Preparation method of mine water treatment filler based on extrusion molding silicon carbide waste

Abstract

The invention relates to the technical field of water treatment, and designs a preparation method of a water treatment filler based on extrusion-molded silicon carbide waste, which comprises the following steps: 1) pouring the recycled silicon carbide waste into a spherical mold, pressing into a spherical green body with the diameter of 10 mm, and controlling the molding pressure to be 10 MPa and the pressure holding time to be 10 seconds; 2) drying the molded spherical green body in a 120 DEG C drying oven for 24 hours; and (3) placing the dried green body sample in a high-temperature electric furnace under the sintering atmosphere of air, heating to 500 DEG C at the speed of 1 DEG C / min and preserving heat for 2 hours, then heating to 1000-1300 DEG C at the speed of 2 DEG C / min and preserving heat for 4 hours, and finally cooling to room temperature along with the furnace. The raw material of the silicon carbide water treatment filler prepared by the invention comes from the recycled extrusion-molded silicon carbide waste mud, the treatment cost is reduced, the resource utilization of the waste is realized, and the silicon carbide has high hardness and good chemical stability, and is wear-resistant and long in service life when being used as the filler.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and designs a method for preparing a water treatment filler based on extruded silicon carbide waste. Background Art

[0002] Membrane separation technology has the advantages of high separation efficiency, low energy consumption, and small footprint. It is also easy to couple with other separation processes to achieve integrated application of separation technology. It has been widely used in many industries such as water treatment, chemical industry, pharmaceuticals, biotechnology, beverages, food, and metallurgy.

[0003] Silicon carbide ceramic membrane is a membrane material that has developed rapidly in recent years. It has received more and more attention due to its excellent mechanical, chemical and high temperature stability, excellent hydrothermal stability and high permeability. Compared with traditional oxide ceramic membranes such as aluminum oxide, it has higher permeability and anti-pollution performance. The application of silicon carbide membrane is mainly concentrated in the fields of liquid separation and gas purification, especially in the fields of oily wastewater treatment and high-temperature flue gas dust removal and purification.

[0004] Tubular silicon carbide membranes have a wider range of applications due to their high packing density and easy packaging. Tubular silicon carbide membrane carriers are usually prepared by extrusion molding. However, waste silicon carbide mud is inevitably produced during the extrusion molding process. Usually, waste silicon carbide mud is treated as solid waste, which not only causes a waste of resources, but also increases production costs.

[0005] Therefore, it is of great value to develop silicon carbide waste into ceramic fillers and apply them in the field of water treatment. Summary of the invention

[0006] The invention aims to prepare filler based on extruded silicon carbide waste material and apply it to the field of mine water treatment.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows: 1) Pour the recycled silicon carbide mud into a spherical mold and press it into a spherical green body with a diameter of 10 mm. The molding pressure is 10 MPa and the holding time is 10 s; 2) Place the formed spherical green body in an oven at 120°C and dry for 24 h; 3) Place the dried green sample in a high-temperature electric furnace with air as the sintering atmosphere. Raise the temperature to 500°C at 1°C / min and keep it for 2 h. Then raise the temperature to 1000-1300°C at 2°C / min and keep it for 4 h. Finally, cool it to room temperature in the furnace.

[0008] Compared with the prior art, the advantages of the present invention include: 1. The raw material of the silicon carbide water treatment filler prepared by the present invention comes from recycled extruded silicon carbide waste mud, which reduces the processing cost and realizes the resource utilization of waste; 2. The water treatment filler prepared by the present invention is made of silicon carbide material, which has high hardness and good chemical stability. It is wear-resistant and has a long service life as a filler; 3. Utilize the plasticity of extruded silicon carbide waste mud to directly press and shape it into a spherical shape, thus shortening the preparation process and time of water treatment fillers. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is the SEM image of the silicon carbide filler prepared in Example 1. DETAILED DESCRIPTION

[0010] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to illustrate the present invention, but are not used to limit the scope of implementation of the present invention. Example

[0011] A method for preparing water treatment filler based on extruded silicon carbide waste, the specific steps of which are as follows: 1) Pour the recycled silicon carbide mud into a mold and press it into a spherical green body with a diameter of 10 mm. The molding pressure is 10 MPa and the holding time is 10 s; 2) Dry the spherical green body in an oven at 120 °C for 24 h; 3) Place the dried green sample in a high-temperature electric furnace with air as the sintering atmosphere. Raise the temperature to 500°C at 1°C / min and keep it for 2 h. Then raise the temperature to 1100°C at 2°C / min and keep it for 4 h. Finally, cool it to room temperature in the furnace.

[0012] 4) The porosity of the prepared silicon carbide filler was tested using the Archimedes drainage method, and the results showed that the porosity was about 50%.

[0013] 5) According to GB / T 17431.2-2010 "Lightweight aggregate and its test methods - Part 2: Lightweight aggregate test methods" The sum of the crushing rate and the wear rate, as well as the bulk density of the filler were measured. The results showed that the sum of the crushing rate and the wear rate, and the bulk density were 1.5% and 0.412 g / cm respectively. 3 . Example

[0014] A method for preparing water treatment filler based on extruded silicon carbide waste, the specific steps of which are as follows: 1) Pour the recycled silicon carbide mud into a spherical mold and press it into a spherical green body with a diameter of 10 mm. The molding pressure is 10 MPa and the holding time is 10 s; 2) Dry the spherical green body in an oven at 120 °C for 24 h; 3) Place the dried green sample in a high-temperature electric furnace with air as the sintering atmosphere. Raise the temperature to 500°C at 1°C / min and keep it for 2 h. Then raise the temperature to 1200°C at 2°C / min and keep it for 4 h. Finally, cool it to room temperature in the furnace.

[0015] 4) The porosity of the prepared silicon carbide filler was tested using the Archimedes drainage method, and the results showed that the porosity was about 47%. Example

[0016] The silicon carbide filler as described in Example 1 was studied for its corrosion resistance.

[0017] The corrosion resistance of the material was studied using H2SO4 as the medium. A 20 wt% H2SO4 acid solution was prepared and the porous silicon carbide filler was immersed in the solution for 14 days. The mass change rate before and after was measured. The weight loss of the porous silicon carbide random filler was ≤0.5%, which was within the weighing error range and basically no corrosion.

Claims

1. A method for preparing water treatment filler based on extruded silicon carbide waste, characterized in that: The recycled silicon carbide waste is mainly composed of silicon carbide aggregate, sintering aid and extruded organic binder, among which the proportion of silicon carbide is 80~90wt%.

2. The water treatment filler based on extruded silicon carbide waste according to claim 1, characterized in that: The silicon carbide filler has a porous structure, and the particle size of the silicon carbide particles is 0.5-300 μm.

3. The water treatment filler based on extruded silicon carbide waste according to claim 1, characterized in that: The silicon carbide filler is spherical and has a diameter of 2-10 mm.

4. The water treatment filler based on extruded silicon carbide waste according to claim 1, characterized in that: The silicon carbide particles can be metal oxides such as aluminum oxide, titanium oxide, zirconium oxide, or non-oxide particles such as silicon nitride, boron carbide, etc.

5. The method for preparing water treatment filler based on extruded silicon carbide waste according to claim 1, characterized in that: The specific steps are as follows: 1) Pour the recycled silicon carbide mud into a spherical mold and press it into a spherical green body with a diameter of 10 mm. The molding pressure is 10 MPa and the holding time is 10 s; 2) Place the formed spherical green body in an oven at 120°C and dry for 24 h; 3) Place the dried green sample in a high-temperature electric furnace with air as the sintering atmosphere. Raise the temperature to 500 °C at 1 °C / min and keep it for 2 h. Then raise the temperature to 1000-1300 °C at 2 °C / min and keep it for 4 h. Finally, cool it to room temperature in the furnace.

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