KR20210086729A - a low-density high-strength ceramsite proppant - Google Patents

Abstract

The present invention relates to a low-density, high-strength ceramsite propant produced by a method comprising the steps of: crushing and dry grinding the raw material into a coarse powder; adding fly ash, disilicon trioxide, cryolite, kaolinite, and the like to the coarse powder; putting a product into a ball mill, performing ball milling for 30 minutes to 2 hours, and sieving the same to obtain a mixed powder; mixing a sodium fluoride silicate solution and a polyvinyl alcohol solution in a mass ratio of 1:7 to 1:15 to obtain a mixed slurry; mixing the mixed powder and the mixed slurry to obtain particles by granulating; producing a ceramsite blank by sintering the particles at a high temperature; and adding alumina powder to the ceramsite blank, grinding, and removing the alumina powder.

Description

Low-density high-strength ceramsite proppant

FIELD OF THE INVENTION The present invention relates to the field of proppants and, more particularly, to low-density, high-strength ceramsite proppants manufactured using industrial waste and tailings.

A proppant is a type of solid particle used for fracturing. After crushing, the proppant supports the wall surface of the crushed rock so that the fractured rock does not narrow again, and as a result, the hydraulically fractured portion is flow-conducting channel (flow-conducting channel) leading to the wellbore. conduction channel). In 1977, the United States developed an artificial proppant called sintered bauxite, which had the characteristics of high compressive strength and high flow conductivity under high closing pressure. In China, artificial proppant manufactured by sintering or spraying bauxite as the main material is collectively called ceramcite. At home and abroad, the relative density of ceramsite proppant is in the range of 2.70 - 3.60, and its bulk density is in the range of ^{1.60-2.10 g/cm 3 .} Both are higher than the relative and bulk density ranges of natural quartz sand.

With the rapid development of China's steel and alumina industry, the emission of industrial waste and bauxite residues has increased, destroying the ecological environment and causing serious impact on people's daily life.

Consequently, in order to recycle industrial wastes and mine residues as secondary resources, improve the ecological environment, turn the harmful into beneficial, and turn the waste into useful, economic and rational methods are adopted to dispose of industrial wastes and residues. Improving practical value has become an important research topic.

In consideration of the technical problems existing in the prior art, the inventors of the present invention have prepared a low-density high-strength ceramsite proppant using industrial waste or residues as raw materials to achieve the purposes of resource saving, waste utilization and environmental protection. Methods have been intensively studied and suggested.

In one aspect, the present invention provides a low-density, high-strength ceramsite proppant manufactured using industrial waste. The ceramsite proppant is prepared by the following steps.

(1) crushing and dry grinding 35-70 parts by weight of industrial waste generated from blast furnace slag into a coarse powder;

(2) 17 - 40 parts by weight of fly ash, 3 - 16 parts by weight of disilicon trioxide, 17 - 30 parts by weight of cryolite, 8 - 30 parts by weight of kaolin, 1 - 3 parts by weight of potassium permanganate, 5 - 7.5 parts by weight of iron oxalate, 0.1 - 3 parts by weight of graphite, and 5 - 25 parts by weight of calcium carbonate;

(3) putting the product into a ball mill to perform a ball mill for 30 minutes to 2 hours, and sieving through a 120-mesh sieve to obtain a mixed powder;

(4) stirring a sodium fluosilicate solution and a polyvinyl alcohol solution in a mass ratio of 1: 7 - 1: 15 to obtain a mixed slurry;

(5) mixing the mixed powder and the mixed slurry in a mass ratio of 5: 2 - 2: 1, and granulating to obtain particles;

(6) preparing a ceramsite blank by sintering the particles at a high temperature; and

(7) grinding by adding 8-10 parts by weight of alumina powder to the ceramsite blank, and removing the alumina powder to obtain a low-density, high-strength ceramsite proppant.

As industrial waste, aluminum-rich and iron-rich waste materials from various sources may be used, and waste refractories and blast furnace slag may be used.

The low-density high-strength ceramsite proppant has ^{a bulk density of 1.20-1.60 g/cm 3} and a compressive strength of 13.0-24.0 MPa.

Advantageous effects of the present invention are as follows.

(1) By using industrial waste and residual waste as raw materials for producing proppant, the present invention can significantly improve the availability of waste, save resources, protect the environment, and prevent pollution.

(2) By adopting the raw material of the present invention as a material for manufacturing, the present invention significantly improves the strength of the ceramsite proppant while maintaining a low density.

(3) The process of the present invention is simple and low in cost.

Hereinafter, the present invention will be described in more detail in combination with specific examples. However, the present invention is not limited to the following examples.

Example 1

40 parts by weight of blast furnace slag was measured, put into a hammer crusher, and pulverized for about 30 minutes to obtain a coarse slag powder. 20 parts by weight of fly ash, 5 parts by weight of disilicon trioxide, 22 parts by weight of cryolite, 30 parts by weight of kaolin, 3 parts by weight of potassium permanganate, 5 parts by weight of iron oxalate, 2 parts by weight of graphite and 5 parts by weight of calcium carbonate Then, these materials were put into a ball mill together with the slag coarse powder, water was added, and the ball mill was performed for about 45 minutes to obtain a mixed powder material. The obtained mixed powder material was put into a disk granulator, and a slurry in which sodium fluoride silicate and polyvinyl alcohol (1:20) (accounting for 35% of the total weight of the mixture material) was mixed was added. did. The product was granulated, filtered through a 120-mesh sieve, and then put into a rotary kiln and sintered at 1280 - 1350° C. to obtain a ceramsite blank. 10 parts by weight of alumina powder was added, the ceramsite blank was polished, and then the alumina powder was removed to obtain a low-density, high-strength ceramsite proppant.

Example 2

55 parts by weight of the waste refractory material was measured, put into a hammer grinder, and pulverized for about 30 minutes to obtain a coarse powder of the waste refractory material. 30 parts by weight of fly ash, 12 parts by weight of disilicon trioxide, 25 parts by weight of cryolite, 20 parts by weight of kaolinite, 2.3 parts by weight of potassium permanganate, 6 parts by weight of iron oxalate, 3 parts by weight of graphite and 22 parts by weight of calcium carbonate Then, these materials were put into a ball mill together with the waste refractory material coarse powder, water was added, and the ball mill was performed for about 55 minutes to obtain a mixed powder material. The obtained mixed powder material was put into a disk granulator, and a slurry in which sodium fluoride silicate and polyvinyl alcohol (1:20) (accounting for 35% of the total weight of the mixture material) were mixed was added. The product was granulated, sieved through a 120-mesh sieve, put into a rotary kiln, and sintered at 1280 - 1350° C. to obtain a ceramsite blank. 10 parts by weight of alumina powder was added, and the ceramsite blank was polished, and then the alumina powder was removed to obtain a low-density, high-strength ceramsite proppant.

Example 3

55 parts by weight of bauxite tailings were measured and put into a hammer grinder and grinded for about 40 minutes to obtain a coarse powder. 35 parts by weight of fly ash, 6 parts by weight of disilicon trioxide, 16 parts by weight of cryolite, 17 parts by weight of kaolinite, 1.5 parts by weight of potassium permanganate, 7 parts by weight of iron oxalate, 4 parts by weight of graphite and 15 parts by weight of calcium carbonate Then, these materials were put into a ball mill together with the coarse powder, water was added, and the ball mill was performed for about 1 hour to obtain a mixed powder material. The obtained mixed powder material was put into a disk granulator, and a slurry in which sodium fluoride silicate and polyvinyl alcohol (1:20) (accounting for 35% of the total weight of the mixture material) were mixed was added. The product was granulated, sieved through a 120-mesh sieve, put into a rotary kiln, and sintered at 1280 - 1350° C. to obtain a ceramsite blank. 6 parts by weight of alumina powder was added, and the ceramsite blank was polished, and then the alumina powder was removed to obtain a low-density, high-strength ceramsite proppant.

Example 4

52 parts by weight of the bauxite residue was weighed, put into a hammer grinder, and pulverized for about 40 minutes to obtain a coarse powder. 33 parts by weight of fly ash 6 parts by weight of disilicon trioxide, 19 parts by weight of cryolite, 20 parts by weight of kaolinite, 1.8 parts by weight of potassium permanganate, 7 parts by weight of iron oxalate, 3 parts by weight of graphite and 25 parts by weight of calcium carbonate Then, these materials were put into a ball mill together with the coarse powder, water was added, and the ball mill was performed for about 1 hour to obtain a mixed powder material. The obtained mixed powder material was put into a disk granulator, and a slurry in which sodium fluoride silicate and polyvinyl alcohol (1:20) (accounting for 35% of the total weight of the mixture material) were mixed was added. The product was granulated, sieved through a 120-mesh sieve, put into a rotary kiln, and sintered at 1280 - 1350° C. to obtain a ceramsite blank. 7 parts by weight of alumina powder was added, and the ceramsite blank was polished, and then the alumina powder was removed to obtain a low-density, high-strength ceramsite proppant.

Example 5

30 parts by weight of blast furnace slag and 52 parts by weight of bauxite residue were measured, put into a hammer grinder, and pulverized for about 55 minutes to obtain a coarse powder. Manganese mineral powder 10 parts by weight, fly ash 41 parts by weight, disilicon trioxide 3 parts by weight, cryolite 20 parts by weight, kaolinite 13 parts by weight, potassium permanganate 3 parts by weight, iron oxalate 7.5 parts by weight, graphite 0.5 parts by weight and carbonic acid After measuring each of 16 parts by weight of calcium, these materials were put into a ball mill together with the coarse powder, water was added, and the ball mill was performed for about 1.5 hours to obtain a mixed powder material. The obtained mixed powder material was put into a disk granulator, and a slurry in which sodium fluoride silicate and polyvinyl alcohol (1:30) (accounting for 20% of the total weight of the mixture material) was mixed was added. The product was granulated, sieved through a 120-mesh sieve, put into a rotary kiln, and sintered at 1280 - 1350° C. to obtain a ceramsite blank. 11 parts by weight of alumina powder was added, the ceramsite blank was polished, and then the alumina powder was removed to obtain a low-density, high-strength ceramsite proppant.

Example 6

52 parts by weight of blast furnace slag and 45 parts by weight of bauxite residue were measured and put into a hammer grinder, and pulverized for about 75 minutes to obtain a coarse powder. Manganese mineral powder 14 parts by weight, fly ash 20 parts by weight, disilicon trioxide 12 parts by weight, cryolite 20 parts by weight, kaolinite 25 parts by weight, potassium permanganate 3 parts by weight, iron oxalate 4 parts by weight, graphite 2 parts by weight and carbonic acid After measuring each of 25 parts by weight of calcium, these materials were put into a ball mill together with the coarse powder, water was added, and the ball mill was performed for about 1.5 hours to obtain a mixed powder material. The obtained mixed powder material was put into a disk granulator, and a slurry in which sodium fluoride silicate and polyvinyl alcohol (1:30) (accounting for 20% of the total weight of the mixture material) was mixed was added. The product was granulated, sieved through a 120-mesh sieve, put into a rotary kiln, and sintered at 1280 - 1350° C. to obtain a ceramsite blank. 12 parts by weight of alumina powder was added, and the ceramsite blank was polished, and then the alumina powder was removed to obtain a low-density, high-strength ceramsite proppant.

In order to more specifically describe the properties of the low-density high-strength ceramsite proppant prepared according to the present invention, the present invention also provides experimental examples for measuring the following technical indicators. The measured indices are shown in Table 1 below.

compressive strength
(Compressive strength)
(MPa) permeability
(Permeability) (μm ² ) Bulk Century
(Bulk intensity) (g/cm ³ ) Example 1 20 degrees Celsius: 14.6 93 1.35 200 degrees Celsius: 15.0 Example 2 20 degrees Celsius: 14.8 95 1.41 200 degrees Celsius: 15.0 Example 3 20 degrees Celsius: 17.3 99 1.6 200 degrees Celsius: 18.5 Example 4 20 degrees Celsius: 18.4 98 1.59 200 degrees Celsius: 19.0 Example 5 20 degrees Celsius: 21.1 96 1.52 200 degrees Celsius: 22.3 Example 6 20 degrees Celsius: 20.9 97 1.47 200 degrees Celsius: 22.7

The ceramsite propant obtained in Examples 1 to 6 was subjected to a permeability test using a permeability tester. The measured transmittance data are shown in Table 1. As can be seen in Table 1, it can be seen that the proppant prepared according to the method of the present invention exhibits high transmittance in the range of ^{93-99 μm 2 .}

After curing the ceramsite propant obtained in Examples 1 to 6 while maintaining the temperature at 20° C. and 200° C. for 2 days under zero closing pressure, a compressive strength test was performed. The measured compressive strength data are shown in Table 1. As can be seen in Table 1, it can be seen that the proppant prepared according to the method of the present invention exhibits a relatively high compressive strength in the range of 14.6 MPa-22.7 MPa.

The above description only exemplifies the preferred embodiment of the present invention, the protection scope of the present invention is not limited thereto, and any equivalent substitution or substitution made by those skilled in the art according to the technical solution of the present invention and the concept of the present invention Modifications should be included within the protection scope of the present invention.

Claims (4)

A ceramsite proppant prepared by a method comprising the steps of:
(1) crushing and dry grinding 35-70 parts by weight of industrial waste generated from blast furnace slag into a coarse powder;
(2) 17 - 40 parts by weight of fly ash, 3 - 16 parts by weight of disilicon trioxide, 17 - 30 parts by weight of cryolite, 8 - 30 parts by weight of kaolin, 1 - 3 parts by weight of potassium permanganate, 5 - 7.5 parts by weight of iron oxalate, 0.1 - 3 parts by weight of graphite, and 5 - 25 parts by weight of calcium carbonate;
(3) putting the product into a ball mill to perform a ball mill for 30 minutes to 2 hours, and sieving through a 120-mesh sieve to obtain a mixed powder;
(4) stirring a sodium fluosilicate solution and a polyvinyl alcohol solution in a mass ratio of 1:7 - 1:15 to obtain a mixed slurry;
(5) mixing the mixed powder and the mixed slurry in a mass ratio of 5: 2 - 2: 1, and granulating to obtain particles;
(6) preparing a ceramsite blank by sintering the particles at a high temperature; and
(7) grinding by adding 8-10 parts by weight of alumina powder to the ceramsite blank, and removing the alumina powder to obtain a low-density high-strength ceramsite proppant According to claim 1,
The blast furnace slag contains dicalcium silicate, tricalcium silicate, magnesium silicate, aluminum silicate, manganese silicate and iron silicate as main components. , Ceramsite Propant. According to claim 1,
The blast furnace slag should be subjected to an iron removal process using a magnet, ceramsite proppant. 4. The method according to any one of claims 1 to 3,
The high temperature sintering is carried out at 1280 - 1350 ° C with a rotary kiln, ceramsite proppant.