement due to the fine granularity, and the tungsten middling products are stockpiled in a warehouse; in addition, the metallurgy of the existing black/white tungsten ore is usually separated, so a large number of magnetic separators are needed in a concentrating mill to magnetically separate the black/white tungsten concentrate.

The method of the invention adopts hydrous sodium silicate as a tungsten ore decomposition reagent to respectively carry out sodium salt roasting and water immersion tests on the white tungsten concentrate, the black/white tungsten mixed concentrate and the tungsten middling, and the method comprises the following specific operation steps: firstly, uniformly mixing water-containing sodium silicate and a tungsten-containing material according to a certain proportion, then grinding the mixed material until the particle size of the mixed material is smaller than 74 micrometers, placing the mixed material in a roasting furnace, dehydrating for 5-20 minutes at 50-300 ℃, roasting for 10-200 minutes at 600-1000 ℃ to generate a sintered material, wherein tungsten elements in the tungsten-containing material can be converted into soluble sodium tungstate during the sintering process, grinding the sintered material to be smaller than 45 micrometers, putting the sintered material into water at 15-95 ℃ according to the liquid-solid ratio of 5mL to 1g, stirring and leaching for 10-200 minutes, and finally filtering to obtain a sodium tungstate-containing leaching solution and insoluble water leaching residues, so that the tungsten elements in the tungsten-containing material are decomposed into a liquid phase and separated from other impurities. The test results are shown in table 1: sodium silicate nonahydrate roasting water leaching decomposition of white tungsten concentrate, black tungsten concentrate and mixed black and white tungsten concentrate, wherein the decomposition rate can reach more than 99%; aiming at the tungsten middling which is difficult to treat, the sodium silicate nonahydrate, the sodium silicate pentahydrate and the sodium silicate roasting decomposition method can respectively reach high leaching rates of 98.86%, 97.44% and 95.32%, and the water-containing sodium silicate decomposition method can effectively treat the white tungsten concentrate, the black/white tungsten mixed concentrate and the tungsten middling.

Control experimental group 1: the anhydrous sodium silicate is adopted to replace the hydrous sodium silicate in the embodiment 1, other conditions are not changed, the sodium salt roasting and water leaching tests are carried out on the white tungsten concentrate, the black/white tungsten mixed concentrate and the tungsten middling, the specific experimental results are shown in table 2, the decomposition efficiency of the tungsten ore is relatively low due to the lack of nanocrystallization in the crystal water removal process, and the tungsten ore cannot be decomposed basically particularly for low-grade tungsten ore, so that the importance of the crystal water on the method for extracting tungsten from sodium silicate is demonstrated.

Control experimental group 2: the effects of decomposing tungsten middlings by the conventional acid leaching, alkaline leaching and roasting water leaching methods were used as a control group, and the results are shown in table 3: aiming at low-grade tungsten middling products, the recovery rate of tungsten in the traditional metallurgy scheme is lower than 75%, and even if the reaction temperature and the reagent ratio are increased, the decomposition rate cannot be increased continuously, which shows that the hydrous sodium silicate dehydration roasting-water leaching tungsten method has advantages compared with the traditional metallurgy scheme aiming at low-grade tungsten middling products.

TABLE 1 test results for tungsten extraction from scheelite concentrate, wolframite concentrate and tungsten middlings using aqueous sodium silicate

TABLE 2 test results for tungsten extraction from scheelite concentrate, wolframite concentrate and tungsten middlings using anhydrous sodium silicate

Table 3 test results for tungsten extraction from tungsten middlings using a conventional metallurgical protocol

It can be seen from fig. 1 that the hydrous sodium silicate can be decomposed into nano-scale sodium silicate particles in the dehydration process, the surface area is greatly increased, and the hydrous sodium silicate is tightly attached to the surface of the tungsten-containing material.

Example 2

Ammonium paratungstate is produced by a certain tungsten smelting plant through an alkali pressure boiling method, a large amount of tungsten slag is generated in the alkali leaching process, and WO in the tungsten slag₃The content fluctuates between 1 percent and 3 percent, the tungsten slag is corrosive slag, the granularity is extremely fine, and the tungsten element in the tungsten slag can not be effectively extracted by adopting the traditional selection smelting process.

Get WO₃Uniformly mixing 1.1% tungsten slag and sodium metasilicate nonahydrate according to the mass ratio of 1:0.3, grinding to less than 74 mu m, dehydrating at 200 ℃ for 5 minutes, then continuously heating to 850 ℃ and roasting for 30 minutes, grinding the roasted material to less than 45 mu m, putting the ground material into water for leaching, leaching and stirring for 30 minutes at the leaching temperature of 50 ℃ according to the liquid-solid ratio of 2:1, filtering to obtain a sodium tungstate leaching solution with the leaching rate of 95.8%, and adding WO (tungsten oxide) in a slag phase₃The content was 0.045%.

Another WO₃Uniformly mixing 1.1% tungsten slag and sodium metasilicate pentahydrate according to the mass ratio of 1:0.2, grinding to less than 74 mu m, dehydrating at 200 ℃ for 3 minutes, continuing to heat to 850 ℃ and roasting for 30 minutes, grinding the roasted material to less than 45 mu m, putting the ground material into water for leaching, leaching and stirring for 30 minutes at the leaching temperature of 50 ℃ according to the liquid-solid ratio of 2:1, filtering to obtain a sodium tungstate leaching solution with the leaching rate of 94.9%, and adding WO in a slag phase₃The content was 0.055%.

Another WO₃Uniformly mixing 1.1% tungsten slag and water glass according to the mass ratio of 1:3, grinding to be less than 74 mu m, dehydrating at 200 ℃ for 20 minutes, continuing to heat to 950 ℃ and roasting for 60 minutes, grinding the roasted material to be less than 45 mu m, putting the roasted material into water for leaching, leaching and stirring for 30 minutes according to the liquid-solid ratio of 3:1 and the leaching temperature of 80 ℃, filtering to obtain a sodium tungstate leaching solution with the leaching rate of 94.3%, and adding WO into a slag phase₃The content is 0.06%.

The test for extracting tungsten from tungsten slag by using the traditional metallurgical scheme is taken as a control group, and the results are shown in table 4: the traditional metallurgical scheme has poor decomposition effect on tungsten slag, the decomposition rate is lower than 62%, and the decomposition rate is far lower than the test effect of the decomposition method of the water-containing sodium silicate, and the combination with the example 1 shows that the more the tungsten-containing raw material with low grade and poor quality is, the more obvious the advantage of the effect of extracting tungsten by the decomposition method of the water-containing sodium silicate is compared with the traditional scheme.

TABLE 4 test results for tungsten extraction from tungsten slag using conventional metallurgical route

Example 3

Uniformly mixing a tungsten-containing waste catalyst with a W content of 4.3% with sodium metasilicate nonahydrate according to a mass ratio of 1:0.4, grinding to be less than 74 mu m, dehydrating for 5 minutes at 200 ℃, continuing to heat to 700 ℃ and roasting for 15 minutes, grinding the roasted material to be less than 45 mu m, putting the ground material into water for leaching, leaching for 30 minutes at a leaching temperature of 80 ℃ according to a liquid-solid ratio of 4:1, and filtering to obtain a sodium tungstate leaching solution with a leaching rate of 98.4%.

Example 4

Uniformly mixing a certain waste tungsten alloy with a W content of 74.1% and sodium metasilicate nonahydrate according to a mass ratio of 1:2, grinding to be less than 74 micrometers, dehydrating at 200 ℃ for 5 minutes, continuing to heat to 700 ℃ and roasting for 40 minutes, grinding the roasted material to be less than 45 micrometers, putting the ground material into water for leaching, leaching for 30 minutes at a leaching temperature of 80 ℃ according to a liquid-solid ratio of 10:1, and filtering to obtain a sodium tungstate leaching solution with a leaching rate of 99.3%.

By combining 4 examples, the method for extracting tungsten from the sodium silicate containing water has strong adaptability to tungsten-containing raw materials with various qualities and sources, and is a relatively popular tungsten extraction method.