CN112174159A

CN112174159A - Process for calcining kaolinite coal gangue

Info

Publication number: CN112174159A
Application number: CN201910602602.7A
Authority: CN
Inventors: 林龙沅; 任玲; 王哲; 张明星; 徐中慧; 陈海焱
Original assignee: Sichuan Liuneng Micro Nano Technology Co ltd; Southwest University of Science and Technology
Current assignee: Sichuan Liuneng Micro Nano Technology Co ltd; Southwest University of Science and Technology
Priority date: 2019-07-05
Filing date: 2019-07-05
Publication date: 2021-01-05

Abstract

The invention discloses a process for calcining kaolinite coal gangue. The invention relates to a process for calcining kaolinite coal gangue, which has less superfine materials, less energy consumption and low processing cost, and the process utilizes the waste heat of flue gas in a calcining furnace as the crushing power of a steam kinetic energy mill to carry out superfine processing on the calcined kaolin after the calcining furnace, and concretely comprises the following key points: 1) crushing the kaolinite coal gangue raw material to 500 meshes in sequence through a coarse crushing system and a grinding system; 2) feeding the processed kaolinite coal gangue into a calcining furnace for calcining to obtain calcined kaolin; 3) the calcined kaolin is sent into a steam kinetic energy mill for ultrafine grinding, and the particle diameter d of the product after grinding is₉₀<2 μm; 4) the superheated steam is used as a working medium of the steam kinetic energy mill and can be prepared by the waste heat of the flue gas in the calcining furnace. The invention provides a new process for calcining kaolinite coal gangue.

Description

Process for calcining kaolinite coal gangue

Technical Field

The patent relates to the technical field of chemical industry, in particular to a process for calcining kaolinite coal gangue.

Background

The process for calcining kaolin by kaolinite coal gangue mainly comprises an ultrafine grinding process and a calcining whitening process. At present, common processes for calcining kaolin by coal gangue include a calcination-then-wet superfine process, a calcination-then-dry superfine process, a calcination-then-wet superfine-then-calcination process, a dry superfine-then-calcination process and the like.

The process of calcining firstly and then superfine is one of the mainstream processes for calcining kaolin, and in the calcining process, the combustion of organic matters and fixed carbon of the materials can reduce the quantity of superfine processing materials and reduce the energy consumption of superfine processing. However, the technique generally has a key technical problem that the particle size d of the ultrafine powder is produced by adopting the conventional ultrafine powder grinding method₉₀Up to 3 μm is the limit of pulverization, and it is difficult to produce d₉₀Ultra-fine products up to 2 μm, and conventional ultra-fine pulverization methods have high energy consumption, and impurities may be introduced during the pulverization.

In recent years, a steam kinetic energy grinding and ultrafine grinding processing device which takes superheated steam as a working medium has been developed by the subject group (such as patents CN 106242339A, CN101654343, CN101654342, CN105742576A, CN103949316A and the like), and compared with the traditional ultrafine grinding device, the steam kinetic energy grinding and ultrafine grinding device has the characteristics of high grinding strength, fine product granularity (the finest can reach submicron level) and the like, and the whole grinding process is carried out under a dry method.

Therefore, the kaolin calcined after the calcining furnace is subjected to dry ultrafine grinding by steam kinetic energy milling to produce the particle size d₉₀<2 μm, and the materials are crushed by mutual collision in the whole crushing process without adding impurities. The method provides a new approach for the calcination process of the kaolinite coal gangue.

Disclosure of Invention

The invention aims to provide a process for calcining kaolinite coal gangue, wherein the whole process is carried out in a dry method, and the granularity of a produced product meets the requirements of the paper-making industry.

A process for calcining kaolinite coal gangue specifically comprises the following steps:

1) crushing the kaolinite coal gangue raw material 1 to a particle size of less than 3-5mm by a coarse crushing system 2;

2) feeding the coarsely crushed materials into a grinding system 3 for further crushing to 500 meshes;

3) feeding the coarsely processed kaolinite coal gangue into a calcining furnace 4 for calcining to obtain calcined kaolin;

4) the calcined kaolin is sent into a steam kinetic energy mill 5 for ultrafine grinding, and a finished product 6 with the particle diameter d is prepared after grinding₉₀<2μm；

5) The waste heat boiler 8 takes the flue gas waste heat 7 as a heat source to prepare saturated steam 9;

6) the saturated steam 9 is passed through a reheating device 10 to form superheated steam 11.

As a working medium of the steam kinetic energy mill 5, superheated steam 11 carries out ultrafine grinding on the materials in a grinding cavity of the steam kinetic energy mill to prepare a finished product 6 meeting the granularity requirement

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

1) through the process, the mode of mutual collision and crushing of materials is directly adopted in the ultrafine grinding process, and a grinding body is not needed, so that the problem of introducing impurities in the traditional grinding process is solved;

2) the process of calcining firstly and then performing superfine treatment is adopted, so that the superfine treated materials are reduced; meanwhile, the flue gas waste heat of the calcining furnace is used as the pulverizing power, so that the cost for preparing the superfine powder is greatly reduced.

Drawings

For a more clear description of the present invention, reference will now be made to the embodiments illustrated in the drawings.

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

Example one

Referring to fig. 1, a process for calcining kaolinite coal gangue specifically comprises the following steps: crushing the kaolinite coal gangue raw material 1 to a particle size of less than 3-5mm by a coarse crushing system 2; feeding the coarsely crushed materials into a grinding system 3 for further crushing to 500 meshes; adding coarse powderFeeding the kaolinite coal gangue after the work into a calcining furnace 4 for calcining to obtain calcined kaolin; the calcined kaolin is sent into a steam kinetic energy mill 5 for ultrafine grinding, and a finished product 6 with the particle diameter d is prepared after grinding₉₀<2 μm; the waste heat boiler 8 takes the flue gas waste heat 7 as a heat source to prepare saturated steam 9; the saturated steam 9 passes through a reheating device 10 to form superheated steam 11; as a working medium of the steam kinetic energy mill 5, superheated steam 11 carries out ultrafine grinding on the materials in a grinding cavity of the steam kinetic energy mill to prepare a finished product 6 meeting the granularity requirement.

Example two

Referring to fig. 1, a process for calcining kaolinite coal gangue specifically comprises the following steps: crushing a gangue-containing type kaolinite raw material 1 to a particle size of less than 3-5mm by a coarse crushing system 2; feeding the coarsely crushed materials into a grinding system 3 for further crushing to 500 meshes; feeding the roughly processed gangue-type kaolinite rock into a calcining furnace 4 for calcining to obtain calcined kaolin; the calcined kaolin is sent into a steam kinetic energy mill 5 for ultrafine grinding, and a finished product 6 with the particle diameter d is prepared after grinding₉₀<2 μm; the waste heat boiler 8 takes the flue gas waste heat 7 as a heat source to prepare saturated steam 9; the saturated steam 9 passes through a reheating device 10 to form superheated steam 11; as a working medium of the steam kinetic energy mill 5, superheated steam 11 carries out ultrafine grinding on the materials in a grinding cavity of the steam kinetic energy mill to prepare a finished product 6 meeting the granularity requirement.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims

1. A process for calcining kaolinite coal gangue is characterized by comprising the following steps:

1) crushing the kaolinite coal gangue raw material 1 to a particle size of less than 3-5mm by a coarse crushing system 2; 2) feeding the coarsely crushed materials into a grinding system 3 for further crushing to 500 meshes; 3) feeding the coarsely processed kaolinite coal gangue into a calcining furnace 4 for calcining to obtain calcined kaolin; 4) calcining kaolinThe soil is sent into a steam kinetic energy mill 5 for ultrafine grinding, and a finished product 6 with the particle diameter d is prepared after grinding₉₀<2 μm; 5) the waste heat boiler 8 takes the flue gas waste heat 7 as a heat source to prepare saturated steam 9; 6) the saturated steam 9 passes through a reheating device 10 to form superheated steam 11; 7) as a working medium of the steam kinetic energy mill 5, superheated steam 11 carries out ultrafine grinding on the materials in a grinding cavity of the steam kinetic energy mill to prepare a finished product 6 meeting the granularity requirement.

2. The process for calcining kaolinite coal gangue as claimed in claim 1, wherein the steam kinetic energy mill 5 uses superheated steam 11 as a working medium, the flow velocity of the superheated steam can reach 1000-2000 m/s, and the flow velocity can be adjusted.

3. The process for calcining the kaolinite coal gangue as claimed in claim 1, wherein the kaolinite coal gangue raw material 1 is processed to 500 meshes by a coarse crushing system 2 and a grinding system 3 and then enters a calcining furnace 4 for calcining and whitening, and the output rate of calcined kaolinite is 75-85%.

4. The process for calcining kaolinite coal gangue as claimed in claim 1, wherein the flue gas waste heat 7 of the calcining furnace 4 is used as a main waste heat source. The pressure of the prepared superheated steam 11 is between 0.3MPa and 0.7MPa, and the temperature is adjustable within the range of 200 ℃ and 5000 ℃.

5. The process for calcining kaolinite coal gangue as claimed in claim 1, wherein the whiteness of the prepared finished product 6 is more than 95%.