Method for preparing ultra-pure coal based on cavitation nano bubble flotation

Abstract

The invention belongs to the technical field of ultra-pure coal preparation, and particularly discloses a method for preparing ultra-pure coal based on cavitation nano bubble flotation, which comprises the following steps: crushing, ball milling, multiple cavitation cycles and flotation, and filtering and drying the obtained clean coal to obtain the ultra-pure coal. Compared with the prior art, the process for preparing the ultra-pure coal by using the physical and chemical method has the advantages that aiming at bituminous coal with relatively high ash content, the ash can be deeply reduced to lt through nano-bubble enhanced flotation; the method can be used for conveniently and quickly preparing the ultra-pure coal, and is beneficial to improving the high-value utilization of the coal.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-pure coal preparation, in particular to a method for preparing ultra-pure coal based on cavitation nano bubble flotation. Background Art

[0002] Clean and efficient utilization of coal is the long-term development goal of coal. Seeking advanced methods and improving and optimizing traditional flotation processes are of great significance to enhancing the high added value of coal. Ultra-pure coal is also of great significance in the production of clean fine coal-water fuel, activated carbon and carbon-based materials. In recent years, ultra-pure coal has shown excellent performance as a coal-based material.

[0003] At present, the commonly used methods for preparing ultra-pure coal include physical method, chemical method and physical and chemical method. The chemical method for producing ultra-pure coal has significant disadvantages such as severe corrosion and pollution. When preparing ultra-pure coal by physical method, strict efficiency requirements must be imposed on grinding equipment and processes. Physical and chemical deashing is mainly based on the difference in the chemical properties of minerals and coal surfaces for selective deashing. Flotation, as a coal washing technology in physical and chemical methods, has the advantages of simple operation, high feasibility, and easy industrial production. However, different operating processes will still affect the ash content of the ultra-pure coal finally obtained. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for preparing ultrapure coal based on cavitation nanobubble flotation.

[0005] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0006] A method for preparing ultrapure coal based on cavitation nanobubble flotation comprises the following steps:

[0007] S1. Take bituminous coal with an ash content Ad of 10%-15%, crush it by a roller crusher to obtain bituminous coal particles with a particle size of less than 1 mm, ball-mill the bituminous coal particles with a particle size of less than 1 mm to fully dissociate the coal and minerals, and obtain bituminous coal particles with a particle size of less than 0.074 mm;

[0008] S2, adding bituminous coal particles with a particle size of less than 0.074 mm into a slurry mixing and stirring barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40-70 g / L; wherein the amount of the collector added to each ton of coal slurry is 2000 g-2500 g, and the amount of the frother added to each ton of coal slurry is 700 g-1100 g; passing the coal slurry into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for roughing to obtain clean coal 1 and tail coal;

[0009] S4, adding clean coal 1 into a slurry mixing barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L-70g / L; wherein the amount of collector added to each ton of coal slurry is 2000g-2500g, and the amount of frother added to each ton of coal slurry is 700g-1100g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for selection to obtain clean coal 2 and medium coal 1;

[0010] S5, adding clean coal 2 into a slurry mixing barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L-70g / L; wherein the amount of collector added to each ton of coal slurry is 2000g-2500g, and the amount of frother added to each ton of coal slurry is 700g-1100g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for selection to obtain clean coal 3 and medium coal 2;

[0011] S6, adding clean coal 3 into a slurry mixing barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L-70g / L; wherein the amount of collector added to each ton of coal slurry is 2000g-2500g, and the amount of frother added to each ton of coal slurry is 700g-1100g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for selection to obtain clean coal and medium coal 3;

[0012] S7. Filter and dry the clean coal to obtain ultra-pure coal.

[0013] Furthermore, the flotation machine has a rotation speed of 1900rad / min-2300rad / min, and an aeration volume of 200L / h-260L / h.

[0014] Furthermore, the duration of each cavitation cycle is 2 min to 4 min.

[0015] Preferably, the collector is kerosene and the foaming agent is octanol.

[0016] Compared with the prior art, the process of preparing ultra-pure coal by physical and chemical methods in the present invention is aimed at bituminous coal with high ash content. Through nano-bubble enhanced flotation, the ash content can be deeply reduced to <2%, and ultra-pure coal can be prepared conveniently and quickly, which is beneficial to improving the high-value utilization of coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the technical roadmap of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0019] Example 1

[0020] like Figure 1 As shown, this embodiment exemplarily shows a method for preparing ultrapure coal based on cavitation nanobubble flotation, and the specific operation process is as follows:

[0021] S1. Take bituminous coal with an ash content Ad of 13%, crush it by a roller crusher to obtain bituminous coal particles with a particle size of less than 1 mm, ball-mill the bituminous coal particles with a particle size of less than 1 mm to fully dissociate the coal and minerals, and obtain bituminous coal particles with a particle size of less than 0.074 mm;

[0022] S2, adding bituminous coal particles with a particle size of less than 0.074 mm into a slurry mixing and stirring barrel filled with water, kerosene as a collector and octanol as a foaming agent for slurry mixing and dosing treatment for 5 minutes to obtain a coal slurry with a concentration of 50 g / L; wherein, the amount of the collector added to each ton of coal slurry is 2300 g, and the amount of the foaming agent added to each ton of coal slurry is 900 g; the coal slurry is passed into a nano bubble generator for cavitation circulation for 4 minutes, and the treated slurry enters a flotation machine for rough selection, the flotation machine speed is 2100 rad / min, and the flotation machine inflation volume is 230 L / h; clean coal 1 and tail coal are obtained;

[0023] S4, adding clean coal 1 into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 50g / L; wherein, the amount of collector added to each ton of coal slurry is 2300g, and the amount of foaming agent added to each ton of coal slurry is 900g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation for 4min, and the treated slurry enters a flotation machine for selection, the flotation machine speed is 2100rad / min, and the flotation machine inflation volume is 230L / h; obtaining clean coal 2 and medium coal 1;

[0024] S5, adding clean coal 2 into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 50g / L; wherein the amount of collector added to each ton of coal slurry is 2300g, and the amount of foaming agent added to each ton of coal slurry is 900g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation for 4min, and the treated ore pulp enters a flotation machine for selection, the flotation machine speed is 2100rad / min, and the flotation machine inflation volume is 230L / h; obtaining clean coal 3 and medium coal 2;

[0025] S6, adding clean coal 3 into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 50g / L; wherein the amount of collector added to each ton of coal slurry is 2300g, and the amount of foaming agent added to each ton of coal slurry is 900g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation for 4min, and the treated ore pulp enters a flotation machine for selection, the flotation machine speed is 2100rad / min, and the flotation machine inflation volume is 230L / h; clean coal and medium coal 3 are obtained;

[0026] S7. Filter and dry the clean coal to obtain ultra-pure coal with an ash content of less than 1%.

[0027] Example 2

[0028] like Figure 1 As shown, this embodiment exemplarily shows a method for preparing ultrapure coal based on cavitation nanobubble flotation, and the specific operation process is as follows:

[0029] S1. Take bituminous coal with an ash content Ad of 11%, crush it by a roller crusher to obtain bituminous coal particles with a particle size of less than 1 mm, ball-mill the bituminous coal particles with a particle size of less than 1 mm to fully dissociate the coal and minerals, and obtain bituminous coal particles with a particle size of less than 0.074 mm;

[0030] S2, adding bituminous coal particles with a particle size of less than 0.074 mm into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment for 5 minutes to obtain a coal slurry with a concentration of 40g / L; wherein, the amount of collector added to each ton of coal slurry is 2000gg, and the amount of foaming agent added to each ton of coal slurry is 700g; the coal slurry is passed into a nano bubble generator for cavitation circulation for 3 minutes, and the treated slurry enters a flotation machine for rough selection, the flotation machine speed is 1900rad / min, and the flotation machine inflation volume is 200L / h; clean coal 1 and tail coal are obtained;

[0031] S4, adding clean coal 1 into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L; wherein, the amount of collector added to each ton of coal slurry is 2000g, and the amount of foaming agent added to each ton of coal slurry is 700g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation for 3min, and the treated ore pulp enters a flotation machine for selection, the flotation machine speed is 1900rad / min, and the flotation machine inflation volume is 200L / h; obtaining clean coal 2 and medium coal 1;

[0032] S5, adding clean coal 2 into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L; wherein, the amount of collector added to each ton of coal slurry is 2000g, and the amount of foaming agent added to each ton of coal slurry is 700g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation for 3min, and the treated slurry enters a flotation machine for selection, the flotation machine speed is 1900rad / min, and the flotation machine inflation volume is 200L / h; obtaining clean coal 3 and medium coal 2;

[0033] S6, adding clean coal 3 into a slurry mixing and stirring barrel filled with water, collector kerosene and foaming agent octanol for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L; wherein, the amount of collector added to each ton of coal slurry is 2000g, and the amount of foaming agent added to each ton of coal slurry is 700g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation for 3min, and the treated ore pulp enters a flotation machine for selection, the flotation machine speed is 1900rad / min, and the flotation machine inflation volume is 200L / h; clean coal and medium coal 3 are obtained;

[0034] S7. Filter and dry the clean coal to obtain ultra-pure coal with an ash content of less than 2%.

[0035] It can be seen from Examples 1 and 2 that the present application aims at bituminous coal with a high ash content, and the ash content can be deeply reduced to <2% by nanobubble enhanced flotation; and it is related to the cavitation cycle time of the nanobubble generator and the subsequent flotation aeration volume. Within the range set in the present application, the longer the cavitation cycle time and the greater the flotation aeration volume, the lower the ash content of the ultra-pure coal finally obtained.

[0036] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing ultrapure coal based on cavitation nanobubble flotation, characterized in that: The following steps are involved: S1. Take bituminous coal with an ash content Ad of 10%-15%, crush it by a roller crusher to obtain bituminous coal particles with a particle size of less than 1 mm, ball-mill the bituminous coal particles with a particle size of less than 1 mm to fully dissociate the coal and minerals, and obtain bituminous coal particles with a particle size of less than 0.074 mm; S2, adding bituminous coal particles with a particle size of less than 0.074 mm into a slurry mixing and stirring barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40-70 g / L; wherein the amount of the collector added to each ton of coal slurry is 2000 g-2500 g, and the amount of the frother added to each ton of coal slurry is 700 g-1100 g; passing the coal slurry into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for roughing to obtain clean coal 1 and tail coal; S4, adding clean coal 1 into a slurry mixing barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L-70g / L; wherein the amount of collector added to each ton of coal slurry is 2000g-2500g, and the amount of frother added to each ton of coal slurry is 700g-1100g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for selection to obtain clean coal 2 and medium coal 1; S5, adding clean coal 2 into a slurry mixing barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L-70g / L; wherein the amount of collector added to each ton of coal slurry is 2000g-2500g, and the amount of frother added to each ton of coal slurry is 700g-1100g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for selection to obtain clean coal 3 and medium coal 2; S6, adding clean coal 3 into a slurry mixing barrel filled with water, a collector and a frother for slurry mixing and dosing treatment to obtain a coal slurry with a concentration of 40g / L-70g / L; wherein the amount of collector added to each ton of coal slurry is 2000g-2500g, and the amount of frother added to each ton of coal slurry is 700g-1100g, and then the coal slurry is passed into a nano bubble generator for cavitation circulation, and the treated slurry enters a flotation machine for selection to obtain clean coal and medium coal 3; S7. Filter and dry the clean coal to obtain ultra-pure coal.

2. The method for preparing ultrapure coal based on cavitation nanobubble flotation according to claim 1, characterized in that: The flotation machine has a rotation speed of 1900rad / min-2300rad / min, and an aeration volume of 200L / h-260L / h.

3. The method for preparing ultrapure coal based on cavitation nanobubble flotation according to claim 1, characterized in that: The duration of each cavitation cycle is 2min-4min.

4. The method for preparing ultrapure coal based on cavitation nanobubble flotation according to claim 1, characterized in that: The collector is kerosene and the foaming agent is octanol.

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