Preparation method of tungsten tailing-based microcrystalline glass

Abstract

The invention belongs to the field of comprehensive utilization of solid wastes or the technical field of glass ceramics, and provides a method for preparing glass ceramics from tungsten tailings. The preparation method comprises the following steps: grinding tungsten tailing powder and auxiliary materials such as silicon oxide, calcium oxide and aluminum oxide, uniformly mixing, and melting the mixture to obtain molten glass; quickly pouring the molten glass into cold water for water quenching to obtain basic glass particles; grinding the basic glass particles to obtain basic glass powder, pressing the obtained powder into sheets, and carrying out nucleation crystallization heat treatment to obtain microcrystalline glass; the main crystal phase of the obtained microcrystalline glass is anorthite. Tests are carried out through different tungsten tailing proportions, the tungsten tailing-based microcrystalline glass with excellent performances such as water absorption, compression strength and microhardness is obtained, and the tungsten tailing-based microcrystalline glass is smooth and flat in surface, high in structural compactness and complete in crystal growth. The production method is simple, the raw material cost is low, the product shape has high plasticity, tailing resource utilization can be achieved, and the high application prospect is achieved.

Description

Technical Field

[0001] The invention belongs to the field of comprehensive utilization of solid waste or preparation of microcrystalline glass, solves the problem of large accumulation of flotation tailings of skarn-type tungsten ore and low comprehensive utilization rate, and specifically relates to a method for preparing tungsten tailings-based microcrystalline glass. Background Art

[0002] Tungsten tailings are a type of solid waste generated during the selection process of tungsten. However, a large amount of tungsten tailings as secondary resources have not been effectively utilized and are often stored in tailings ponds or backfilled in mines, causing waste of resources and damage to the environment. Therefore, based on the properties of tungsten tailings, comprehensive utilization research can not only solve the problems of resource waste and environmental pollution, but also greatly benefit the improvement of corporate benefits.

[0003] At present, the comprehensive utilization research of tungsten tailings mainly focuses on the recovery of valuable components such as tungsten, copper, molybdenum, bismuth and non-metals, as well as the preparation of building materials such as concrete, ceramic plates and polymer materials. For the recovery of valuable components, due to the low content of recyclable components, high recovery cost, and low utilization rate of tungsten tailings, most enterprises have not been well implemented. When used as a raw material for concrete preparation, due to the high Fe content in the tailings of skarn-type tungsten ore, the durability and stability of the concrete prepared with it are less competitive than other existing products. In addition, the use of tungsten tailings for the preparation of ceramic plates and polymer materials faces the dilemma of small tailings consumption and low added value. Glass-ceramics is a new multifunctional material with high strength and high chemical stability. Compared with traditional cement, gel materials, ceramics and other building materials, it has better performance and higher added value. The composition of tungsten tailings is highly matched with the main components of glass-ceramics. Tungsten tailings-based glass-ceramics has a good preparation basis and has broad application prospects. It is an important way to promote the high consumption and high added value of tungsten tailings.

[0004] At present, the research on the preparation of microcrystalline glass from tailings has received widespread attention, and several methods for preparing microcrystalline glass from tailings have been disclosed in patents. For example, patent CN200810306559.1 discloses low-expansion microcrystalline glass and its manufacturing method using spodumene tailings as the main raw material. The advantage of this method is that the content of added spodumene is relatively high, but many other ingredients are added, and the sintering temperature is too high, between 1550~1620℃, and the temperature control process is complicated. Summary of the invention

[0005] In view of the problem of low consumption of tungsten tailings, the present invention aims to provide a method for preparing tungsten tailings-based microcrystalline glass, which forms microcrystalline glass with the main crystal phase of anorthite or chalcite by adjusting the amount of tungsten tailings. The product has high performance, can meet relevant industry standards, and greatly improves the comprehensive utilization rate of tungsten tailings.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: The present invention provides a preparation method of tungsten tailings-based microcrystalline glass, comprising the steps of grinding and mixing tungsten tailings with silicon oxide, calcium oxide, aluminum oxide, sodium oxide and the like by a planetary mill, melting the mixture and quenching with water to obtain basic glass particles, crushing and pressing the basic glass particles into shape, and then performing secondary sintering to obtain tungsten tailings-based microcrystalline glass.

[0007] The present invention provides a method for preparing tungsten tailings-based microcrystalline glass. Since the composition of tungsten tailings is similar to the main formula components of CAS-based microcrystalline glass, tungsten tailings are used as the main raw material to prepare microcrystalline glass, and the characteristics of tungsten tailings are fully utilized to achieve bulk consumption of tungsten tailings.

[0008] In the present invention, a small amount of iron oxide contained in tungsten tailings can act as a nucleating agent to help the nucleation and crystallization process of the glass-ceramics, and induce the formation of feldspar crystal phase in the glass-ceramics without adding any nucleating agent. However, in order to prepare tungsten tailings-based glass-ceramics with calcium feldspar as the main crystal phase, it is necessary to control the amount of tungsten tailings added. If too much tailings are added, the Fe content in the mixture is too high, which will lead to excessive viscosity of the glass liquid during melting, and structural defects will appear inside the glass-ceramics during crystallization, resulting in reduced strength performance.

[0009] The present invention provides a method for preparing tungsten tailings-based microcrystalline glass. In the glass preparation raw materials, the mass ratio of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide is (10-70): (10-70): (0-8): (3-8): (4-8).

[0010] The method for preparing tungsten tailings-based glass-ceramics specifically comprises the following steps: S1: Use a shaking table to pre-de-sludge the tungsten tailings to remove surface fine mud and residual reagents; S2: weighing raw materials, grinding and mixing them using a planetary mill to obtain a mixed material; S3: taking a certain amount of the mixture and placing it in a crucible, melting and keeping it warm in a box-type resistance furnace at a temperature of 1480-1550°C for 1-2 hours, and then pouring the molten glass liquid into cold water to obtain basic glass particles; S4: Grind the basic glass particles, pass them through a 75 μm sieve, and take the powder under the sieve for pressing and molding; S5: The pressed blank is nucleated and kept at 750-900°C for 0.5-1.5h, and then crystallized and kept at 950-1150°C for 1-3h, and then cooled in the furnace to obtain microcrystalline glass.

[0011] Preferably, the chemical composition of the raw materials is as follows: SiO 245.85~56.73wt.%; CaO 15.05~20.83wt.%; Al 2 O 3 5.04~7.08wt.%;Na 2 O 3.91~5wt.%;Fe 2 O 3 1.27~8.88wt.%.

[0012] Preferably, in the mixture, SiO 2 With Al 2 O 3 The sum of the mass ratios is 57.8~63.2wt.%.

[0013] Preferably, the heating rate during melting is 5-7° C. / min, and the melting time is 1-2 h.

[0014] Preferably, the pressing pressure is 10-20 MPa, and the pressing time is 30 s-2 min.

[0015] Preferably, when the blank is pressed, 3-5% PVA binder is mixed with the base glass powder.

[0016] Preferably, the secondary sintering heating rate is 5-10° C. / min, and the sintering time is 1-3 h.

[0017] Preferably, the melting and secondary sintering are both performed in an air atmosphere.

[0018] In the preparation process, during the sintering process, heavy metals such as iron oxide in the tungsten tailings participate in the formation of the crystalline phase and are effectively solidified in the microcrystalline glass.

[0019] The application of the technical solution of the present invention has at least the following beneficial effects: (1) The present invention uses tungsten tailings as the main raw material, which greatly reduces the raw material cost of microcrystalline glass and can consume a large amount of tungsten tailings. Compared with concrete, tiles and other building materials prepared from tungsten tailings, it has a larger absorption capacity and higher added value, thus realizing high absorption and high value utilization of tungsten tailings.

[0020] (2) The present invention adjusts the proportion of tungsten tailings in the mixture to control the size and number of crystals in the microcrystalline glass, thereby obtaining a microcrystalline glass product with excellent properties, such as good water absorption, compressive strength, hardness and other properties, and meets the industry standard JC / T 872-2019 for microcrystalline glass for architectural decoration.

[0021] (3) The present invention uses tungsten tailings as the main raw material. Heavy metal elements such as iron oxide in the tailings can be used as nucleating agents to help the nucleation and crystallization of microcrystalline glass, without the need to add expensive nucleating agents. Heavy metal elements participate in the crystal growth process and can be effectively fixed in the crystal, reducing the pollution risks caused by tungsten tailings and achieving sustainable development in the field of mineral processing. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0023] The chemical composition of the tungsten tailings used in the examples of the present invention is shown in Table 1.

[0024] Table 1 Chemical composition of tungsten tailings (%) <![CDATA[SiO 2 ]]> CaO <![CDATA[Al 2 THE 3 ]]> MgO <![CDATA[Fe 2 THE 3 ]]> MnO <![CDATA[SO 3 ]]> F <![CDATA[K 2 The]]> <![CDATA[TiO 2 ]]> <![CDATA[Na 2 The]]> 35.39 28.63 6.158 2.64 13.49 2.107 0.487 0.36 0.28 0.125 0.052 Example 1

[0025] A method for preparing tungsten tailings-based glass-ceramics, the main steps are as follows: 1. Use a shaking table to reselect the tungsten tailings, remove the surface fine mud and residual reagents in the slurry, and dry and mix the deslimed tungsten tailings in a 105℃ oven for later use; 2. Weigh four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in a mass ratio of 10:53:18:6.5:7, and use a planetary ball mill to mill for 1 hour to obtain a uniform mixture; 3. Take a certain amount of the mixture and put it into a crucible, place it in a box-type resistance furnace, heat it to 1500°C at a rate of 5°C / min, and keep it warm for 120 minutes. After the mixture is completely melted into glass liquid, pour the glass liquid into cold water for quenching to obtain basic glass particles of different particle sizes; 4. Dry, crush and grind the base glass, use a 200-mesh sieve to sieve out the base glass powder with a particle size of less than 75 μm, add 3% PVA to the powder and mix well, then press at a pressure of 10 MPa and hold the pressure for 1 minute to obtain the blank; 5. Place the blank in a resistance furnace, heat it to 750℃ for nucleation at a heating rate of 5℃ / min, keep it warm for 1h, then heat it to 1000℃ for crystallization at a heating rate of 5℃ / min, keep it warm for 2h, and finally cool it to room temperature to obtain tungsten tailings-based microcrystalline glass products①.

[0026] Embodiment 2: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 20:48:14:5.8:7, and a tungsten tailings-based microcrystalline glass product ② is obtained.

[0027] Embodiment 3: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 30:45:8:5:7, and a tungsten tailings-based microcrystalline glass product ③ is obtained.

[0028] Embodiment 4: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 40:40:4:5:7, and a tungsten tailings-based microcrystalline glass product ④ is obtained.

[0029] Embodiment 5: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 50:33:2:3:7, and a tungsten tailings-based microcrystalline glass product ⑤ is obtained.

[0030] Embodiment 6: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 60:25:0:2:7, and a tungsten tailings-based microcrystalline glass product ⑥ is obtained.

[0031] Embodiment 7: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 70:20:0:1:7, and a tungsten tailings-based microcrystalline glass product ⑦ is obtained.

[0032] Figure 1 This is the appearance picture of the tungsten tailings-based microcrystalline glass (samples ①-⑦) obtained by crystallization at 1000℃ for 2h in Examples 1-7. It can be seen from the figure that with the increase of tungsten tailings dosage, the color of the microcrystalline glass product gradually deepens, the sintering shrinkage rate of the sample decreases, and the surface of sample ⑦ is rougher.

[0033] Embodiment 8: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 40:40:4:5:7, the crystallization temperature in step 5 is 900°C, and a tungsten tailings-based microcrystalline glass product⑧ is obtained.

[0034] Embodiment 9: The difference from Example 1 is that the mass ratio of the four raw materials of tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide in step 2 is 40:40:4:5:7, the crystallization temperature in step 5 is 1100°C, and a tungsten tailings-based microcrystalline glass product ⑨ is obtained.

[0035] Figure 2 This is a comparison of the appearance of samples ④, ⑧ and ⑨. The three samples have the same raw material composition, but the crystallization temperature is inconsistent. As can be seen from the figure, with the increase of crystallization temperature, the number of unsintered particles on the surface of the sample decreases, but when the temperature reaches 1100℃, the microcrystalline glass undergoes severe deformation, indicating that the temperature is too high and the sample has begun to melt. The increase in crystallization temperature helps to increase the growth integrity of the calcium feldspar crystals in the microcrystalline glass, and also increases the number and size of the crystals, improving the overall density of the microcrystalline glass.

[0036] The description of the above specific embodiments is only a preferred embodiment of the present invention. Without departing from the core spirit and basic features of the present invention, the present invention can be implemented in other specific forms. Therefore, no matter from which perspective, the above embodiments should be regarded as exemplary rather than restrictive. The scope of protection of the present invention should be defined by the attached claims rather than the specific description of this specification. In other words, all changes and modifications that fall within the scope of equivalents of the claims should be included in the scope of protection of the present invention.

Claims

1. A method for preparing tungsten tailings-based glass-ceramics, characterized in that: The tungsten tailings are ground and mixed with silicon oxide, calcium oxide, aluminum oxide and sodium oxide by a planetary mill, and the mixture is melted and quenched with water to obtain basic glass particles. The basic glass particles are crushed and pressed into shape, and then sintered for a second time to obtain tungsten tailings-based microcrystalline glass.

2. The method for preparing tungsten tailings-based glass-ceramics according to claim 1, characterized in that: The mass ratio of the tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide is (10-70): (10-70): (0-8): (3-8): (4-8).

3. The method for preparing tungsten tailings-based glass-ceramics according to claim 1, characterized in that: The specific steps include: S1: Use a shaking table to pre-de-sludge the tungsten tailings to remove surface fine mud and residual reagents; S2: weighing raw materials, grinding and mixing them using a planetary mill to obtain a mixed material; S3: taking a certain amount of the mixture and placing it in a crucible, melting and keeping it warm in a box-type resistance furnace at a temperature of 1480-1550°C for 1-2 hours, and then pouring the molten glass liquid into cold water to obtain basic glass particles; S4: Grind the basic glass particles, pass them through a 75 μm sieve, and take the powder under the sieve for pressing and molding; S5: The pressed blank is nucleated and kept at 750-900°C for 0.5-1.5h, and then crystallized and kept at 950-1150°C for 1-3h, and then cooled in the furnace to obtain microcrystalline glass.

4. The method for preparing tungsten tailings-based glass-ceramics according to claim 2 or 3, characterized in that: The chemical composition of the tungsten tailings, silicon oxide, calcium oxide, aluminum oxide and sodium oxide is as follows: SiO2 45.85~56.73wt.%; CaO 15.05~20.83wt.%; Al2O3 5.04~7.08wt.%; Na2O 3.91~5wt.%; Fe2O3 1.27~8.88wt.%.

5. The method for preparing tungsten tailings-based glass-ceramics according to claim 3, characterized in that: In the mixture, the sum of the mass ratios of SiO2 and Al2O3 is 57.8-62.5wt.%.

6. The method for preparing tungsten tailings-based glass-ceramics according to claim 3, characterized in that: The heating rate during melting is 5~7℃ / min, and the melting time is 1~2h.

7. The method for preparing tungsten tailings-based glass-ceramics according to claim 3, characterized in that: The pressing pressure is 10~20MPa, and the pressing time is 30s~2min.

8. The method for preparing tungsten tailings-based glass-ceramics according to claim 3, characterized in that: When pressing the blank, 3~5% PVA binder is mixed with the base glass powder.

9. The method for preparing tungsten tailings-based glass-ceramics according to claim 3, characterized in that: The secondary sintering heating rate is 5-10°C / min, and the sintering time is 1-3h.

10. The method for preparing tungsten tailings-based glass-ceramics according to claim 3, characterized in that: Both melting and secondary sintering are carried out in air atmosphere.

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