阅读说明：本技术 一种高强度石油压裂硅酸镁铝支撑剂及其制备方法 (High-strength oil fracturing magnesium aluminum silicate proppant and preparation method thereof ) 是由 彭同江 唐颂 孙红娟 罗利明 王璨 于 2021-08-31 设计创作，主要内容包括：本发明提供了一种高强度石油压裂硅酸镁铝支撑剂及其制备方法。制备方法包括：将含蛇纹石矿物的原料进行干燥和破碎,得到第一粉体；将第一粉体进行焙烧,得到第二粉体；将第一粉体、第二粉体和配料进行混合,获得混合物料粉体；将混合物料粉体进行造粒,获得球形颗粒状坯体；将球形颗粒状坯体进行干燥和烧结,获得所述高强度石油压裂硅酸镁铝支撑剂。高强度石油压裂硅酸镁铝支撑剂的直径介于106～3350μm之间,在86～103MPa闭合压力下破碎率≤2～8％。本发明以主要含蛇纹石的岩石、废石、尾矿为原料生产高强度低密度石油压裂硅酸镁铝支撑剂,实现了多种固体废物的资源化利用。(The invention provides a high-strength oil fracturing magnesium aluminum silicate proppant and a preparation method thereof. The preparation method comprises the following steps: drying and crushing a raw material containing a serpentine mineral to obtain first powder; roasting the first powder to obtain second powder; mixing the first powder, the second powder and the ingredients to obtain mixed material powder; granulating the mixed material powder to obtain a spherical granular blank; and drying and sintering the spherical granular green body to obtain the high-strength petroleum fracturing magnesium aluminum silicate proppant. The diameter of the high-strength oil fracturing magnesium aluminum silicate propping agent is 106-3350 mu m, and the breaking rate is less than or equal to 2-8% under the closed pressure of 86-103 MPa. The invention uses rocks, waste rocks and tailings mainly containing serpentine as raw materials to produce the high-strength low-density petroleum fracturing magnesium aluminum silicate proppant, thereby realizing resource utilization of various solid wastes.)

1. A preparation method of a high-strength petroleum fracturing magnesium aluminum silicate proppant is characterized by comprising the following steps:

drying and crushing a raw material containing a serpentine mineral to obtain first powder;

roasting the first powder to obtain second powder;

mixing the first powder, the second powder and the ingredients to obtain mixed material powder;

granulating the mixed material powder to obtain a spherical granular blank; and

and drying and sintering the spherical granular green body to obtain the high-strength petroleum fracturing magnesium aluminum silicate proppant.

2. The method for preparing the high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 1, wherein the serpentine mineral-containing raw material comprises one or more of serpentine, serpentine tailings, chrysotile tailings, stripped serpentine waste rock, and ultrabasic rock type metal mineral tailings.

3. The preparation method of the high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 1, wherein the first powder comprises, by mass: 25-40% of MgO and 35-40% of SiO₂2-10% of CaO, 5-15% of Fe₂O₃1 to 5% of Al₂O₃The particle diameter of the raw material powder is less than 75 μm.

4. The method for preparing the high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 1, wherein the roasting process is roasting at 650-1200 ℃ for 3-90 min in a roasting kiln, the roasting kiln comprising one of a vertical kiln, a rotary kiln and a pre-decomposition kiln.

5. The method for preparing the high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 1, wherein the ingredients comprise one or more of quicklime powder, fly ash powder, yellow sand powder, quartz powder, potassium feldspar powder and illite powder, and the particle size of the ingredients is 75 μm or less.

6. The preparation method of the high-strength oil fracturing magnesium aluminum silicate proppant as claimed in claim 1, wherein the mass ratio of the first powder, the second powder and the ingredients is (40-80): (10-40): (10-30), wherein the main crystal phase of the second powder is olivine.

7. The method for preparing the high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 1, wherein the granulation process is wet granulation, and specifically comprises: placing the mixed material powder in a granulator, and rotating for 5-20 min at the rotating speed of 30-70 r/min; then adding water and a binder, and continuously carrying out rotary granulation for 30-90 min, wherein the adding amount of the water is 10-15% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder; and after granulation is finished, shaping for 5-30 min on a spherical shaping machine to obtain a spherical granular blank.

8. The method for preparing the high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 1, wherein the process for drying the spherical granular green body comprises: drying for 60-120 min at 60-80 ℃, wherein the sintering process comprises the following steps: sintering at 750-1200 deg.C for 3-120 min.

9. The high-strength oil fracturing magnesium aluminum silicate proppant is prepared by the preparation method of any one of claims 1 to 8.

10. The high-strength oil fracturing magnesium aluminum silicate proppant as set forth in claim 9, wherein the diameter of the high-strength oil fracturing magnesium aluminum silicate proppant is 106-3350 μm, the sphericity and roundness are not less than 0.9, and the bulk density is 0.8-2.5 g/cm³And the breaking rate is less than or equal to 2-8% under the closed pressure of 86-103 MPa.

Technical Field

The invention belongs to the field of oil and gas application materials, and particularly relates to a preparation method for preparing a high-strength petroleum fracturing magnesium aluminum silicate propping agent by using a raw material containing serpentine minerals as a raw material, and a high-strength petroleum fracturing magnesium aluminum silicate propping agent product.

Background

When the petroleum and natural gas deep well is exploited, in order to improve the yield of an oil well, petroleum propping agents and high-pressure solutions enter a stratum and are filled in rock stratum fractures, so that the rock stratum around a shaft is fractured, and oil and gas products can smoothly pass through the rock stratum, so that the yield is increased.

Because of the difference of oil layer depth and grease viscosity, the requirements of different oil fields on the propping agents are different, and four kinds of propping agents with high strength and high density, high strength and medium density, high strength and low density and high strength and ultralow density are available in the market at present, and the common mesh number is as follows: 16-30 meshes, 20-40 meshes, 30-50 meshes, 40-70 meshes and the like.

The conventional proppant mainly comprises quartz sand, bauxite ceramsite sand, resin-coated composite particles and the like. The quartz sand is low in cost, low in density and easy to pump, occupies more than 50% of the market share of the proppant at present, but the proppant is not suitable for deep wells with high closing pressure due to low strength and poor sphericity. Although the sphericity of the composite particles of the resin-coated quartz sand is improved, the corrosion resistance is stronger, and the flow conductivity is also better, the product retention period is short, and the manufacturing cost is too high to popularize. The fracturing propping agent taking magnesium aluminum silicate as a main component does not exist in China.

Disclosure of Invention

The present invention aims to address at least one of the above-mentioned deficiencies of the prior art. For example, the invention aims to provide a preparation method of a high-strength petroleum fracturing magnesium aluminum silicate proppant.

In order to achieve the above object, one aspect of the present invention provides a method for preparing a high-strength oil fracturing magnesium aluminum silicate proppant, comprising the steps of: drying and crushing a raw material containing a serpentine mineral to obtain first powder; roasting the first powder to obtain second powder; mixing the first powder, the second powder and the ingredients to obtain mixed material powder; granulating the mixed material powder to obtain a spherical granular blank; and drying and sintering the spherical granular green body to obtain the high-strength petroleum fracturing magnesium aluminum silicate proppant.

In an exemplary embodiment of the invention, the serpentine mineral-containing feedstock may include one or more of serpentine, serpentine mill tailings, chrysotile mill tailings, stripped serpentine rejects, and ultrabedrock type metal mineral mill tailings.

In an exemplary embodiment of the present invention, the first powder may include, by mass percent: 25-40% of MgO and 35-40% of SiO₂2-10% of CaO, 5-15% of Fe₂O₃1 to 5% of Al₂O₃The particle size of the raw material powder may be 75 μm or less.

In an exemplary embodiment of the present invention, the roasting process may be roasting at 650 to 1200 ℃ for 3 to 90min in a roasting kiln, which may include one of a shaft kiln, a rotary kiln, and a pre-decomposition kiln.

In an exemplary embodiment of the present invention, the ingredient may include one or more of quicklime powder, fly ash powder, yellow sand powder, quartz powder, potassium feldspar powder, and illite powder, and the particle size of the ingredient may be 75 μm or less.

In an exemplary embodiment of the invention, the mass ratio of the first powder, the second powder and the ingredients to be mixed may be (40-80): (10-40): (10-30), wherein the main crystal phase of the second powder is olivine.

In an exemplary embodiment of the present invention, the granulation process may be wet granulation, and specifically may include: placing the mixed material powder in a granulator, and rotating for 5-20 min at the rotating speed of 30-70 r/min; then adding water and a binder, and continuously carrying out rotary granulation for 30-90 min, wherein the adding amount of the water is 10-15% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder; and after granulation is finished, shaping for 5-30 min on a spherical shaping machine to obtain a spherical granular blank.

In an exemplary embodiment of the present invention, the process of drying the spherical granular green body may include: drying for 60-120 min at 60-80 ℃.

In an exemplary embodiment of the present invention, the sintering process may be sintering at 750 to 1200 ℃ for 3 to 120 min.

According to another aspect of the invention, the high-strength oil fracturing magnesium aluminum silicate proppant can be prepared by adopting the preparation method of any one of the above.

In an exemplary embodiment of the invention, the high-strength petroleum fracturing magnesium aluminum silicate proppant has a diameter of 106-3350 μm, a sphericity and roundness of not less than 0.9, and a bulk density of 0.8-2.5 g/cm³And the breaking rate is less than or equal to 2-8% under the closed pressure of 86-103 MPa.

Compared with the prior art, the beneficial effects of the invention can comprise at least one of the following:

(1) the product takes rocks, waste rocks and tailings mainly containing serpentine as raw materials to produce the high-strength oil fracturing magnesium aluminum silicate proppant, so that the resource utilization of various solid wastes is realized, and the product has important ecological and sustainable development significance on resource protection, saving and high-value utilization;

(2) the recycling of the tailings, the waste rocks and the tailings has important ecological and environmental significance on the safety, environmental protection, reclamation and greenness of the tailings pond;

(3) the preparation method for obtaining the novel high-strength petroleum fracturing magnesium aluminum silicate proppant by processing and treating rocks, waste rocks and tailings mainly containing serpentine as raw materials has the advantages of simple preparation method, energy conservation and emission reduction, high product added value, high ecological environmental benefit and the like, and has important significance for developing new material industry and social economy;

(4) magnesium-aluminum-magnesium silicate powder with olivine as a main crystal phase is obtained by roasting a raw material containing serpentine, phase transformation of serpentine can be realized, phase transformation detoxification is facilitated, the environment is protected, and the hardness and strength of the powder can be remarkably improved;

(5) the fracturing propping agent is prepared by using the magnesium aluminum silicate for the first time, so that a good direction is provided for resource utilization of the solid waste containing serpentine;

(6) the strength of the product can be effectively improved and the acid corrosion resistance can be improved by proportioning, granulating and sintering the mixture;

(7) compared with the traditional proppant, the aluminum magnesium silicate proppant has the advantages that a large amount of quartz sand can be saved, the defects of low strength and poor sphericity of the quartz sand are overcome, the prepared proppant has a wide application pressure range and a wide market prospect;

(8) the prepared magnesium aluminum silicate proppant has the advantages of high strength, high sphericity, good acid corrosion resistance and the like, and has wide market prospect and remarkable economic, environmental and social benefits.

Drawings

Figure 1 shows a flow chart of a method of preparation of an exemplary embodiment 1 of the method of the present invention.

Detailed Description

Hereinafter, the high strength oil fracturing magnesium aluminum silicate proppant and the method for preparing the same according to the present invention will be described in detail with reference to the exemplary embodiments.

The main technical conception of the invention is as follows: rock, waste stone and tailings containing serpentine are used as raw materials, and the magnesium aluminum silicate proppant with high strength, high sphericity and good corrosion resistance is prepared through the working procedures of drying, crushing, roasting and the like. The preparation method is simple, energy-saving and emission-reducing, and has high added value of products and high ecological environmental benefit.

Exemplary embodiment 1

As shown in fig. 1, in the present exemplary embodiment, the preparation method of the high strength oil fracturing magnesium aluminum silicate proppant may be implemented by the following steps:

s1, drying and crushing to obtain first powder.

Specifically, a raw material containing a serpentine mineral is dried and crushed to obtain a raw material powder. Here, the serpentine mineral-containing raw material may include one or more of serpentine, serpentine mill tailings, chrysotile mill tailings, exfoliated serpentine gangue, and ultrabasic rock type metal mineral mill tailings.

The drying process can be carried out in a dryer, and parameters such as the temperature and the time of the dryer can be adjusted to ensure that the moisture content of the dried raw material containing the serpentine mineral is less than or equal to 5 percent, such as 3.0 percent, 4.5 percent and the like, so as to obtain the dried powder after crushing. Avoiding the agglomeration of the powder after crushing, improving the crushing efficiency, and ensuring that the temperature of the dryer can be 60-150 ℃ and the drying time is 30-150 min. In addition, the drying can be carried out in vacuum drying equipment, so that the drying speed is accelerated, and meanwhile, the dust caused by drying is prevented from diffusing into the air.

The crushing process can be carried out by adopting a closed crushing mode, so that the crushing efficiency is improved, and the uniform granularity can be ensured. The crushing is preferably carried out in a dust-free workshop, so that the environment is protected, and the serpentine fiber can be prevented from diffusing into the environment to cause adverse effects.

The water content (free water) of the obtained first powder is below 5%, and when the water content is higher than 5%, the obtained powder is easy to agglomerate, so that the uniformity of subsequent ingredients is influenced, and the quality of subsequent products is adversely affected.

The first powder obtained comprises the following components in a mass ratio of 25-40: 35-40: 2-10: 5-15: 1 to 5 of MgO and SiO₂、CaO、Fe₂O₃And Al₂O₃. That is, the chemical composition of the powder comprises the following components in percentage by mass: 25-40% of MgO and SiO₂35～40％，CaO 2～10％，Fe₂O₃ 5～15％，Al₂O₃ 1～5％，H₂O⁺(bound water) 8-15%. In addition, the particle size of the first powder is 75 μm or less, for example, the particle size of the first powder is 2 to 75 μm, and when the particle size is all less than 2 μm, the specific surface area of the first powder is too large, the surface energy is high, the powder is easily agglomerated, and excessive energy is consumed in the production process, which is uneconomical; when the particle size is over 75 mu m, although the powder processing cost is reduced, because the particle size is too coarse and the specific surface area is too small, when preparing the high-strength petroleum fracturing magnesium aluminum silicate proppant product,can influence the homogeneity, circularity, sphericity and compressive strength of product to sum up, 2 mu m ~ 75 mu m can be selected to the suitable particle diameter scope of first powder, has so both guaranteed certain fineness, is convenient for the later stage granulation, has avoided the powder that leads to too thin to reunite again simultaneously, influences later stage granulation.

And S2, roasting to obtain second powder.

Specifically, the first powder obtained in step S1 is fired to obtain a second powder. Here, the main crystal phase of the obtained second powder was olivine.

The roasting process can be carried out for 3min to 90min at the temperature of 650 ℃ to 1200 ℃, and the heating rate can be 3 to 20 ℃/min. The first powder can be placed in one of a vertical kiln, a rotary kiln or a roller kiln for roasting. The calcination may also be performed using a calcination kiln commonly used in the art, and will not be described herein in any greater detail. When the calcination temperature is lower than 650 ℃, complete phase inversion is difficult to perform, and when the temperature is too high (e.g., higher than 1200 ℃), energy is wasted, the conversion rate of the crystal phase is low, which is not economical, and the calcination time is also so, so that the calcination temperature and the calcination time are both in an optimal range.

And S3, mixing the first powder, the second powder and the ingredients to obtain mixed material powder.

Specifically, the first powder obtained in step S1 and the second powder obtained in step S2 are mixed with ingredients to obtain a mixed material powder.

Here, the compounding may include one or more of quicklime powder, fly ash powder, yellow sand powder, quartz powder, potassium feldspar powder, illite powder, and further, the particle size of the compounding may be 75 μm or less, for example, between 2 μm and 75 μm. The mixing mass ratio of the first powder to the second powder to the ingredients is (40-80): (10-40): (10-30), for example, mixing 40-80% of first powder, 10-40% of second powder and 10-20% of ingredients in percentage by mass, wherein the mass ratio can fully utilize the raw material containing the serpentine mineral, so that the content of each component after mixing is within a required range, and the performance of the product is ensured.

And S4, granulating to obtain a spherical granular blank.

Specifically, the mixed material powder obtained in step S3 is granulated to obtain a spherical granular green body.

The granulation process is wet granulation, and the mixed material powder is put in a granulator and rotated for 5-20 min at the rotating speed of 30-70 r/min; and then adding water and a binder, and continuously performing rotary granulation for 30-90 min, wherein the adding amount of the water is 10-15% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder. And after granulation is finished, shaping for 5-30 min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

And S5, obtaining the high-strength oil fracturing magnesium aluminum silicate proppant.

Specifically, the spherical granular green body obtained in the step S4 is dried and sintered to obtain the high-strength petroleum fracturing magnesium aluminum silicate proppant. For example, the diameter of the prepared high-strength oil fracturing magnesium aluminum silicate proppant is 106-3350 mu m, the sphericity and roundness are not lower than 0.8, and the volume density is 0.8-2.5 g/cm³The breaking rate is less than or equal to 6 percent under the closed pressure of 103MPa, and the 9 percent breaking grade is 15K.

The drying process can comprise drying the spherical granular blank at the temperature of 60-80 ℃ for 60-120 min.

The sintering process may include: raising the temperature from room temperature to 700-850 ℃ at the speed of 5-15 ℃/min, then raising the temperature to 700-1200 ℃ at the speed of 3-7 ℃/min, and keeping the temperature for 3-90 min. And obtaining the high-strength petroleum fracturing magnesium aluminum silicate proppant.

The drying process may also be performed in a kiln used for sintering to optimize the process and increase efficiency. For example, the drying and sintering may be performed in a shaft kiln, a roller kiln or a rotary kiln, or, for example, the drying and sintering may be performed in other apparatuses commonly used in the art, which will not be described in detail herein. Here, after the tail gas introduced into the roasting process is used for drying the spherical granular blank, the temperature of the tail gas is reduced to be lower than 120 ℃, for example, 80-120 ℃.

Within the temperature range, a better sintering effect can be achieved, so that the high-strength petroleum fracturing magnesium aluminum silicate propping agent obtained after sintering is high in strength and low in density, when the temperature is lower than 750 ℃, the strength of the sintered product is low and is difficult to reach the high-strength standard, and the temperature is higher than 1200 ℃, so that not only is energy consumption easy, but also the density of the sintered product can be increased, and the product performance and the use quality are reduced.

The high-strength oil fracturing magnesium aluminum silicate proppant prepared by the invention can reach and exceed various performance standards required by the industry. For example, in the invention, the breaking rate of the prepared 16-30-mesh high-strength petroleum fracturing magnesium aluminum silicate proppant is less than or equal to 8% under the closing pressure of 69MPa, and is far lower than the requirement of 18% in the Q/SH 10201598-2013 standard; the volume density of the prepared 20-40 mesh high-strength oil fracturing magnesium aluminum silicate proppant is 1.65-1.70 g/cm³Apparent density of 3.00-3.15 g/cm³And under the closing pressure of 103MPa, the breakage rate is less than or equal to 7 percent, and the grade of 9 percent breakage rate can reach 15K according to the standard of ' method for testing the performance of proppant for hydraulic fracturing and gravel packing operation ' (SY/T5108-2014) in the oil and gas industry of the people's republic of China.

Exemplary embodiment 2

In the exemplary embodiment, the method for preparing the large-size aragonite whisker by batch carbonization of the calcareous raw material containing impurities can also be realized by the following steps:

1) drying the raw materials containing the serpentine minerals until the moisture content of each raw material is less than 1.5%, and crushing to obtain first powder, wherein the first powder comprises the following components in percentage by mass: 35-40: 2-10: 5-15: 1 to 5 of MgO and SiO₂、CaO、Fe₂O₃And Al₂O₃And the grain diameter of the obtained first powder is larger than 2 μm and smaller than 75 μm.

2) And roasting the first powder in a vertical kiln, a rotary kiln or a pre-decomposition kiln at 650-1200 ℃ for 2-90 min to obtain second powder with the main crystal phase of olivine.

3) The first powder, the second powder and the ingredients are mixed according to the mass ratio of 40-80: 10-40: 10-30, and the ingredients can comprise one or more of quicklime powder, fly ash powder, yellow sand powder, quartz powder, potassium feldspar powder and illite powder to obtain mixed material powder.

4) And (3) rotating the mixed material powder for 5-20 min at the rotating speed of 30-70 r/min in a granulator, then adding water and a binder, and continuing to perform rotary granulation for 30-90 min, wherein the adding amount of the water is 10-15% of the mass of the mixed material powder, and the adding amount of the binder is 4-20% of the mass of the mixed material powder. And after granulation is finished, shaping for 5-30 min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

5) And (3) drying the spherical granular green body in a vertical kiln, a roller kiln or a rotary kiln for 30-90 min by using tail gas generated by roasting in the step 2) when the temperature is reduced to 80-120 ℃, then heating from room temperature to 700-850 ℃ at the speed of 5-15 ℃/min, and when the temperature exceeds 850 ℃, continuously heating to 800-1200 ℃ at the heating speed of 3-7 ℃/min and preserving the heat for 3-90 min to obtain the high-strength low-density magnesium aluminum silicate proppant, wherein the drying and sintering can adopt but not limited to a vertical kiln, a roller kiln or a rotary kiln.

The technical solution of the present invention is further explained by detailed examples below.

Example 1

The specific preparation method of this example is as follows:

(1) and (3) placing the serpentine beneficiation tailings in a dryer, drying at 80 ℃ for 70min, and crushing in a closed-circuit crushing mode to obtain first powder with the water content of 3%. The obtained raw material powder comprises 38 percent of MgO and 38 percent of SiO in percentage by mass₂8% of CaO, 9% of Fe₂O₃And 4% of Al₂O₃The particle size of the first powder is less than or equal to 75 μm and mainly ranges from 30 μm to 75 μm.

(2) And (3) placing the obtained raw material powder in a vertical kiln, heating the raw material powder from room temperature to 850 ℃ at the speed of 15 ℃/min, and roasting the raw material powder for 40min at the temperature to obtain second powder of which the main crystal phase is olivine, wherein the particle size of the second powder is 30-75 mu m.

(3) The first powder, the second powder and the fly ash powder are mixed according to the mass ratio of 70: 15: 15, and uniformly mixing in a dry powder mixer for 30min to obtain mixed material powder. Wherein the particle size of the fly ash is 5-20 μm.

(4) And granulating the mixed material powder by adopting a wet method, wherein the granulating method comprises the steps of rotating the mixed material powder in a granulator for 10min at a rotating speed of 50r/min, then adding water and a binder, and continuously rotating and granulating for 60min, wherein the adding amount of the water is 10% of the mass of the mixed material powder, and the adding amount of the binder is 12% of the mass of the mixed material powder. And after granulation is finished, shaping for 15min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

(5) And (3) drying the spherical granular blank in the vertical kiln for 60min when the temperature is reduced to 80-90 ℃ by utilizing the hot tail gas generated by the roasting kiln in the step (2), heating to 750 ℃ at a speed of 10 ℃/h, then heating to 1100 ℃ at a speed of 5 ℃/min, and preserving the heat for 20min to obtain a finished product A.

The diameter of the finished product A is 425-850 mu m, the sphericity and roundness are not less than 0.9, and the volume density is 1.65-1.75 g/cm³The breaking rate is less than or equal to 6% under the closed pressure of 103MPa, the 9% breaking grade is 15K, HCl: HF-12: 3, the acid solubility is less than or equal to 3 percent.

Example 2

The specific preparation method of this example is as follows:

(1) and (3) drying the peeled serpentine waste rock in a dryer, drying for 60min at 90 ℃, and crushing in a closed-circuit crushing mode to obtain first powder with the water content of 4%. The obtained first powder comprises 40% of MgO and 35% of SiO₂6 percent of CaO, 12 percent of Fe₂O₃And 3% of Al₂O₃The particle size of the first powder is 2-75 μm.

(2) And (3) heating the obtained first powder to 750 ℃ at a speed of 20 ℃/min from room temperature in a roller kiln, and roasting for 100min at the temperature to obtain second powder with the main crystal phase of olivine, wherein the particle size of the second powder is 20-50 mu m.

(3) Mixing the first powder, the second powder and illite powder according to a mass ratio of 55: 20: 25, and uniformly mixing in a dry powder mixer for 20min to obtain mixed material powder. Wherein the particle size of the illite powder is 30-75 μm.

(4) And granulating the mixed material powder by adopting a wet method, wherein the granulating method comprises the steps of rotating the mixed material powder in a granulator for 8min at the rotating speed of 60r/min, then adding water and a binder, and continuously rotating and granulating for 50min, wherein the adding amount of the water is 11% of the mass of the mixed material powder, and the adding amount of the binder is 10% of the mass of the mixed material powder. And after granulation is finished, shaping for 20min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

(5) And (3) drying the spherical granular blank in the vertical kiln for 70min when the temperature is reduced to 70-80 ℃ by utilizing the hot tail gas generated by the roasting kiln in the step (2), heating to 700 ℃ at a speed of 15 ℃/h, then heating to 1050 ℃ at a speed of 4 ℃/min, and preserving the heat for 30min to obtain a finished product B.

The diameter of the finished product B is 300-600 mu m, the sphericity and roundness are not less than 0.9, and the volume density is 1.60-1.70 g/cm³The breaking rate is less than or equal to 6% under the closed pressure of 103MPa, the 9% breaking grade is 15K, HCl: HF-12: 3, the acid solubility is less than or equal to 3 percent.

Example 3

The specific preparation method of this example is as follows:

(1) drying the chrysotile mill tailings in a dryer, drying for 90min at 70 ℃, and then crushing in a closed-circuit crushing mode to obtain first powder with the water content of 2%. The obtained first powder comprises 35% of MgO and 40% of SiO₂7% of CaO, 11% of Fe₂O₃And 5% of Al₂O₃The particle size of the first powder is 20-70 μm.

(2) And (3) heating the obtained first powder from room temperature to 900 ℃ at a speed of 20 ℃/min in a rotary kiln, and roasting for 10min to obtain second powder with the main crystal phase of olivine, wherein the particle size of the second powder is 20-70 mu m.

(3) Mixing the first powder, the second powder and potassium feldspar powder according to a mass ratio of 50: 20: 30, and uniformly mixing in a dry powder mixer for 25min to obtain mixed material powder.

(4) And granulating the mixed material powder by a wet method, wherein the granulating method comprises the steps of rotating the mixed material powder in a granulator for 5min at a rotating speed of 70r/min, then adding water and a binder, and continuing to rotate and granulate for 30min, wherein the adding amount of the water is 12% of the mass of the mixed material powder, and the adding amount of the binder is 8% of the mass of the mixed material powder. And after granulation is finished, shaping for 10min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

(5) And (3) drying the spherical granular blank in the vertical kiln for 90min by using the hot tail gas generated by the roasting kiln in the step (2) when the temperature is reduced to 60-70 ℃, heating to 700 ℃ at a speed of 5 ℃/h, then heating to 1050 ℃ at a speed of 3 ℃/min, and preserving the heat for 50min to obtain a finished product C.

The diameter of the finished product C is 425-850 mu m, the sphericity and roundness are not less than 0.9, and the volume density is 1.70-1.75 g/cm³The breaking rate is less than or equal to 4% under the closed pressure of 103MPa, the 9% breaking grade is 15K, HCl: HF-12: 3, the acid solubility is less than or equal to 3 percent.

Example 4

The specific preparation method of this example is as follows:

(1) placing the mineral processing tailings of the super-basic rock type metal mineral products in a dryer for drying, drying for 90min at 60 ℃, and then crushing in a closed crushing mode to obtain first powder with the water content of 5%. The obtained first powder comprises 32% of MgO and 38% of SiO₂9% of CaO, 11% of Fe₂O₃And 5% of Al₂O₃The particle size of the first powder is mainly 2-75 μm, and the maximum particle size is less than or equal to 75 μm.

(2) And (3) placing the obtained first powder in a roller kiln, heating the first powder from room temperature to 800 ℃ at a speed of 10 ℃/min, and roasting the first powder for 60min to obtain second powder with a main crystal phase of olivine, wherein the particle size of the second powder is 2-75 mu m.

(3) Mixing the first powder, the second powder and the yellow sand powder according to a mass ratio of 60: 30: 10, mixing in a dry powder mixer for 15min to obtain mixed material powder.

(4) And granulating the mixed material powder by a wet method, wherein the granulating method comprises the steps of rotating the mixed material powder in a granulator for 10min at the rotating speed of 60r/min, then adding water and a binder, and continuing to rotate and granulate for 40min, wherein the adding amount of the water is 14% of the mass of the mixed material powder, and the adding amount of the binder is 9% of the mass of the mixed material powder. And after granulation is finished, shaping for 15min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

(5) And (3) drying the spherical granular blank in the vertical kiln for 40min by using the hot tail gas generated by the roasting kiln in the step (2) when the temperature is reduced to 100-110 ℃, heating to 700 ℃ at a speed of 7 ℃/h, then heating to 1000 ℃ at a speed of 6 ℃/min, and preserving the heat for 60min to obtain a finished product D.

The diameter of the finished product D is between 212 and 425 mu m, the sphericity and roundness are not less than 0.9, and the volume density is 1.65 to 1.75g/cm³The breaking rate is less than or equal to 5% under the closed pressure of 103MPa, the 9% breaking grade is 15K, HCl: HF-12: 3, the acid solubility is less than or equal to 3 percent.

Example 5

The specific preparation method of this example is as follows:

(1) placing the serpentine in a dryer for drying, drying at 80 ℃ for 70min, and then crushing in a closed-circuit crushing mode to obtain first powder with the water content of 4%. The obtained first powder comprises 36% of MgO and 37% of SiO₂10% of CaO, 10% of Fe₂O₃And 3% of Al₂O₃The particle size of the first powder is mainly 20-75 μm, and the maximum particle size is less than or equal to 75 μm.

(2) And (3) placing the obtained first powder in a roller kiln, heating the first powder from room temperature to 900 ℃ at a speed of 15 ℃/min, and roasting the first powder for 30min to obtain second powder with a main crystal phase of olivine, wherein the particle size of the second powder is 2-75 mu m.

(3) Mixing the first powder, the second powder and the yellow sand powder according to a mass ratio of 80: 10: 10, and uniformly mixing in a dry powder mixer for 10min to obtain mixed material powder.

(4) And granulating the mixed material powder by a wet method, wherein the granulating method comprises the steps of rotating the mixed material powder in a granulator for 18min at a rotating speed of 40r/min, then adding water and a binder, and continuing to rotate and granulate for 70min, wherein the adding amount of the water is 13% of the mass of the mixed material powder, and the adding amount of the binder is 11% of the mass of the mixed material powder. And after granulation is finished, shaping for 17min on a spherical shaping machine to obtain a spherical granular blank with better sphericity and roundness.

(5) And (3) drying the spherical granular blank in the vertical kiln for 30min by using the hot tail gas generated by the roasting kiln in the step (2) when the temperature is reduced to 110-120 ℃, heating to 700 ℃ at 8 ℃/h, then heating to 950 ℃ at 5 ℃/min, and preserving the heat for 90min to obtain a finished product E.

The diameter of the finished product D is between 1000 and 1700 mu m, the sphericity and roundness are not less than 0.9, and the volume density is 1.60 to 1.70g/cm³The breaking rate is less than or equal to 6% under the closed pressure of 103MPa, the 9% breaking grade is 15K, HCl: HF-12: 3, the acid solubility is less than or equal to 3 percent.

In conclusion, the invention takes rocks, waste rocks and tailings mainly containing serpentine as raw materials to produce the magnesium-aluminum proppant for fracturing petroleum or natural gas, thereby realizing resource utilization of various solid wastes. The high-strength oil fracturing magnesium aluminum silicate proppant and the preparation method thereof have the beneficial effects that at least one of the following substances is adopted:

1) rocks, waste rocks and tailings mainly containing serpentine are used as raw materials, and low-grade resources and solid waste residues are utilized;

2) the preparation method has the advantages of simplicity, energy conservation, emission reduction, high added value of products, high ecological environmental benefit and the like, and has important significance for developing new material industry and social economy;

3) the recycling of the tailings, the waste rocks and the tailings has important ecological and environmental significance on the safety, environmental protection, reclamation and greenness of the tailings pond;

4) the breaking rate of the aluminum magnesium silicate proppant prepared by the preparation method is less than or equal to 3-6% under the closed pressure of 86-103 MPa, the applicable pressure range is wide, and the market prospect is wide;

5) the magnesium aluminum silicate proppant prepared by the preparation method has the advantages of high strength, low density, good acid corrosion resistance and the like, and has wide market prospect and remarkable economic, environmental and social benefits;

6) compared with the traditional proppant, the aluminum magnesium silicate proppant can save a large amount of quartz sand and make up the defects of low strength, poor roundness and poor sphericity of the quartz sand.

Although the present invention has been described above in connection with the exemplary embodiments and the accompanying drawings, it will be apparent to those of ordinary skill in the art that various modifications may be made to the above-described embodiments without departing from the spirit and scope of the claims.